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android-kvm / linux / cbfdfd5624ebd6493c39d7f6400feaa03962e6ef / . / fs / btrfs / tree-log.c
blob: 813986e38258b78ceed6f4207dd1e38b3e66a8b2 [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (C) 2008 Oracle. All rights reserved.
*/
#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/blkdev.h>
#include <linux/list_sort.h>
#include <linux/iversion.h>
#include "misc.h"
#include "ctree.h"
#include "tree-log.h"
#include "disk-io.h"
#include "locking.h"
#include "print-tree.h"
#include "backref.h"
#include "compression.h"
#include "qgroup.h"
#include "block-group.h"
#include "space-info.h"
#include "zoned.h"
#include "inode-item.h"
#define MAX_CONFLICT_INODES 10
/* magic values for the inode_only field in btrfs_log_inode:
*
* LOG_INODE_ALL means to log everything
* LOG_INODE_EXISTS means to log just enough to recreate the inode
* during log replay
*/
enum {
LOG_INODE_ALL,
LOG_INODE_EXISTS,
};
/*
* directory trouble cases
*
* 1) on rename or unlink, if the inode being unlinked isn't in the fsync
* log, we must force a full commit before doing an fsync of the directory
* where the unlink was done.
* ---> record transid of last unlink/rename per directory
*
* mkdir foo/some_dir
* normal commit
* rename foo/some_dir foo2/some_dir
* mkdir foo/some_dir
* fsync foo/some_dir/some_file
*
* The fsync above will unlink the original some_dir without recording
* it in its new location (foo2). After a crash, some_dir will be gone
* unless the fsync of some_file forces a full commit
*
* 2) we must log any new names for any file or dir that is in the fsync
* log. ---> check inode while renaming/linking.
*
* 2a) we must log any new names for any file or dir during rename
* when the directory they are being removed from was logged.
* ---> check inode and old parent dir during rename
*
* 2a is actually the more important variant. With the extra logging
* a crash might unlink the old name without recreating the new one
*
* 3) after a crash, we must go through any directories with a link count
* of zero and redo the rm -rf
*
* mkdir f1/foo
* normal commit
* rm -rf f1/foo
* fsync(f1)
*
* The directory f1 was fully removed from the FS, but fsync was never
* called on f1, only its parent dir. After a crash the rm -rf must
* be replayed. This must be able to recurse down the entire
* directory tree. The inode link count fixup code takes care of the
* ugly details.
*/
/*
* stages for the tree walking. The first
* stage (0) is to only pin down the blocks we find
* the second stage (1) is to make sure that all the inodes
* we find in the log are created in the subvolume.
*
* The last stage is to deal with directories and links and extents
* and all the other fun semantics
*/
enum {
LOG_WALK_PIN_ONLY,
LOG_WALK_REPLAY_INODES,
LOG_WALK_REPLAY_DIR_INDEX,
LOG_WALK_REPLAY_ALL,
};
static int btrfs_log_inode(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
int inode_only,
struct btrfs_log_ctx *ctx);
static int link_to_fixup_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, u64 objectid);
static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
u64 dirid, int del_all);
static void wait_log_commit(struct btrfs_root *root, int transid);
/*
* tree logging is a special write ahead log used to make sure that
* fsyncs and O_SYNCs can happen without doing full tree commits.
*
* Full tree commits are expensive because they require commonly
* modified blocks to be recowed, creating many dirty pages in the
* extent tree an 4x-6x higher write load than ext3.
*
* Instead of doing a tree commit on every fsync, we use the
* key ranges and transaction ids to find items for a given file or directory
* that have changed in this transaction. Those items are copied into
* a special tree (one per subvolume root), that tree is written to disk
* and then the fsync is considered complete.
*
* After a crash, items are copied out of the log-tree back into the
* subvolume tree. Any file data extents found are recorded in the extent
* allocation tree, and the log-tree freed.
*
* The log tree is read three times, once to pin down all the extents it is
* using in ram and once, once to create all the inodes logged in the tree
* and once to do all the other items.
*/
/*
* start a sub transaction and setup the log tree
* this increments the log tree writer count to make the people
* syncing the tree wait for us to finish
*/
static int start_log_trans(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_log_ctx *ctx)
{
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_root *tree_root = fs_info->tree_root;
const bool zoned = btrfs_is_zoned(fs_info);
int ret = 0;
bool created = false;
/*
* First check if the log root tree was already created. If not, create
* it before locking the root's log_mutex, just to keep lockdep happy.
*/
if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state)) {
mutex_lock(&tree_root->log_mutex);
if (!fs_info->log_root_tree) {
ret = btrfs_init_log_root_tree(trans, fs_info);
if (!ret) {
set_bit(BTRFS_ROOT_HAS_LOG_TREE, &tree_root->state);
created = true;
}
}
mutex_unlock(&tree_root->log_mutex);
if (ret)
return ret;
}
mutex_lock(&root->log_mutex);
again:
if (root->log_root) {
int index = (root->log_transid + 1) % 2;
if (btrfs_need_log_full_commit(trans)) {
ret = BTRFS_LOG_FORCE_COMMIT;
goto out;
}
if (zoned && atomic_read(&root->log_commit[index])) {
wait_log_commit(root, root->log_transid - 1);
goto again;
}
if (!root->log_start_pid) {
clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
root->log_start_pid = current->pid;
} else if (root->log_start_pid != current->pid) {
set_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
}
} else {
/*
* This means fs_info->log_root_tree was already created
* for some other FS trees. Do the full commit not to mix
* nodes from multiple log transactions to do sequential
* writing.
*/
if (zoned && !created) {
ret = BTRFS_LOG_FORCE_COMMIT;
goto out;
}
ret = btrfs_add_log_tree(trans, root);
if (ret)
goto out;
set_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state);
clear_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state);
root->log_start_pid = current->pid;
}
atomic_inc(&root->log_writers);
if (!ctx->logging_new_name) {
int index = root->log_transid % 2;
list_add_tail(&ctx->list, &root->log_ctxs[index]);
ctx->log_transid = root->log_transid;
}
out:
mutex_unlock(&root->log_mutex);
return ret;
}
/*
* returns 0 if there was a log transaction running and we were able
* to join, or returns -ENOENT if there were not transactions
* in progress
*/
static int join_running_log_trans(struct btrfs_root *root)
{
const bool zoned = btrfs_is_zoned(root->fs_info);
int ret = -ENOENT;
if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state))
return ret;
mutex_lock(&root->log_mutex);
again:
if (root->log_root) {
int index = (root->log_transid + 1) % 2;
ret = 0;
if (zoned && atomic_read(&root->log_commit[index])) {
wait_log_commit(root, root->log_transid - 1);
goto again;
}
atomic_inc(&root->log_writers);
}
mutex_unlock(&root->log_mutex);
return ret;
}
/*
* This either makes the current running log transaction wait
* until you call btrfs_end_log_trans() or it makes any future
* log transactions wait until you call btrfs_end_log_trans()
*/
void btrfs_pin_log_trans(struct btrfs_root *root)
{
atomic_inc(&root->log_writers);
}
/*
* indicate we're done making changes to the log tree
* and wake up anyone waiting to do a sync
*/
void btrfs_end_log_trans(struct btrfs_root *root)
{
if (atomic_dec_and_test(&root->log_writers)) {
/* atomic_dec_and_test implies a barrier */
cond_wake_up_nomb(&root->log_writer_wait);
}
}
static void btrfs_wait_tree_block_writeback(struct extent_buffer *buf)
{
filemap_fdatawait_range(buf->pages[0]->mapping,
buf->start, buf->start + buf->len - 1);
}
/*
* the walk control struct is used to pass state down the chain when
* processing the log tree. The stage field tells us which part
* of the log tree processing we are currently doing. The others
* are state fields used for that specific part
*/
struct walk_control {
/* should we free the extent on disk when done? This is used
* at transaction commit time while freeing a log tree
*/
int free;
/* pin only walk, we record which extents on disk belong to the
* log trees
*/
int pin;
/* what stage of the replay code we're currently in */
int stage;
/*
* Ignore any items from the inode currently being processed. Needs
* to be set every time we find a BTRFS_INODE_ITEM_KEY and we are in
* the LOG_WALK_REPLAY_INODES stage.
*/
bool ignore_cur_inode;
/* the root we are currently replaying */
struct btrfs_root *replay_dest;
/* the trans handle for the current replay */
struct btrfs_trans_handle *trans;
/* the function that gets used to process blocks we find in the
* tree. Note the extent_buffer might not be up to date when it is
* passed in, and it must be checked or read if you need the data
* inside it
*/
int (*process_func)(struct btrfs_root *log, struct extent_buffer *eb,
struct walk_control *wc, u64 gen, int level);
};
/*
* process_func used to pin down extents, write them or wait on them
*/
static int process_one_buffer(struct btrfs_root *log,
struct extent_buffer *eb,
struct walk_control *wc, u64 gen, int level)
{
struct btrfs_fs_info *fs_info = log->fs_info;
int ret = 0;
/*
* If this fs is mixed then we need to be able to process the leaves to
* pin down any logged extents, so we have to read the block.
*/
if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
ret = btrfs_read_extent_buffer(eb, gen, level, NULL);
if (ret)
return ret;
}
if (wc->pin) {
ret = btrfs_pin_extent_for_log_replay(wc->trans, eb->start,
eb->len);
if (ret)
return ret;
if (btrfs_buffer_uptodate(eb, gen, 0) &&
btrfs_header_level(eb) == 0)
ret = btrfs_exclude_logged_extents(eb);
}
return ret;
}
static int do_overwrite_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
int ret;
u32 item_size;
u64 saved_i_size = 0;
int save_old_i_size = 0;
unsigned long src_ptr;
unsigned long dst_ptr;
int overwrite_root = 0;
bool inode_item = key->type == BTRFS_INODE_ITEM_KEY;
if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID)
overwrite_root = 1;
item_size = btrfs_item_size(eb, slot);
src_ptr = btrfs_item_ptr_offset(eb, slot);
/* Our caller must have done a search for the key for us. */
ASSERT(path->nodes[0] != NULL);
/*
* And the slot must point to the exact key or the slot where the key
* should be at (the first item with a key greater than 'key')
*/
if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) {
struct btrfs_key found_key;
btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
ret = btrfs_comp_cpu_keys(&found_key, key);
ASSERT(ret >= 0);
} else {
ret = 1;
}
if (ret == 0) {
char *src_copy;
char *dst_copy;
u32 dst_size = btrfs_item_size(path->nodes[0],
path->slots[0]);
if (dst_size != item_size)
goto insert;
if (item_size == 0) {
btrfs_release_path(path);
return 0;
}
dst_copy = kmalloc(item_size, GFP_NOFS);
src_copy = kmalloc(item_size, GFP_NOFS);
if (!dst_copy || !src_copy) {
btrfs_release_path(path);
kfree(dst_copy);
kfree(src_copy);
return -ENOMEM;
}
read_extent_buffer(eb, src_copy, src_ptr, item_size);
dst_ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
read_extent_buffer(path->nodes[0], dst_copy, dst_ptr,
item_size);
ret = memcmp(dst_copy, src_copy, item_size);
kfree(dst_copy);
kfree(src_copy);
/*
* they have the same contents, just return, this saves
* us from cowing blocks in the destination tree and doing
* extra writes that may not have been done by a previous
* sync
*/
if (ret == 0) {
btrfs_release_path(path);
return 0;
}
/*
* We need to load the old nbytes into the inode so when we
* replay the extents we've logged we get the right nbytes.
*/
if (inode_item) {
struct btrfs_inode_item *item;
u64 nbytes;
u32 mode;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
nbytes = btrfs_inode_nbytes(path->nodes[0], item);
item = btrfs_item_ptr(eb, slot,
struct btrfs_inode_item);
btrfs_set_inode_nbytes(eb, item, nbytes);
/*
* If this is a directory we need to reset the i_size to
* 0 so that we can set it up properly when replaying
* the rest of the items in this log.
*/
mode = btrfs_inode_mode(eb, item);
if (S_ISDIR(mode))
btrfs_set_inode_size(eb, item, 0);
}
} else if (inode_item) {
struct btrfs_inode_item *item;
u32 mode;
/*
* New inode, set nbytes to 0 so that the nbytes comes out
* properly when we replay the extents.
*/
item = btrfs_item_ptr(eb, slot, struct btrfs_inode_item);
btrfs_set_inode_nbytes(eb, item, 0);
/*
* If this is a directory we need to reset the i_size to 0 so
* that we can set it up properly when replaying the rest of
* the items in this log.
*/
mode = btrfs_inode_mode(eb, item);
if (S_ISDIR(mode))
btrfs_set_inode_size(eb, item, 0);
}
insert:
btrfs_release_path(path);
/* try to insert the key into the destination tree */
path->skip_release_on_error = 1;
ret = btrfs_insert_empty_item(trans, root, path,
key, item_size);
path->skip_release_on_error = 0;
/* make sure any existing item is the correct size */
if (ret == -EEXIST || ret == -EOVERFLOW) {
u32 found_size;
found_size = btrfs_item_size(path->nodes[0],
path->slots[0]);
if (found_size > item_size)
btrfs_truncate_item(path, item_size, 1);
else if (found_size < item_size)
btrfs_extend_item(path, item_size - found_size);
} else if (ret) {
return ret;
}
dst_ptr = btrfs_item_ptr_offset(path->nodes[0],
path->slots[0]);
/* don't overwrite an existing inode if the generation number
* was logged as zero. This is done when the tree logging code
* is just logging an inode to make sure it exists after recovery.
*
* Also, don't overwrite i_size on directories during replay.
* log replay inserts and removes directory items based on the
* state of the tree found in the subvolume, and i_size is modified
* as it goes
*/
if (key->type == BTRFS_INODE_ITEM_KEY && ret == -EEXIST) {
struct btrfs_inode_item *src_item;
struct btrfs_inode_item *dst_item;
src_item = (struct btrfs_inode_item *)src_ptr;
dst_item = (struct btrfs_inode_item *)dst_ptr;
if (btrfs_inode_generation(eb, src_item) == 0) {
struct extent_buffer *dst_eb = path->nodes[0];
const u64 ino_size = btrfs_inode_size(eb, src_item);
/*
* For regular files an ino_size == 0 is used only when
* logging that an inode exists, as part of a directory
* fsync, and the inode wasn't fsynced before. In this
* case don't set the size of the inode in the fs/subvol
* tree, otherwise we would be throwing valid data away.
*/
if (S_ISREG(btrfs_inode_mode(eb, src_item)) &&
S_ISREG(btrfs_inode_mode(dst_eb, dst_item)) &&
ino_size != 0)
btrfs_set_inode_size(dst_eb, dst_item, ino_size);
goto no_copy;
}
if (overwrite_root &&
S_ISDIR(btrfs_inode_mode(eb, src_item)) &&
S_ISDIR(btrfs_inode_mode(path->nodes[0], dst_item))) {
save_old_i_size = 1;
saved_i_size = btrfs_inode_size(path->nodes[0],
dst_item);
}
}
copy_extent_buffer(path->nodes[0], eb, dst_ptr,
src_ptr, item_size);
if (save_old_i_size) {
struct btrfs_inode_item *dst_item;
dst_item = (struct btrfs_inode_item *)dst_ptr;
btrfs_set_inode_size(path->nodes[0], dst_item, saved_i_size);
}
/* make sure the generation is filled in */
if (key->type == BTRFS_INODE_ITEM_KEY) {
struct btrfs_inode_item *dst_item;
dst_item = (struct btrfs_inode_item *)dst_ptr;
if (btrfs_inode_generation(path->nodes[0], dst_item) == 0) {
btrfs_set_inode_generation(path->nodes[0], dst_item,
trans->transid);
}
}
no_copy:
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(path);
return 0;
}
/*
* Item overwrite used by replay and tree logging. eb, slot and key all refer
* to the src data we are copying out.
*
* root is the tree we are copying into, and path is a scratch
* path for use in this function (it should be released on entry and
* will be released on exit).
*
* If the key is already in the destination tree the existing item is
* overwritten. If the existing item isn't big enough, it is extended.
* If it is too large, it is truncated.
*
* If the key isn't in the destination yet, a new item is inserted.
*/
static int overwrite_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
int ret;
/* Look for the key in the destination tree. */
ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
if (ret < 0)
return ret;
return do_overwrite_item(trans, root, path, eb, slot, key);
}
/*
* simple helper to read an inode off the disk from a given root
* This can only be called for subvolume roots and not for the log
*/
static noinline struct inode *read_one_inode(struct btrfs_root *root,
u64 objectid)
{
struct inode *inode;
inode = btrfs_iget(root->fs_info->sb, objectid, root);
if (IS_ERR(inode))
inode = NULL;
return inode;
}
/* replays a single extent in 'eb' at 'slot' with 'key' into the
* subvolume 'root'. path is released on entry and should be released
* on exit.
*
* extents in the log tree have not been allocated out of the extent
* tree yet. So, this completes the allocation, taking a reference
* as required if the extent already exists or creating a new extent
* if it isn't in the extent allocation tree yet.
*
* The extent is inserted into the file, dropping any existing extents
* from the file that overlap the new one.
*/
static noinline int replay_one_extent(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
struct btrfs_drop_extents_args drop_args = { 0 };
struct btrfs_fs_info *fs_info = root->fs_info;
int found_type;
u64 extent_end;
u64 start = key->offset;
u64 nbytes = 0;
struct btrfs_file_extent_item *item;
struct inode *inode = NULL;
unsigned long size;
int ret = 0;
item = btrfs_item_ptr(eb, slot, struct btrfs_file_extent_item);
found_type = btrfs_file_extent_type(eb, item);
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
nbytes = btrfs_file_extent_num_bytes(eb, item);
extent_end = start + nbytes;
/*
* We don't add to the inodes nbytes if we are prealloc or a
* hole.
*/
if (btrfs_file_extent_disk_bytenr(eb, item) == 0)
nbytes = 0;
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
size = btrfs_file_extent_ram_bytes(eb, item);
nbytes = btrfs_file_extent_ram_bytes(eb, item);
extent_end = ALIGN(start + size,
fs_info->sectorsize);
} else {
ret = 0;
goto out;
}
inode = read_one_inode(root, key->objectid);
if (!inode) {
ret = -EIO;
goto out;
}
/*
* first check to see if we already have this extent in the
* file. This must be done before the btrfs_drop_extents run
* so we don't try to drop this extent.
*/
ret = btrfs_lookup_file_extent(trans, root, path,
btrfs_ino(BTRFS_I(inode)), start, 0);
if (ret == 0 &&
(found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC)) {
struct btrfs_file_extent_item cmp1;
struct btrfs_file_extent_item cmp2;
struct btrfs_file_extent_item *existing;
struct extent_buffer *leaf;
leaf = path->nodes[0];
existing = btrfs_item_ptr(leaf, path->slots[0],
struct btrfs_file_extent_item);
read_extent_buffer(eb, &cmp1, (unsigned long)item,
sizeof(cmp1));
read_extent_buffer(leaf, &cmp2, (unsigned long)existing,
sizeof(cmp2));
/*
* we already have a pointer to this exact extent,
* we don't have to do anything
*/
if (memcmp(&cmp1, &cmp2, sizeof(cmp1)) == 0) {
btrfs_release_path(path);
goto out;
}
}
btrfs_release_path(path);
/* drop any overlapping extents */
drop_args.start = start;
drop_args.end = extent_end;
drop_args.drop_cache = true;
ret = btrfs_drop_extents(trans, root, BTRFS_I(inode), &drop_args);
if (ret)
goto out;
if (found_type == BTRFS_FILE_EXTENT_REG ||
found_type == BTRFS_FILE_EXTENT_PREALLOC) {
u64 offset;
unsigned long dest_offset;
struct btrfs_key ins;
if (btrfs_file_extent_disk_bytenr(eb, item) == 0 &&
btrfs_fs_incompat(fs_info, NO_HOLES))
goto update_inode;
ret = btrfs_insert_empty_item(trans, root, path, key,
sizeof(*item));
if (ret)
goto out;
dest_offset = btrfs_item_ptr_offset(path->nodes[0],
path->slots[0]);
copy_extent_buffer(path->nodes[0], eb, dest_offset,
(unsigned long)item, sizeof(*item));
ins.objectid = btrfs_file_extent_disk_bytenr(eb, item);
ins.offset = btrfs_file_extent_disk_num_bytes(eb, item);
ins.type = BTRFS_EXTENT_ITEM_KEY;
offset = key->offset - btrfs_file_extent_offset(eb, item);
/*
* Manually record dirty extent, as here we did a shallow
* file extent item copy and skip normal backref update,
* but modifying extent tree all by ourselves.
* So need to manually record dirty extent for qgroup,
* as the owner of the file extent changed from log tree
* (doesn't affect qgroup) to fs/file tree(affects qgroup)
*/
ret = btrfs_qgroup_trace_extent(trans,
btrfs_file_extent_disk_bytenr(eb, item),
btrfs_file_extent_disk_num_bytes(eb, item),
GFP_NOFS);
if (ret < 0)
goto out;
if (ins.objectid > 0) {
struct btrfs_ref ref = { 0 };
u64 csum_start;
u64 csum_end;
LIST_HEAD(ordered_sums);
/*
* is this extent already allocated in the extent
* allocation tree? If so, just add a reference
*/
ret = btrfs_lookup_data_extent(fs_info, ins.objectid,
ins.offset);
if (ret < 0) {
goto out;
} else if (ret == 0) {
btrfs_init_generic_ref(&ref,
BTRFS_ADD_DELAYED_REF,
ins.objectid, ins.offset, 0);
btrfs_init_data_ref(&ref,
root->root_key.objectid,
key->objectid, offset, 0, false);
ret = btrfs_inc_extent_ref(trans, &ref);
if (ret)
goto out;
} else {
/*
* insert the extent pointer in the extent
* allocation tree
*/
ret = btrfs_alloc_logged_file_extent(trans,
root->root_key.objectid,
key->objectid, offset, &ins);
if (ret)
goto out;
}
btrfs_release_path(path);
if (btrfs_file_extent_compression(eb, item)) {
csum_start = ins.objectid;
csum_end = csum_start + ins.offset;
} else {
csum_start = ins.objectid +
btrfs_file_extent_offset(eb, item);
csum_end = csum_start +
btrfs_file_extent_num_bytes(eb, item);
}
ret = btrfs_lookup_csums_range(root->log_root,
csum_start, csum_end - 1,
&ordered_sums, 0, false);
if (ret)
goto out;
/*
* Now delete all existing cums in the csum root that
* cover our range. We do this because we can have an
* extent that is completely referenced by one file
* extent item and partially referenced by another
* file extent item (like after using the clone or
* extent_same ioctls). In this case if we end up doing
* the replay of the one that partially references the
* extent first, and we do not do the csum deletion
* below, we can get 2 csum items in the csum tree that
* overlap each other. For example, imagine our log has
* the two following file extent items:
*
* key (257 EXTENT_DATA 409600)
* extent data disk byte 12845056 nr 102400
* extent data offset 20480 nr 20480 ram 102400
*
* key (257 EXTENT_DATA 819200)
* extent data disk byte 12845056 nr 102400
* extent data offset 0 nr 102400 ram 102400
*
* Where the second one fully references the 100K extent
* that starts at disk byte 12845056, and the log tree
* has a single csum item that covers the entire range
* of the extent:
*
* key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
*
* After the first file extent item is replayed, the
* csum tree gets the following csum item:
*
* key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
*
* Which covers the 20K sub-range starting at offset 20K
* of our extent. Now when we replay the second file
* extent item, if we do not delete existing csum items
* that cover any of its blocks, we end up getting two
* csum items in our csum tree that overlap each other:
*
* key (EXTENT_CSUM EXTENT_CSUM 12845056) itemsize 100
* key (EXTENT_CSUM EXTENT_CSUM 12865536) itemsize 20
*
* Which is a problem, because after this anyone trying
* to lookup up for the checksum of any block of our
* extent starting at an offset of 40K or higher, will
* end up looking at the second csum item only, which
* does not contain the checksum for any block starting
* at offset 40K or higher of our extent.
*/
while (!list_empty(&ordered_sums)) {
struct btrfs_ordered_sum *sums;
struct btrfs_root *csum_root;
sums = list_entry(ordered_sums.next,
struct btrfs_ordered_sum,
list);
csum_root = btrfs_csum_root(fs_info,
sums->bytenr);
if (!ret)
ret = btrfs_del_csums(trans, csum_root,
sums->bytenr,
sums->len);
if (!ret)
ret = btrfs_csum_file_blocks(trans,
csum_root,
sums);
list_del(&sums->list);
kfree(sums);
}
if (ret)
goto out;
} else {
btrfs_release_path(path);
}
} else if (found_type == BTRFS_FILE_EXTENT_INLINE) {
/* inline extents are easy, we just overwrite them */
ret = overwrite_item(trans, root, path, eb, slot, key);
if (ret)
goto out;
}
ret = btrfs_inode_set_file_extent_range(BTRFS_I(inode), start,
extent_end - start);
if (ret)
goto out;
update_inode:
btrfs_update_inode_bytes(BTRFS_I(inode), nbytes, drop_args.bytes_found);
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
out:
iput(inode);
return ret;
}
static int unlink_inode_for_log_replay(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir,
struct btrfs_inode *inode,
const char *name,
int name_len)
{
int ret;
ret = btrfs_unlink_inode(trans, dir, inode, name, name_len);
if (ret)
return ret;
/*
* Whenever we need to check if a name exists or not, we check the
* fs/subvolume tree. So after an unlink we must run delayed items, so
* that future checks for a name during log replay see that the name
* does not exists anymore.
*/
return btrfs_run_delayed_items(trans);
}
/*
* when cleaning up conflicts between the directory names in the
* subvolume, directory names in the log and directory names in the
* inode back references, we may have to unlink inodes from directories.
*
* This is a helper function to do the unlink of a specific directory
* item
*/
static noinline int drop_one_dir_item(struct btrfs_trans_handle *trans,
struct btrfs_path *path,
struct btrfs_inode *dir,
struct btrfs_dir_item *di)
{
struct btrfs_root *root = dir->root;
struct inode *inode;
char *name;
int name_len;
struct extent_buffer *leaf;
struct btrfs_key location;
int ret;
leaf = path->nodes[0];
btrfs_dir_item_key_to_cpu(leaf, di, &location);
name_len = btrfs_dir_name_len(leaf, di);
name = kmalloc(name_len, GFP_NOFS);
if (!name)
return -ENOMEM;
read_extent_buffer(leaf, name, (unsigned long)(di + 1), name_len);
btrfs_release_path(path);
inode = read_one_inode(root, location.objectid);
if (!inode) {
ret = -EIO;
goto out;
}
ret = link_to_fixup_dir(trans, root, path, location.objectid);
if (ret)
goto out;
ret = unlink_inode_for_log_replay(trans, dir, BTRFS_I(inode), name,
name_len);
out:
kfree(name);
iput(inode);
return ret;
}
/*
* See if a given name and sequence number found in an inode back reference are
* already in a directory and correctly point to this inode.
*
* Returns: < 0 on error, 0 if the directory entry does not exists and 1 if it
* exists.
*/
static noinline int inode_in_dir(struct btrfs_root *root,
struct btrfs_path *path,
u64 dirid, u64 objectid, u64 index,
const char *name, int name_len)
{
struct btrfs_dir_item *di;
struct btrfs_key location;
int ret = 0;
di = btrfs_lookup_dir_index_item(NULL, root, path, dirid,
index, name, name_len, 0);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out;
} else if (di) {
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
if (location.objectid != objectid)
goto out;
} else {
goto out;
}
btrfs_release_path(path);
di = btrfs_lookup_dir_item(NULL, root, path, dirid, name, name_len, 0);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out;
} else if (di) {
btrfs_dir_item_key_to_cpu(path->nodes[0], di, &location);
if (location.objectid == objectid)
ret = 1;
}
out:
btrfs_release_path(path);
return ret;
}
/*
* helper function to check a log tree for a named back reference in
* an inode. This is used to decide if a back reference that is
* found in the subvolume conflicts with what we find in the log.
*
* inode backreferences may have multiple refs in a single item,
* during replay we process one reference at a time, and we don't
* want to delete valid links to a file from the subvolume if that
* link is also in the log.
*/
static noinline int backref_in_log(struct btrfs_root *log,
struct btrfs_key *key,
u64 ref_objectid,
const char *name, int namelen)
{
struct btrfs_path *path;
int ret;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = btrfs_search_slot(NULL, log, key, path, 0, 0);
if (ret < 0) {
goto out;
} else if (ret == 1) {
ret = 0;
goto out;
}
if (key->type == BTRFS_INODE_EXTREF_KEY)
ret = !!btrfs_find_name_in_ext_backref(path->nodes[0],
path->slots[0],
ref_objectid,
name, namelen);
else
ret = !!btrfs_find_name_in_backref(path->nodes[0],
path->slots[0],
name, namelen);
out:
btrfs_free_path(path);
return ret;
}
static inline int __add_inode_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_root *log_root,
struct btrfs_inode *dir,
struct btrfs_inode *inode,
u64 inode_objectid, u64 parent_objectid,
u64 ref_index, char *name, int namelen)
{
int ret;
char *victim_name;
int victim_name_len;
struct extent_buffer *leaf;
struct btrfs_dir_item *di;
struct btrfs_key search_key;
struct btrfs_inode_extref *extref;
again:
/* Search old style refs */
search_key.objectid = inode_objectid;
search_key.type = BTRFS_INODE_REF_KEY;
search_key.offset = parent_objectid;
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret == 0) {
struct btrfs_inode_ref *victim_ref;
unsigned long ptr;
unsigned long ptr_end;
leaf = path->nodes[0];
/* are we trying to overwrite a back ref for the root directory
* if so, just jump out, we're done
*/
if (search_key.objectid == search_key.offset)
return 1;
/* check all the names in this back reference to see
* if they are in the log. if so, we allow them to stay
* otherwise they must be unlinked as a conflict
*/
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
ptr_end = ptr + btrfs_item_size(leaf, path->slots[0]);
while (ptr < ptr_end) {
victim_ref = (struct btrfs_inode_ref *)ptr;
victim_name_len = btrfs_inode_ref_name_len(leaf,
victim_ref);
victim_name = kmalloc(victim_name_len, GFP_NOFS);
if (!victim_name)
return -ENOMEM;
read_extent_buffer(leaf, victim_name,
(unsigned long)(victim_ref + 1),
victim_name_len);
ret = backref_in_log(log_root, &search_key,
parent_objectid, victim_name,
victim_name_len);
if (ret < 0) {
kfree(victim_name);
return ret;
} else if (!ret) {
inc_nlink(&inode->vfs_inode);
btrfs_release_path(path);
ret = unlink_inode_for_log_replay(trans, dir, inode,
victim_name, victim_name_len);
kfree(victim_name);
if (ret)
return ret;
goto again;
}
kfree(victim_name);
ptr = (unsigned long)(victim_ref + 1) + victim_name_len;
}
}
btrfs_release_path(path);
/* Same search but for extended refs */
extref = btrfs_lookup_inode_extref(NULL, root, path, name, namelen,
inode_objectid, parent_objectid, 0,
0);
if (IS_ERR(extref)) {
return PTR_ERR(extref);
} else if (extref) {
u32 item_size;
u32 cur_offset = 0;
unsigned long base;
struct inode *victim_parent;
leaf = path->nodes[0];
item_size = btrfs_item_size(leaf, path->slots[0]);
base = btrfs_item_ptr_offset(leaf, path->slots[0]);
while (cur_offset < item_size) {
extref = (struct btrfs_inode_extref *)(base + cur_offset);
victim_name_len = btrfs_inode_extref_name_len(leaf, extref);
if (btrfs_inode_extref_parent(leaf, extref) != parent_objectid)
goto next;
victim_name = kmalloc(victim_name_len, GFP_NOFS);
if (!victim_name)
return -ENOMEM;
read_extent_buffer(leaf, victim_name, (unsigned long)&extref->name,
victim_name_len);
search_key.objectid = inode_objectid;
search_key.type = BTRFS_INODE_EXTREF_KEY;
search_key.offset = btrfs_extref_hash(parent_objectid,
victim_name,
victim_name_len);
ret = backref_in_log(log_root, &search_key,
parent_objectid, victim_name,
victim_name_len);
if (ret < 0) {
kfree(victim_name);
return ret;
} else if (!ret) {
ret = -ENOENT;
victim_parent = read_one_inode(root,
parent_objectid);
if (victim_parent) {
inc_nlink(&inode->vfs_inode);
btrfs_release_path(path);
ret = unlink_inode_for_log_replay(trans,
BTRFS_I(victim_parent),
inode,
victim_name,
victim_name_len);
}
iput(victim_parent);
kfree(victim_name);
if (ret)
return ret;
goto again;
}
kfree(victim_name);
next:
cur_offset += victim_name_len + sizeof(*extref);
}
}
btrfs_release_path(path);
/* look for a conflicting sequence number */
di = btrfs_lookup_dir_index_item(trans, root, path, btrfs_ino(dir),
ref_index, name, namelen, 0);
if (IS_ERR(di)) {
return PTR_ERR(di);
} else if (di) {
ret = drop_one_dir_item(trans, path, dir, di);
if (ret)
return ret;
}
btrfs_release_path(path);
/* look for a conflicting name */
di = btrfs_lookup_dir_item(trans, root, path, btrfs_ino(dir),
name, namelen, 0);
if (IS_ERR(di)) {
return PTR_ERR(di);
} else if (di) {
ret = drop_one_dir_item(trans, path, dir, di);
if (ret)
return ret;
}
btrfs_release_path(path);
return 0;
}
static int extref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
u32 *namelen, char **name, u64 *index,
u64 *parent_objectid)
{
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)ref_ptr;
*namelen = btrfs_inode_extref_name_len(eb, extref);
*name = kmalloc(*namelen, GFP_NOFS);
if (*name == NULL)
return -ENOMEM;
read_extent_buffer(eb, *name, (unsigned long)&extref->name,
*namelen);
if (index)
*index = btrfs_inode_extref_index(eb, extref);
if (parent_objectid)
*parent_objectid = btrfs_inode_extref_parent(eb, extref);
return 0;
}
static int ref_get_fields(struct extent_buffer *eb, unsigned long ref_ptr,
u32 *namelen, char **name, u64 *index)
{
struct btrfs_inode_ref *ref;
ref = (struct btrfs_inode_ref *)ref_ptr;
*namelen = btrfs_inode_ref_name_len(eb, ref);
*name = kmalloc(*namelen, GFP_NOFS);
if (*name == NULL)
return -ENOMEM;
read_extent_buffer(eb, *name, (unsigned long)(ref + 1), *namelen);
if (index)
*index = btrfs_inode_ref_index(eb, ref);
return 0;
}
/*
* Take an inode reference item from the log tree and iterate all names from the
* inode reference item in the subvolume tree with the same key (if it exists).
* For any name that is not in the inode reference item from the log tree, do a
* proper unlink of that name (that is, remove its entry from the inode
* reference item and both dir index keys).
*/
static int unlink_old_inode_refs(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_inode *inode,
struct extent_buffer *log_eb,
int log_slot,
struct btrfs_key *key)
{
int ret;
unsigned long ref_ptr;
unsigned long ref_end;
struct extent_buffer *eb;
again:
btrfs_release_path(path);
ret = btrfs_search_slot(NULL, root, key, path, 0, 0);
if (ret > 0) {
ret = 0;
goto out;
}
if (ret < 0)
goto out;
eb = path->nodes[0];
ref_ptr = btrfs_item_ptr_offset(eb, path->slots[0]);
ref_end = ref_ptr + btrfs_item_size(eb, path->slots[0]);
while (ref_ptr < ref_end) {
char *name = NULL;
int namelen;
u64 parent_id;
if (key->type == BTRFS_INODE_EXTREF_KEY) {
ret = extref_get_fields(eb, ref_ptr, &namelen, &name,
NULL, &parent_id);
} else {
parent_id = key->offset;
ret = ref_get_fields(eb, ref_ptr, &namelen, &name,
NULL);
}
if (ret)
goto out;
if (key->type == BTRFS_INODE_EXTREF_KEY)
ret = !!btrfs_find_name_in_ext_backref(log_eb, log_slot,
parent_id, name,
namelen);
else
ret = !!btrfs_find_name_in_backref(log_eb, log_slot,
name, namelen);
if (!ret) {
struct inode *dir;
btrfs_release_path(path);
dir = read_one_inode(root, parent_id);
if (!dir) {
ret = -ENOENT;
kfree(name);
goto out;
}
ret = unlink_inode_for_log_replay(trans, BTRFS_I(dir),
inode, name, namelen);
kfree(name);
iput(dir);
if (ret)
goto out;
goto again;
}
kfree(name);
ref_ptr += namelen;
if (key->type == BTRFS_INODE_EXTREF_KEY)
ref_ptr += sizeof(struct btrfs_inode_extref);
else
ref_ptr += sizeof(struct btrfs_inode_ref);
}
ret = 0;
out:
btrfs_release_path(path);
return ret;
}
/*
* replay one inode back reference item found in the log tree.
* eb, slot and key refer to the buffer and key found in the log tree.
* root is the destination we are replaying into, and path is for temp
* use by this function. (it should be released on return).
*/
static noinline int add_inode_ref(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
struct inode *dir = NULL;
struct inode *inode = NULL;
unsigned long ref_ptr;
unsigned long ref_end;
char *name = NULL;
int namelen;
int ret;
int log_ref_ver = 0;
u64 parent_objectid;
u64 inode_objectid;
u64 ref_index = 0;
int ref_struct_size;
ref_ptr = btrfs_item_ptr_offset(eb, slot);
ref_end = ref_ptr + btrfs_item_size(eb, slot);
if (key->type == BTRFS_INODE_EXTREF_KEY) {
struct btrfs_inode_extref *r;
ref_struct_size = sizeof(struct btrfs_inode_extref);
log_ref_ver = 1;
r = (struct btrfs_inode_extref *)ref_ptr;
parent_objectid = btrfs_inode_extref_parent(eb, r);
} else {
ref_struct_size = sizeof(struct btrfs_inode_ref);
parent_objectid = key->offset;
}
inode_objectid = key->objectid;
/*
* it is possible that we didn't log all the parent directories
* for a given inode. If we don't find the dir, just don't
* copy the back ref in. The link count fixup code will take
* care of the rest
*/
dir = read_one_inode(root, parent_objectid);
if (!dir) {
ret = -ENOENT;
goto out;
}
inode = read_one_inode(root, inode_objectid);
if (!inode) {
ret = -EIO;
goto out;
}
while (ref_ptr < ref_end) {
if (log_ref_ver) {
ret = extref_get_fields(eb, ref_ptr, &namelen, &name,
&ref_index, &parent_objectid);
/*
* parent object can change from one array
* item to another.
*/
if (!dir)
dir = read_one_inode(root, parent_objectid);
if (!dir) {
ret = -ENOENT;
goto out;
}
} else {
ret = ref_get_fields(eb, ref_ptr, &namelen, &name,
&ref_index);
}
if (ret)
goto out;
ret = inode_in_dir(root, path, btrfs_ino(BTRFS_I(dir)),
btrfs_ino(BTRFS_I(inode)), ref_index,
name, namelen);
if (ret < 0) {
goto out;
} else if (ret == 0) {
/*
* look for a conflicting back reference in the
* metadata. if we find one we have to unlink that name
* of the file before we add our new link. Later on, we
* overwrite any existing back reference, and we don't
* want to create dangling pointers in the directory.
*/
ret = __add_inode_ref(trans, root, path, log,
BTRFS_I(dir), BTRFS_I(inode),
inode_objectid, parent_objectid,
ref_index, name, namelen);
if (ret) {
if (ret == 1)
ret = 0;
goto out;
}
/* insert our name */
ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode),
name, namelen, 0, ref_index);
if (ret)
goto out;
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
if (ret)
goto out;
}
/* Else, ret == 1, we already have a perfect match, we're done. */
ref_ptr = (unsigned long)(ref_ptr + ref_struct_size) + namelen;
kfree(name);
name = NULL;
if (log_ref_ver) {
iput(dir);
dir = NULL;
}
}
/*
* Before we overwrite the inode reference item in the subvolume tree
* with the item from the log tree, we must unlink all names from the
* parent directory that are in the subvolume's tree inode reference
* item, otherwise we end up with an inconsistent subvolume tree where
* dir index entries exist for a name but there is no inode reference
* item with the same name.
*/
ret = unlink_old_inode_refs(trans, root, path, BTRFS_I(inode), eb, slot,
key);
if (ret)
goto out;
/* finally write the back reference in the inode */
ret = overwrite_item(trans, root, path, eb, slot, key);
out:
btrfs_release_path(path);
kfree(name);
iput(dir);
iput(inode);
return ret;
}
static int count_inode_extrefs(struct btrfs_root *root,
struct btrfs_inode *inode, struct btrfs_path *path)
{
int ret = 0;
int name_len;
unsigned int nlink = 0;
u32 item_size;
u32 cur_offset = 0;
u64 inode_objectid = btrfs_ino(inode);
u64 offset = 0;
unsigned long ptr;
struct btrfs_inode_extref *extref;
struct extent_buffer *leaf;
while (1) {
ret = btrfs_find_one_extref(root, inode_objectid, offset, path,
&extref, &offset);
if (ret)
break;
leaf = path->nodes[0];
item_size = btrfs_item_size(leaf, path->slots[0]);
ptr = btrfs_item_ptr_offset(leaf, path->slots[0]);
cur_offset = 0;
while (cur_offset < item_size) {
extref = (struct btrfs_inode_extref *) (ptr + cur_offset);
name_len = btrfs_inode_extref_name_len(leaf, extref);
nlink++;
cur_offset += name_len + sizeof(*extref);
}
offset++;
btrfs_release_path(path);
}
btrfs_release_path(path);
if (ret < 0 && ret != -ENOENT)
return ret;
return nlink;
}
static int count_inode_refs(struct btrfs_root *root,
struct btrfs_inode *inode, struct btrfs_path *path)
{
int ret;
struct btrfs_key key;
unsigned int nlink = 0;
unsigned long ptr;
unsigned long ptr_end;
int name_len;
u64 ino = btrfs_ino(inode);
key.objectid = ino;
key.type = BTRFS_INODE_REF_KEY;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
break;
if (ret > 0) {
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
process_slot:
btrfs_item_key_to_cpu(path->nodes[0], &key,
path->slots[0]);
if (key.objectid != ino ||
key.type != BTRFS_INODE_REF_KEY)
break;
ptr = btrfs_item_ptr_offset(path->nodes[0], path->slots[0]);
ptr_end = ptr + btrfs_item_size(path->nodes[0],
path->slots[0]);
while (ptr < ptr_end) {
struct btrfs_inode_ref *ref;
ref = (struct btrfs_inode_ref *)ptr;
name_len = btrfs_inode_ref_name_len(path->nodes[0],
ref);
ptr = (unsigned long)(ref + 1) + name_len;
nlink++;
}
if (key.offset == 0)
break;
if (path->slots[0] > 0) {
path->slots[0]--;
goto process_slot;
}
key.offset--;
btrfs_release_path(path);
}
btrfs_release_path(path);
return nlink;
}
/*
* There are a few corners where the link count of the file can't
* be properly maintained during replay. So, instead of adding
* lots of complexity to the log code, we just scan the backrefs
* for any file that has been through replay.
*
* The scan will update the link count on the inode to reflect the
* number of back refs found. If it goes down to zero, the iput
* will free the inode.
*/
static noinline int fixup_inode_link_count(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct inode *inode)
{
struct btrfs_path *path;
int ret;
u64 nlink = 0;
u64 ino = btrfs_ino(BTRFS_I(inode));
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
ret = count_inode_refs(root, BTRFS_I(inode), path);
if (ret < 0)
goto out;
nlink = ret;
ret = count_inode_extrefs(root, BTRFS_I(inode), path);
if (ret < 0)
goto out;
nlink += ret;
ret = 0;
if (nlink != inode->i_nlink) {
set_nlink(inode, nlink);
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
if (ret)
goto out;
}
BTRFS_I(inode)->index_cnt = (u64)-1;
if (inode->i_nlink == 0) {
if (S_ISDIR(inode->i_mode)) {
ret = replay_dir_deletes(trans, root, NULL, path,
ino, 1);
if (ret)
goto out;
}
ret = btrfs_insert_orphan_item(trans, root, ino);
if (ret == -EEXIST)
ret = 0;
}
out:
btrfs_free_path(path);
return ret;
}
static noinline int fixup_inode_link_counts(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path)
{
int ret;
struct btrfs_key key;
struct inode *inode;
key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(trans, root, &key, path, -1, 1);
if (ret < 0)
break;
if (ret == 1) {
ret = 0;
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.objectid != BTRFS_TREE_LOG_FIXUP_OBJECTID ||
key.type != BTRFS_ORPHAN_ITEM_KEY)
break;
ret = btrfs_del_item(trans, root, path);
if (ret)
break;
btrfs_release_path(path);
inode = read_one_inode(root, key.offset);
if (!inode) {
ret = -EIO;
break;
}
ret = fixup_inode_link_count(trans, root, inode);
iput(inode);
if (ret)
break;
/*
* fixup on a directory may create new entries,
* make sure we always look for the highset possible
* offset
*/
key.offset = (u64)-1;
}
btrfs_release_path(path);
return ret;
}
/*
* record a given inode in the fixup dir so we can check its link
* count when replay is done. The link count is incremented here
* so the inode won't go away until we check it
*/
static noinline int link_to_fixup_dir(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 objectid)
{
struct btrfs_key key;
int ret = 0;
struct inode *inode;
inode = read_one_inode(root, objectid);
if (!inode)
return -EIO;
key.objectid = BTRFS_TREE_LOG_FIXUP_OBJECTID;
key.type = BTRFS_ORPHAN_ITEM_KEY;
key.offset = objectid;
ret = btrfs_insert_empty_item(trans, root, path, &key, 0);
btrfs_release_path(path);
if (ret == 0) {
if (!inode->i_nlink)
set_nlink(inode, 1);
else
inc_nlink(inode);
ret = btrfs_update_inode(trans, root, BTRFS_I(inode));
} else if (ret == -EEXIST) {
ret = 0;
}
iput(inode);
return ret;
}
/*
* when replaying the log for a directory, we only insert names
* for inodes that actually exist. This means an fsync on a directory
* does not implicitly fsync all the new files in it
*/
static noinline int insert_one_name(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
u64 dirid, u64 index,
char *name, int name_len,
struct btrfs_key *location)
{
struct inode *inode;
struct inode *dir;
int ret;
inode = read_one_inode(root, location->objectid);
if (!inode)
return -ENOENT;
dir = read_one_inode(root, dirid);
if (!dir) {
iput(inode);
return -EIO;
}
ret = btrfs_add_link(trans, BTRFS_I(dir), BTRFS_I(inode), name,
name_len, 1, index);
/* FIXME, put inode into FIXUP list */
iput(inode);
iput(dir);
return ret;
}
static int delete_conflicting_dir_entry(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir,
struct btrfs_path *path,
struct btrfs_dir_item *dst_di,
const struct btrfs_key *log_key,
u8 log_type,
bool exists)
{
struct btrfs_key found_key;
btrfs_dir_item_key_to_cpu(path->nodes[0], dst_di, &found_key);
/* The existing dentry points to the same inode, don't delete it. */
if (found_key.objectid == log_key->objectid &&
found_key.type == log_key->type &&
found_key.offset == log_key->offset &&
btrfs_dir_type(path->nodes[0], dst_di) == log_type)
return 1;
/*
* Don't drop the conflicting directory entry if the inode for the new
* entry doesn't exist.
*/
if (!exists)
return 0;
return drop_one_dir_item(trans, path, dir, dst_di);
}
/*
* take a single entry in a log directory item and replay it into
* the subvolume.
*
* if a conflicting item exists in the subdirectory already,
* the inode it points to is unlinked and put into the link count
* fix up tree.
*
* If a name from the log points to a file or directory that does
* not exist in the FS, it is skipped. fsyncs on directories
* do not force down inodes inside that directory, just changes to the
* names or unlinks in a directory.
*
* Returns < 0 on error, 0 if the name wasn't replayed (dentry points to a
* non-existing inode) and 1 if the name was replayed.
*/
static noinline int replay_one_name(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb,
struct btrfs_dir_item *di,
struct btrfs_key *key)
{
char *name;
int name_len;
struct btrfs_dir_item *dir_dst_di;
struct btrfs_dir_item *index_dst_di;
bool dir_dst_matches = false;
bool index_dst_matches = false;
struct btrfs_key log_key;
struct btrfs_key search_key;
struct inode *dir;
u8 log_type;
bool exists;
int ret;
bool update_size = true;
bool name_added = false;
dir = read_one_inode(root, key->objectid);
if (!dir)
return -EIO;
name_len = btrfs_dir_name_len(eb, di);
name = kmalloc(name_len, GFP_NOFS);
if (!name) {
ret = -ENOMEM;
goto out;
}
log_type = btrfs_dir_type(eb, di);
read_extent_buffer(eb, name, (unsigned long)(di + 1),
name_len);
btrfs_dir_item_key_to_cpu(eb, di, &log_key);
ret = btrfs_lookup_inode(trans, root, path, &log_key, 0);
btrfs_release_path(path);
if (ret < 0)
goto out;
exists = (ret == 0);
ret = 0;
dir_dst_di = btrfs_lookup_dir_item(trans, root, path, key->objectid,
name, name_len, 1);
if (IS_ERR(dir_dst_di)) {
ret = PTR_ERR(dir_dst_di);
goto out;
} else if (dir_dst_di) {
ret = delete_conflicting_dir_entry(trans, BTRFS_I(dir), path,
dir_dst_di, &log_key, log_type,
exists);
if (ret < 0)
goto out;
dir_dst_matches = (ret == 1);
}
btrfs_release_path(path);
index_dst_di = btrfs_lookup_dir_index_item(trans, root, path,
key->objectid, key->offset,
name, name_len, 1);
if (IS_ERR(index_dst_di)) {
ret = PTR_ERR(index_dst_di);
goto out;
} else if (index_dst_di) {
ret = delete_conflicting_dir_entry(trans, BTRFS_I(dir), path,
index_dst_di, &log_key,
log_type, exists);
if (ret < 0)
goto out;
index_dst_matches = (ret == 1);
}
btrfs_release_path(path);
if (dir_dst_matches && index_dst_matches) {
ret = 0;
update_size = false;
goto out;
}
/*
* Check if the inode reference exists in the log for the given name,
* inode and parent inode
*/
search_key.objectid = log_key.objectid;
search_key.type = BTRFS_INODE_REF_KEY;
search_key.offset = key->objectid;
ret = backref_in_log(root->log_root, &search_key, 0, name, name_len);
if (ret < 0) {
goto out;
} else if (ret) {
/* The dentry will be added later. */
ret = 0;
update_size = false;
goto out;
}
search_key.objectid = log_key.objectid;
search_key.type = BTRFS_INODE_EXTREF_KEY;
search_key.offset = key->objectid;
ret = backref_in_log(root->log_root, &search_key, key->objectid, name,
name_len);
if (ret < 0) {
goto out;
} else if (ret) {
/* The dentry will be added later. */
ret = 0;
update_size = false;
goto out;
}
btrfs_release_path(path);
ret = insert_one_name(trans, root, key->objectid, key->offset,
name, name_len, &log_key);
if (ret && ret != -ENOENT && ret != -EEXIST)
goto out;
if (!ret)
name_added = true;
update_size = false;
ret = 0;
out:
if (!ret && update_size) {
btrfs_i_size_write(BTRFS_I(dir), dir->i_size + name_len * 2);
ret = btrfs_update_inode(trans, root, BTRFS_I(dir));
}
kfree(name);
iput(dir);
if (!ret && name_added)
ret = 1;
return ret;
}
/* Replay one dir item from a BTRFS_DIR_INDEX_KEY key. */
static noinline int replay_one_dir_item(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct extent_buffer *eb, int slot,
struct btrfs_key *key)
{
int ret;
struct btrfs_dir_item *di;
/* We only log dir index keys, which only contain a single dir item. */
ASSERT(key->type == BTRFS_DIR_INDEX_KEY);
di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
ret = replay_one_name(trans, root, path, eb, di, key);
if (ret < 0)
return ret;
/*
* If this entry refers to a non-directory (directories can not have a
* link count > 1) and it was added in the transaction that was not
* committed, make sure we fixup the link count of the inode the entry
* points to. Otherwise something like the following would result in a
* directory pointing to an inode with a wrong link that does not account
* for this dir entry:
*
* mkdir testdir
* touch testdir/foo
* touch testdir/bar
* sync
*
* ln testdir/bar testdir/bar_link
* ln testdir/foo testdir/foo_link
* xfs_io -c "fsync" testdir/bar
*
* <power failure>
*
* mount fs, log replay happens
*
* File foo would remain with a link count of 1 when it has two entries
* pointing to it in the directory testdir. This would make it impossible
* to ever delete the parent directory has it would result in stale
* dentries that can never be deleted.
*/
if (ret == 1 && btrfs_dir_type(eb, di) != BTRFS_FT_DIR) {
struct btrfs_path *fixup_path;
struct btrfs_key di_key;
fixup_path = btrfs_alloc_path();
if (!fixup_path)
return -ENOMEM;
btrfs_dir_item_key_to_cpu(eb, di, &di_key);
ret = link_to_fixup_dir(trans, root, fixup_path, di_key.objectid);
btrfs_free_path(fixup_path);
}
return ret;
}
/*
* directory replay has two parts. There are the standard directory
* items in the log copied from the subvolume, and range items
* created in the log while the subvolume was logged.
*
* The range items tell us which parts of the key space the log
* is authoritative for. During replay, if a key in the subvolume
* directory is in a logged range item, but not actually in the log
* that means it was deleted from the directory before the fsync
* and should be removed.
*/
static noinline int find_dir_range(struct btrfs_root *root,
struct btrfs_path *path,
u64 dirid,
u64 *start_ret, u64 *end_ret)
{
struct btrfs_key key;
u64 found_end;
struct btrfs_dir_log_item *item;
int ret;
int nritems;
if (*start_ret == (u64)-1)
return 1;
key.objectid = dirid;
key.type = BTRFS_DIR_LOG_INDEX_KEY;
key.offset = *start_ret;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
if (ret > 0) {
if (path->slots[0] == 0)
goto out;
path->slots[0]--;
}
if (ret != 0)
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.type != BTRFS_DIR_LOG_INDEX_KEY || key.objectid != dirid) {
ret = 1;
goto next;
}
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_dir_log_item);
found_end = btrfs_dir_log_end(path->nodes[0], item);
if (*start_ret >= key.offset && *start_ret <= found_end) {
ret = 0;
*start_ret = key.offset;
*end_ret = found_end;
goto out;
}
ret = 1;
next:
/* check the next slot in the tree to see if it is a valid item */
nritems = btrfs_header_nritems(path->nodes[0]);
path->slots[0]++;
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret)
goto out;
}
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]);
if (key.type != BTRFS_DIR_LOG_INDEX_KEY || key.objectid != dirid) {
ret = 1;
goto out;
}
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_dir_log_item);
found_end = btrfs_dir_log_end(path->nodes[0], item);
*start_ret = key.offset;
*end_ret = found_end;
ret = 0;
out:
btrfs_release_path(path);
return ret;
}
/*
* this looks for a given directory item in the log. If the directory
* item is not in the log, the item is removed and the inode it points
* to is unlinked
*/
static noinline int check_item_in_log(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_path *path,
struct btrfs_path *log_path,
struct inode *dir,
struct btrfs_key *dir_key)
{
struct btrfs_root *root = BTRFS_I(dir)->root;
int ret;
struct extent_buffer *eb;
int slot;
struct btrfs_dir_item *di;
int name_len;
char *name;
struct inode *inode = NULL;
struct btrfs_key location;
/*
* Currently we only log dir index keys. Even if we replay a log created
* by an older kernel that logged both dir index and dir item keys, all
* we need to do is process the dir index keys, we (and our caller) can
* safely ignore dir item keys (key type BTRFS_DIR_ITEM_KEY).
*/
ASSERT(dir_key->type == BTRFS_DIR_INDEX_KEY);
eb = path->nodes[0];
slot = path->slots[0];
di = btrfs_item_ptr(eb, slot, struct btrfs_dir_item);
name_len = btrfs_dir_name_len(eb, di);
name = kmalloc(name_len, GFP_NOFS);
if (!name) {
ret = -ENOMEM;
goto out;
}
read_extent_buffer(eb, name, (unsigned long)(di + 1), name_len);
if (log) {
struct btrfs_dir_item *log_di;
log_di = btrfs_lookup_dir_index_item(trans, log, log_path,
dir_key->objectid,
dir_key->offset,
name, name_len, 0);
if (IS_ERR(log_di)) {
ret = PTR_ERR(log_di);
goto out;
} else if (log_di) {
/* The dentry exists in the log, we have nothing to do. */
ret = 0;
goto out;
}
}
btrfs_dir_item_key_to_cpu(eb, di, &location);
btrfs_release_path(path);
btrfs_release_path(log_path);
inode = read_one_inode(root, location.objectid);
if (!inode) {
ret = -EIO;
goto out;
}
ret = link_to_fixup_dir(trans, root, path, location.objectid);
if (ret)
goto out;
inc_nlink(inode);
ret = unlink_inode_for_log_replay(trans, BTRFS_I(dir), BTRFS_I(inode),
name, name_len);
/*
* Unlike dir item keys, dir index keys can only have one name (entry) in
* them, as there are no key collisions since each key has a unique offset
* (an index number), so we're done.
*/
out:
btrfs_release_path(path);
btrfs_release_path(log_path);
kfree(name);
iput(inode);
return ret;
}
static int replay_xattr_deletes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
const u64 ino)
{
struct btrfs_key search_key;
struct btrfs_path *log_path;
int i;
int nritems;
int ret;
log_path = btrfs_alloc_path();
if (!log_path)
return -ENOMEM;
search_key.objectid = ino;
search_key.type = BTRFS_XATTR_ITEM_KEY;
search_key.offset = 0;
again:
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret < 0)
goto out;
process_leaf:
nritems = btrfs_header_nritems(path->nodes[0]);
for (i = path->slots[0]; i < nritems; i++) {
struct btrfs_key key;
struct btrfs_dir_item *di;
struct btrfs_dir_item *log_di;
u32 total_size;
u32 cur;
btrfs_item_key_to_cpu(path->nodes[0], &key, i);
if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY) {
ret = 0;
goto out;
}
di = btrfs_item_ptr(path->nodes[0], i, struct btrfs_dir_item);
total_size = btrfs_item_size(path->nodes[0], i);
cur = 0;
while (cur < total_size) {
u16 name_len = btrfs_dir_name_len(path->nodes[0], di);
u16 data_len = btrfs_dir_data_len(path->nodes[0], di);
u32 this_len = sizeof(*di) + name_len + data_len;
char *name;
name = kmalloc(name_len, GFP_NOFS);
if (!name) {
ret = -ENOMEM;
goto out;
}
read_extent_buffer(path->nodes[0], name,
(unsigned long)(di + 1), name_len);
log_di = btrfs_lookup_xattr(NULL, log, log_path, ino,
name, name_len, 0);
btrfs_release_path(log_path);
if (!log_di) {
/* Doesn't exist in log tree, so delete it. */
btrfs_release_path(path);
di = btrfs_lookup_xattr(trans, root, path, ino,
name, name_len, -1);
kfree(name);
if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out;
}
ASSERT(di);
ret = btrfs_delete_one_dir_name(trans, root,
path, di);
if (ret)
goto out;
btrfs_release_path(path);
search_key = key;
goto again;
}
kfree(name);
if (IS_ERR(log_di)) {
ret = PTR_ERR(log_di);
goto out;
}
cur += this_len;
di = (struct btrfs_dir_item *)((char *)di + this_len);
}
}
ret = btrfs_next_leaf(root, path);
if (ret > 0)
ret = 0;
else if (ret == 0)
goto process_leaf;
out:
btrfs_free_path(log_path);
btrfs_release_path(path);
return ret;
}
/*
* deletion replay happens before we copy any new directory items
* out of the log or out of backreferences from inodes. It
* scans the log to find ranges of keys that log is authoritative for,
* and then scans the directory to find items in those ranges that are
* not present in the log.
*
* Anything we don't find in the log is unlinked and removed from the
* directory.
*/
static noinline int replay_dir_deletes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_root *log,
struct btrfs_path *path,
u64 dirid, int del_all)
{
u64 range_start;
u64 range_end;
int ret = 0;
struct btrfs_key dir_key;
struct btrfs_key found_key;
struct btrfs_path *log_path;
struct inode *dir;
dir_key.objectid = dirid;
dir_key.type = BTRFS_DIR_INDEX_KEY;
log_path = btrfs_alloc_path();
if (!log_path)
return -ENOMEM;
dir = read_one_inode(root, dirid);
/* it isn't an error if the inode isn't there, that can happen
* because we replay the deletes before we copy in the inode item
* from the log
*/
if (!dir) {
btrfs_free_path(log_path);
return 0;
}
range_start = 0;
range_end = 0;
while (1) {
if (del_all)
range_end = (u64)-1;
else {
ret = find_dir_range(log, path, dirid,
&range_start, &range_end);
if (ret < 0)
goto out;
else if (ret > 0)
break;
}
dir_key.offset = range_start;
while (1) {
int nritems;
ret = btrfs_search_slot(NULL, root, &dir_key, path,
0, 0);
if (ret < 0)
goto out;
nritems = btrfs_header_nritems(path->nodes[0]);
if (path->slots[0] >= nritems) {
ret = btrfs_next_leaf(root, path);
if (ret == 1)
break;
else if (ret < 0)
goto out;
}
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
if (found_key.objectid != dirid ||
found_key.type != dir_key.type) {
ret = 0;
goto out;
}
if (found_key.offset > range_end)
break;
ret = check_item_in_log(trans, log, path,
log_path, dir,
&found_key);
if (ret)
goto out;
if (found_key.offset == (u64)-1)
break;
dir_key.offset = found_key.offset + 1;
}
btrfs_release_path(path);
if (range_end == (u64)-1)
break;
range_start = range_end + 1;
}
ret = 0;
out:
btrfs_release_path(path);
btrfs_free_path(log_path);
iput(dir);
return ret;
}
/*
* the process_func used to replay items from the log tree. This
* gets called in two different stages. The first stage just looks
* for inodes and makes sure they are all copied into the subvolume.
*
* The second stage copies all the other item types from the log into
* the subvolume. The two stage approach is slower, but gets rid of
* lots of complexity around inodes referencing other inodes that exist
* only in the log (references come from either directory items or inode
* back refs).
*/
static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
struct walk_control *wc, u64 gen, int level)
{
int nritems;
struct btrfs_path *path;
struct btrfs_root *root = wc->replay_dest;
struct btrfs_key key;
int i;
int ret;
ret = btrfs_read_extent_buffer(eb, gen, level, NULL);
if (ret)
return ret;
level = btrfs_header_level(eb);
if (level != 0)
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
nritems = btrfs_header_nritems(eb);
for (i = 0; i < nritems; i++) {
btrfs_item_key_to_cpu(eb, &key, i);
/* inode keys are done during the first stage */
if (key.type == BTRFS_INODE_ITEM_KEY &&
wc->stage == LOG_WALK_REPLAY_INODES) {
struct btrfs_inode_item *inode_item;
u32 mode;
inode_item = btrfs_item_ptr(eb, i,
struct btrfs_inode_item);
/*
* If we have a tmpfile (O_TMPFILE) that got fsync'ed
* and never got linked before the fsync, skip it, as
* replaying it is pointless since it would be deleted
* later. We skip logging tmpfiles, but it's always
* possible we are replaying a log created with a kernel
* that used to log tmpfiles.
*/
if (btrfs_inode_nlink(eb, inode_item) == 0) {
wc->ignore_cur_inode = true;
continue;
} else {
wc->ignore_cur_inode = false;
}
ret = replay_xattr_deletes(wc->trans, root, log,
path, key.objectid);
if (ret)
break;
mode = btrfs_inode_mode(eb, inode_item);
if (S_ISDIR(mode)) {
ret = replay_dir_deletes(wc->trans,
root, log, path, key.objectid, 0);
if (ret)
break;
}
ret = overwrite_item(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
/*
* Before replaying extents, truncate the inode to its
* size. We need to do it now and not after log replay
* because before an fsync we can have prealloc extents
* added beyond the inode's i_size. If we did it after,
* through orphan cleanup for example, we would drop
* those prealloc extents just after replaying them.
*/
if (S_ISREG(mode)) {
struct btrfs_drop_extents_args drop_args = { 0 };
struct inode *inode;
u64 from;
inode = read_one_inode(root, key.objectid);
if (!inode) {
ret = -EIO;
break;
}
from = ALIGN(i_size_read(inode),
root->fs_info->sectorsize);
drop_args.start = from;
drop_args.end = (u64)-1;
drop_args.drop_cache = true;
ret = btrfs_drop_extents(wc->trans, root,
BTRFS_I(inode),
&drop_args);
if (!ret) {
inode_sub_bytes(inode,
drop_args.bytes_found);
/* Update the inode's nbytes. */
ret = btrfs_update_inode(wc->trans,
root, BTRFS_I(inode));
}
iput(inode);
if (ret)
break;
}
ret = link_to_fixup_dir(wc->trans, root,
path, key.objectid);
if (ret)
break;
}
if (wc->ignore_cur_inode)
continue;
if (key.type == BTRFS_DIR_INDEX_KEY &&
wc->stage == LOG_WALK_REPLAY_DIR_INDEX) {
ret = replay_one_dir_item(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
}
if (wc->stage < LOG_WALK_REPLAY_ALL)
continue;
/* these keys are simply copied */
if (key.type == BTRFS_XATTR_ITEM_KEY) {
ret = overwrite_item(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
} else if (key.type == BTRFS_INODE_REF_KEY ||
key.type == BTRFS_INODE_EXTREF_KEY) {
ret = add_inode_ref(wc->trans, root, log, path,
eb, i, &key);
if (ret && ret != -ENOENT)
break;
ret = 0;
} else if (key.type == BTRFS_EXTENT_DATA_KEY) {
ret = replay_one_extent(wc->trans, root, path,
eb, i, &key);
if (ret)
break;
}
/*
* We don't log BTRFS_DIR_ITEM_KEY keys anymore, only the
* BTRFS_DIR_INDEX_KEY items which we use to derive the
* BTRFS_DIR_ITEM_KEY items. If we are replaying a log from an
* older kernel with such keys, ignore them.
*/
}
btrfs_free_path(path);
return ret;
}
/*
* Correctly adjust the reserved bytes occupied by a log tree extent buffer
*/
static void unaccount_log_buffer(struct btrfs_fs_info *fs_info, u64 start)
{
struct btrfs_block_group *cache;
cache = btrfs_lookup_block_group(fs_info, start);
if (!cache) {
btrfs_err(fs_info, "unable to find block group for %llu", start);
return;
}
spin_lock(&cache->space_info->lock);
spin_lock(&cache->lock);
cache->reserved -= fs_info->nodesize;
cache->space_info->bytes_reserved -= fs_info->nodesize;
spin_unlock(&cache->lock);
spin_unlock(&cache->space_info->lock);
btrfs_put_block_group(cache);
}
static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int *level,
struct walk_control *wc)
{
struct btrfs_fs_info *fs_info = root->fs_info;
u64 bytenr;
u64 ptr_gen;
struct extent_buffer *next;
struct extent_buffer *cur;
u32 blocksize;
int ret = 0;
while (*level > 0) {
struct btrfs_key first_key;
cur = path->nodes[*level];
WARN_ON(btrfs_header_level(cur) != *level);
if (path->slots[*level] >=
btrfs_header_nritems(cur))
break;
bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
btrfs_node_key_to_cpu(cur, &first_key, path->slots[*level]);
blocksize = fs_info->nodesize;
next = btrfs_find_create_tree_block(fs_info, bytenr,
btrfs_header_owner(cur),
*level - 1);
if (IS_ERR(next))
return PTR_ERR(next);
if (*level == 1) {
ret = wc->process_func(root, next, wc, ptr_gen,
*level - 1);
if (ret) {
free_extent_buffer(next);
return ret;
}
path->slots[*level]++;
if (wc->free) {
ret = btrfs_read_extent_buffer(next, ptr_gen,
*level - 1, &first_key);
if (ret) {
free_extent_buffer(next);
return ret;
}
if (trans) {
btrfs_tree_lock(next);
btrfs_clean_tree_block(next);
btrfs_wait_tree_block_writeback(next);
btrfs_tree_unlock(next);
ret = btrfs_pin_reserved_extent(trans,
bytenr, blocksize);
if (ret) {
free_extent_buffer(next);
return ret;
}
btrfs_redirty_list_add(
trans->transaction, next);
} else {
if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
clear_extent_buffer_dirty(next);
unaccount_log_buffer(fs_info, bytenr);
}
}
free_extent_buffer(next);
continue;
}
ret = btrfs_read_extent_buffer(next, ptr_gen, *level - 1, &first_key);
if (ret) {
free_extent_buffer(next);
return ret;
}
if (path->nodes[*level-1])
free_extent_buffer(path->nodes[*level-1]);
path->nodes[*level-1] = next;
*level = btrfs_header_level(next);
path->slots[*level] = 0;
cond_resched();
}
path->slots[*level] = btrfs_header_nritems(path->nodes[*level]);
cond_resched();
return 0;
}
static noinline int walk_up_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path, int *level,
struct walk_control *wc)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int i;
int slot;
int ret;
for (i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) {
slot = path->slots[i];
if (slot + 1 < btrfs_header_nritems(path->nodes[i])) {
path->slots[i]++;
*level = i;
WARN_ON(*level == 0);
return 0;
} else {
ret = wc->process_func(root, path->nodes[*level], wc,
btrfs_header_generation(path->nodes[*level]),
*level);
if (ret)
return ret;
if (wc->free) {
struct extent_buffer *next;
next = path->nodes[*level];
if (trans) {
btrfs_tree_lock(next);
btrfs_clean_tree_block(next);
btrfs_wait_tree_block_writeback(next);
btrfs_tree_unlock(next);
ret = btrfs_pin_reserved_extent(trans,
path->nodes[*level]->start,
path->nodes[*level]->len);
if (ret)
return ret;
btrfs_redirty_list_add(trans->transaction,
next);
} else {
if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
clear_extent_buffer_dirty(next);
unaccount_log_buffer(fs_info,
path->nodes[*level]->start);
}
}
free_extent_buffer(path->nodes[*level]);
path->nodes[*level] = NULL;
*level = i + 1;
}
}
return 1;
}
/*
* drop the reference count on the tree rooted at 'snap'. This traverses
* the tree freeing any blocks that have a ref count of zero after being
* decremented.
*/
static int walk_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *log, struct walk_control *wc)
{
struct btrfs_fs_info *fs_info = log->fs_info;
int ret = 0;
int wret;
int level;
struct btrfs_path *path;
int orig_level;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
level = btrfs_header_level(log->node);
orig_level = level;
path->nodes[level] = log->node;
atomic_inc(&log->node->refs);
path->slots[level] = 0;
while (1) {
wret = walk_down_log_tree(trans, log, path, &level, wc);
if (wret > 0)
break;
if (wret < 0) {
ret = wret;
goto out;
}
wret = walk_up_log_tree(trans, log, path, &level, wc);
if (wret > 0)
break;
if (wret < 0) {
ret = wret;
goto out;
}
}
/* was the root node processed? if not, catch it here */
if (path->nodes[orig_level]) {
ret = wc->process_func(log, path->nodes[orig_level], wc,
btrfs_header_generation(path->nodes[orig_level]),
orig_level);
if (ret)
goto out;
if (wc->free) {
struct extent_buffer *next;
next = path->nodes[orig_level];
if (trans) {
btrfs_tree_lock(next);
btrfs_clean_tree_block(next);
btrfs_wait_tree_block_writeback(next);
btrfs_tree_unlock(next);
ret = btrfs_pin_reserved_extent(trans,
next->start, next->len);
if (ret)
goto out;
btrfs_redirty_list_add(trans->transaction, next);
} else {
if (test_and_clear_bit(EXTENT_BUFFER_DIRTY, &next->bflags))
clear_extent_buffer_dirty(next);
unaccount_log_buffer(fs_info, next->start);
}
}
}
out:
btrfs_free_path(path);
return ret;
}
/*
* helper function to update the item for a given subvolumes log root
* in the tree of log roots
*/
static int update_log_root(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_root_item *root_item)
{
struct btrfs_fs_info *fs_info = log->fs_info;
int ret;
if (log->log_transid == 1) {
/* insert root item on the first sync */
ret = btrfs_insert_root(trans, fs_info->log_root_tree,
&log->root_key, root_item);
} else {
ret = btrfs_update_root(trans, fs_info->log_root_tree,
&log->root_key, root_item);
}
return ret;
}
static void wait_log_commit(struct btrfs_root *root, int transid)
{
DEFINE_WAIT(wait);
int index = transid % 2;
/*
* we only allow two pending log transactions at a time,
* so we know that if ours is more than 2 older than the
* current transaction, we're done
*/
for (;;) {
prepare_to_wait(&root->log_commit_wait[index],
&wait, TASK_UNINTERRUPTIBLE);
if (!(root->log_transid_committed < transid &&
atomic_read(&root->log_commit[index])))
break;
mutex_unlock(&root->log_mutex);
schedule();
mutex_lock(&root->log_mutex);
}
finish_wait(&root->log_commit_wait[index], &wait);
}
static void wait_for_writer(struct btrfs_root *root)
{
DEFINE_WAIT(wait);
for (;;) {
prepare_to_wait(&root->log_writer_wait, &wait,
TASK_UNINTERRUPTIBLE);
if (!atomic_read(&root->log_writers))
break;
mutex_unlock(&root->log_mutex);
schedule();
mutex_lock(&root->log_mutex);
}
finish_wait(&root->log_writer_wait, &wait);
}
static inline void btrfs_remove_log_ctx(struct btrfs_root *root,
struct btrfs_log_ctx *ctx)
{
mutex_lock(&root->log_mutex);
list_del_init(&ctx->list);
mutex_unlock(&root->log_mutex);
}
/*
* Invoked in log mutex context, or be sure there is no other task which
* can access the list.
*/
static inline void btrfs_remove_all_log_ctxs(struct btrfs_root *root,
int index, int error)
{
struct btrfs_log_ctx *ctx;
struct btrfs_log_ctx *safe;
list_for_each_entry_safe(ctx, safe, &root->log_ctxs[index], list) {
list_del_init(&ctx->list);
ctx->log_ret = error;
}
}
/*
* btrfs_sync_log does sends a given tree log down to the disk and
* updates the super blocks to record it. When this call is done,
* you know that any inodes previously logged are safely on disk only
* if it returns 0.
*
* Any other return value means you need to call btrfs_commit_transaction.
* Some of the edge cases for fsyncing directories that have had unlinks
* or renames done in the past mean that sometimes the only safe
* fsync is to commit the whole FS. When btrfs_sync_log returns -EAGAIN,
* that has happened.
*/
int btrfs_sync_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root, struct btrfs_log_ctx *ctx)
{
int index1;
int index2;
int mark;
int ret;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_root *log = root->log_root;
struct btrfs_root *log_root_tree = fs_info->log_root_tree;
struct btrfs_root_item new_root_item;
int log_transid = 0;
struct btrfs_log_ctx root_log_ctx;
struct blk_plug plug;
u64 log_root_start;
u64 log_root_level;
mutex_lock(&root->log_mutex);
log_transid = ctx->log_transid;
if (root->log_transid_committed >= log_transid) {
mutex_unlock(&root->log_mutex);
return ctx->log_ret;
}
index1 = log_transid % 2;
if (atomic_read(&root->log_commit[index1])) {
wait_log_commit(root, log_transid);
mutex_unlock(&root->log_mutex);
return ctx->log_ret;
}
ASSERT(log_transid == root->log_transid);
atomic_set(&root->log_commit[index1], 1);
/* wait for previous tree log sync to complete */
if (atomic_read(&root->log_commit[(index1 + 1) % 2]))
wait_log_commit(root, log_transid - 1);
while (1) {
int batch = atomic_read(&root->log_batch);
/* when we're on an ssd, just kick the log commit out */
if (!btrfs_test_opt(fs_info, SSD) &&
test_bit(BTRFS_ROOT_MULTI_LOG_TASKS, &root->state)) {
mutex_unlock(&root->log_mutex);
schedule_timeout_uninterruptible(1);
mutex_lock(&root->log_mutex);
}
wait_for_writer(root);
if (batch == atomic_read(&root->log_batch))
break;
}
/* bail out if we need to do a full commit */
if (btrfs_need_log_full_commit(trans)) {
ret = BTRFS_LOG_FORCE_COMMIT;
mutex_unlock(&root->log_mutex);
goto out;
}
if (log_transid % 2 == 0)
mark = EXTENT_DIRTY;
else
mark = EXTENT_NEW;
/* we start IO on all the marked extents here, but we don't actually
* wait for them until later.
*/
blk_start_plug(&plug);
ret = btrfs_write_marked_extents(fs_info, &log->dirty_log_pages, mark);
/*
* -EAGAIN happens when someone, e.g., a concurrent transaction
* commit, writes a dirty extent in this tree-log commit. This
* concurrent write will create a hole writing out the extents,
* and we cannot proceed on a zoned filesystem, requiring
* sequential writing. While we can bail out to a full commit
* here, but we can continue hoping the concurrent writing fills
* the hole.
*/
if (ret == -EAGAIN && btrfs_is_zoned(fs_info))
ret = 0;
if (ret) {
blk_finish_plug(&plug);
btrfs_abort_transaction(trans, ret);
btrfs_set_log_full_commit(trans);
mutex_unlock(&root->log_mutex);
goto out;
}
/*
* We _must_ update under the root->log_mutex in order to make sure we
* have a consistent view of the log root we are trying to commit at
* this moment.
*
* We _must_ copy this into a local copy, because we are not holding the
* log_root_tree->log_mutex yet. This is important because when we
* commit the log_root_tree we must have a consistent view of the
* log_root_tree when we update the super block to point at the
* log_root_tree bytenr. If we update the log_root_tree here we'll race
* with the commit and possibly point at the new block which we may not
* have written out.
*/
btrfs_set_root_node(&log->root_item, log->node);
memcpy(&new_root_item, &log->root_item, sizeof(new_root_item));
root->log_transid++;
log->log_transid = root->log_transid;
root->log_start_pid = 0;
/*
* IO has been started, blocks of the log tree have WRITTEN flag set
* in their headers. new modifications of the log will be written to
* new positions. so it's safe to allow log writers to go in.
*/
mutex_unlock(&root->log_mutex);
if (btrfs_is_zoned(fs_info)) {
mutex_lock(&fs_info->tree_root->log_mutex);
if (!log_root_tree->node) {
ret = btrfs_alloc_log_tree_node(trans, log_root_tree);
if (ret) {
mutex_unlock(&fs_info->tree_root->log_mutex);
blk_finish_plug(&plug);
goto out;
}
}
mutex_unlock(&fs_info->tree_root->log_mutex);
}
btrfs_init_log_ctx(&root_log_ctx, NULL);
mutex_lock(&log_root_tree->log_mutex);
index2 = log_root_tree->log_transid % 2;
list_add_tail(&root_log_ctx.list, &log_root_tree->log_ctxs[index2]);
root_log_ctx.log_transid = log_root_tree->log_transid;
/*
* Now we are safe to update the log_root_tree because we're under the
* log_mutex, and we're a current writer so we're holding the commit
* open until we drop the log_mutex.
*/
ret = update_log_root(trans, log, &new_root_item);
if (ret) {
if (!list_empty(&root_log_ctx.list))
list_del_init(&root_log_ctx.list);
blk_finish_plug(&plug);
btrfs_set_log_full_commit(trans);
if (ret != -ENOSPC) {
btrfs_abort_transaction(trans, ret);
mutex_unlock(&log_root_tree->log_mutex);
goto out;
}
btrfs_wait_tree_log_extents(log, mark);
mutex_unlock(&log_root_tree->log_mutex);
ret = BTRFS_LOG_FORCE_COMMIT;
goto out;
}
if (log_root_tree->log_transid_committed >= root_log_ctx.log_transid) {
blk_finish_plug(&plug);
list_del_init(&root_log_ctx.list);
mutex_unlock(&log_root_tree->log_mutex);
ret = root_log_ctx.log_ret;
goto out;
}
index2 = root_log_ctx.log_transid % 2;
if (atomic_read(&log_root_tree->log_commit[index2])) {
blk_finish_plug(&plug);
ret = btrfs_wait_tree_log_extents(log, mark);
wait_log_commit(log_root_tree,
root_log_ctx.log_transid);
mutex_unlock(&log_root_tree->log_mutex);
if (!ret)
ret = root_log_ctx.log_ret;
goto out;
}
ASSERT(root_log_ctx.log_transid == log_root_tree->log_transid);
atomic_set(&log_root_tree->log_commit[index2], 1);
if (atomic_read(&log_root_tree->log_commit[(index2 + 1) % 2])) {
wait_log_commit(log_root_tree,
root_log_ctx.log_transid - 1);
}
/*
* now that we've moved on to the tree of log tree roots,
* check the full commit flag again
*/
if (btrfs_need_log_full_commit(trans)) {
blk_finish_plug(&plug);
btrfs_wait_tree_log_extents(log, mark);
mutex_unlock(&log_root_tree->log_mutex);
ret = BTRFS_LOG_FORCE_COMMIT;
goto out_wake_log_root;
}
ret = btrfs_write_marked_extents(fs_info,
&log_root_tree->dirty_log_pages,
EXTENT_DIRTY | EXTENT_NEW);
blk_finish_plug(&plug);
/*
* As described above, -EAGAIN indicates a hole in the extents. We
* cannot wait for these write outs since the waiting cause a
* deadlock. Bail out to the full commit instead.
*/
if (ret == -EAGAIN && btrfs_is_zoned(fs_info)) {
btrfs_set_log_full_commit(trans);
btrfs_wait_tree_log_extents(log, mark);
mutex_unlock(&log_root_tree->log_mutex);
goto out_wake_log_root;
} else if (ret) {
btrfs_set_log_full_commit(trans);
btrfs_abort_transaction(trans, ret);
mutex_unlock(&log_root_tree->log_mutex);
goto out_wake_log_root;
}
ret = btrfs_wait_tree_log_extents(log, mark);
if (!ret)
ret = btrfs_wait_tree_log_extents(log_root_tree,
EXTENT_NEW | EXTENT_DIRTY);
if (ret) {
btrfs_set_log_full_commit(trans);
mutex_unlock(&log_root_tree->log_mutex);
goto out_wake_log_root;
}
log_root_start = log_root_tree->node->start;
log_root_level = btrfs_header_level(log_root_tree->node);
log_root_tree->log_transid++;
mutex_unlock(&log_root_tree->log_mutex);
/*
* Here we are guaranteed that nobody is going to write the superblock
* for the current transaction before us and that neither we do write
* our superblock before the previous transaction finishes its commit
* and writes its superblock, because:
*
* 1) We are holding a handle on the current transaction, so no body
* can commit it until we release the handle;
*
* 2) Before writing our superblock we acquire the tree_log_mutex, so
* if the previous transaction is still committing, and hasn't yet
* written its superblock, we wait for it to do it, because a
* transaction commit acquires the tree_log_mutex when the commit
* begins and releases it only after writing its superblock.
*/
mutex_lock(&fs_info->tree_log_mutex);
/*
* The previous transaction writeout phase could have failed, and thus
* marked the fs in an error state. We must not commit here, as we
* could have updated our generation in the super_for_commit and
* writing the super here would result in transid mismatches. If there
* is an error here just bail.
*/
if (BTRFS_FS_ERROR(fs_info)) {
ret = -EIO;
btrfs_set_log_full_commit(trans);
btrfs_abort_transaction(trans, ret);
mutex_unlock(&fs_info->tree_log_mutex);
goto out_wake_log_root;
}
btrfs_set_super_log_root(fs_info->super_for_commit, log_root_start);
btrfs_set_super_log_root_level(fs_info->super_for_commit, log_root_level);
ret = write_all_supers(fs_info, 1);
mutex_unlock(&fs_info->tree_log_mutex);
if (ret) {
btrfs_set_log_full_commit(trans);
btrfs_abort_transaction(trans, ret);
goto out_wake_log_root;
}
/*
* We know there can only be one task here, since we have not yet set
* root->log_commit[index1] to 0 and any task attempting to sync the
* log must wait for the previous log transaction to commit if it's
* still in progress or wait for the current log transaction commit if
* someone else already started it. We use <= and not < because the
* first log transaction has an ID of 0.
*/
ASSERT(root->last_log_commit <= log_transid);
root->last_log_commit = log_transid;
out_wake_log_root:
mutex_lock(&log_root_tree->log_mutex);
btrfs_remove_all_log_ctxs(log_root_tree, index2, ret);
log_root_tree->log_transid_committed++;
atomic_set(&log_root_tree->log_commit[index2], 0);
mutex_unlock(&log_root_tree->log_mutex);
/*
* The barrier before waitqueue_active (in cond_wake_up) is needed so
* all the updates above are seen by the woken threads. It might not be
* necessary, but proving that seems to be hard.
*/
cond_wake_up(&log_root_tree->log_commit_wait[index2]);
out:
mutex_lock(&root->log_mutex);
btrfs_remove_all_log_ctxs(root, index1, ret);
root->log_transid_committed++;
atomic_set(&root->log_commit[index1], 0);
mutex_unlock(&root->log_mutex);
/*
* The barrier before waitqueue_active (in cond_wake_up) is needed so
* all the updates above are seen by the woken threads. It might not be
* necessary, but proving that seems to be hard.
*/
cond_wake_up(&root->log_commit_wait[index1]);
return ret;
}
static void free_log_tree(struct btrfs_trans_handle *trans,
struct btrfs_root *log)
{
int ret;
struct walk_control wc = {
.free = 1,
.process_func = process_one_buffer
};
if (log->node) {
ret = walk_log_tree(trans, log, &wc);
if (ret) {
/*
* We weren't able to traverse the entire log tree, the
* typical scenario is getting an -EIO when reading an
* extent buffer of the tree, due to a previous writeback
* failure of it.
*/
set_bit(BTRFS_FS_STATE_LOG_CLEANUP_ERROR,
&log->fs_info->fs_state);
/*
* Some extent buffers of the log tree may still be dirty
* and not yet written back to storage, because we may
* have updates to a log tree without syncing a log tree,
* such as during rename and link operations. So flush
* them out and wait for their writeback to complete, so
* that we properly cleanup their state and pages.
*/
btrfs_write_marked_extents(log->fs_info,
&log->dirty_log_pages,
EXTENT_DIRTY | EXTENT_NEW);
btrfs_wait_tree_log_extents(log,
EXTENT_DIRTY | EXTENT_NEW);
if (trans)
btrfs_abort_transaction(trans, ret);
else
btrfs_handle_fs_error(log->fs_info, ret, NULL);
}
}
clear_extent_bits(&log->dirty_log_pages, 0, (u64)-1,
EXTENT_DIRTY | EXTENT_NEW | EXTENT_NEED_WAIT);
extent_io_tree_release(&log->log_csum_range);
btrfs_put_root(log);
}
/*
* free all the extents used by the tree log. This should be called
* at commit time of the full transaction
*/
int btrfs_free_log(struct btrfs_trans_handle *trans, struct btrfs_root *root)
{
if (root->log_root) {
free_log_tree(trans, root->log_root);
root->log_root = NULL;
clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &root->state);
}
return 0;
}
int btrfs_free_log_root_tree(struct btrfs_trans_handle *trans,
struct btrfs_fs_info *fs_info)
{
if (fs_info->log_root_tree) {
free_log_tree(trans, fs_info->log_root_tree);
fs_info->log_root_tree = NULL;
clear_bit(BTRFS_ROOT_HAS_LOG_TREE, &fs_info->tree_root->state);
}
return 0;
}
/*
* Check if an inode was logged in the current transaction. This correctly deals
* with the case where the inode was logged but has a logged_trans of 0, which
* happens if the inode is evicted and loaded again, as logged_trans is an in
* memory only field (not persisted).
*
* Returns 1 if the inode was logged before in the transaction, 0 if it was not,
* and < 0 on error.
*/
static int inode_logged(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path_in)
{
struct btrfs_path *path = path_in;
struct btrfs_key key;
int ret;
if (inode->logged_trans == trans->transid)
return 1;
/*
* If logged_trans is not 0, then we know the inode logged was not logged
* in this transaction, so we can return false right away.
*/
if (inode->logged_trans > 0)
return 0;
/*
* If no log tree was created for this root in this transaction, then
* the inode can not have been logged in this transaction. In that case
* set logged_trans to anything greater than 0 and less than the current
* transaction's ID, to avoid the search below in a future call in case
* a log tree gets created after this.
*/
if (!test_bit(BTRFS_ROOT_HAS_LOG_TREE, &inode->root->state)) {
inode->logged_trans = trans->transid - 1;
return 0;
}
/*
* We have a log tree and the inode's logged_trans is 0. We can't tell
* for sure if the inode was logged before in this transaction by looking
* only at logged_trans. We could be pessimistic and assume it was, but
* that can lead to unnecessarily logging an inode during rename and link
* operations, and then further updating the log in followup rename and
* link operations, specially if it's a directory, which adds latency
* visible to applications doing a series of rename or link operations.
*
* A logged_trans of 0 here can mean several things:
*
* 1) The inode was never logged since the filesystem was mounted, and may
* or may have not been evicted and loaded again;
*
* 2) The inode was logged in a previous transaction, then evicted and
* then loaded again;
*
* 3) The inode was logged in the current transaction, then evicted and
* then loaded again.
*
* For cases 1) and 2) we don't want to return true, but we need to detect
* case 3) and return true. So we do a search in the log root for the inode
* item.
*/
key.objectid = btrfs_ino(inode);
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
if (!path) {
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
}
ret = btrfs_search_slot(NULL, inode->root->log_root, &key, path, 0, 0);
if (path_in)
btrfs_release_path(path);
else
btrfs_free_path(path);
/*
* Logging an inode always results in logging its inode item. So if we
* did not find the item we know the inode was not logged for sure.
*/
if (ret < 0) {
return ret;
} else if (ret > 0) {
/*
* Set logged_trans to a value greater than 0 and less then the
* current transaction to avoid doing the search in future calls.
*/
inode->logged_trans = trans->transid - 1;
return 0;
}
/*
* The inode was previously logged and then evicted, set logged_trans to
* the current transacion's ID, to avoid future tree searches as long as
* the inode is not evicted again.
*/
inode->logged_trans = trans->transid;
/*
* If it's a directory, then we must set last_dir_index_offset to the
* maximum possible value, so that the next attempt to log the inode does
* not skip checking if dir index keys found in modified subvolume tree
* leaves have been logged before, otherwise it would result in attempts
* to insert duplicate dir index keys in the log tree. This must be done
* because last_dir_index_offset is an in-memory only field, not persisted
* in the inode item or any other on-disk structure, so its value is lost
* once the inode is evicted.
*/
if (S_ISDIR(inode->vfs_inode.i_mode))
inode->last_dir_index_offset = (u64)-1;
return 1;
}
/*
* Delete a directory entry from the log if it exists.
*
* Returns < 0 on error
* 1 if the entry does not exists
* 0 if the entry existed and was successfully deleted
*/
static int del_logged_dentry(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_path *path,
u64 dir_ino,
const char *name, int name_len,
u64 index)
{
struct btrfs_dir_item *di;
/*
* We only log dir index items of a directory, so we don't need to look
* for dir item keys.
*/
di = btrfs_lookup_dir_index_item(trans, log, path, dir_ino,
index, name, name_len, -1);
if (IS_ERR(di))
return PTR_ERR(di);
else if (!di)
return 1;
/*
* We do not need to update the size field of the directory's
* inode item because on log replay we update the field to reflect
* all existing entries in the directory (see overwrite_item()).
*/
return btrfs_delete_one_dir_name(trans, log, path, di);
}
/*
* If both a file and directory are logged, and unlinks or renames are
* mixed in, we have a few interesting corners:
*
* create file X in dir Y
* link file X to X.link in dir Y
* fsync file X
* unlink file X but leave X.link
* fsync dir Y
*
* After a crash we would expect only X.link to exist. But file X
* didn't get fsync'd again so the log has back refs for X and X.link.
*
* We solve this by removing directory entries and inode backrefs from the
* log when a file that was logged in the current transaction is
* unlinked. Any later fsync will include the updated log entries, and
* we'll be able to reconstruct the proper directory items from backrefs.
*
* This optimizations allows us to avoid relogging the entire inode
* or the entire directory.
*/
void btrfs_del_dir_entries_in_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
struct btrfs_inode *dir, u64 index)
{
struct btrfs_path *path;
int ret;
ret = inode_logged(trans, dir, NULL);
if (ret == 0)
return;
else if (ret < 0) {
btrfs_set_log_full_commit(trans);
return;
}
ret = join_running_log_trans(root);
if (ret)
return;
mutex_lock(&dir->log_mutex);
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out_unlock;
}
ret = del_logged_dentry(trans, root->log_root, path, btrfs_ino(dir),
name, name_len, index);
btrfs_free_path(path);
out_unlock:
mutex_unlock(&dir->log_mutex);
if (ret < 0)
btrfs_set_log_full_commit(trans);
btrfs_end_log_trans(root);
}
/* see comments for btrfs_del_dir_entries_in_log */
void btrfs_del_inode_ref_in_log(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
const char *name, int name_len,
struct btrfs_inode *inode, u64 dirid)
{
struct btrfs_root *log;
u64 index;
int ret;
ret = inode_logged(trans, inode, NULL);
if (ret == 0)
return;
else if (ret < 0) {
btrfs_set_log_full_commit(trans);
return;
}
ret = join_running_log_trans(root);
if (ret)
return;
log = root->log_root;
mutex_lock(&inode->log_mutex);
ret = btrfs_del_inode_ref(trans, log, name, name_len, btrfs_ino(inode),
dirid, &index);
mutex_unlock(&inode->log_mutex);
if (ret < 0 && ret != -ENOENT)
btrfs_set_log_full_commit(trans);
btrfs_end_log_trans(root);
}
/*
* creates a range item in the log for 'dirid'. first_offset and
* last_offset tell us which parts of the key space the log should
* be considered authoritative for.
*/
static noinline int insert_dir_log_key(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_path *path,
u64 dirid,
u64 first_offset, u64 last_offset)
{
int ret;
struct btrfs_key key;
struct btrfs_dir_log_item *item;
key.objectid = dirid;
key.offset = first_offset;
key.type = BTRFS_DIR_LOG_INDEX_KEY;
ret = btrfs_insert_empty_item(trans, log, path, &key, sizeof(*item));
/*
* -EEXIST is fine and can happen sporadically when we are logging a
* directory and have concurrent insertions in the subvolume's tree for
* items from other inodes and that result in pushing off some dir items
* from one leaf to another in order to accommodate for the new items.
* This results in logging the same dir index range key.
*/
if (ret && ret != -EEXIST)
return ret;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_dir_log_item);
if (ret == -EEXIST) {
const u64 curr_end = btrfs_dir_log_end(path->nodes[0], item);
/*
* btrfs_del_dir_entries_in_log() might have been called during
* an unlink between the initial insertion of this key and the
* current update, or we might be logging a single entry deletion
* during a rename, so set the new last_offset to the max value.
*/
last_offset = max(last_offset, curr_end);
}
btrfs_set_dir_log_end(path->nodes[0], item, last_offset);
btrfs_mark_buffer_dirty(path->nodes[0]);
btrfs_release_path(path);
return 0;
}
static int flush_dir_items_batch(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct extent_buffer *src,
struct btrfs_path *dst_path,
int start_slot,
int count)
{
char *ins_data = NULL;
struct btrfs_item_batch batch;
struct extent_buffer *dst;
unsigned long src_offset;
unsigned long dst_offset;
struct btrfs_key key;
u32 item_size;
int ret;
int i;
ASSERT(count > 0);
batch.nr = count;
if (count == 1) {
btrfs_item_key_to_cpu(src, &key, start_slot);
item_size = btrfs_item_size(src, start_slot);
batch.keys = &key;
batch.data_sizes = &item_size;
batch.total_data_size = item_size;
} else {
struct btrfs_key *ins_keys;
u32 *ins_sizes;
ins_data = kmalloc(count * sizeof(u32) +
count * sizeof(struct btrfs_key), GFP_NOFS);
if (!ins_data)
return -ENOMEM;
ins_sizes = (u32 *)ins_data;
ins_keys = (struct btrfs_key *)(ins_data + count * sizeof(u32));
batch.keys = ins_keys;
batch.data_sizes = ins_sizes;
batch.total_data_size = 0;
for (i = 0; i < count; i++) {
const int slot = start_slot + i;
btrfs_item_key_to_cpu(src, &ins_keys[i], slot);
ins_sizes[i] = btrfs_item_size(src, slot);
batch.total_data_size += ins_sizes[i];
}
}
ret = btrfs_insert_empty_items(trans, log, dst_path, &batch);
if (ret)
goto out;
dst = dst_path->nodes[0];
/*
* Copy all the items in bulk, in a single copy operation. Item data is
* organized such that it's placed at the end of a leaf and from right
* to left. For example, the data for the second item ends at an offset
* that matches the offset where the data for the first item starts, the
* data for the third item ends at an offset that matches the offset
* where the data of the second items starts, and so on.
* Therefore our source and destination start offsets for copy match the
* offsets of the last items (highest slots).
*/
dst_offset = btrfs_item_ptr_offset(dst, dst_path->slots[0] + count - 1);
src_offset = btrfs_item_ptr_offset(src, start_slot + count - 1);
copy_extent_buffer(dst, src, dst_offset, src_offset, batch.total_data_size);
btrfs_release_path(dst_path);
out:
kfree(ins_data);
return ret;
}
static int process_dir_items_leaf(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path,
struct btrfs_path *dst_path,
struct btrfs_log_ctx *ctx,
u64 *last_old_dentry_offset)
{
struct btrfs_root *log = inode->root->log_root;
struct extent_buffer *src = path->nodes[0];
const int nritems = btrfs_header_nritems(src);
const u64 ino = btrfs_ino(inode);
bool last_found = false;
int batch_start = 0;
int batch_size = 0;
int i;
for (i = path->slots[0]; i < nritems; i++) {
struct btrfs_dir_item *di;
struct btrfs_key key;
int ret;
btrfs_item_key_to_cpu(src, &key, i);
if (key.objectid != ino || key.type != BTRFS_DIR_INDEX_KEY) {
last_found = true;
break;
}
di = btrfs_item_ptr(src, i, struct btrfs_dir_item);
ctx->last_dir_item_offset = key.offset;
/*
* Skip ranges of items that consist only of dir item keys created
* in past transactions. However if we find a gap, we must log a
* dir index range item for that gap, so that index keys in that
* gap are deleted during log replay.
*/
if (btrfs_dir_transid(src, di) < trans->transid) {
if (key.offset > *last_old_dentry_offset + 1) {
ret = insert_dir_log_key(trans, log, dst_path,
ino, *last_old_dentry_offset + 1,
key.offset - 1);
if (ret < 0)
return ret;
}
*last_old_dentry_offset = key.offset;
continue;
}
/* If we logged this dir index item before, we can skip it. */
if (key.offset <= inode->last_dir_index_offset)
continue;
/*
* We must make sure that when we log a directory entry, the
* corresponding inode, after log replay, has a matching link
* count. For example:
*
* touch foo
* mkdir mydir
* sync
* ln foo mydir/bar
* xfs_io -c "fsync" mydir
* <crash>
* <mount fs and log replay>
*
* Would result in a fsync log that when replayed, our file inode
* would have a link count of 1, but we get two directory entries
* pointing to the same inode. After removing one of the names,
* it would not be possible to remove the other name, which
* resulted always in stale file handle errors, and would not be
* possible to rmdir the parent directory, since its i_size could
* never be decremented to the value BTRFS_EMPTY_DIR_SIZE,
* resulting in -ENOTEMPTY errors.
*/
if (!ctx->log_new_dentries) {
struct btrfs_key di_key;
btrfs_dir_item_key_to_cpu(src, di, &di_key);
if (di_key.type != BTRFS_ROOT_ITEM_KEY)
ctx->log_new_dentries = true;
}
if (batch_size == 0)
batch_start = i;
batch_size++;
}
if (batch_size > 0) {
int ret;
ret = flush_dir_items_batch(trans, log, src, dst_path,
batch_start, batch_size);
if (ret < 0)
return ret;
}
return last_found ? 1 : 0;
}
/*
* log all the items included in the current transaction for a given
* directory. This also creates the range items in the log tree required
* to replay anything deleted before the fsync
*/
static noinline int log_dir_items(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path,
struct btrfs_path *dst_path,
struct btrfs_log_ctx *ctx,
u64 min_offset, u64 *last_offset_ret)
{
struct btrfs_key min_key;
struct btrfs_root *root = inode->root;
struct btrfs_root *log = root->log_root;
int err = 0;
int ret;
u64 last_old_dentry_offset = min_offset - 1;
u64 last_offset = (u64)-1;
u64 ino = btrfs_ino(inode);
min_key.objectid = ino;
min_key.type = BTRFS_DIR_INDEX_KEY;
min_key.offset = min_offset;
ret = btrfs_search_forward(root, &min_key, path, trans->transid);
/*
* we didn't find anything from this transaction, see if there
* is anything at all
*/
if (ret != 0 || min_key.objectid != ino ||
min_key.type != BTRFS_DIR_INDEX_KEY) {
min_key.objectid = ino;
min_key.type = BTRFS_DIR_INDEX_KEY;
min_key.offset = (u64)-1;
btrfs_release_path(path);
ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
if (ret < 0) {
btrfs_release_path(path);
return ret;
}
ret = btrfs_previous_item(root, path, ino, BTRFS_DIR_INDEX_KEY);
/* if ret == 0 there are items for this type,
* create a range to tell us the last key of this type.
* otherwise, there are no items in this directory after
* *min_offset, and we create a range to indicate that.
*/
if (ret == 0) {
struct btrfs_key tmp;
btrfs_item_key_to_cpu(path->nodes[0], &tmp,
path->slots[0]);
if (tmp.type == BTRFS_DIR_INDEX_KEY)
last_old_dentry_offset = tmp.offset;
}
goto done;
}
/* go backward to find any previous key */
ret = btrfs_previous_item(root, path, ino, BTRFS_DIR_INDEX_KEY);
if (ret == 0) {
struct btrfs_key tmp;
btrfs_item_key_to_cpu(path->nodes[0], &tmp, path->slots[0]);
/*
* The dir index key before the first one we found that needs to
* be logged might be in a previous leaf, and there might be a
* gap between these keys, meaning that we had deletions that
* happened. So the key range item we log (key type
* BTRFS_DIR_LOG_INDEX_KEY) must cover a range that starts at the
* previous key's offset plus 1, so that those deletes are replayed.
*/
if (tmp.type == BTRFS_DIR_INDEX_KEY)
last_old_dentry_offset = tmp.offset;
}
btrfs_release_path(path);
/*
* Find the first key from this transaction again. See the note for
* log_new_dir_dentries, if we're logging a directory recursively we
* won't be holding its i_mutex, which means we can modify the directory
* while we're logging it. If we remove an entry between our first
* search and this search we'll not find the key again and can just
* bail.
*/
search:
ret = btrfs_search_slot(NULL, root, &min_key, path, 0, 0);
if (ret != 0)
goto done;
/*
* we have a block from this transaction, log every item in it
* from our directory
*/
while (1) {
ret = process_dir_items_leaf(trans, inode, path, dst_path, ctx,
&last_old_dentry_offset);
if (ret != 0) {
if (ret < 0)
err = ret;
goto done;
}
path->slots[0] = btrfs_header_nritems(path->nodes[0]);
/*
* look ahead to the next item and see if it is also
* from this directory and from this transaction
*/
ret = btrfs_next_leaf(root, path);
if (ret) {
if (ret == 1)
last_offset = (u64)-1;
else
err = ret;
goto done;
}
btrfs_item_key_to_cpu(path->nodes[0], &min_key, path->slots[0]);
if (min_key.objectid != ino || min_key.type != BTRFS_DIR_INDEX_KEY) {
last_offset = (u64)-1;
goto done;
}
if (btrfs_header_generation(path->nodes[0]) != trans->transid) {
/*
* The next leaf was not changed in the current transaction
* and has at least one dir index key.
* We check for the next key because there might have been
* one or more deletions between the last key we logged and
* that next key. So the key range item we log (key type
* BTRFS_DIR_LOG_INDEX_KEY) must end at the next key's
* offset minus 1, so that those deletes are replayed.
*/
last_offset = min_key.offset - 1;
goto done;
}
if (need_resched()) {
btrfs_release_path(path);
cond_resched();
goto search;
}
}
done:
btrfs_release_path(path);
btrfs_release_path(dst_path);
if (err == 0) {
*last_offset_ret = last_offset;
/*
* In case the leaf was changed in the current transaction but
* all its dir items are from a past transaction, the last item
* in the leaf is a dir item and there's no gap between that last
* dir item and the first one on the next leaf (which did not
* change in the current transaction), then we don't need to log
* a range, last_old_dentry_offset is == to last_offset.
*/
ASSERT(last_old_dentry_offset <= last_offset);
if (last_old_dentry_offset < last_offset) {
ret = insert_dir_log_key(trans, log, path, ino,
last_old_dentry_offset + 1,
last_offset);
if (ret)
err = ret;
}
}
return err;
}
/*
* If the inode was logged before and it was evicted, then its
* last_dir_index_offset is (u64)-1, so we don't the value of the last index
* key offset. If that's the case, search for it and update the inode. This
* is to avoid lookups in the log tree every time we try to insert a dir index
* key from a leaf changed in the current transaction, and to allow us to always
* do batch insertions of dir index keys.
*/
static int update_last_dir_index_offset(struct btrfs_inode *inode,
struct btrfs_path *path,
const struct btrfs_log_ctx *ctx)
{
const u64 ino = btrfs_ino(inode);
struct btrfs_key key;
int ret;
lockdep_assert_held(&inode->log_mutex);
if (inode->last_dir_index_offset != (u64)-1)
return 0;
if (!ctx->logged_before) {
inode->last_dir_index_offset = BTRFS_DIR_START_INDEX - 1;
return 0;
}
key.objectid = ino;
key.type = BTRFS_DIR_INDEX_KEY;
key.offset = (u64)-1;
ret = btrfs_search_slot(NULL, inode->root->log_root, &key, path, 0, 0);
/*
* An error happened or we actually have an index key with an offset
* value of (u64)-1. Bail out, we're done.
*/
if (ret <= 0)
goto out;
ret = 0;
inode->last_dir_index_offset = BTRFS_DIR_START_INDEX - 1;
/*
* No dir index items, bail out and leave last_dir_index_offset with
* the value right before the first valid index value.
*/
if (path->slots[0] == 0)
goto out;
/*
* btrfs_search_slot() left us at one slot beyond the slot with the last
* index key, or beyond the last key of the directory that is not an
* index key. If we have an index key before, set last_dir_index_offset
* to its offset value, otherwise leave it with a value right before the
* first valid index value, as it means we have an empty directory.
*/
btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0] - 1);
if (key.objectid == ino && key.type == BTRFS_DIR_INDEX_KEY)
inode->last_dir_index_offset = key.offset;
out:
btrfs_release_path(path);
return ret;
}
/*
* logging directories is very similar to logging inodes, We find all the items
* from the current transaction and write them to the log.
*
* The recovery code scans the directory in the subvolume, and if it finds a
* key in the range logged that is not present in the log tree, then it means
* that dir entry was unlinked during the transaction.
*
* In order for that scan to work, we must include one key smaller than
* the smallest logged by this transaction and one key larger than the largest
* key logged by this transaction.
*/
static noinline int log_directory_changes(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path,
struct btrfs_path *dst_path,
struct btrfs_log_ctx *ctx)
{
u64 min_key;
u64 max_key;
int ret;
ret = update_last_dir_index_offset(inode, path, ctx);
if (ret)
return ret;
min_key = BTRFS_DIR_START_INDEX;
max_key = 0;
ctx->last_dir_item_offset = inode->last_dir_index_offset;
while (1) {
ret = log_dir_items(trans, inode, path, dst_path,
ctx, min_key, &max_key);
if (ret)
return ret;
if (max_key == (u64)-1)
break;
min_key = max_key + 1;
}
inode->last_dir_index_offset = ctx->last_dir_item_offset;
return 0;
}
/*
* a helper function to drop items from the log before we relog an
* inode. max_key_type indicates the highest item type to remove.
* This cannot be run for file data extents because it does not
* free the extents they point to.
*/
static int drop_inode_items(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_path *path,
struct btrfs_inode *inode,
int max_key_type)
{
int ret;
struct btrfs_key key;
struct btrfs_key found_key;
int start_slot;
key.objectid = btrfs_ino(inode);
key.type = max_key_type;
key.offset = (u64)-1;
while (1) {
ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
BUG_ON(ret == 0); /* Logic error */
if (ret < 0)
break;
if (path->slots[0] == 0)
break;
path->slots[0]--;
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
if (found_key.objectid != key.objectid)
break;
found_key.offset = 0;
found_key.type = 0;
ret = btrfs_bin_search(path->nodes[0], &found_key, &start_slot);
if (ret < 0)
break;
ret = btrfs_del_items(trans, log, path, start_slot,
path->slots[0] - start_slot + 1);
/*
* If start slot isn't 0 then we don't need to re-search, we've
* found the last guy with the objectid in this tree.
*/
if (ret || start_slot != 0)
break;
btrfs_release_path(path);
}
btrfs_release_path(path);
if (ret > 0)
ret = 0;
return ret;
}
static int truncate_inode_items(struct btrfs_trans_handle *trans,
struct btrfs_root *log_root,
struct btrfs_inode *inode,
u64 new_size, u32 min_type)
{
struct btrfs_truncate_control control = {
.new_size = new_size,
.ino = btrfs_ino(inode),
.min_type = min_type,
.skip_ref_updates = true,
};
return btrfs_truncate_inode_items(trans, log_root, &control);
}
static void fill_inode_item(struct btrfs_trans_handle *trans,
struct extent_buffer *leaf,
struct btrfs_inode_item *item,
struct inode *inode, int log_inode_only,
u64 logged_isize)
{
struct btrfs_map_token token;
u64 flags;
btrfs_init_map_token(&token, leaf);
if (log_inode_only) {
/* set the generation to zero so the recover code
* can tell the difference between an logging
* just to say 'this inode exists' and a logging
* to say 'update this inode with these values'
*/
btrfs_set_token_inode_generation(&token, item, 0);
btrfs_set_token_inode_size(&token, item, logged_isize);
} else {
btrfs_set_token_inode_generation(&token, item,
BTRFS_I(inode)->generation);
btrfs_set_token_inode_size(&token, item, inode->i_size);
}
btrfs_set_token_inode_uid(&token, item, i_uid_read(inode));
btrfs_set_token_inode_gid(&token, item, i_gid_read(inode));
btrfs_set_token_inode_mode(&token, item, inode->i_mode);
btrfs_set_token_inode_nlink(&token, item, inode->i_nlink);
btrfs_set_token_timespec_sec(&token, &item->atime,
inode->i_atime.tv_sec);
btrfs_set_token_timespec_nsec(&token, &item->atime,
inode->i_atime.tv_nsec);
btrfs_set_token_timespec_sec(&token, &item->mtime,
inode->i_mtime.tv_sec);
btrfs_set_token_timespec_nsec(&token, &item->mtime,
inode->i_mtime.tv_nsec);
btrfs_set_token_timespec_sec(&token, &item->ctime,
inode->i_ctime.tv_sec);
btrfs_set_token_timespec_nsec(&token, &item->ctime,
inode->i_ctime.tv_nsec);
/*
* We do not need to set the nbytes field, in fact during a fast fsync
* its value may not even be correct, since a fast fsync does not wait
* for ordered extent completion, which is where we update nbytes, it
* only waits for writeback to complete. During log replay as we find
* file extent items and replay them, we adjust the nbytes field of the
* inode item in subvolume tree as needed (see overwrite_item()).
*/
btrfs_set_token_inode_sequence(&token, item, inode_peek_iversion(inode));
btrfs_set_token_inode_transid(&token, item, trans->transid);
btrfs_set_token_inode_rdev(&token, item, inode->i_rdev);
flags = btrfs_inode_combine_flags(BTRFS_I(inode)->flags,
BTRFS_I(inode)->ro_flags);
btrfs_set_token_inode_flags(&token, item, flags);
btrfs_set_token_inode_block_group(&token, item, 0);
}
static int log_inode_item(struct btrfs_trans_handle *trans,
struct btrfs_root *log, struct btrfs_path *path,
struct btrfs_inode *inode, bool inode_item_dropped)
{
struct btrfs_inode_item *inode_item;
int ret;
/*
* If we are doing a fast fsync and the inode was logged before in the
* current transaction, then we know the inode was previously logged and
* it exists in the log tree. For performance reasons, in this case use
* btrfs_search_slot() directly with ins_len set to 0 so that we never
* attempt a write lock on the leaf's parent, which adds unnecessary lock
* contention in case there are concurrent fsyncs for other inodes of the
* same subvolume. Using btrfs_insert_empty_item() when the inode item
* already exists can also result in unnecessarily splitting a leaf.
*/
if (!inode_item_dropped && inode->logged_trans == trans->transid) {
ret = btrfs_search_slot(trans, log, &inode->location, path, 0, 1);
ASSERT(ret <= 0);
if (ret > 0)
ret = -ENOENT;
} else {
/*
* This means it is the first fsync in the current transaction,
* so the inode item is not in the log and we need to insert it.
* We can never get -EEXIST because we are only called for a fast
* fsync and in case an inode eviction happens after the inode was
* logged before in the current transaction, when we load again
* the inode, we set BTRFS_INODE_NEEDS_FULL_SYNC on its runtime
* flags and set ->logged_trans to 0.
*/
ret = btrfs_insert_empty_item(trans, log, path, &inode->location,
sizeof(*inode_item));
ASSERT(ret != -EEXIST);
}
if (ret)
return ret;
inode_item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
fill_inode_item(trans, path->nodes[0], inode_item, &inode->vfs_inode,
0, 0);
btrfs_release_path(path);
return 0;
}
static int log_csums(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_root *log_root,
struct btrfs_ordered_sum *sums)
{
const u64 lock_end = sums->bytenr + sums->len - 1;
struct extent_state *cached_state = NULL;
int ret;
/*
* If this inode was not used for reflink operations in the current
* transaction with new extents, then do the fast path, no need to
* worry about logging checksum items with overlapping ranges.
*/
if (inode->last_reflink_trans < trans->transid)
return btrfs_csum_file_blocks(trans, log_root, sums);
/*
* Serialize logging for checksums. This is to avoid racing with the
* same checksum being logged by another task that is logging another
* file which happens to refer to the same extent as well. Such races
* can leave checksum items in the log with overlapping ranges.
*/
ret = lock_extent(&log_root->log_csum_range, sums->bytenr, lock_end,
&cached_state);
if (ret)
return ret;
/*
* Due to extent cloning, we might have logged a csum item that covers a
* subrange of a cloned extent, and later we can end up logging a csum
* item for a larger subrange of the same extent or the entire range.
* This would leave csum items in the log tree that cover the same range
* and break the searches for checksums in the log tree, resulting in
* some checksums missing in the fs/subvolume tree. So just delete (or
* trim and adjust) any existing csum items in the log for this range.
*/
ret = btrfs_del_csums(trans, log_root, sums->bytenr, sums->len);
if (!ret)
ret = btrfs_csum_file_blocks(trans, log_root, sums);
unlock_extent(&log_root->log_csum_range, sums->bytenr, lock_end,
&cached_state);
return ret;
}
static noinline int copy_items(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *dst_path,
struct btrfs_path *src_path,
int start_slot, int nr, int inode_only,
u64 logged_isize)
{
struct btrfs_root *log = inode->root->log_root;
struct btrfs_file_extent_item *extent;
struct extent_buffer *src = src_path->nodes[0];
int ret = 0;
struct btrfs_key *ins_keys;
u32 *ins_sizes;
struct btrfs_item_batch batch;
char *ins_data;
int i;
int dst_index;
const bool skip_csum = (inode->flags & BTRFS_INODE_NODATASUM);
const u64 i_size = i_size_read(&inode->vfs_inode);
ins_data = kmalloc(nr * sizeof(struct btrfs_key) +
nr * sizeof(u32), GFP_NOFS);
if (!ins_data)
return -ENOMEM;
ins_sizes = (u32 *)ins_data;
ins_keys = (struct btrfs_key *)(ins_data + nr * sizeof(u32));
batch.keys = ins_keys;
batch.data_sizes = ins_sizes;
batch.total_data_size = 0;
batch.nr = 0;
dst_index = 0;
for (i = 0; i < nr; i++) {
const int src_slot = start_slot + i;
struct btrfs_root *csum_root;
struct btrfs_ordered_sum *sums;
struct btrfs_ordered_sum *sums_next;
LIST_HEAD(ordered_sums);
u64 disk_bytenr;
u64 disk_num_bytes;
u64 extent_offset;
u64 extent_num_bytes;
bool is_old_extent;
btrfs_item_key_to_cpu(src, &ins_keys[dst_index], src_slot);
if (ins_keys[dst_index].type != BTRFS_EXTENT_DATA_KEY)
goto add_to_batch;
extent = btrfs_item_ptr(src, src_slot,
struct btrfs_file_extent_item);
is_old_extent = (btrfs_file_extent_generation(src, extent) <
trans->transid);
/*
* Don't copy extents from past generations. That would make us
* log a lot more metadata for common cases like doing only a
* few random writes into a file and then fsync it for the first
* time or after the full sync flag is set on the inode. We can
* get leaves full of extent items, most of which are from past
* generations, so we can skip them - as long as the inode has
* not been the target of a reflink operation in this transaction,
* as in that case it might have had file extent items with old
* generations copied into it. We also must always log prealloc
* extents that start at or beyond eof, otherwise we would lose
* them on log replay.
*/
if (is_old_extent &&
ins_keys[dst_index].offset < i_size &&
inode->last_reflink_trans < trans->transid)
continue;
if (skip_csum)
goto add_to_batch;
/* Only regular extents have checksums. */
if (btrfs_file_extent_type(src, extent) != BTRFS_FILE_EXTENT_REG)
goto add_to_batch;
/*
* If it's an extent created in a past transaction, then its
* checksums are already accessible from the committed csum tree,
* no need to log them.
*/
if (is_old_extent)
goto add_to_batch;
disk_bytenr = btrfs_file_extent_disk_bytenr(src, extent);
/* If it's an explicit hole, there are no checksums. */
if (disk_bytenr == 0)
goto add_to_batch;
disk_num_bytes = btrfs_file_extent_disk_num_bytes(src, extent);
if (btrfs_file_extent_compression(src, extent)) {
extent_offset = 0;
extent_num_bytes = disk_num_bytes;
} else {
extent_offset = btrfs_file_extent_offset(src, extent);
extent_num_bytes = btrfs_file_extent_num_bytes(src, extent);
}
csum_root = btrfs_csum_root(trans->fs_info, disk_bytenr);
disk_bytenr += extent_offset;
ret = btrfs_lookup_csums_range(csum_root, disk_bytenr,
disk_bytenr + extent_num_bytes - 1,
&ordered_sums, 0, false);
if (ret)
goto out;
list_for_each_entry_safe(sums, sums_next, &ordered_sums, list) {
if (!ret)
ret = log_csums(trans, inode, log, sums);
list_del(&sums->list);
kfree(sums);
}
if (ret)
goto out;
add_to_batch:
ins_sizes[dst_index] = btrfs_item_size(src, src_slot);
batch.total_data_size += ins_sizes[dst_index];
batch.nr++;
dst_index++;
}
/*
* We have a leaf full of old extent items that don't need to be logged,
* so we don't need to do anything.
*/
if (batch.nr == 0)
goto out;
ret = btrfs_insert_empty_items(trans, log, dst_path, &batch);
if (ret)
goto out;
dst_index = 0;
for (i = 0; i < nr; i++) {
const int src_slot = start_slot + i;
const int dst_slot = dst_path->slots[0] + dst_index;
struct btrfs_key key;
unsigned long src_offset;
unsigned long dst_offset;
/*
* We're done, all the remaining items in the source leaf
* correspond to old file extent items.
*/
if (dst_index >= batch.nr)
break;
btrfs_item_key_to_cpu(src, &key, src_slot);
if (key.type != BTRFS_EXTENT_DATA_KEY)
goto copy_item;
extent = btrfs_item_ptr(src, src_slot,
struct btrfs_file_extent_item);
/* See the comment in the previous loop, same logic. */
if (btrfs_file_extent_generation(src, extent) < trans->transid &&
key.offset < i_size &&
inode->last_reflink_trans < trans->transid)
continue;
copy_item:
dst_offset = btrfs_item_ptr_offset(dst_path->nodes[0], dst_slot);
src_offset = btrfs_item_ptr_offset(src, src_slot);
if (key.type == BTRFS_INODE_ITEM_KEY) {
struct btrfs_inode_item *inode_item;
inode_item = btrfs_item_ptr(dst_path->nodes[0], dst_slot,
struct btrfs_inode_item);
fill_inode_item(trans, dst_path->nodes[0], inode_item,
&inode->vfs_inode,
inode_only == LOG_INODE_EXISTS,
logged_isize);
} else {
copy_extent_buffer(dst_path->nodes[0], src, dst_offset,
src_offset, ins_sizes[dst_index]);
}
dst_index++;
}
btrfs_mark_buffer_dirty(dst_path->nodes[0]);
btrfs_release_path(dst_path);
out:
kfree(ins_data);
return ret;
}
static int extent_cmp(void *priv, const struct list_head *a,
const struct list_head *b)
{
const struct extent_map *em1, *em2;
em1 = list_entry(a, struct extent_map, list);
em2 = list_entry(b, struct extent_map, list);
if (em1->start < em2->start)
return -1;
else if (em1->start > em2->start)
return 1;
return 0;
}
static int log_extent_csums(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_root *log_root,
const struct extent_map *em,
struct btrfs_log_ctx *ctx)
{
struct btrfs_ordered_extent *ordered;
struct btrfs_root *csum_root;
u64 csum_offset;
u64 csum_len;
u64 mod_start = em->mod_start;
u64 mod_len = em->mod_len;
LIST_HEAD(ordered_sums);
int ret = 0;
if (inode->flags & BTRFS_INODE_NODATASUM ||
test_bit(EXTENT_FLAG_PREALLOC, &em->flags) ||
em->block_start == EXTENT_MAP_HOLE)
return 0;
list_for_each_entry(ordered, &ctx->ordered_extents, log_list) {
const u64 ordered_end = ordered->file_offset + ordered->num_bytes;
const u64 mod_end = mod_start + mod_len;
struct btrfs_ordered_sum *sums;
if (mod_len == 0)
break;
if (ordered_end <= mod_start)
continue;
if (mod_end <= ordered->file_offset)
break;
/*
* We are going to copy all the csums on this ordered extent, so
* go ahead and adjust mod_start and mod_len in case this ordered
* extent has already been logged.
*/
if (ordered->file_offset > mod_start) {
if (ordered_end >= mod_end)
mod_len = ordered->file_offset - mod_start;
/*
* If we have this case
*
* |--------- logged extent ---------|
* |----- ordered extent ----|
*
* Just don't mess with mod_start and mod_len, we'll
* just end up logging more csums than we need and it
* will be ok.
*/
} else {
if (ordered_end < mod_end) {
mod_len = mod_end - ordered_end;
mod_start = ordered_end;
} else {
mod_len = 0;
}
}
/*
* To keep us from looping for the above case of an ordered
* extent that falls inside of the logged extent.
*/
if (test_and_set_bit(BTRFS_ORDERED_LOGGED_CSUM, &ordered->flags))
continue;
list_for_each_entry(sums, &ordered->list, list) {
ret = log_csums(trans, inode, log_root, sums);
if (ret)
return ret;
}
}
/* We're done, found all csums in the ordered extents. */
if (mod_len == 0)
return 0;
/* If we're compressed we have to save the entire range of csums. */
if (em->compress_type) {
csum_offset = 0;
csum_len = max(em->block_len, em->orig_block_len);
} else {
csum_offset = mod_start - em->start;
csum_len = mod_len;
}
/* block start is already adjusted for the file extent offset. */
csum_root = btrfs_csum_root(trans->fs_info, em->block_start);
ret = btrfs_lookup_csums_range(csum_root,
em->block_start + csum_offset,
em->block_start + csum_offset +
csum_len - 1, &ordered_sums, 0, false);
if (ret)
return ret;
while (!list_empty(&ordered_sums)) {
struct btrfs_ordered_sum *sums = list_entry(ordered_sums.next,
struct btrfs_ordered_sum,
list);
if (!ret)
ret = log_csums(trans, inode, log_root, sums);
list_del(&sums->list);
kfree(sums);
}
return ret;
}
static int log_one_extent(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
const struct extent_map *em,
struct btrfs_path *path,
struct btrfs_log_ctx *ctx)
{
struct btrfs_drop_extents_args drop_args = { 0 };
struct btrfs_root *log = inode->root->log_root;
struct btrfs_file_extent_item fi = { 0 };
struct extent_buffer *leaf;
struct btrfs_key key;
u64 extent_offset = em->start - em->orig_start;
u64 block_len;
int ret;
btrfs_set_stack_file_extent_generation(&fi, trans->transid);
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags))
btrfs_set_stack_file_extent_type(&fi, BTRFS_FILE_EXTENT_PREALLOC);
else
btrfs_set_stack_file_extent_type(&fi, BTRFS_FILE_EXTENT_REG);
block_len = max(em->block_len, em->orig_block_len);
if (em->compress_type != BTRFS_COMPRESS_NONE) {
btrfs_set_stack_file_extent_disk_bytenr(&fi, em->block_start);
btrfs_set_stack_file_extent_disk_num_bytes(&fi, block_len);
} else if (em->block_start < EXTENT_MAP_LAST_BYTE) {
btrfs_set_stack_file_extent_disk_bytenr(&fi, em->block_start -
extent_offset);
btrfs_set_stack_file_extent_disk_num_bytes(&fi, block_len);
}
btrfs_set_stack_file_extent_offset(&fi, extent_offset);
btrfs_set_stack_file_extent_num_bytes(&fi, em->len);
btrfs_set_stack_file_extent_ram_bytes(&fi, em->ram_bytes);
btrfs_set_stack_file_extent_compression(&fi, em->compress_type);
ret = log_extent_csums(trans, inode, log, em, ctx);
if (ret)
return ret;
/*
* If this is the first time we are logging the inode in the current
* transaction, we can avoid btrfs_drop_extents(), which is expensive
* because it does a deletion search, which always acquires write locks
* for extent buffers at levels 2, 1 and 0. This not only wastes time
* but also adds significant contention in a log tree, since log trees
* are small, with a root at level 2 or 3 at most, due to their short
* life span.
*/
if (ctx->logged_before) {
drop_args.path = path;
drop_args.start = em->start;
drop_args.end = em->start + em->len;
drop_args.replace_extent = true;
drop_args.extent_item_size = sizeof(fi);
ret = btrfs_drop_extents(trans, log, inode, &drop_args);
if (ret)
return ret;
}
if (!drop_args.extent_inserted) {
key.objectid = btrfs_ino(inode);
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = em->start;
ret = btrfs_insert_empty_item(trans, log, path, &key,
sizeof(fi));
if (ret)
return ret;
}
leaf = path->nodes[0];
write_extent_buffer(leaf, &fi,
btrfs_item_ptr_offset(leaf, path->slots[0]),
sizeof(fi));
btrfs_mark_buffer_dirty(leaf);
btrfs_release_path(path);
return ret;
}
/*
* Log all prealloc extents beyond the inode's i_size to make sure we do not
* lose them after doing a full/fast fsync and replaying the log. We scan the
* subvolume's root instead of iterating the inode's extent map tree because
* otherwise we can log incorrect extent items based on extent map conversion.
* That can happen due to the fact that extent maps are merged when they
* are not in the extent map tree's list of modified extents.
*/
static int btrfs_log_prealloc_extents(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path)
{
struct btrfs_root *root = inode->root;
struct btrfs_key key;
const u64 i_size = i_size_read(&inode->vfs_inode);
const u64 ino = btrfs_ino(inode);
struct btrfs_path *dst_path = NULL;
bool dropped_extents = false;
u64 truncate_offset = i_size;
struct extent_buffer *leaf;
int slot;
int ins_nr = 0;
int start_slot;
int ret;
if (!(inode->flags & BTRFS_INODE_PREALLOC))
return 0;
key.objectid = ino;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = i_size;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
/*
* We must check if there is a prealloc extent that starts before the
* i_size and crosses the i_size boundary. This is to ensure later we
* truncate down to the end of that extent and not to the i_size, as
* otherwise we end up losing part of the prealloc extent after a log
* replay and with an implicit hole if there is another prealloc extent
* that starts at an offset beyond i_size.
*/
ret = btrfs_previous_item(root, path, ino, BTRFS_EXTENT_DATA_KEY);
if (ret < 0)
goto out;
if (ret == 0) {
struct btrfs_file_extent_item *ei;
leaf = path->nodes[0];
slot = path->slots[0];
ei = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item);
if (btrfs_file_extent_type(leaf, ei) ==
BTRFS_FILE_EXTENT_PREALLOC) {
u64 extent_end;
btrfs_item_key_to_cpu(leaf, &key, slot);
extent_end = key.offset +
btrfs_file_extent_num_bytes(leaf, ei);
if (extent_end > i_size)
truncate_offset = extent_end;
}
} else {
ret = 0;
}
while (true) {
leaf = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
if (ins_nr > 0) {
ret = copy_items(trans, inode, dst_path, path,
start_slot, ins_nr, 1, 0);
if (ret < 0)
goto out;
ins_nr = 0;
}
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
if (ret > 0) {
ret = 0;
break;
}
continue;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid > ino)
break;
if (WARN_ON_ONCE(key.objectid < ino) ||
key.type < BTRFS_EXTENT_DATA_KEY ||
key.offset < i_size) {
path->slots[0]++;
continue;
}
if (!dropped_extents) {
/*
* Avoid logging extent items logged in past fsync calls
* and leading to duplicate keys in the log tree.
*/
ret = truncate_inode_items(trans, root->log_root, inode,
truncate_offset,
BTRFS_EXTENT_DATA_KEY);
if (ret)
goto out;
dropped_extents = true;
}
if (ins_nr == 0)
start_slot = slot;
ins_nr++;
path->slots[0]++;
if (!dst_path) {
dst_path = btrfs_alloc_path();
if (!dst_path) {
ret = -ENOMEM;
goto out;
}
}
}
if (ins_nr > 0)
ret = copy_items(trans, inode, dst_path, path,
start_slot, ins_nr, 1, 0);
out:
btrfs_release_path(path);
btrfs_free_path(dst_path);
return ret;
}
static int btrfs_log_changed_extents(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path,
struct btrfs_log_ctx *ctx)
{
struct btrfs_ordered_extent *ordered;
struct btrfs_ordered_extent *tmp;
struct extent_map *em, *n;
struct list_head extents;
struct extent_map_tree *tree = &inode->extent_tree;
int ret = 0;
int num = 0;
INIT_LIST_HEAD(&extents);
write_lock(&tree->lock);
list_for_each_entry_safe(em, n, &tree->modified_extents, list) {
list_del_init(&em->list);
/*
* Just an arbitrary number, this can be really CPU intensive
* once we start getting a lot of extents, and really once we
* have a bunch of extents we just want to commit since it will
* be faster.
*/
if (++num > 32768) {
list_del_init(&tree->modified_extents);
ret = -EFBIG;
goto process;
}
if (em->generation < trans->transid)
continue;
/* We log prealloc extents beyond eof later. */
if (test_bit(EXTENT_FLAG_PREALLOC, &em->flags) &&
em->start >= i_size_read(&inode->vfs_inode))
continue;
/* Need a ref to keep it from getting evicted from cache */
refcount_inc(&em->refs);
set_bit(EXTENT_FLAG_LOGGING, &em->flags);
list_add_tail(&em->list, &extents);
num++;
}
list_sort(NULL, &extents, extent_cmp);
process:
while (!list_empty(&extents)) {
em = list_entry(extents.next, struct extent_map, list);
list_del_init(&em->list);
/*
* If we had an error we just need to delete everybody from our
* private list.
*/
if (ret) {
clear_em_logging(tree, em);
free_extent_map(em);
continue;
}
write_unlock(&tree->lock);
ret = log_one_extent(trans, inode, em, path, ctx);
write_lock(&tree->lock);
clear_em_logging(tree, em);
free_extent_map(em);
}
WARN_ON(!list_empty(&extents));
write_unlock(&tree->lock);
if (!ret)
ret = btrfs_log_prealloc_extents(trans, inode, path);
if (ret)
return ret;
/*
* We have logged all extents successfully, now make sure the commit of
* the current transaction waits for the ordered extents to complete
* before it commits and wipes out the log trees, otherwise we would
* lose data if an ordered extents completes after the transaction
* commits and a power failure happens after the transaction commit.
*/
list_for_each_entry_safe(ordered, tmp, &ctx->ordered_extents, log_list) {
list_del_init(&ordered->log_list);
set_bit(BTRFS_ORDERED_LOGGED, &ordered->flags);
if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
spin_lock_irq(&inode->ordered_tree.lock);
if (!test_bit(BTRFS_ORDERED_COMPLETE, &ordered->flags)) {
set_bit(BTRFS_ORDERED_PENDING, &ordered->flags);
atomic_inc(&trans->transaction->pending_ordered);
}
spin_unlock_irq(&inode->ordered_tree.lock);
}
btrfs_put_ordered_extent(ordered);
}
return 0;
}
static int logged_inode_size(struct btrfs_root *log, struct btrfs_inode *inode,
struct btrfs_path *path, u64 *size_ret)
{
struct btrfs_key key;
int ret;
key.objectid = btrfs_ino(inode);
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, log, &key, path, 0, 0);
if (ret < 0) {
return ret;
} else if (ret > 0) {
*size_ret = 0;
} else {
struct btrfs_inode_item *item;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
*size_ret = btrfs_inode_size(path->nodes[0], item);
/*
* If the in-memory inode's i_size is smaller then the inode
* size stored in the btree, return the inode's i_size, so
* that we get a correct inode size after replaying the log
* when before a power failure we had a shrinking truncate
* followed by addition of a new name (rename / new hard link).
* Otherwise return the inode size from the btree, to avoid
* data loss when replaying a log due to previously doing a
* write that expands the inode's size and logging a new name
* immediately after.
*/
if (*size_ret > inode->vfs_inode.i_size)
*size_ret = inode->vfs_inode.i_size;
}
btrfs_release_path(path);
return 0;
}
/*
* At the moment we always log all xattrs. This is to figure out at log replay
* time which xattrs must have their deletion replayed. If a xattr is missing
* in the log tree and exists in the fs/subvol tree, we delete it. This is
* because if a xattr is deleted, the inode is fsynced and a power failure
* happens, causing the log to be replayed the next time the fs is mounted,
* we want the xattr to not exist anymore (same behaviour as other filesystems
* with a journal, ext3/4, xfs, f2fs, etc).
*/
static int btrfs_log_all_xattrs(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path,
struct btrfs_path *dst_path)
{
struct btrfs_root *root = inode->root;
int ret;
struct btrfs_key key;
const u64 ino = btrfs_ino(inode);
int ins_nr = 0;
int start_slot = 0;
bool found_xattrs = false;
if (test_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags))
return 0;
key.objectid = ino;
key.type = BTRFS_XATTR_ITEM_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
return ret;
while (true) {
int slot = path->slots[0];
struct extent_buffer *leaf = path->nodes[0];
int nritems = btrfs_header_nritems(leaf);
if (slot >= nritems) {
if (ins_nr > 0) {
ret = copy_items(trans, inode, dst_path, path,
start_slot, ins_nr, 1, 0);
if (ret < 0)
return ret;
ins_nr = 0;
}
ret = btrfs_next_leaf(root, path);
if (ret < 0)
return ret;
else if (ret > 0)
break;
continue;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid != ino || key.type != BTRFS_XATTR_ITEM_KEY)
break;
if (ins_nr == 0)
start_slot = slot;
ins_nr++;
path->slots[0]++;
found_xattrs = true;
cond_resched();
}
if (ins_nr > 0) {
ret = copy_items(trans, inode, dst_path, path,
start_slot, ins_nr, 1, 0);
if (ret < 0)
return ret;
}
if (!found_xattrs)
set_bit(BTRFS_INODE_NO_XATTRS, &inode->runtime_flags);
return 0;
}
/*
* When using the NO_HOLES feature if we punched a hole that causes the
* deletion of entire leafs or all the extent items of the first leaf (the one
* that contains the inode item and references) we may end up not processing
* any extents, because there are no leafs with a generation matching the
* current transaction that have extent items for our inode. So we need to find
* if any holes exist and then log them. We also need to log holes after any
* truncate operation that changes the inode's size.
*/
static int btrfs_log_holes(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path)
{
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_key key;
const u64 ino = btrfs_ino(inode);
const u64 i_size = i_size_read(&inode->vfs_inode);
u64 prev_extent_end = 0;
int ret;
if (!btrfs_fs_incompat(fs_info, NO_HOLES) || i_size == 0)
return 0;
key.objectid = ino;
key.type = BTRFS_EXTENT_DATA_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
return ret;
while (true) {
struct extent_buffer *leaf = path->nodes[0];
if (path->slots[0] >= btrfs_header_nritems(path->nodes[0])) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
return ret;
if (ret > 0) {
ret = 0;
break;
}
leaf = path->nodes[0];
}
btrfs_item_key_to_cpu(leaf, &key, path->slots[0]);
if (key.objectid != ino || key.type != BTRFS_EXTENT_DATA_KEY)
break;
/* We have a hole, log it. */
if (prev_extent_end < key.offset) {
const u64 hole_len = key.offset - prev_extent_end;
/*
* Release the path to avoid deadlocks with other code
* paths that search the root while holding locks on
* leafs from the log root.
*/
btrfs_release_path(path);
ret = btrfs_insert_hole_extent(trans, root->log_root,
ino, prev_extent_end,
hole_len);
if (ret < 0)
return ret;
/*
* Search for the same key again in the root. Since it's
* an extent item and we are holding the inode lock, the
* key must still exist. If it doesn't just emit warning
* and return an error to fall back to a transaction
* commit.
*/
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
return ret;
if (WARN_ON(ret > 0))
return -ENOENT;
leaf = path->nodes[0];
}
prev_extent_end = btrfs_file_extent_end(path);
path->slots[0]++;
cond_resched();
}
if (prev_extent_end < i_size) {
u64 hole_len;
btrfs_release_path(path);
hole_len = ALIGN(i_size - prev_extent_end, fs_info->sectorsize);
ret = btrfs_insert_hole_extent(trans, root->log_root, ino,
prev_extent_end, hole_len);
if (ret < 0)
return ret;
}
return 0;
}
/*
* When we are logging a new inode X, check if it doesn't have a reference that
* matches the reference from some other inode Y created in a past transaction
* and that was renamed in the current transaction. If we don't do this, then at
* log replay time we can lose inode Y (and all its files if it's a directory):
*
* mkdir /mnt/x
* echo "hello world" > /mnt/x/foobar
* sync
* mv /mnt/x /mnt/y
* mkdir /mnt/x # or touch /mnt/x
* xfs_io -c fsync /mnt/x
* <power fail>
* mount fs, trigger log replay
*
* After the log replay procedure, we would lose the first directory and all its
* files (file foobar).
* For the case where inode Y is not a directory we simply end up losing it:
*
* echo "123" > /mnt/foo
* sync
* mv /mnt/foo /mnt/bar
* echo "abc" > /mnt/foo
* xfs_io -c fsync /mnt/foo
* <power fail>
*
* We also need this for cases where a snapshot entry is replaced by some other
* entry (file or directory) otherwise we end up with an unreplayable log due to
* attempts to delete the snapshot entry (entry of type BTRFS_ROOT_ITEM_KEY) as
* if it were a regular entry:
*
* mkdir /mnt/x
* btrfs subvolume snapshot /mnt /mnt/x/snap
* btrfs subvolume delete /mnt/x/snap
* rmdir /mnt/x
* mkdir /mnt/x
* fsync /mnt/x or fsync some new file inside it
* <power fail>
*
* The snapshot delete, rmdir of x, mkdir of a new x and the fsync all happen in
* the same transaction.
*/
static int btrfs_check_ref_name_override(struct extent_buffer *eb,
const int slot,
const struct btrfs_key *key,
struct btrfs_inode *inode,
u64 *other_ino, u64 *other_parent)
{
int ret;
struct btrfs_path *search_path;
char *name = NULL;
u32 name_len = 0;
u32 item_size = btrfs_item_size(eb, slot);
u32 cur_offset = 0;
unsigned long ptr = btrfs_item_ptr_offset(eb, slot);
search_path = btrfs_alloc_path();
if (!search_path)
return -ENOMEM;
search_path->search_commit_root = 1;
search_path->skip_locking = 1;
while (cur_offset < item_size) {
u64 parent;
u32 this_name_len;
u32 this_len;
unsigned long name_ptr;
struct btrfs_dir_item *di;
if (key->type == BTRFS_INODE_REF_KEY) {
struct btrfs_inode_ref *iref;
iref = (struct btrfs_inode_ref *)(ptr + cur_offset);
parent = key->offset;
this_name_len = btrfs_inode_ref_name_len(eb, iref);
name_ptr = (unsigned long)(iref + 1);
this_len = sizeof(*iref) + this_name_len;
} else {
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)(ptr +
cur_offset);
parent = btrfs_inode_extref_parent(eb, extref);
this_name_len = btrfs_inode_extref_name_len(eb, extref);
name_ptr = (unsigned long)&extref->name;
this_len = sizeof(*extref) + this_name_len;
}
if (this_name_len > name_len) {
char *new_name;
new_name = krealloc(name, this_name_len, GFP_NOFS);
if (!new_name) {
ret = -ENOMEM;
goto out;
}
name_len = this_name_len;
name = new_name;
}
read_extent_buffer(eb, name, name_ptr, this_name_len);
di = btrfs_lookup_dir_item(NULL, inode->root, search_path,
parent, name, this_name_len, 0);
if (di && !IS_ERR(di)) {
struct btrfs_key di_key;
btrfs_dir_item_key_to_cpu(search_path->nodes[0],
di, &di_key);
if (di_key.type == BTRFS_INODE_ITEM_KEY) {
if (di_key.objectid != key->objectid) {
ret = 1;
*other_ino = di_key.objectid;
*other_parent = parent;
} else {
ret = 0;
}
} else {
ret = -EAGAIN;
}
goto out;
} else if (IS_ERR(di)) {
ret = PTR_ERR(di);
goto out;
}
btrfs_release_path(search_path);
cur_offset += this_len;
}
ret = 0;
out:
btrfs_free_path(search_path);
kfree(name);
return ret;
}
/*
* Check if we need to log an inode. This is used in contexts where while
* logging an inode we need to log another inode (either that it exists or in
* full mode). This is used instead of btrfs_inode_in_log() because the later
* requires the inode to be in the log and have the log transaction committed,
* while here we do not care if the log transaction was already committed - our
* caller will commit the log later - and we want to avoid logging an inode
* multiple times when multiple tasks have joined the same log transaction.
*/
static bool need_log_inode(const struct btrfs_trans_handle *trans,
const struct btrfs_inode *inode)
{
/*
* If a directory was not modified, no dentries added or removed, we can
* and should avoid logging it.
*/
if (S_ISDIR(inode->vfs_inode.i_mode) && inode->last_trans < trans->transid)
return false;
/*
* If this inode does not have new/updated/deleted xattrs since the last
* time it was logged and is flagged as logged in the current transaction,
* we can skip logging it. As for new/deleted names, those are updated in
* the log by link/unlink/rename operations.
* In case the inode was logged and then evicted and reloaded, its
* logged_trans will be 0, in which case we have to fully log it since
* logged_trans is a transient field, not persisted.
*/
if (inode->logged_trans == trans->transid &&
!test_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags))
return false;
return true;
}
struct btrfs_dir_list {
u64 ino;
struct list_head list;
};
/*
* Log the inodes of the new dentries of a directory.
* See process_dir_items_leaf() for details about why it is needed.
* This is a recursive operation - if an existing dentry corresponds to a
* directory, that directory's new entries are logged too (same behaviour as
* ext3/4, xfs, f2fs, reiserfs, nilfs2). Note that when logging the inodes
* the dentries point to we do not acquire their VFS lock, otherwise lockdep
* complains about the following circular lock dependency / possible deadlock:
*
* CPU0 CPU1
* ---- ----
* lock(&type->i_mutex_dir_key#3/2);
* lock(sb_internal#2);
* lock(&type->i_mutex_dir_key#3/2);
* lock(&sb->s_type->i_mutex_key#14);
*
* Where sb_internal is the lock (a counter that works as a lock) acquired by
* sb_start_intwrite() in btrfs_start_transaction().
* Not acquiring the VFS lock of the inodes is still safe because:
*
* 1) For regular files we log with a mode of LOG_INODE_EXISTS. It's possible
* that while logging the inode new references (names) are added or removed
* from the inode, leaving the logged inode item with a link count that does
* not match the number of logged inode reference items. This is fine because
* at log replay time we compute the real number of links and correct the
* link count in the inode item (see replay_one_buffer() and
* link_to_fixup_dir());
*
* 2) For directories we log with a mode of LOG_INODE_ALL. It's possible that
* while logging the inode's items new index items (key type
* BTRFS_DIR_INDEX_KEY) are added to fs/subvol tree and the logged inode item
* has a size that doesn't match the sum of the lengths of all the logged
* names - this is ok, not a problem, because at log replay time we set the
* directory's i_size to the correct value (see replay_one_name() and
* do_overwrite_item()).
*/
static int log_new_dir_dentries(struct btrfs_trans_handle *trans,
struct btrfs_inode *start_inode,
struct btrfs_log_ctx *ctx)
{
struct btrfs_root *root = start_inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
struct btrfs_path *path;
LIST_HEAD(dir_list);
struct btrfs_dir_list *dir_elem;
u64 ino = btrfs_ino(start_inode);
int ret = 0;
/*
* If we are logging a new name, as part of a link or rename operation,
* don't bother logging new dentries, as we just want to log the names
* of an inode and that any new parents exist.
*/
if (ctx->logging_new_name)
return 0;
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
while (true) {
struct extent_buffer *leaf;
struct btrfs_key min_key;
bool continue_curr_inode = true;
int nritems;
int i;
min_key.objectid = ino;
min_key.type = BTRFS_DIR_INDEX_KEY;
min_key.offset = 0;
again:
btrfs_release_path(path);
ret = btrfs_search_forward(root, &min_key, path, trans->transid);
if (ret < 0) {
break;
} else if (ret > 0) {
ret = 0;
goto next;
}
leaf = path->nodes[0];
nritems = btrfs_header_nritems(leaf);
for (i = path->slots[0]; i < nritems; i++) {
struct btrfs_dir_item *di;
struct btrfs_key di_key;
struct inode *di_inode;
int log_mode = LOG_INODE_EXISTS;
int type;
btrfs_item_key_to_cpu(leaf, &min_key, i);
if (min_key.objectid != ino ||
min_key.type != BTRFS_DIR_INDEX_KEY) {
continue_curr_inode = false;
break;
}
di = btrfs_item_ptr(leaf, i, struct btrfs_dir_item);
type = btrfs_dir_type(leaf, di);
if (btrfs_dir_transid(leaf, di) < trans->transid)
continue;
btrfs_dir_item_key_to_cpu(leaf, di, &di_key);
if (di_key.type == BTRFS_ROOT_ITEM_KEY)
continue;
btrfs_release_path(path);
di_inode = btrfs_iget(fs_info->sb, di_key.objectid, root);
if (IS_ERR(di_inode)) {
ret = PTR_ERR(di_inode);
goto out;
}
if (!need_log_inode(trans, BTRFS_I(di_inode))) {
btrfs_add_delayed_iput(di_inode);
break;
}
ctx->log_new_dentries = false;
if (type == BTRFS_FT_DIR)
log_mode = LOG_INODE_ALL;
ret = btrfs_log_inode(trans, BTRFS_I(di_inode),
log_mode, ctx);
btrfs_add_delayed_iput(di_inode);
if (ret)
goto out;
if (ctx->log_new_dentries) {
dir_elem = kmalloc(sizeof(*dir_elem), GFP_NOFS);
if (!dir_elem) {
ret = -ENOMEM;
goto out;
}
dir_elem->ino = di_key.objectid;
list_add_tail(&dir_elem->list, &dir_list);
}
break;
}
if (continue_curr_inode && min_key.offset < (u64)-1) {
min_key.offset++;
goto again;
}
next:
if (list_empty(&dir_list))
break;
dir_elem = list_first_entry(&dir_list, struct btrfs_dir_list, list);
ino = dir_elem->ino;
list_del(&dir_elem->list);
kfree(dir_elem);
}
out:
btrfs_free_path(path);
if (ret) {
struct btrfs_dir_list *next;
list_for_each_entry_safe(dir_elem, next, &dir_list, list)
kfree(dir_elem);
}
return ret;
}
struct btrfs_ino_list {
u64 ino;
u64 parent;
struct list_head list;
};
static void free_conflicting_inodes(struct btrfs_log_ctx *ctx)
{
struct btrfs_ino_list *curr;
struct btrfs_ino_list *next;
list_for_each_entry_safe(curr, next, &ctx->conflict_inodes, list) {
list_del(&curr->list);
kfree(curr);
}
}
static int conflicting_inode_is_dir(struct btrfs_root *root, u64 ino,
struct btrfs_path *path)
{
struct btrfs_key key;
int ret;
key.objectid = ino;
key.type = BTRFS_INODE_ITEM_KEY;
key.offset = 0;
path->search_commit_root = 1;
path->skip_locking = 1;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (WARN_ON_ONCE(ret > 0)) {
/*
* We have previously found the inode through the commit root
* so this should not happen. If it does, just error out and
* fallback to a transaction commit.
*/
ret = -ENOENT;
} else if (ret == 0) {
struct btrfs_inode_item *item;
item = btrfs_item_ptr(path->nodes[0], path->slots[0],
struct btrfs_inode_item);
if (S_ISDIR(btrfs_inode_mode(path->nodes[0], item)))
ret = 1;
}
btrfs_release_path(path);
path->search_commit_root = 0;
path->skip_locking = 0;
return ret;
}
static int add_conflicting_inode(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
u64 ino, u64 parent,
struct btrfs_log_ctx *ctx)
{
struct btrfs_ino_list *ino_elem;
struct inode *inode;
/*
* It's rare to have a lot of conflicting inodes, in practice it is not
* common to have more than 1 or 2. We don't want to collect too many,
* as we could end up logging too many inodes (even if only in
* LOG_INODE_EXISTS mode) and slow down other fsyncs or transaction
* commits.
*/
if (ctx->num_conflict_inodes >= MAX_CONFLICT_INODES)
return BTRFS_LOG_FORCE_COMMIT;
inode = btrfs_iget(root->fs_info->sb, ino, root);
/*
* If the other inode that had a conflicting dir entry was deleted in
* the current transaction then we either:
*
* 1) Log the parent directory (later after adding it to the list) if
* the inode is a directory. This is because it may be a deleted
* subvolume/snapshot or it may be a regular directory that had
* deleted subvolumes/snapshots (or subdirectories that had them),
* and at the moment we can't deal with dropping subvolumes/snapshots
* during log replay. So we just log the parent, which will result in
* a fallback to a transaction commit if we are dealing with those
* cases (last_unlink_trans will match the current transaction);
*
* 2) Do nothing if it's not a directory. During log replay we simply
* unlink the conflicting dentry from the parent directory and then
* add the dentry for our inode. Like this we can avoid logging the
* parent directory (and maybe fallback to a transaction commit in
* case it has a last_unlink_trans == trans->transid, due to moving
* some inode from it to some other directory).
*/
if (IS_ERR(inode)) {
int ret = PTR_ERR(inode);
if (ret != -ENOENT)
return ret;
ret = conflicting_inode_is_dir(root, ino, path);
/* Not a directory or we got an error. */
if (ret <= 0)
return ret;
/* Conflicting inode is a directory, so we'll log its parent. */
ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS);
if (!ino_elem)
return -ENOMEM;
ino_elem->ino = ino;
ino_elem->parent = parent;
list_add_tail(&ino_elem->list, &ctx->conflict_inodes);
ctx->num_conflict_inodes++;
return 0;
}
/*
* If the inode was already logged skip it - otherwise we can hit an
* infinite loop. Example:
*
* From the commit root (previous transaction) we have the following
* inodes:
*
* inode 257 a directory
* inode 258 with references "zz" and "zz_link" on inode 257
* inode 259 with reference "a" on inode 257
*
* And in the current (uncommitted) transaction we have:
*
* inode 257 a directory, unchanged
* inode 258 with references "a" and "a2" on inode 257
* inode 259 with reference "zz_link" on inode 257
* inode 261 with reference "zz" on inode 257
*
* When logging inode 261 the following infinite loop could
* happen if we don't skip already logged inodes:
*
* - we detect inode 258 as a conflicting inode, with inode 261
* on reference "zz", and log it;
*
* - we detect inode 259 as a conflicting inode, with inode 258
* on reference "a", and log it;
*
* - we detect inode 258 as a conflicting inode, with inode 259
* on reference "zz_link", and log it - again! After this we
* repeat the above steps forever.
*
* Here we can use need_log_inode() because we only need to log the
* inode in LOG_INODE_EXISTS mode and rename operations update the log,
* so that the log ends up with the new name and without the old name.
*/
if (!need_log_inode(trans, BTRFS_I(inode))) {
btrfs_add_delayed_iput(inode);
return 0;
}
btrfs_add_delayed_iput(inode);
ino_elem = kmalloc(sizeof(*ino_elem), GFP_NOFS);
if (!ino_elem)
return -ENOMEM;
ino_elem->ino = ino;
ino_elem->parent = parent;
list_add_tail(&ino_elem->list, &ctx->conflict_inodes);
ctx->num_conflict_inodes++;
return 0;
}
static int log_conflicting_inodes(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_log_ctx *ctx)
{
struct btrfs_fs_info *fs_info = root->fs_info;
int ret = 0;
/*
* Conflicting inodes are logged by the first call to btrfs_log_inode(),
* otherwise we could have unbounded recursion of btrfs_log_inode()
* calls. This check guarantees we can have only 1 level of recursion.
*/
if (ctx->logging_conflict_inodes)
return 0;
ctx->logging_conflict_inodes = true;
/*
* New conflicting inodes may be found and added to the list while we
* are logging a conflicting inode, so keep iterating while the list is
* not empty.
*/
while (!list_empty(&ctx->conflict_inodes)) {
struct btrfs_ino_list *curr;
struct inode *inode;
u64 ino;
u64 parent;
curr = list_first_entry(&ctx->conflict_inodes,
struct btrfs_ino_list, list);
ino = curr->ino;
parent = curr->parent;
list_del(&curr->list);
kfree(curr);
inode = btrfs_iget(fs_info->sb, ino, root);
/*
* If the other inode that had a conflicting dir entry was
* deleted in the current transaction, we need to log its parent
* directory. See the comment at add_conflicting_inode().
*/
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
if (ret != -ENOENT)
break;
inode = btrfs_iget(fs_info->sb, parent, root);
if (IS_ERR(inode)) {
ret = PTR_ERR(inode);
break;
}
/*
* Always log the directory, we cannot make this
* conditional on need_log_inode() because the directory
* might have been logged in LOG_INODE_EXISTS mode or
* the dir index of the conflicting inode is not in a
* dir index key range logged for the directory. So we
* must make sure the deletion is recorded.
*/
ret = btrfs_log_inode(trans, BTRFS_I(inode),
LOG_INODE_ALL, ctx);
btrfs_add_delayed_iput(inode);
if (ret)
break;
continue;
}
/*
* Here we can use need_log_inode() because we only need to log
* the inode in LOG_INODE_EXISTS mode and rename operations
* update the log, so that the log ends up with the new name and
* without the old name.
*
* We did this check at add_conflicting_inode(), but here we do
* it again because if some other task logged the inode after
* that, we can avoid doing it again.
*/
if (!need_log_inode(trans, BTRFS_I(inode))) {
btrfs_add_delayed_iput(inode);
continue;
}
/*
* We are safe logging the other inode without acquiring its
* lock as long as we log with the LOG_INODE_EXISTS mode. We
* are safe against concurrent renames of the other inode as
* well because during a rename we pin the log and update the
* log with the new name before we unpin it.
*/
ret = btrfs_log_inode(trans, BTRFS_I(inode), LOG_INODE_EXISTS, ctx);
btrfs_add_delayed_iput(inode);
if (ret)
break;
}
ctx->logging_conflict_inodes = false;
if (ret)
free_conflicting_inodes(ctx);
return ret;
}
static int copy_inode_items_to_log(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_key *min_key,
const struct btrfs_key *max_key,
struct btrfs_path *path,
struct btrfs_path *dst_path,
const u64 logged_isize,
const int inode_only,
struct btrfs_log_ctx *ctx,
bool *need_log_inode_item)
{
const u64 i_size = i_size_read(&inode->vfs_inode);
struct btrfs_root *root = inode->root;
int ins_start_slot = 0;
int ins_nr = 0;
int ret;
while (1) {
ret = btrfs_search_forward(root, min_key, path, trans->transid);
if (ret < 0)
return ret;
if (ret > 0) {
ret = 0;
break;
}
again:
/* Note, ins_nr might be > 0 here, cleanup outside the loop */
if (min_key->objectid != max_key->objectid)
break;
if (min_key->type > max_key->type)
break;
if (min_key->type == BTRFS_INODE_ITEM_KEY) {
*need_log_inode_item = false;
} else if (min_key->type == BTRFS_EXTENT_DATA_KEY &&
min_key->offset >= i_size) {
/*
* Extents at and beyond eof are logged with
* btrfs_log_prealloc_extents().
* Only regular files have BTRFS_EXTENT_DATA_KEY keys,
* and no keys greater than that, so bail out.
*/
break;
} else if ((min_key->type == BTRFS_INODE_REF_KEY ||
min_key->type == BTRFS_INODE_EXTREF_KEY) &&
(inode->generation == trans->transid ||
ctx->logging_conflict_inodes)) {
u64 other_ino = 0;
u64 other_parent = 0;
ret = btrfs_check_ref_name_override(path->nodes[0],
path->slots[0], min_key, inode,
&other_ino, &other_parent);
if (ret < 0) {
return ret;
} else if (ret > 0 &&
other_ino != btrfs_ino(BTRFS_I(ctx->inode))) {
if (ins_nr > 0) {
ins_nr++;
} else {
ins_nr = 1;
ins_start_slot = path->slots[0];
}
ret = copy_items(trans, inode, dst_path, path,
ins_start_slot, ins_nr,
inode_only, logged_isize);
if (ret < 0)
return ret;
ins_nr = 0;
btrfs_release_path(path);
ret = add_conflicting_inode(trans, root, path,
other_ino,
other_parent, ctx);
if (ret)
return ret;
goto next_key;
}
} else if (min_key->type == BTRFS_XATTR_ITEM_KEY) {
/* Skip xattrs, logged later with btrfs_log_all_xattrs() */
if (ins_nr == 0)
goto next_slot;
ret = copy_items(trans, inode, dst_path, path,
ins_start_slot,
ins_nr, inode_only, logged_isize);
if (ret < 0)
return ret;
ins_nr = 0;
goto next_slot;
}
if (ins_nr && ins_start_slot + ins_nr == path->slots[0]) {
ins_nr++;
goto next_slot;
} else if (!ins_nr) {
ins_start_slot = path->slots[0];
ins_nr = 1;
goto next_slot;
}
ret = copy_items(trans, inode, dst_path, path, ins_start_slot,
ins_nr, inode_only, logged_isize);
if (ret < 0)
return ret;
ins_nr = 1;
ins_start_slot = path->slots[0];
next_slot:
path->slots[0]++;
if (path->slots[0] < btrfs_header_nritems(path->nodes[0])) {
btrfs_item_key_to_cpu(path->nodes[0], min_key,
path->slots[0]);
goto again;
}
if (ins_nr) {
ret = copy_items(trans, inode, dst_path, path,
ins_start_slot, ins_nr, inode_only,
logged_isize);
if (ret < 0)
return ret;
ins_nr = 0;
}
btrfs_release_path(path);
next_key:
if (min_key->offset < (u64)-1) {
min_key->offset++;
} else if (min_key->type < max_key->type) {
min_key->type++;
min_key->offset = 0;
} else {
break;
}
/*
* We may process many leaves full of items for our inode, so
* avoid monopolizing a cpu for too long by rescheduling while
* not holding locks on any tree.
*/
cond_resched();
}
if (ins_nr) {
ret = copy_items(trans, inode, dst_path, path, ins_start_slot,
ins_nr, inode_only, logged_isize);
if (ret)
return ret;
}
if (inode_only == LOG_INODE_ALL && S_ISREG(inode->vfs_inode.i_mode)) {
/*
* Release the path because otherwise we might attempt to double
* lock the same leaf with btrfs_log_prealloc_extents() below.
*/
btrfs_release_path(path);
ret = btrfs_log_prealloc_extents(trans, inode, dst_path);
}
return ret;
}
static int insert_delayed_items_batch(struct btrfs_trans_handle *trans,
struct btrfs_root *log,
struct btrfs_path *path,
const struct btrfs_item_batch *batch,
const struct btrfs_delayed_item *first_item)
{
const struct btrfs_delayed_item *curr = first_item;
int ret;
ret = btrfs_insert_empty_items(trans, log, path, batch);
if (ret)
return ret;
for (int i = 0; i < batch->nr; i++) {
char *data_ptr;
data_ptr = btrfs_item_ptr(path->nodes[0], path->slots[0], char);
write_extent_buffer(path->nodes[0], &curr->data,
(unsigned long)data_ptr, curr->data_len);
curr = list_next_entry(curr, log_list);
path->slots[0]++;
}
btrfs_release_path(path);
return 0;
}
static int log_delayed_insertion_items(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path,
const struct list_head *delayed_ins_list,
struct btrfs_log_ctx *ctx)
{
/* 195 (4095 bytes of keys and sizes) fits in a single 4K page. */
const int max_batch_size = 195;
const int leaf_data_size = BTRFS_LEAF_DATA_SIZE(trans->fs_info);
const u64 ino = btrfs_ino(inode);
struct btrfs_root *log = inode->root->log_root;
struct btrfs_item_batch batch = {
.nr = 0,
.total_data_size = 0,
};
const struct btrfs_delayed_item *first = NULL;
const struct btrfs_delayed_item *curr;
char *ins_data;
struct btrfs_key *ins_keys;
u32 *ins_sizes;
u64 curr_batch_size = 0;
int batch_idx = 0;
int ret;
/* We are adding dir index items to the log tree. */
lockdep_assert_held(&inode->log_mutex);
/*
* We collect delayed items before copying index keys from the subvolume
* to the log tree. However just after we collected them, they may have
* been flushed (all of them or just some of them), and therefore we
* could have copied them from the subvolume tree to the log tree.
* So find the first delayed item that was not yet logged (they are
* sorted by index number).
*/
list_for_each_entry(curr, delayed_ins_list, log_list) {
if (curr->index > inode->last_dir_index_offset) {
first = curr;
break;
}
}
/* Empty list or all delayed items were already logged. */
if (!first)
return 0;
ins_data = kmalloc(max_batch_size * sizeof(u32) +
max_batch_size * sizeof(struct btrfs_key), GFP_NOFS);
if (!ins_data)
return -ENOMEM;
ins_sizes = (u32 *)ins_data;
batch.data_sizes = ins_sizes;
ins_keys = (struct btrfs_key *)(ins_data + max_batch_size * sizeof(u32));
batch.keys = ins_keys;
curr = first;
while (!list_entry_is_head(curr, delayed_ins_list, log_list)) {
const u32 curr_size = curr->data_len + sizeof(struct btrfs_item);
if (curr_batch_size + curr_size > leaf_data_size ||
batch.nr == max_batch_size) {
ret = insert_delayed_items_batch(trans, log, path,
&batch, first);
if (ret)
goto out;
batch_idx = 0;
batch.nr = 0;
batch.total_data_size = 0;
curr_batch_size = 0;
first = curr;
}
ins_sizes[batch_idx] = curr->data_len;
ins_keys[batch_idx].objectid = ino;
ins_keys[batch_idx].type = BTRFS_DIR_INDEX_KEY;
ins_keys[batch_idx].offset = curr->index;
curr_batch_size += curr_size;
batch.total_data_size += curr->data_len;
batch.nr++;
batch_idx++;
curr = list_next_entry(curr, log_list);
}
ASSERT(batch.nr >= 1);
ret = insert_delayed_items_batch(trans, log, path, &batch, first);
curr = list_last_entry(delayed_ins_list, struct btrfs_delayed_item,
log_list);
inode->last_dir_index_offset = curr->index;
out:
kfree(ins_data);
return ret;
}
static int log_delayed_deletions_full(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path,
const struct list_head *delayed_del_list,
struct btrfs_log_ctx *ctx)
{
const u64 ino = btrfs_ino(inode);
const struct btrfs_delayed_item *curr;
curr = list_first_entry(delayed_del_list, struct btrfs_delayed_item,
log_list);
while (!list_entry_is_head(curr, delayed_del_list, log_list)) {
u64 first_dir_index = curr->index;
u64 last_dir_index;
const struct btrfs_delayed_item *next;
int ret;
/*
* Find a range of consecutive dir index items to delete. Like
* this we log a single dir range item spanning several contiguous
* dir items instead of logging one range item per dir index item.
*/
next = list_next_entry(curr, log_list);
while (!list_entry_is_head(next, delayed_del_list, log_list)) {
if (next->index != curr->index + 1)
break;
curr = next;
next = list_next_entry(next, log_list);
}
last_dir_index = curr->index;
ASSERT(last_dir_index >= first_dir_index);
ret = insert_dir_log_key(trans, inode->root->log_root, path,
ino, first_dir_index, last_dir_index);
if (ret)
return ret;
curr = list_next_entry(curr, log_list);
}
return 0;
}
static int batch_delete_dir_index_items(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path,
struct btrfs_log_ctx *ctx,
const struct list_head *delayed_del_list,
const struct btrfs_delayed_item *first,
const struct btrfs_delayed_item **last_ret)
{
const struct btrfs_delayed_item *next;
struct extent_buffer *leaf = path->nodes[0];
const int last_slot = btrfs_header_nritems(leaf) - 1;
int slot = path->slots[0] + 1;
const u64 ino = btrfs_ino(inode);
next = list_next_entry(first, log_list);
while (slot < last_slot &&
!list_entry_is_head(next, delayed_del_list, log_list)) {
struct btrfs_key key;
btrfs_item_key_to_cpu(leaf, &key, slot);
if (key.objectid != ino ||
key.type != BTRFS_DIR_INDEX_KEY ||
key.offset != next->index)
break;
slot++;
*last_ret = next;
next = list_next_entry(next, log_list);
}
return btrfs_del_items(trans, inode->root->log_root, path,
path->slots[0], slot - path->slots[0]);
}
static int log_delayed_deletions_incremental(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path,
const struct list_head *delayed_del_list,
struct btrfs_log_ctx *ctx)
{
struct btrfs_root *log = inode->root->log_root;
const struct btrfs_delayed_item *curr;
u64 last_range_start;
u64 last_range_end = 0;
struct btrfs_key key;
key.objectid = btrfs_ino(inode);
key.type = BTRFS_DIR_INDEX_KEY;
curr = list_first_entry(delayed_del_list, struct btrfs_delayed_item,
log_list);
while (!list_entry_is_head(curr, delayed_del_list, log_list)) {
const struct btrfs_delayed_item *last = curr;
u64 first_dir_index = curr->index;
u64 last_dir_index;
bool deleted_items = false;
int ret;
key.offset = curr->index;
ret = btrfs_search_slot(trans, log, &key, path, -1, 1);
if (ret < 0) {
return ret;
} else if (ret == 0) {
ret = batch_delete_dir_index_items(trans, inode, path, ctx,
delayed_del_list, curr,
&last);
if (ret)
return ret;
deleted_items = true;
}
btrfs_release_path(path);
/*
* If we deleted items from the leaf, it means we have a range
* item logging their range, so no need to add one or update an
* existing one. Otherwise we have to log a dir range item.
*/
if (deleted_items)
goto next_batch;
last_dir_index = last->index;
ASSERT(last_dir_index >= first_dir_index);
/*
* If this range starts right after where the previous one ends,
* then we want to reuse the previous range item and change its
* end offset to the end of this range. This is just to minimize
* leaf space usage, by avoiding adding a new range item.
*/
if (last_range_end != 0 && first_dir_index == last_range_end + 1)
first_dir_index = last_range_start;
ret = insert_dir_log_key(trans, log, path, key.objectid,
first_dir_index, last_dir_index);
if (ret)
return ret;
last_range_start = first_dir_index;
last_range_end = last_dir_index;
next_batch:
curr = list_next_entry(last, log_list);
}
return 0;
}
static int log_delayed_deletion_items(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_path *path,
const struct list_head *delayed_del_list,
struct btrfs_log_ctx *ctx)
{
/*
* We are deleting dir index items from the log tree or adding range
* items to it.
*/
lockdep_assert_held(&inode->log_mutex);
if (list_empty(delayed_del_list))
return 0;
if (ctx->logged_before)
return log_delayed_deletions_incremental(trans, inode, path,
delayed_del_list, ctx);
return log_delayed_deletions_full(trans, inode, path, delayed_del_list,
ctx);
}
/*
* Similar logic as for log_new_dir_dentries(), but it iterates over the delayed
* items instead of the subvolume tree.
*/
static int log_new_delayed_dentries(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
const struct list_head *delayed_ins_list,
struct btrfs_log_ctx *ctx)
{
const bool orig_log_new_dentries = ctx->log_new_dentries;
struct btrfs_fs_info *fs_info = trans->fs_info;
struct btrfs_delayed_item *item;
int ret = 0;
/*
* No need for the log mutex, plus to avoid potential deadlocks or
* lockdep annotations due to nesting of delayed inode mutexes and log
* mutexes.
*/
lockdep_assert_not_held(&inode->log_mutex);
ASSERT(!ctx->logging_new_delayed_dentries);
ctx->logging_new_delayed_dentries = true;
list_for_each_entry(item, delayed_ins_list, log_list) {
struct btrfs_dir_item *dir_item;
struct inode *di_inode;
struct btrfs_key key;
int log_mode = LOG_INODE_EXISTS;
dir_item = (struct btrfs_dir_item *)item->data;
btrfs_disk_key_to_cpu(&key, &dir_item->location);
if (key.type == BTRFS_ROOT_ITEM_KEY)
continue;
di_inode = btrfs_iget(fs_info->sb, key.objectid, inode->root);
if (IS_ERR(di_inode)) {
ret = PTR_ERR(di_inode);
break;
}
if (!need_log_inode(trans, BTRFS_I(di_inode))) {
btrfs_add_delayed_iput(di_inode);
continue;
}
if (btrfs_stack_dir_type(dir_item) == BTRFS_FT_DIR)
log_mode = LOG_INODE_ALL;
ctx->log_new_dentries = false;
ret = btrfs_log_inode(trans, BTRFS_I(di_inode), log_mode, ctx);
if (!ret && ctx->log_new_dentries)
ret = log_new_dir_dentries(trans, BTRFS_I(di_inode), ctx);
btrfs_add_delayed_iput(di_inode);
if (ret)
break;
}
ctx->log_new_dentries = orig_log_new_dentries;
ctx->logging_new_delayed_dentries = false;
return ret;
}
/* log a single inode in the tree log.
* At least one parent directory for this inode must exist in the tree
* or be logged already.
*
* Any items from this inode changed by the current transaction are copied
* to the log tree. An extra reference is taken on any extents in this
* file, allowing us to avoid a whole pile of corner cases around logging
* blocks that have been removed from the tree.
*
* See LOG_INODE_ALL and related defines for a description of what inode_only
* does.
*
* This handles both files and directories.
*/
static int btrfs_log_inode(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
int inode_only,
struct btrfs_log_ctx *ctx)
{
struct btrfs_path *path;
struct btrfs_path *dst_path;
struct btrfs_key min_key;
struct btrfs_key max_key;
struct btrfs_root *log = inode->root->log_root;
int ret;
bool fast_search = false;
u64 ino = btrfs_ino(inode);
struct extent_map_tree *em_tree = &inode->extent_tree;
u64 logged_isize = 0;
bool need_log_inode_item = true;
bool xattrs_logged = false;
bool inode_item_dropped = true;
bool full_dir_logging = false;
LIST_HEAD(delayed_ins_list);
LIST_HEAD(delayed_del_list);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
dst_path = btrfs_alloc_path();
if (!dst_path) {
btrfs_free_path(path);
return -ENOMEM;
}
min_key.objectid = ino;
min_key.type = BTRFS_INODE_ITEM_KEY;
min_key.offset = 0;
max_key.objectid = ino;
/* today the code can only do partial logging of directories */
if (S_ISDIR(inode->vfs_inode.i_mode) ||
(!test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&inode->runtime_flags) &&
inode_only >= LOG_INODE_EXISTS))
max_key.type = BTRFS_XATTR_ITEM_KEY;
else
max_key.type = (u8)-1;
max_key.offset = (u64)-1;
if (S_ISDIR(inode->vfs_inode.i_mode) && inode_only == LOG_INODE_ALL)
full_dir_logging = true;
/*
* If we are logging a directory while we are logging dentries of the
* delayed items of some other inode, then we need to flush the delayed
* items of this directory and not log the delayed items directly. This
* is to prevent more than one level of recursion into btrfs_log_inode()
* by having something like this:
*
* $ mkdir -p a/b/c/d/e/f/g/h/...
* $ xfs_io -c "fsync" a
*
* Where all directories in the path did not exist before and are
* created in the current transaction.
* So in such a case we directly log the delayed items of the main
* directory ("a") without flushing them first, while for each of its
* subdirectories we flush their delayed items before logging them.
* This prevents a potential unbounded recursion like this:
*
* btrfs_log_inode()
* log_new_delayed_dentries()
* btrfs_log_inode()
* log_new_delayed_dentries()
* btrfs_log_inode()
* log_new_delayed_dentries()
* (...)
*
* We have thresholds for the maximum number of delayed items to have in
* memory, and once they are hit, the items are flushed asynchronously.
* However the limit is quite high, so lets prevent deep levels of
* recursion to happen by limiting the maximum depth to be 1.
*/
if (full_dir_logging && ctx->logging_new_delayed_dentries) {
ret = btrfs_commit_inode_delayed_items(trans, inode);
if (ret)
goto out;
}
mutex_lock(&inode->log_mutex);
/*
* For symlinks, we must always log their content, which is stored in an
* inline extent, otherwise we could end up with an empty symlink after
* log replay, which is invalid on linux (symlink(2) returns -ENOENT if
* one attempts to create an empty symlink).
* We don't need to worry about flushing delalloc, because when we create
* the inline extent when the symlink is created (we never have delalloc
* for symlinks).
*/
if (S_ISLNK(inode->vfs_inode.i_mode))
inode_only = LOG_INODE_ALL;
/*
* Before logging the inode item, cache the value returned by
* inode_logged(), because after that we have the need to figure out if
* the inode was previously logged in this transaction.
*/
ret = inode_logged(trans, inode, path);
if (ret < 0)
goto out_unlock;
ctx->logged_before = (ret == 1);
ret = 0;
/*
* This is for cases where logging a directory could result in losing a
* a file after replaying the log. For example, if we move a file from a
* directory A to a directory B, then fsync directory A, we have no way
* to known the file was moved from A to B, so logging just A would
* result in losing the file after a log replay.
*/
if (full_dir_logging && inode->last_unlink_trans >= trans->transid) {
btrfs_set_log_full_commit(trans);
ret = BTRFS_LOG_FORCE_COMMIT;
goto out_unlock;
}
/*
* a brute force approach to making sure we get the most uptodate
* copies of everything.
*/
if (S_ISDIR(inode->vfs_inode.i_mode)) {
clear_bit(BTRFS_INODE_COPY_EVERYTHING, &inode->runtime_flags);
if (ctx->logged_before)
ret = drop_inode_items(trans, log, path, inode,
BTRFS_XATTR_ITEM_KEY);
} else {
if (inode_only == LOG_INODE_EXISTS && ctx->logged_before) {
/*
* Make sure the new inode item we write to the log has
* the same isize as the current one (if it exists).
* This is necessary to prevent data loss after log
* replay, and also to prevent doing a wrong expanding
* truncate - for e.g. create file, write 4K into offset
* 0, fsync, write 4K into offset 4096, add hard link,
* fsync some other file (to sync log), power fail - if
* we use the inode's current i_size, after log replay
* we get a 8Kb file, with the last 4Kb extent as a hole
* (zeroes), as if an expanding truncate happened,
* instead of getting a file of 4Kb only.
*/
ret = logged_inode_size(log, inode, path, &logged_isize);
if (ret)
goto out_unlock;
}
if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&inode->runtime_flags)) {
if (inode_only == LOG_INODE_EXISTS) {
max_key.type = BTRFS_XATTR_ITEM_KEY;
if (ctx->logged_before)
ret = drop_inode_items(trans, log, path,
inode, max_key.type);
} else {
clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&inode->runtime_flags);
clear_bit(BTRFS_INODE_COPY_EVERYTHING,
&inode->runtime_flags);
if (ctx->logged_before)
ret = truncate_inode_items(trans, log,
inode, 0, 0);
}
} else if (test_and_clear_bit(BTRFS_INODE_COPY_EVERYTHING,
&inode->runtime_flags) ||
inode_only == LOG_INODE_EXISTS) {
if (inode_only == LOG_INODE_ALL)
fast_search = true;
max_key.type = BTRFS_XATTR_ITEM_KEY;
if (ctx->logged_before)
ret = drop_inode_items(trans, log, path, inode,
max_key.type);
} else {
if (inode_only == LOG_INODE_ALL)
fast_search = true;
inode_item_dropped = false;
goto log_extents;
}
}
if (ret)
goto out_unlock;
/*
* If we are logging a directory in full mode, collect the delayed items
* before iterating the subvolume tree, so that we don't miss any new
* dir index items in case they get flushed while or right after we are
* iterating the subvolume tree.
*/
if (full_dir_logging && !ctx->logging_new_delayed_dentries)
btrfs_log_get_delayed_items(inode, &delayed_ins_list,
&delayed_del_list);
ret = copy_inode_items_to_log(trans, inode, &min_key, &max_key,
path, dst_path, logged_isize,
inode_only, ctx,
&need_log_inode_item);
if (ret)
goto out_unlock;
btrfs_release_path(path);
btrfs_release_path(dst_path);
ret = btrfs_log_all_xattrs(trans, inode, path, dst_path);
if (ret)
goto out_unlock;
xattrs_logged = true;
if (max_key.type >= BTRFS_EXTENT_DATA_KEY && !fast_search) {
btrfs_release_path(path);
btrfs_release_path(dst_path);
ret = btrfs_log_holes(trans, inode, path);
if (ret)
goto out_unlock;
}
log_extents:
btrfs_release_path(path);
btrfs_release_path(dst_path);
if (need_log_inode_item) {
ret = log_inode_item(trans, log, dst_path, inode, inode_item_dropped);
if (ret)
goto out_unlock;
/*
* If we are doing a fast fsync and the inode was logged before
* in this transaction, we don't need to log the xattrs because
* they were logged before. If xattrs were added, changed or
* deleted since the last time we logged the inode, then we have
* already logged them because the inode had the runtime flag
* BTRFS_INODE_COPY_EVERYTHING set.
*/
if (!xattrs_logged && inode->logged_trans < trans->transid) {
ret = btrfs_log_all_xattrs(trans, inode, path, dst_path);
if (ret)
goto out_unlock;
btrfs_release_path(path);
}
}
if (fast_search) {
ret = btrfs_log_changed_extents(trans, inode, dst_path, ctx);
if (ret)
goto out_unlock;
} else if (inode_only == LOG_INODE_ALL) {
struct extent_map *em, *n;
write_lock(&em_tree->lock);
list_for_each_entry_safe(em, n, &em_tree->modified_extents, list)
list_del_init(&em->list);
write_unlock(&em_tree->lock);
}
if (full_dir_logging) {
ret = log_directory_changes(trans, inode, path, dst_path, ctx);
if (ret)
goto out_unlock;
ret = log_delayed_insertion_items(trans, inode, path,
&delayed_ins_list, ctx);
if (ret)
goto out_unlock;
ret = log_delayed_deletion_items(trans, inode, path,
&delayed_del_list, ctx);
if (ret)
goto out_unlock;
}
spin_lock(&inode->lock);
inode->logged_trans = trans->transid;
/*
* Don't update last_log_commit if we logged that an inode exists.
* We do this for three reasons:
*
* 1) We might have had buffered writes to this inode that were
* flushed and had their ordered extents completed in this
* transaction, but we did not previously log the inode with
* LOG_INODE_ALL. Later the inode was evicted and after that
* it was loaded again and this LOG_INODE_EXISTS log operation
* happened. We must make sure that if an explicit fsync against
* the inode is performed later, it logs the new extents, an
* updated inode item, etc, and syncs the log. The same logic
* applies to direct IO writes instead of buffered writes.
*
* 2) When we log the inode with LOG_INODE_EXISTS, its inode item
* is logged with an i_size of 0 or whatever value was logged
* before. If later the i_size of the inode is increased by a
* truncate operation, the log is synced through an fsync of
* some other inode and then finally an explicit fsync against
* this inode is made, we must make sure this fsync logs the
* inode with the new i_size, the hole between old i_size and
* the new i_size, and syncs the log.
*
* 3) If we are logging that an ancestor inode exists as part of
* logging a new name from a link or rename operation, don't update
* its last_log_commit - otherwise if an explicit fsync is made
* against an ancestor, the fsync considers the inode in the log
* and doesn't sync the log, resulting in the ancestor missing after
* a power failure unless the log was synced as part of an fsync
* against any other unrelated inode.
*/
if (inode_only != LOG_INODE_EXISTS)
inode->last_log_commit = inode->last_sub_trans;
spin_unlock(&inode->lock);
/*
* Reset the last_reflink_trans so that the next fsync does not need to
* go through the slower path when logging extents and their checksums.
*/
if (inode_only == LOG_INODE_ALL)
inode->last_reflink_trans = 0;
out_unlock:
mutex_unlock(&inode->log_mutex);
out:
btrfs_free_path(path);
btrfs_free_path(dst_path);
if (ret)
free_conflicting_inodes(ctx);
else
ret = log_conflicting_inodes(trans, inode->root, ctx);
if (full_dir_logging && !ctx->logging_new_delayed_dentries) {
if (!ret)
ret = log_new_delayed_dentries(trans, inode,
&delayed_ins_list, ctx);
btrfs_log_put_delayed_items(inode, &delayed_ins_list,
&delayed_del_list);
}
return ret;
}
static int btrfs_log_all_parents(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct btrfs_log_ctx *ctx)
{
struct btrfs_fs_info *fs_info = trans->fs_info;
int ret;
struct btrfs_path *path;
struct btrfs_key key;
struct btrfs_root *root = inode->root;
const u64 ino = btrfs_ino(inode);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
path->skip_locking = 1;
path->search_commit_root = 1;
key.objectid = ino;
key.type = BTRFS_INODE_REF_KEY;
key.offset = 0;
ret = btrfs_search_slot(NULL, root, &key, path, 0, 0);
if (ret < 0)
goto out;
while (true) {
struct extent_buffer *leaf = path->nodes[0];
int slot = path->slots[0];
u32 cur_offset = 0;
u32 item_size;
unsigned long ptr;
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
else if (ret > 0)
break;
continue;
}
btrfs_item_key_to_cpu(leaf, &key, slot);
/* BTRFS_INODE_EXTREF_KEY is BTRFS_INODE_REF_KEY + 1 */
if (key.objectid != ino || key.type > BTRFS_INODE_EXTREF_KEY)
break;
item_size = btrfs_item_size(leaf, slot);
ptr = btrfs_item_ptr_offset(leaf, slot);
while (cur_offset < item_size) {
struct btrfs_key inode_key;
struct inode *dir_inode;
inode_key.type = BTRFS_INODE_ITEM_KEY;
inode_key.offset = 0;
if (key.type == BTRFS_INODE_EXTREF_KEY) {
struct btrfs_inode_extref *extref;
extref = (struct btrfs_inode_extref *)
(ptr + cur_offset);
inode_key.objectid = btrfs_inode_extref_parent(
leaf, extref);
cur_offset += sizeof(*extref);
cur_offset += btrfs_inode_extref_name_len(leaf,
extref);
} else {
inode_key.objectid = key.offset;
cur_offset = item_size;
}
dir_inode = btrfs_iget(fs_info->sb, inode_key.objectid,
root);
/*
* If the parent inode was deleted, return an error to
* fallback to a transaction commit. This is to prevent
* getting an inode that was moved from one parent A to
* a parent B, got its former parent A deleted and then
* it got fsync'ed, from existing at both parents after
* a log replay (and the old parent still existing).
* Example:
*
* mkdir /mnt/A
* mkdir /mnt/B
* touch /mnt/B/bar
* sync
* mv /mnt/B/bar /mnt/A/bar
* mv -T /mnt/A /mnt/B
* fsync /mnt/B/bar
* <power fail>
*
* If we ignore the old parent B which got deleted,
* after a log replay we would have file bar linked
* at both parents and the old parent B would still
* exist.
*/
if (IS_ERR(dir_inode)) {
ret = PTR_ERR(dir_inode);
goto out;
}
if (!need_log_inode(trans, BTRFS_I(dir_inode))) {
btrfs_add_delayed_iput(dir_inode);
continue;
}
ctx->log_new_dentries = false;
ret = btrfs_log_inode(trans, BTRFS_I(dir_inode),
LOG_INODE_ALL, ctx);
if (!ret && ctx->log_new_dentries)
ret = log_new_dir_dentries(trans,
BTRFS_I(dir_inode), ctx);
btrfs_add_delayed_iput(dir_inode);
if (ret)
goto out;
}
path->slots[0]++;
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
static int log_new_ancestors(struct btrfs_trans_handle *trans,
struct btrfs_root *root,
struct btrfs_path *path,
struct btrfs_log_ctx *ctx)
{
struct btrfs_key found_key;
btrfs_item_key_to_cpu(path->nodes[0], &found_key, path->slots[0]);
while (true) {
struct btrfs_fs_info *fs_info = root->fs_info;
struct extent_buffer *leaf = path->nodes[0];
int slot = path->slots[0];
struct btrfs_key search_key;
struct inode *inode;
u64 ino;
int ret = 0;
btrfs_release_path(path);
ino = found_key.offset;
search_key.objectid = found_key.offset;
search_key.type = BTRFS_INODE_ITEM_KEY;
search_key.offset = 0;
inode = btrfs_iget(fs_info->sb, ino, root);
if (IS_ERR(inode))
return PTR_ERR(inode);
if (BTRFS_I(inode)->generation >= trans->transid &&
need_log_inode(trans, BTRFS_I(inode)))
ret = btrfs_log_inode(trans, BTRFS_I(inode),
LOG_INODE_EXISTS, ctx);
btrfs_add_delayed_iput(inode);
if (ret)
return ret;
if (search_key.objectid == BTRFS_FIRST_FREE_OBJECTID)
break;
search_key.type = BTRFS_INODE_REF_KEY;
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret < 0)
return ret;
leaf = path->nodes[0];
slot = path->slots[0];
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
return ret;
else if (ret > 0)
return -ENOENT;
leaf = path->nodes[0];
slot = path->slots[0];
}
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid != search_key.objectid ||
found_key.type != BTRFS_INODE_REF_KEY)
return -ENOENT;
}
return 0;
}
static int log_new_ancestors_fast(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct dentry *parent,
struct btrfs_log_ctx *ctx)
{
struct btrfs_root *root = inode->root;
struct dentry *old_parent = NULL;
struct super_block *sb = inode->vfs_inode.i_sb;
int ret = 0;
while (true) {
if (!parent || d_really_is_negative(parent) ||
sb != parent->d_sb)
break;
inode = BTRFS_I(d_inode(parent));
if (root != inode->root)
break;
if (inode->generation >= trans->transid &&
need_log_inode(trans, inode)) {
ret = btrfs_log_inode(trans, inode,
LOG_INODE_EXISTS, ctx);
if (ret)
break;
}
if (IS_ROOT(parent))
break;
parent = dget_parent(parent);
dput(old_parent);
old_parent = parent;
}
dput(old_parent);
return ret;
}
static int log_all_new_ancestors(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct dentry *parent,
struct btrfs_log_ctx *ctx)
{
struct btrfs_root *root = inode->root;
const u64 ino = btrfs_ino(inode);
struct btrfs_path *path;
struct btrfs_key search_key;
int ret;
/*
* For a single hard link case, go through a fast path that does not
* need to iterate the fs/subvolume tree.
*/
if (inode->vfs_inode.i_nlink < 2)
return log_new_ancestors_fast(trans, inode, parent, ctx);
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
search_key.objectid = ino;
search_key.type = BTRFS_INODE_REF_KEY;
search_key.offset = 0;
again:
ret = btrfs_search_slot(NULL, root, &search_key, path, 0, 0);
if (ret < 0)
goto out;
if (ret == 0)
path->slots[0]++;
while (true) {
struct extent_buffer *leaf = path->nodes[0];
int slot = path->slots[0];
struct btrfs_key found_key;
if (slot >= btrfs_header_nritems(leaf)) {
ret = btrfs_next_leaf(root, path);
if (ret < 0)
goto out;
else if (ret > 0)
break;
continue;
}
btrfs_item_key_to_cpu(leaf, &found_key, slot);
if (found_key.objectid != ino ||
found_key.type > BTRFS_INODE_EXTREF_KEY)
break;
/*
* Don't deal with extended references because they are rare
* cases and too complex to deal with (we would need to keep
* track of which subitem we are processing for each item in
* this loop, etc). So just return some error to fallback to
* a transaction commit.
*/
if (found_key.type == BTRFS_INODE_EXTREF_KEY) {
ret = -EMLINK;
goto out;
}
/*
* Logging ancestors needs to do more searches on the fs/subvol
* tree, so it releases the path as needed to avoid deadlocks.
* Keep track of the last inode ref key and resume from that key
* after logging all new ancestors for the current hard link.
*/
memcpy(&search_key, &found_key, sizeof(search_key));
ret = log_new_ancestors(trans, root, path, ctx);
if (ret)
goto out;
btrfs_release_path(path);
goto again;
}
ret = 0;
out:
btrfs_free_path(path);
return ret;
}
/*
* helper function around btrfs_log_inode to make sure newly created
* parent directories also end up in the log. A minimal inode and backref
* only logging is done of any parent directories that are older than
* the last committed transaction
*/
static int btrfs_log_inode_parent(struct btrfs_trans_handle *trans,
struct btrfs_inode *inode,
struct dentry *parent,
int inode_only,
struct btrfs_log_ctx *ctx)
{
struct btrfs_root *root = inode->root;
struct btrfs_fs_info *fs_info = root->fs_info;
int ret = 0;
bool log_dentries = false;
if (btrfs_test_opt(fs_info, NOTREELOG)) {
ret = BTRFS_LOG_FORCE_COMMIT;
goto end_no_trans;
}
if (btrfs_root_refs(&root->root_item) == 0) {
ret = BTRFS_LOG_FORCE_COMMIT;
goto end_no_trans;
}
/*
* Skip already logged inodes or inodes corresponding to tmpfiles
* (since logging them is pointless, a link count of 0 means they
* will never be accessible).
*/
if ((btrfs_inode_in_log(inode, trans->transid) &&
list_empty(&ctx->ordered_extents)) ||
inode->vfs_inode.i_nlink == 0) {
ret = BTRFS_NO_LOG_SYNC;
goto end_no_trans;
}
ret = start_log_trans(trans, root, ctx);
if (ret)
goto end_no_trans;
ret = btrfs_log_inode(trans, inode, inode_only, ctx);
if (ret)
goto end_trans;
/*
* for regular files, if its inode is already on disk, we don't
* have to worry about the parents at all. This is because
* we can use the last_unlink_trans field to record renames
* and other fun in this file.
*/
if (S_ISREG(inode->vfs_inode.i_mode) &&
inode->generation < trans->transid &&
inode->last_unlink_trans < trans->transid) {
ret = 0;
goto end_trans;
}
if (S_ISDIR(inode->vfs_inode.i_mode) && ctx->log_new_dentries)
log_dentries = true;
/*
* On unlink we must make sure all our current and old parent directory
* inodes are fully logged. This is to prevent leaving dangling
* directory index entries in directories that were our parents but are
* not anymore. Not doing this results in old parent directory being
* impossible to delete after log replay (rmdir will always fail with
* error -ENOTEMPTY).
*
* Example 1:
*
* mkdir testdir
* touch testdir/foo
* ln testdir/foo testdir/bar
* sync
* unlink testdir/bar
* xfs_io -c fsync testdir/foo
* <power failure>
* mount fs, triggers log replay
*
* If we don't log the parent directory (testdir), after log replay the
* directory still has an entry pointing to the file inode using the bar
* name, but a matching BTRFS_INODE_[REF|EXTREF]_KEY does not exist and
* the file inode has a link count of 1.
*
* Example 2:
*
* mkdir testdir
* touch foo
* ln foo testdir/foo2
* ln foo testdir/foo3
* sync
* unlink testdir/foo3
* xfs_io -c fsync foo
* <power failure>
* mount fs, triggers log replay
*
* Similar as the first example, after log replay the parent directory
* testdir still has an entry pointing to the inode file with name foo3
* but the file inode does not have a matching BTRFS_INODE_REF_KEY item
* and has a link count of 2.
*/
if (inode->last_unlink_trans >= trans->transid) {
ret = btrfs_log_all_parents(trans, inode, ctx);
if (ret)
goto end_trans;
}
ret = log_all_new_ancestors(trans, inode, parent, ctx);
if (ret)
goto end_trans;
if (log_dentries)
ret = log_new_dir_dentries(trans, inode, ctx);
else
ret = 0;
end_trans:
if (ret < 0) {
btrfs_set_log_full_commit(trans);
ret = BTRFS_LOG_FORCE_COMMIT;
}
if (ret)
btrfs_remove_log_ctx(root, ctx);
btrfs_end_log_trans(root);
end_no_trans:
return ret;
}
/*
* it is not safe to log dentry if the chunk root has added new
* chunks. This returns 0 if the dentry was logged, and 1 otherwise.
* If this returns 1, you must commit the transaction to safely get your
* data on disk.
*/
int btrfs_log_dentry_safe(struct btrfs_trans_handle *trans,
struct dentry *dentry,
struct btrfs_log_ctx *ctx)
{
struct dentry *parent = dget_parent(dentry);
int ret;
ret = btrfs_log_inode_parent(trans, BTRFS_I(d_inode(dentry)), parent,
LOG_INODE_ALL, ctx);
dput(parent);
return ret;
}
/*
* should be called during mount to recover any replay any log trees
* from the FS
*/
int btrfs_recover_log_trees(struct btrfs_root *log_root_tree)
{
int ret;
struct btrfs_path *path;
struct btrfs_trans_handle *trans;
struct btrfs_key key;
struct btrfs_key found_key;
struct btrfs_root *log;
struct btrfs_fs_info *fs_info = log_root_tree->fs_info;
struct walk_control wc = {
.process_func = process_one_buffer,
.stage = LOG_WALK_PIN_ONLY,
};
path = btrfs_alloc_path();
if (!path)
return -ENOMEM;
set_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
trans = btrfs_start_transaction(fs_info->tree_root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
goto error;
}
wc.trans = trans;
wc.pin = 1;
ret = walk_log_tree(trans, log_root_tree, &wc);
if (ret) {
btrfs_abort_transaction(trans, ret);
goto error;
}
again:
key.objectid = BTRFS_TREE_LOG_OBJECTID;
key.offset = (u64)-1;
key.type = BTRFS_ROOT_ITEM_KEY;
while (1) {
ret = btrfs_search_slot(NULL, log_root_tree, &key, path, 0, 0);
if (ret < 0) {
btrfs_abort_transaction(trans, ret);
goto error;
}
if (ret > 0) {
if (path->slots[0] == 0)
break;
path->slots[0]--;
}
btrfs_item_key_to_cpu(path->nodes[0], &found_key,
path->slots[0]);
btrfs_release_path(path);
if (found_key.objectid != BTRFS_TREE_LOG_OBJECTID)
break;
log = btrfs_read_tree_root(log_root_tree, &found_key);
if (IS_ERR(log)) {
ret = PTR_ERR(log);
btrfs_abort_transaction(trans, ret);
goto error;
}
wc.replay_dest = btrfs_get_fs_root(fs_info, found_key.offset,
true);
if (IS_ERR(wc.replay_dest)) {
ret = PTR_ERR(wc.replay_dest);
/*
* We didn't find the subvol, likely because it was
* deleted. This is ok, simply skip this log and go to
* the next one.
*
* We need to exclude the root because we can't have
* other log replays overwriting this log as we'll read
* it back in a few more times. This will keep our
* block from being modified, and we'll just bail for
* each subsequent pass.
*/
if (ret == -ENOENT)
ret = btrfs_pin_extent_for_log_replay(trans,
log->node->start,
log->node->len);
btrfs_put_root(log);
if (!ret)
goto next;
btrfs_abort_transaction(trans, ret);
goto error;
}
wc.replay_dest->log_root = log;
ret = btrfs_record_root_in_trans(trans, wc.replay_dest);
if (ret)
/* The loop needs to continue due to the root refs */
btrfs_abort_transaction(trans, ret);
else
ret = walk_log_tree(trans, log, &wc);
if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
ret = fixup_inode_link_counts(trans, wc.replay_dest,
path);
if (ret)
btrfs_abort_transaction(trans, ret);
}
if (!ret && wc.stage == LOG_WALK_REPLAY_ALL) {
struct btrfs_root *root = wc.replay_dest;
btrfs_release_path(path);
/*
* We have just replayed everything, and the highest
* objectid of fs roots probably has changed in case
* some inode_item's got replayed.
*
* root->objectid_mutex is not acquired as log replay
* could only happen during mount.
*/
ret = btrfs_init_root_free_objectid(root);
if (ret)
btrfs_abort_transaction(trans, ret);
}
wc.replay_dest->log_root = NULL;
btrfs_put_root(wc.replay_dest);
btrfs_put_root(log);
if (ret)
goto error;
next:
if (found_key.offset == 0)
break;
key.offset = found_key.offset - 1;
}
btrfs_release_path(path);
/* step one is to pin it all, step two is to replay just inodes */
if (wc.pin) {
wc.pin = 0;
wc.process_func = replay_one_buffer;
wc.stage = LOG_WALK_REPLAY_INODES;
goto again;
}
/* step three is to replay everything */
if (wc.stage < LOG_WALK_REPLAY_ALL) {
wc.stage++;
goto again;
}
btrfs_free_path(path);
/* step 4: commit the transaction, which also unpins the blocks */
ret = btrfs_commit_transaction(trans);
if (ret)
return ret;
log_root_tree->log_root = NULL;
clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
btrfs_put_root(log_root_tree);
return 0;
error:
if (wc.trans)
btrfs_end_transaction(wc.trans);
clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
btrfs_free_path(path);
return ret;
}
/*
* there are some corner cases where we want to force a full
* commit instead of allowing a directory to be logged.
*
* They revolve around files there were unlinked from the directory, and
* this function updates the parent directory so that a full commit is
* properly done if it is fsync'd later after the unlinks are done.
*
* Must be called before the unlink operations (updates to the subvolume tree,
* inodes, etc) are done.
*/
void btrfs_record_unlink_dir(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir, struct btrfs_inode *inode,
int for_rename)
{
/*
* when we're logging a file, if it hasn't been renamed
* or unlinked, and its inode is fully committed on disk,
* we don't have to worry about walking up the directory chain
* to log its parents.
*
* So, we use the last_unlink_trans field to put this transid
* into the file. When the file is logged we check it and
* don't log the parents if the file is fully on disk.
*/
mutex_lock(&inode->log_mutex);
inode->last_unlink_trans = trans->transid;
mutex_unlock(&inode->log_mutex);
/*
* if this directory was already logged any new
* names for this file/dir will get recorded
*/
if (dir->logged_trans == trans->transid)
return;
/*
* if the inode we're about to unlink was logged,
* the log will be properly updated for any new names
*/
if (inode->logged_trans == trans->transid)
return;
/*
* when renaming files across directories, if the directory
* there we're unlinking from gets fsync'd later on, there's
* no way to find the destination directory later and fsync it
* properly. So, we have to be conservative and force commits
* so the new name gets discovered.
*/
if (for_rename)
goto record;
/* we can safely do the unlink without any special recording */
return;
record:
mutex_lock(&dir->log_mutex);
dir->last_unlink_trans = trans->transid;
mutex_unlock(&dir->log_mutex);
}
/*
* Make sure that if someone attempts to fsync the parent directory of a deleted
* snapshot, it ends up triggering a transaction commit. This is to guarantee
* that after replaying the log tree of the parent directory's root we will not
* see the snapshot anymore and at log replay time we will not see any log tree
* corresponding to the deleted snapshot's root, which could lead to replaying
* it after replaying the log tree of the parent directory (which would replay
* the snapshot delete operation).
*
* Must be called before the actual snapshot destroy operation (updates to the
* parent root and tree of tree roots trees, etc) are done.
*/
void btrfs_record_snapshot_destroy(struct btrfs_trans_handle *trans,
struct btrfs_inode *dir)
{
mutex_lock(&dir->log_mutex);
dir->last_unlink_trans = trans->transid;
mutex_unlock(&dir->log_mutex);
}
/**
* Update the log after adding a new name for an inode.
*
* @trans: Transaction handle.
* @old_dentry: The dentry associated with the old name and the old
* parent directory.
* @old_dir: The inode of the previous parent directory for the case
* of a rename. For a link operation, it must be NULL.
* @old_dir_index: The index number associated with the old name, meaningful
* only for rename operations (when @old_dir is not NULL).
* Ignored for link operations.
* @parent: The dentry associated with the directory under which the
* new name is located.
*
* Call this after adding a new name for an inode, as a result of a link or
* rename operation, and it will properly update the log to reflect the new name.
*/
void btrfs_log_new_name(struct btrfs_trans_handle *trans,
struct dentry *old_dentry, struct btrfs_inode *old_dir,
u64 old_dir_index, struct dentry *parent)
{
struct btrfs_inode *inode = BTRFS_I(d_inode(old_dentry));
struct btrfs_root *root = inode->root;
struct btrfs_log_ctx ctx;
bool log_pinned = false;
int ret;
/*
* this will force the logging code to walk the dentry chain
* up for the file
*/
if (!S_ISDIR(inode->vfs_inode.i_mode))
inode->last_unlink_trans = trans->transid;
/*
* if this inode hasn't been logged and directory we're renaming it
* from hasn't been logged, we don't need to log it
*/
ret = inode_logged(trans, inode, NULL);
if (ret < 0) {
goto out;
} else if (ret == 0) {
if (!old_dir)
return;
/*
* If the inode was not logged and we are doing a rename (old_dir is not
* NULL), check if old_dir was logged - if it was not we can return and
* do nothing.
*/
ret = inode_logged(trans, old_dir, NULL);
if (ret < 0)
goto out;
else if (ret == 0)
return;
}
ret = 0;
/*
* If we are doing a rename (old_dir is not NULL) from a directory that
* was previously logged, make sure that on log replay we get the old
* dir entry deleted. This is needed because we will also log the new
* name of the renamed inode, so we need to make sure that after log
* replay we don't end up with both the new and old dir entries existing.
*/
if (old_dir && old_dir->logged_trans == trans->transid) {
struct btrfs_root *log = old_dir->root->log_root;
struct btrfs_path *path;
ASSERT(old_dir_index >= BTRFS_DIR_START_INDEX);
/*
* We have two inodes to update in the log, the old directory and
* the inode that got renamed, so we must pin the log to prevent
* anyone from syncing the log until we have updated both inodes
* in the log.
*/
ret = join_running_log_trans(root);
/*
* At least one of the inodes was logged before, so this should
* not fail, but if it does, it's not serious, just bail out and
* mark the log for a full commit.
*/
if (WARN_ON_ONCE(ret < 0))
goto out;
log_pinned = true;
path = btrfs_alloc_path();
if (!path) {
ret = -ENOMEM;
goto out;
}
/*
* Other concurrent task might be logging the old directory,
* as it can be triggered when logging other inode that had or
* still has a dentry in the old directory. We lock the old
* directory's log_mutex to ensure the deletion of the old
* name is persisted, because during directory logging we
* delete all BTRFS_DIR_LOG_INDEX_KEY keys and the deletion of
* the old name's dir index item is in the delayed items, so
* it could be missed by an in progress directory logging.
*/
mutex_lock(&old_dir->log_mutex);
ret = del_logged_dentry(trans, log, path, btrfs_ino(old_dir),
old_dentry->d_name.name,
old_dentry->d_name.len, old_dir_index);
if (ret > 0) {
/*
* The dentry does not exist in the log, so record its
* deletion.
*/
btrfs_release_path(path);
ret = insert_dir_log_key(trans, log, path,
btrfs_ino(old_dir),
old_dir_index, old_dir_index);
}
mutex_unlock(&old_dir->log_mutex);
btrfs_free_path(path);
if (ret < 0)
goto out;
}
btrfs_init_log_ctx(&ctx, &inode->vfs_inode);
ctx.logging_new_name = true;
/*
* We don't care about the return value. If we fail to log the new name
* then we know the next attempt to sync the log will fallback to a full
* transaction commit (due to a call to btrfs_set_log_full_commit()), so
* we don't need to worry about getting a log committed that has an
* inconsistent state after a rename operation.
*/
btrfs_log_inode_parent(trans, inode, parent, LOG_INODE_EXISTS, &ctx);
ASSERT(list_empty(&ctx.conflict_inodes));
out:
/*
* If an error happened mark the log for a full commit because it's not
* consistent and up to date or we couldn't find out if one of the
* inodes was logged before in this transaction. Do it before unpinning
* the log, to avoid any races with someone else trying to commit it.
*/
if (ret < 0)
btrfs_set_log_full_commit(trans);
if (log_pinned)
btrfs_end_log_trans(root);
}