| // SPDX-License-Identifier: GPL-2.0 |
| /* |
| * Copyright (C) 2007 Oracle. All rights reserved. |
| */ |
| |
| #include <linux/fs.h> |
| #include <linux/pagemap.h> |
| #include <linux/time.h> |
| #include <linux/init.h> |
| #include <linux/string.h> |
| #include <linux/backing-dev.h> |
| #include <linux/falloc.h> |
| #include <linux/writeback.h> |
| #include <linux/compat.h> |
| #include <linux/slab.h> |
| #include <linux/btrfs.h> |
| #include <linux/uio.h> |
| #include <linux/iversion.h> |
| #include <linux/fsverity.h> |
| #include "ctree.h" |
| #include "direct-io.h" |
| #include "disk-io.h" |
| #include "transaction.h" |
| #include "btrfs_inode.h" |
| #include "tree-log.h" |
| #include "locking.h" |
| #include "qgroup.h" |
| #include "compression.h" |
| #include "delalloc-space.h" |
| #include "reflink.h" |
| #include "subpage.h" |
| #include "fs.h" |
| #include "accessors.h" |
| #include "extent-tree.h" |
| #include "file-item.h" |
| #include "ioctl.h" |
| #include "file.h" |
| #include "super.h" |
| |
| /* simple helper to fault in pages and copy. This should go away |
| * and be replaced with calls into generic code. |
| */ |
| static noinline int btrfs_copy_from_user(loff_t pos, size_t write_bytes, |
| struct page **prepared_pages, |
| struct iov_iter *i) |
| { |
| size_t copied = 0; |
| size_t total_copied = 0; |
| int pg = 0; |
| int offset = offset_in_page(pos); |
| |
| while (write_bytes > 0) { |
| size_t count = min_t(size_t, |
| PAGE_SIZE - offset, write_bytes); |
| struct page *page = prepared_pages[pg]; |
| /* |
| * Copy data from userspace to the current page |
| */ |
| copied = copy_page_from_iter_atomic(page, offset, count, i); |
| |
| /* Flush processor's dcache for this page */ |
| flush_dcache_page(page); |
| |
| /* |
| * if we get a partial write, we can end up with |
| * partially up to date pages. These add |
| * a lot of complexity, so make sure they don't |
| * happen by forcing this copy to be retried. |
| * |
| * The rest of the btrfs_file_write code will fall |
| * back to page at a time copies after we return 0. |
| */ |
| if (unlikely(copied < count)) { |
| if (!PageUptodate(page)) { |
| iov_iter_revert(i, copied); |
| copied = 0; |
| } |
| if (!copied) |
| break; |
| } |
| |
| write_bytes -= copied; |
| total_copied += copied; |
| offset += copied; |
| if (offset == PAGE_SIZE) { |
| pg++; |
| offset = 0; |
| } |
| } |
| return total_copied; |
| } |
| |
| /* |
| * unlocks pages after btrfs_file_write is done with them |
| */ |
| static void btrfs_drop_pages(struct btrfs_fs_info *fs_info, |
| struct page **pages, size_t num_pages, |
| u64 pos, u64 copied) |
| { |
| size_t i; |
| u64 block_start = round_down(pos, fs_info->sectorsize); |
| u64 block_len = round_up(pos + copied, fs_info->sectorsize) - block_start; |
| |
| ASSERT(block_len <= U32_MAX); |
| for (i = 0; i < num_pages; i++) { |
| /* page checked is some magic around finding pages that |
| * have been modified without going through btrfs_set_page_dirty |
| * clear it here. There should be no need to mark the pages |
| * accessed as prepare_pages should have marked them accessed |
| * in prepare_pages via find_or_create_page() |
| */ |
| btrfs_folio_clamp_clear_checked(fs_info, page_folio(pages[i]), |
| block_start, block_len); |
| unlock_page(pages[i]); |
| put_page(pages[i]); |
| } |
| } |
| |
| /* |
| * After btrfs_copy_from_user(), update the following things for delalloc: |
| * - Mark newly dirtied pages as DELALLOC in the io tree. |
| * Used to advise which range is to be written back. |
| * - Mark modified pages as Uptodate/Dirty and not needing COW fixup |
| * - Update inode size for past EOF write |
| */ |
| int btrfs_dirty_pages(struct btrfs_inode *inode, struct page **pages, |
| size_t num_pages, loff_t pos, size_t write_bytes, |
| struct extent_state **cached, bool noreserve) |
| { |
| struct btrfs_fs_info *fs_info = inode->root->fs_info; |
| int ret = 0; |
| int i; |
| u64 num_bytes; |
| u64 start_pos; |
| u64 end_of_last_block; |
| u64 end_pos = pos + write_bytes; |
| loff_t isize = i_size_read(&inode->vfs_inode); |
| unsigned int extra_bits = 0; |
| |
| if (write_bytes == 0) |
| return 0; |
| |
| if (noreserve) |
| extra_bits |= EXTENT_NORESERVE; |
| |
| start_pos = round_down(pos, fs_info->sectorsize); |
| num_bytes = round_up(write_bytes + pos - start_pos, |
| fs_info->sectorsize); |
| ASSERT(num_bytes <= U32_MAX); |
| |
| end_of_last_block = start_pos + num_bytes - 1; |
| |
| /* |
| * The pages may have already been dirty, clear out old accounting so |
| * we can set things up properly |
| */ |
| clear_extent_bit(&inode->io_tree, start_pos, end_of_last_block, |
| EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, |
| cached); |
| |
| ret = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block, |
| extra_bits, cached); |
| if (ret) |
| return ret; |
| |
| for (i = 0; i < num_pages; i++) { |
| struct page *p = pages[i]; |
| |
| btrfs_folio_clamp_set_uptodate(fs_info, page_folio(p), |
| start_pos, num_bytes); |
| btrfs_folio_clamp_clear_checked(fs_info, page_folio(p), |
| start_pos, num_bytes); |
| btrfs_folio_clamp_set_dirty(fs_info, page_folio(p), |
| start_pos, num_bytes); |
| } |
| |
| /* |
| * we've only changed i_size in ram, and we haven't updated |
| * the disk i_size. There is no need to log the inode |
| * at this time. |
| */ |
| if (end_pos > isize) |
| i_size_write(&inode->vfs_inode, end_pos); |
| return 0; |
| } |
| |
| /* |
| * this is very complex, but the basic idea is to drop all extents |
| * in the range start - end. hint_block is filled in with a block number |
| * that would be a good hint to the block allocator for this file. |
| * |
| * If an extent intersects the range but is not entirely inside the range |
| * it is either truncated or split. Anything entirely inside the range |
| * is deleted from the tree. |
| * |
| * Note: the VFS' inode number of bytes is not updated, it's up to the caller |
| * to deal with that. We set the field 'bytes_found' of the arguments structure |
| * with the number of allocated bytes found in the target range, so that the |
| * caller can update the inode's number of bytes in an atomic way when |
| * replacing extents in a range to avoid races with stat(2). |
| */ |
| int btrfs_drop_extents(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, struct btrfs_inode *inode, |
| struct btrfs_drop_extents_args *args) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| struct extent_buffer *leaf; |
| struct btrfs_file_extent_item *fi; |
| struct btrfs_key key; |
| struct btrfs_key new_key; |
| u64 ino = btrfs_ino(inode); |
| u64 search_start = args->start; |
| u64 disk_bytenr = 0; |
| u64 num_bytes = 0; |
| u64 extent_offset = 0; |
| u64 extent_end = 0; |
| u64 last_end = args->start; |
| int del_nr = 0; |
| int del_slot = 0; |
| int extent_type; |
| int recow; |
| int ret; |
| int modify_tree = -1; |
| int update_refs; |
| int found = 0; |
| struct btrfs_path *path = args->path; |
| |
| args->bytes_found = 0; |
| args->extent_inserted = false; |
| |
| /* Must always have a path if ->replace_extent is true */ |
| ASSERT(!(args->replace_extent && !args->path)); |
| |
| if (!path) { |
| path = btrfs_alloc_path(); |
| if (!path) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| } |
| |
| if (args->drop_cache) |
| btrfs_drop_extent_map_range(inode, args->start, args->end - 1, false); |
| |
| if (args->start >= inode->disk_i_size && !args->replace_extent) |
| modify_tree = 0; |
| |
| update_refs = (btrfs_root_id(root) != BTRFS_TREE_LOG_OBJECTID); |
| while (1) { |
| recow = 0; |
| ret = btrfs_lookup_file_extent(trans, root, path, ino, |
| search_start, modify_tree); |
| if (ret < 0) |
| break; |
| if (ret > 0 && path->slots[0] > 0 && search_start == args->start) { |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0] - 1); |
| if (key.objectid == ino && |
| key.type == BTRFS_EXTENT_DATA_KEY) |
| path->slots[0]--; |
| } |
| ret = 0; |
| next_slot: |
| leaf = path->nodes[0]; |
| if (path->slots[0] >= btrfs_header_nritems(leaf)) { |
| BUG_ON(del_nr > 0); |
| ret = btrfs_next_leaf(root, path); |
| if (ret < 0) |
| break; |
| if (ret > 0) { |
| ret = 0; |
| break; |
| } |
| leaf = path->nodes[0]; |
| recow = 1; |
| } |
| |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| |
| if (key.objectid > ino) |
| break; |
| if (WARN_ON_ONCE(key.objectid < ino) || |
| key.type < BTRFS_EXTENT_DATA_KEY) { |
| ASSERT(del_nr == 0); |
| path->slots[0]++; |
| goto next_slot; |
| } |
| if (key.type > BTRFS_EXTENT_DATA_KEY || key.offset >= args->end) |
| break; |
| |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| extent_type = btrfs_file_extent_type(leaf, fi); |
| |
| if (extent_type == BTRFS_FILE_EXTENT_REG || |
| extent_type == BTRFS_FILE_EXTENT_PREALLOC) { |
| disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); |
| num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); |
| extent_offset = btrfs_file_extent_offset(leaf, fi); |
| extent_end = key.offset + |
| btrfs_file_extent_num_bytes(leaf, fi); |
| } else if (extent_type == BTRFS_FILE_EXTENT_INLINE) { |
| extent_end = key.offset + |
| btrfs_file_extent_ram_bytes(leaf, fi); |
| } else { |
| /* can't happen */ |
| BUG(); |
| } |
| |
| /* |
| * Don't skip extent items representing 0 byte lengths. They |
| * used to be created (bug) if while punching holes we hit |
| * -ENOSPC condition. So if we find one here, just ensure we |
| * delete it, otherwise we would insert a new file extent item |
| * with the same key (offset) as that 0 bytes length file |
| * extent item in the call to setup_items_for_insert() later |
| * in this function. |
| */ |
| if (extent_end == key.offset && extent_end >= search_start) { |
| last_end = extent_end; |
| goto delete_extent_item; |
| } |
| |
| if (extent_end <= search_start) { |
| path->slots[0]++; |
| goto next_slot; |
| } |
| |
| found = 1; |
| search_start = max(key.offset, args->start); |
| if (recow || !modify_tree) { |
| modify_tree = -1; |
| btrfs_release_path(path); |
| continue; |
| } |
| |
| /* |
| * | - range to drop - | |
| * | -------- extent -------- | |
| */ |
| if (args->start > key.offset && args->end < extent_end) { |
| BUG_ON(del_nr > 0); |
| if (extent_type == BTRFS_FILE_EXTENT_INLINE) { |
| ret = -EOPNOTSUPP; |
| break; |
| } |
| |
| memcpy(&new_key, &key, sizeof(new_key)); |
| new_key.offset = args->start; |
| ret = btrfs_duplicate_item(trans, root, path, |
| &new_key); |
| if (ret == -EAGAIN) { |
| btrfs_release_path(path); |
| continue; |
| } |
| if (ret < 0) |
| break; |
| |
| leaf = path->nodes[0]; |
| fi = btrfs_item_ptr(leaf, path->slots[0] - 1, |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| args->start - key.offset); |
| |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| |
| extent_offset += args->start - key.offset; |
| btrfs_set_file_extent_offset(leaf, fi, extent_offset); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| extent_end - args->start); |
| btrfs_mark_buffer_dirty(trans, leaf); |
| |
| if (update_refs && disk_bytenr > 0) { |
| struct btrfs_ref ref = { |
| .action = BTRFS_ADD_DELAYED_REF, |
| .bytenr = disk_bytenr, |
| .num_bytes = num_bytes, |
| .parent = 0, |
| .owning_root = btrfs_root_id(root), |
| .ref_root = btrfs_root_id(root), |
| }; |
| btrfs_init_data_ref(&ref, new_key.objectid, |
| args->start - extent_offset, |
| 0, false); |
| ret = btrfs_inc_extent_ref(trans, &ref); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| break; |
| } |
| } |
| key.offset = args->start; |
| } |
| /* |
| * From here on out we will have actually dropped something, so |
| * last_end can be updated. |
| */ |
| last_end = extent_end; |
| |
| /* |
| * | ---- range to drop ----- | |
| * | -------- extent -------- | |
| */ |
| if (args->start <= key.offset && args->end < extent_end) { |
| if (extent_type == BTRFS_FILE_EXTENT_INLINE) { |
| ret = -EOPNOTSUPP; |
| break; |
| } |
| |
| memcpy(&new_key, &key, sizeof(new_key)); |
| new_key.offset = args->end; |
| btrfs_set_item_key_safe(trans, path, &new_key); |
| |
| extent_offset += args->end - key.offset; |
| btrfs_set_file_extent_offset(leaf, fi, extent_offset); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| extent_end - args->end); |
| btrfs_mark_buffer_dirty(trans, leaf); |
| if (update_refs && disk_bytenr > 0) |
| args->bytes_found += args->end - key.offset; |
| break; |
| } |
| |
| search_start = extent_end; |
| /* |
| * | ---- range to drop ----- | |
| * | -------- extent -------- | |
| */ |
| if (args->start > key.offset && args->end >= extent_end) { |
| BUG_ON(del_nr > 0); |
| if (extent_type == BTRFS_FILE_EXTENT_INLINE) { |
| ret = -EOPNOTSUPP; |
| break; |
| } |
| |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| args->start - key.offset); |
| btrfs_mark_buffer_dirty(trans, leaf); |
| if (update_refs && disk_bytenr > 0) |
| args->bytes_found += extent_end - args->start; |
| if (args->end == extent_end) |
| break; |
| |
| path->slots[0]++; |
| goto next_slot; |
| } |
| |
| /* |
| * | ---- range to drop ----- | |
| * | ------ extent ------ | |
| */ |
| if (args->start <= key.offset && args->end >= extent_end) { |
| delete_extent_item: |
| if (del_nr == 0) { |
| del_slot = path->slots[0]; |
| del_nr = 1; |
| } else { |
| BUG_ON(del_slot + del_nr != path->slots[0]); |
| del_nr++; |
| } |
| |
| if (update_refs && |
| extent_type == BTRFS_FILE_EXTENT_INLINE) { |
| args->bytes_found += extent_end - key.offset; |
| extent_end = ALIGN(extent_end, |
| fs_info->sectorsize); |
| } else if (update_refs && disk_bytenr > 0) { |
| struct btrfs_ref ref = { |
| .action = BTRFS_DROP_DELAYED_REF, |
| .bytenr = disk_bytenr, |
| .num_bytes = num_bytes, |
| .parent = 0, |
| .owning_root = btrfs_root_id(root), |
| .ref_root = btrfs_root_id(root), |
| }; |
| btrfs_init_data_ref(&ref, key.objectid, |
| key.offset - extent_offset, |
| 0, false); |
| ret = btrfs_free_extent(trans, &ref); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| break; |
| } |
| args->bytes_found += extent_end - key.offset; |
| } |
| |
| if (args->end == extent_end) |
| break; |
| |
| if (path->slots[0] + 1 < btrfs_header_nritems(leaf)) { |
| path->slots[0]++; |
| goto next_slot; |
| } |
| |
| ret = btrfs_del_items(trans, root, path, del_slot, |
| del_nr); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| break; |
| } |
| |
| del_nr = 0; |
| del_slot = 0; |
| |
| btrfs_release_path(path); |
| continue; |
| } |
| |
| BUG(); |
| } |
| |
| if (!ret && del_nr > 0) { |
| /* |
| * Set path->slots[0] to first slot, so that after the delete |
| * if items are move off from our leaf to its immediate left or |
| * right neighbor leafs, we end up with a correct and adjusted |
| * path->slots[0] for our insertion (if args->replace_extent). |
| */ |
| path->slots[0] = del_slot; |
| ret = btrfs_del_items(trans, root, path, del_slot, del_nr); |
| if (ret) |
| btrfs_abort_transaction(trans, ret); |
| } |
| |
| leaf = path->nodes[0]; |
| /* |
| * If btrfs_del_items() was called, it might have deleted a leaf, in |
| * which case it unlocked our path, so check path->locks[0] matches a |
| * write lock. |
| */ |
| if (!ret && args->replace_extent && |
| path->locks[0] == BTRFS_WRITE_LOCK && |
| btrfs_leaf_free_space(leaf) >= |
| sizeof(struct btrfs_item) + args->extent_item_size) { |
| |
| key.objectid = ino; |
| key.type = BTRFS_EXTENT_DATA_KEY; |
| key.offset = args->start; |
| if (!del_nr && path->slots[0] < btrfs_header_nritems(leaf)) { |
| struct btrfs_key slot_key; |
| |
| btrfs_item_key_to_cpu(leaf, &slot_key, path->slots[0]); |
| if (btrfs_comp_cpu_keys(&key, &slot_key) > 0) |
| path->slots[0]++; |
| } |
| btrfs_setup_item_for_insert(trans, root, path, &key, |
| args->extent_item_size); |
| args->extent_inserted = true; |
| } |
| |
| if (!args->path) |
| btrfs_free_path(path); |
| else if (!args->extent_inserted) |
| btrfs_release_path(path); |
| out: |
| args->drop_end = found ? min(args->end, last_end) : args->end; |
| |
| return ret; |
| } |
| |
| static int extent_mergeable(struct extent_buffer *leaf, int slot, |
| u64 objectid, u64 bytenr, u64 orig_offset, |
| u64 *start, u64 *end) |
| { |
| struct btrfs_file_extent_item *fi; |
| struct btrfs_key key; |
| u64 extent_end; |
| |
| if (slot < 0 || slot >= btrfs_header_nritems(leaf)) |
| return 0; |
| |
| btrfs_item_key_to_cpu(leaf, &key, slot); |
| if (key.objectid != objectid || key.type != BTRFS_EXTENT_DATA_KEY) |
| return 0; |
| |
| fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); |
| if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG || |
| btrfs_file_extent_disk_bytenr(leaf, fi) != bytenr || |
| btrfs_file_extent_offset(leaf, fi) != key.offset - orig_offset || |
| btrfs_file_extent_compression(leaf, fi) || |
| btrfs_file_extent_encryption(leaf, fi) || |
| btrfs_file_extent_other_encoding(leaf, fi)) |
| return 0; |
| |
| extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); |
| if ((*start && *start != key.offset) || (*end && *end != extent_end)) |
| return 0; |
| |
| *start = key.offset; |
| *end = extent_end; |
| return 1; |
| } |
| |
| /* |
| * Mark extent in the range start - end as written. |
| * |
| * This changes extent type from 'pre-allocated' to 'regular'. If only |
| * part of extent is marked as written, the extent will be split into |
| * two or three. |
| */ |
| int btrfs_mark_extent_written(struct btrfs_trans_handle *trans, |
| struct btrfs_inode *inode, u64 start, u64 end) |
| { |
| struct btrfs_root *root = inode->root; |
| struct extent_buffer *leaf; |
| struct btrfs_path *path; |
| struct btrfs_file_extent_item *fi; |
| struct btrfs_ref ref = { 0 }; |
| struct btrfs_key key; |
| struct btrfs_key new_key; |
| u64 bytenr; |
| u64 num_bytes; |
| u64 extent_end; |
| u64 orig_offset; |
| u64 other_start; |
| u64 other_end; |
| u64 split; |
| int del_nr = 0; |
| int del_slot = 0; |
| int recow; |
| int ret = 0; |
| u64 ino = btrfs_ino(inode); |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| again: |
| recow = 0; |
| split = start; |
| key.objectid = ino; |
| key.type = BTRFS_EXTENT_DATA_KEY; |
| key.offset = split; |
| |
| ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| if (ret < 0) |
| goto out; |
| if (ret > 0 && path->slots[0] > 0) |
| path->slots[0]--; |
| |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| if (key.objectid != ino || |
| key.type != BTRFS_EXTENT_DATA_KEY) { |
| ret = -EINVAL; |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_PREALLOC) { |
| ret = -EINVAL; |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| extent_end = key.offset + btrfs_file_extent_num_bytes(leaf, fi); |
| if (key.offset > start || extent_end < end) { |
| ret = -EINVAL; |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| |
| bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); |
| num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); |
| orig_offset = key.offset - btrfs_file_extent_offset(leaf, fi); |
| memcpy(&new_key, &key, sizeof(new_key)); |
| |
| if (start == key.offset && end < extent_end) { |
| other_start = 0; |
| other_end = start; |
| if (extent_mergeable(leaf, path->slots[0] - 1, |
| ino, bytenr, orig_offset, |
| &other_start, &other_end)) { |
| new_key.offset = end; |
| btrfs_set_item_key_safe(trans, path, &new_key); |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_generation(leaf, fi, |
| trans->transid); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| extent_end - end); |
| btrfs_set_file_extent_offset(leaf, fi, |
| end - orig_offset); |
| fi = btrfs_item_ptr(leaf, path->slots[0] - 1, |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_generation(leaf, fi, |
| trans->transid); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| end - other_start); |
| btrfs_mark_buffer_dirty(trans, leaf); |
| goto out; |
| } |
| } |
| |
| if (start > key.offset && end == extent_end) { |
| other_start = end; |
| other_end = 0; |
| if (extent_mergeable(leaf, path->slots[0] + 1, |
| ino, bytenr, orig_offset, |
| &other_start, &other_end)) { |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| start - key.offset); |
| btrfs_set_file_extent_generation(leaf, fi, |
| trans->transid); |
| path->slots[0]++; |
| new_key.offset = start; |
| btrfs_set_item_key_safe(trans, path, &new_key); |
| |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_generation(leaf, fi, |
| trans->transid); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| other_end - start); |
| btrfs_set_file_extent_offset(leaf, fi, |
| start - orig_offset); |
| btrfs_mark_buffer_dirty(trans, leaf); |
| goto out; |
| } |
| } |
| |
| while (start > key.offset || end < extent_end) { |
| if (key.offset == start) |
| split = end; |
| |
| new_key.offset = split; |
| ret = btrfs_duplicate_item(trans, root, path, &new_key); |
| if (ret == -EAGAIN) { |
| btrfs_release_path(path); |
| goto again; |
| } |
| if (ret < 0) { |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| |
| leaf = path->nodes[0]; |
| fi = btrfs_item_ptr(leaf, path->slots[0] - 1, |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_generation(leaf, fi, trans->transid); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| split - key.offset); |
| |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| |
| btrfs_set_file_extent_generation(leaf, fi, trans->transid); |
| btrfs_set_file_extent_offset(leaf, fi, split - orig_offset); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| extent_end - split); |
| btrfs_mark_buffer_dirty(trans, leaf); |
| |
| ref.action = BTRFS_ADD_DELAYED_REF; |
| ref.bytenr = bytenr; |
| ref.num_bytes = num_bytes; |
| ref.parent = 0; |
| ref.owning_root = btrfs_root_id(root); |
| ref.ref_root = btrfs_root_id(root); |
| btrfs_init_data_ref(&ref, ino, orig_offset, 0, false); |
| ret = btrfs_inc_extent_ref(trans, &ref); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| |
| if (split == start) { |
| key.offset = start; |
| } else { |
| if (start != key.offset) { |
| ret = -EINVAL; |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| path->slots[0]--; |
| extent_end = end; |
| } |
| recow = 1; |
| } |
| |
| other_start = end; |
| other_end = 0; |
| |
| ref.action = BTRFS_DROP_DELAYED_REF; |
| ref.bytenr = bytenr; |
| ref.num_bytes = num_bytes; |
| ref.parent = 0; |
| ref.owning_root = btrfs_root_id(root); |
| ref.ref_root = btrfs_root_id(root); |
| btrfs_init_data_ref(&ref, ino, orig_offset, 0, false); |
| if (extent_mergeable(leaf, path->slots[0] + 1, |
| ino, bytenr, orig_offset, |
| &other_start, &other_end)) { |
| if (recow) { |
| btrfs_release_path(path); |
| goto again; |
| } |
| extent_end = other_end; |
| del_slot = path->slots[0] + 1; |
| del_nr++; |
| ret = btrfs_free_extent(trans, &ref); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| } |
| other_start = 0; |
| other_end = start; |
| if (extent_mergeable(leaf, path->slots[0] - 1, |
| ino, bytenr, orig_offset, |
| &other_start, &other_end)) { |
| if (recow) { |
| btrfs_release_path(path); |
| goto again; |
| } |
| key.offset = other_start; |
| del_slot = path->slots[0]; |
| del_nr++; |
| ret = btrfs_free_extent(trans, &ref); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| } |
| if (del_nr == 0) { |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_type(leaf, fi, |
| BTRFS_FILE_EXTENT_REG); |
| btrfs_set_file_extent_generation(leaf, fi, trans->transid); |
| btrfs_mark_buffer_dirty(trans, leaf); |
| } else { |
| fi = btrfs_item_ptr(leaf, del_slot - 1, |
| struct btrfs_file_extent_item); |
| btrfs_set_file_extent_type(leaf, fi, |
| BTRFS_FILE_EXTENT_REG); |
| btrfs_set_file_extent_generation(leaf, fi, trans->transid); |
| btrfs_set_file_extent_num_bytes(leaf, fi, |
| extent_end - key.offset); |
| btrfs_mark_buffer_dirty(trans, leaf); |
| |
| ret = btrfs_del_items(trans, root, path, del_slot, del_nr); |
| if (ret < 0) { |
| btrfs_abort_transaction(trans, ret); |
| goto out; |
| } |
| } |
| out: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| /* |
| * on error we return an unlocked page and the error value |
| * on success we return a locked page and 0 |
| */ |
| static int prepare_uptodate_page(struct inode *inode, |
| struct page *page, u64 pos, |
| bool force_uptodate) |
| { |
| struct folio *folio = page_folio(page); |
| int ret = 0; |
| |
| if (((pos & (PAGE_SIZE - 1)) || force_uptodate) && |
| !PageUptodate(page)) { |
| ret = btrfs_read_folio(NULL, folio); |
| if (ret) |
| return ret; |
| lock_page(page); |
| if (!PageUptodate(page)) { |
| unlock_page(page); |
| return -EIO; |
| } |
| |
| /* |
| * Since btrfs_read_folio() will unlock the folio before it |
| * returns, there is a window where btrfs_release_folio() can be |
| * called to release the page. Here we check both inode |
| * mapping and PagePrivate() to make sure the page was not |
| * released. |
| * |
| * The private flag check is essential for subpage as we need |
| * to store extra bitmap using folio private. |
| */ |
| if (page->mapping != inode->i_mapping || !folio_test_private(folio)) { |
| unlock_page(page); |
| return -EAGAIN; |
| } |
| } |
| return 0; |
| } |
| |
| static fgf_t get_prepare_fgp_flags(bool nowait) |
| { |
| fgf_t fgp_flags = FGP_LOCK | FGP_ACCESSED | FGP_CREAT; |
| |
| if (nowait) |
| fgp_flags |= FGP_NOWAIT; |
| |
| return fgp_flags; |
| } |
| |
| static gfp_t get_prepare_gfp_flags(struct inode *inode, bool nowait) |
| { |
| gfp_t gfp; |
| |
| gfp = btrfs_alloc_write_mask(inode->i_mapping); |
| if (nowait) { |
| gfp &= ~__GFP_DIRECT_RECLAIM; |
| gfp |= GFP_NOWAIT; |
| } |
| |
| return gfp; |
| } |
| |
| /* |
| * this just gets pages into the page cache and locks them down. |
| */ |
| static noinline int prepare_pages(struct inode *inode, struct page **pages, |
| size_t num_pages, loff_t pos, |
| size_t write_bytes, bool force_uptodate, |
| bool nowait) |
| { |
| int i; |
| unsigned long index = pos >> PAGE_SHIFT; |
| gfp_t mask = get_prepare_gfp_flags(inode, nowait); |
| fgf_t fgp_flags = get_prepare_fgp_flags(nowait); |
| int ret = 0; |
| int faili; |
| |
| for (i = 0; i < num_pages; i++) { |
| again: |
| pages[i] = pagecache_get_page(inode->i_mapping, index + i, |
| fgp_flags, mask | __GFP_WRITE); |
| if (!pages[i]) { |
| faili = i - 1; |
| if (nowait) |
| ret = -EAGAIN; |
| else |
| ret = -ENOMEM; |
| goto fail; |
| } |
| |
| ret = set_page_extent_mapped(pages[i]); |
| if (ret < 0) { |
| faili = i; |
| goto fail; |
| } |
| |
| if (i == 0) |
| ret = prepare_uptodate_page(inode, pages[i], pos, |
| force_uptodate); |
| if (!ret && i == num_pages - 1) |
| ret = prepare_uptodate_page(inode, pages[i], |
| pos + write_bytes, false); |
| if (ret) { |
| put_page(pages[i]); |
| if (!nowait && ret == -EAGAIN) { |
| ret = 0; |
| goto again; |
| } |
| faili = i - 1; |
| goto fail; |
| } |
| wait_on_page_writeback(pages[i]); |
| } |
| |
| return 0; |
| fail: |
| while (faili >= 0) { |
| unlock_page(pages[faili]); |
| put_page(pages[faili]); |
| faili--; |
| } |
| return ret; |
| |
| } |
| |
| /* |
| * This function locks the extent and properly waits for data=ordered extents |
| * to finish before allowing the pages to be modified if need. |
| * |
| * The return value: |
| * 1 - the extent is locked |
| * 0 - the extent is not locked, and everything is OK |
| * -EAGAIN - need re-prepare the pages |
| * the other < 0 number - Something wrong happens |
| */ |
| static noinline int |
| lock_and_cleanup_extent_if_need(struct btrfs_inode *inode, struct page **pages, |
| size_t num_pages, loff_t pos, |
| size_t write_bytes, |
| u64 *lockstart, u64 *lockend, bool nowait, |
| struct extent_state **cached_state) |
| { |
| struct btrfs_fs_info *fs_info = inode->root->fs_info; |
| u64 start_pos; |
| u64 last_pos; |
| int i; |
| int ret = 0; |
| |
| start_pos = round_down(pos, fs_info->sectorsize); |
| last_pos = round_up(pos + write_bytes, fs_info->sectorsize) - 1; |
| |
| if (start_pos < inode->vfs_inode.i_size) { |
| struct btrfs_ordered_extent *ordered; |
| |
| if (nowait) { |
| if (!try_lock_extent(&inode->io_tree, start_pos, last_pos, |
| cached_state)) { |
| for (i = 0; i < num_pages; i++) { |
| unlock_page(pages[i]); |
| put_page(pages[i]); |
| pages[i] = NULL; |
| } |
| |
| return -EAGAIN; |
| } |
| } else { |
| lock_extent(&inode->io_tree, start_pos, last_pos, cached_state); |
| } |
| |
| ordered = btrfs_lookup_ordered_range(inode, start_pos, |
| last_pos - start_pos + 1); |
| if (ordered && |
| ordered->file_offset + ordered->num_bytes > start_pos && |
| ordered->file_offset <= last_pos) { |
| unlock_extent(&inode->io_tree, start_pos, last_pos, |
| cached_state); |
| for (i = 0; i < num_pages; i++) { |
| unlock_page(pages[i]); |
| put_page(pages[i]); |
| } |
| btrfs_start_ordered_extent(ordered); |
| btrfs_put_ordered_extent(ordered); |
| return -EAGAIN; |
| } |
| if (ordered) |
| btrfs_put_ordered_extent(ordered); |
| |
| *lockstart = start_pos; |
| *lockend = last_pos; |
| ret = 1; |
| } |
| |
| /* |
| * We should be called after prepare_pages() which should have locked |
| * all pages in the range. |
| */ |
| for (i = 0; i < num_pages; i++) |
| WARN_ON(!PageLocked(pages[i])); |
| |
| return ret; |
| } |
| |
| /* |
| * Check if we can do nocow write into the range [@pos, @pos + @write_bytes) |
| * |
| * @pos: File offset. |
| * @write_bytes: The length to write, will be updated to the nocow writeable |
| * range. |
| * |
| * This function will flush ordered extents in the range to ensure proper |
| * nocow checks. |
| * |
| * Return: |
| * > 0 If we can nocow, and updates @write_bytes. |
| * 0 If we can't do a nocow write. |
| * -EAGAIN If we can't do a nocow write because snapshoting of the inode's |
| * root is in progress. |
| * < 0 If an error happened. |
| * |
| * NOTE: Callers need to call btrfs_check_nocow_unlock() if we return > 0. |
| */ |
| int btrfs_check_nocow_lock(struct btrfs_inode *inode, loff_t pos, |
| size_t *write_bytes, bool nowait) |
| { |
| struct btrfs_fs_info *fs_info = inode->root->fs_info; |
| struct btrfs_root *root = inode->root; |
| struct extent_state *cached_state = NULL; |
| u64 lockstart, lockend; |
| u64 num_bytes; |
| int ret; |
| |
| if (!(inode->flags & (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC))) |
| return 0; |
| |
| if (!btrfs_drew_try_write_lock(&root->snapshot_lock)) |
| return -EAGAIN; |
| |
| lockstart = round_down(pos, fs_info->sectorsize); |
| lockend = round_up(pos + *write_bytes, |
| fs_info->sectorsize) - 1; |
| num_bytes = lockend - lockstart + 1; |
| |
| if (nowait) { |
| if (!btrfs_try_lock_ordered_range(inode, lockstart, lockend, |
| &cached_state)) { |
| btrfs_drew_write_unlock(&root->snapshot_lock); |
| return -EAGAIN; |
| } |
| } else { |
| btrfs_lock_and_flush_ordered_range(inode, lockstart, lockend, |
| &cached_state); |
| } |
| ret = can_nocow_extent(&inode->vfs_inode, lockstart, &num_bytes, |
| NULL, nowait, false); |
| if (ret <= 0) |
| btrfs_drew_write_unlock(&root->snapshot_lock); |
| else |
| *write_bytes = min_t(size_t, *write_bytes , |
| num_bytes - pos + lockstart); |
| unlock_extent(&inode->io_tree, lockstart, lockend, &cached_state); |
| |
| return ret; |
| } |
| |
| void btrfs_check_nocow_unlock(struct btrfs_inode *inode) |
| { |
| btrfs_drew_write_unlock(&inode->root->snapshot_lock); |
| } |
| |
| static void update_time_for_write(struct inode *inode) |
| { |
| struct timespec64 now, ts; |
| |
| if (IS_NOCMTIME(inode)) |
| return; |
| |
| now = current_time(inode); |
| ts = inode_get_mtime(inode); |
| if (!timespec64_equal(&ts, &now)) |
| inode_set_mtime_to_ts(inode, now); |
| |
| ts = inode_get_ctime(inode); |
| if (!timespec64_equal(&ts, &now)) |
| inode_set_ctime_to_ts(inode, now); |
| |
| if (IS_I_VERSION(inode)) |
| inode_inc_iversion(inode); |
| } |
| |
| int btrfs_write_check(struct kiocb *iocb, struct iov_iter *from, size_t count) |
| { |
| struct file *file = iocb->ki_filp; |
| struct inode *inode = file_inode(file); |
| struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); |
| loff_t pos = iocb->ki_pos; |
| int ret; |
| loff_t oldsize; |
| loff_t start_pos; |
| |
| /* |
| * Quickly bail out on NOWAIT writes if we don't have the nodatacow or |
| * prealloc flags, as without those flags we always have to COW. We will |
| * later check if we can really COW into the target range (using |
| * can_nocow_extent() at btrfs_get_blocks_direct_write()). |
| */ |
| if ((iocb->ki_flags & IOCB_NOWAIT) && |
| !(BTRFS_I(inode)->flags & (BTRFS_INODE_NODATACOW | BTRFS_INODE_PREALLOC))) |
| return -EAGAIN; |
| |
| ret = file_remove_privs(file); |
| if (ret) |
| return ret; |
| |
| /* |
| * We reserve space for updating the inode when we reserve space for the |
| * extent we are going to write, so we will enospc out there. We don't |
| * need to start yet another transaction to update the inode as we will |
| * update the inode when we finish writing whatever data we write. |
| */ |
| update_time_for_write(inode); |
| |
| start_pos = round_down(pos, fs_info->sectorsize); |
| oldsize = i_size_read(inode); |
| if (start_pos > oldsize) { |
| /* Expand hole size to cover write data, preventing empty gap */ |
| loff_t end_pos = round_up(pos + count, fs_info->sectorsize); |
| |
| ret = btrfs_cont_expand(BTRFS_I(inode), oldsize, end_pos); |
| if (ret) |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| ssize_t btrfs_buffered_write(struct kiocb *iocb, struct iov_iter *i) |
| { |
| struct file *file = iocb->ki_filp; |
| loff_t pos; |
| struct inode *inode = file_inode(file); |
| struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); |
| struct page **pages = NULL; |
| struct extent_changeset *data_reserved = NULL; |
| u64 release_bytes = 0; |
| u64 lockstart; |
| u64 lockend; |
| size_t num_written = 0; |
| int nrptrs; |
| ssize_t ret; |
| bool only_release_metadata = false; |
| bool force_page_uptodate = false; |
| loff_t old_isize = i_size_read(inode); |
| unsigned int ilock_flags = 0; |
| const bool nowait = (iocb->ki_flags & IOCB_NOWAIT); |
| unsigned int bdp_flags = (nowait ? BDP_ASYNC : 0); |
| |
| if (nowait) |
| ilock_flags |= BTRFS_ILOCK_TRY; |
| |
| ret = btrfs_inode_lock(BTRFS_I(inode), ilock_flags); |
| if (ret < 0) |
| return ret; |
| |
| ret = generic_write_checks(iocb, i); |
| if (ret <= 0) |
| goto out; |
| |
| ret = btrfs_write_check(iocb, i, ret); |
| if (ret < 0) |
| goto out; |
| |
| pos = iocb->ki_pos; |
| nrptrs = min(DIV_ROUND_UP(iov_iter_count(i), PAGE_SIZE), |
| PAGE_SIZE / (sizeof(struct page *))); |
| nrptrs = min(nrptrs, current->nr_dirtied_pause - current->nr_dirtied); |
| nrptrs = max(nrptrs, 8); |
| pages = kmalloc_array(nrptrs, sizeof(struct page *), GFP_KERNEL); |
| if (!pages) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| while (iov_iter_count(i) > 0) { |
| struct extent_state *cached_state = NULL; |
| size_t offset = offset_in_page(pos); |
| size_t sector_offset; |
| size_t write_bytes = min(iov_iter_count(i), |
| nrptrs * (size_t)PAGE_SIZE - |
| offset); |
| size_t num_pages; |
| size_t reserve_bytes; |
| size_t dirty_pages; |
| size_t copied; |
| size_t dirty_sectors; |
| size_t num_sectors; |
| int extents_locked; |
| |
| /* |
| * Fault pages before locking them in prepare_pages |
| * to avoid recursive lock |
| */ |
| if (unlikely(fault_in_iov_iter_readable(i, write_bytes))) { |
| ret = -EFAULT; |
| break; |
| } |
| |
| only_release_metadata = false; |
| sector_offset = pos & (fs_info->sectorsize - 1); |
| |
| extent_changeset_release(data_reserved); |
| ret = btrfs_check_data_free_space(BTRFS_I(inode), |
| &data_reserved, pos, |
| write_bytes, nowait); |
| if (ret < 0) { |
| int can_nocow; |
| |
| if (nowait && (ret == -ENOSPC || ret == -EAGAIN)) { |
| ret = -EAGAIN; |
| break; |
| } |
| |
| /* |
| * If we don't have to COW at the offset, reserve |
| * metadata only. write_bytes may get smaller than |
| * requested here. |
| */ |
| can_nocow = btrfs_check_nocow_lock(BTRFS_I(inode), pos, |
| &write_bytes, nowait); |
| if (can_nocow < 0) |
| ret = can_nocow; |
| if (can_nocow > 0) |
| ret = 0; |
| if (ret) |
| break; |
| only_release_metadata = true; |
| } |
| |
| num_pages = DIV_ROUND_UP(write_bytes + offset, PAGE_SIZE); |
| WARN_ON(num_pages > nrptrs); |
| reserve_bytes = round_up(write_bytes + sector_offset, |
| fs_info->sectorsize); |
| WARN_ON(reserve_bytes == 0); |
| ret = btrfs_delalloc_reserve_metadata(BTRFS_I(inode), |
| reserve_bytes, |
| reserve_bytes, nowait); |
| if (ret) { |
| if (!only_release_metadata) |
| btrfs_free_reserved_data_space(BTRFS_I(inode), |
| data_reserved, pos, |
| write_bytes); |
| else |
| btrfs_check_nocow_unlock(BTRFS_I(inode)); |
| |
| if (nowait && ret == -ENOSPC) |
| ret = -EAGAIN; |
| break; |
| } |
| |
| release_bytes = reserve_bytes; |
| again: |
| ret = balance_dirty_pages_ratelimited_flags(inode->i_mapping, bdp_flags); |
| if (ret) { |
| btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes); |
| break; |
| } |
| |
| /* |
| * This is going to setup the pages array with the number of |
| * pages we want, so we don't really need to worry about the |
| * contents of pages from loop to loop |
| */ |
| ret = prepare_pages(inode, pages, num_pages, |
| pos, write_bytes, force_page_uptodate, false); |
| if (ret) { |
| btrfs_delalloc_release_extents(BTRFS_I(inode), |
| reserve_bytes); |
| break; |
| } |
| |
| extents_locked = lock_and_cleanup_extent_if_need( |
| BTRFS_I(inode), pages, |
| num_pages, pos, write_bytes, &lockstart, |
| &lockend, nowait, &cached_state); |
| if (extents_locked < 0) { |
| if (!nowait && extents_locked == -EAGAIN) |
| goto again; |
| |
| btrfs_delalloc_release_extents(BTRFS_I(inode), |
| reserve_bytes); |
| ret = extents_locked; |
| break; |
| } |
| |
| copied = btrfs_copy_from_user(pos, write_bytes, pages, i); |
| |
| num_sectors = BTRFS_BYTES_TO_BLKS(fs_info, reserve_bytes); |
| dirty_sectors = round_up(copied + sector_offset, |
| fs_info->sectorsize); |
| dirty_sectors = BTRFS_BYTES_TO_BLKS(fs_info, dirty_sectors); |
| |
| /* |
| * if we have trouble faulting in the pages, fall |
| * back to one page at a time |
| */ |
| if (copied < write_bytes) |
| nrptrs = 1; |
| |
| if (copied == 0) { |
| force_page_uptodate = true; |
| dirty_sectors = 0; |
| dirty_pages = 0; |
| } else { |
| force_page_uptodate = false; |
| dirty_pages = DIV_ROUND_UP(copied + offset, |
| PAGE_SIZE); |
| } |
| |
| if (num_sectors > dirty_sectors) { |
| /* release everything except the sectors we dirtied */ |
| release_bytes -= dirty_sectors << fs_info->sectorsize_bits; |
| if (only_release_metadata) { |
| btrfs_delalloc_release_metadata(BTRFS_I(inode), |
| release_bytes, true); |
| } else { |
| u64 __pos; |
| |
| __pos = round_down(pos, |
| fs_info->sectorsize) + |
| (dirty_pages << PAGE_SHIFT); |
| btrfs_delalloc_release_space(BTRFS_I(inode), |
| data_reserved, __pos, |
| release_bytes, true); |
| } |
| } |
| |
| release_bytes = round_up(copied + sector_offset, |
| fs_info->sectorsize); |
| |
| ret = btrfs_dirty_pages(BTRFS_I(inode), pages, |
| dirty_pages, pos, copied, |
| &cached_state, only_release_metadata); |
| |
| /* |
| * If we have not locked the extent range, because the range's |
| * start offset is >= i_size, we might still have a non-NULL |
| * cached extent state, acquired while marking the extent range |
| * as delalloc through btrfs_dirty_pages(). Therefore free any |
| * possible cached extent state to avoid a memory leak. |
| */ |
| if (extents_locked) |
| unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, |
| lockend, &cached_state); |
| else |
| free_extent_state(cached_state); |
| |
| btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes); |
| if (ret) { |
| btrfs_drop_pages(fs_info, pages, num_pages, pos, copied); |
| break; |
| } |
| |
| release_bytes = 0; |
| if (only_release_metadata) |
| btrfs_check_nocow_unlock(BTRFS_I(inode)); |
| |
| btrfs_drop_pages(fs_info, pages, num_pages, pos, copied); |
| |
| cond_resched(); |
| |
| pos += copied; |
| num_written += copied; |
| } |
| |
| kfree(pages); |
| |
| if (release_bytes) { |
| if (only_release_metadata) { |
| btrfs_check_nocow_unlock(BTRFS_I(inode)); |
| btrfs_delalloc_release_metadata(BTRFS_I(inode), |
| release_bytes, true); |
| } else { |
| btrfs_delalloc_release_space(BTRFS_I(inode), |
| data_reserved, |
| round_down(pos, fs_info->sectorsize), |
| release_bytes, true); |
| } |
| } |
| |
| extent_changeset_free(data_reserved); |
| if (num_written > 0) { |
| pagecache_isize_extended(inode, old_isize, iocb->ki_pos); |
| iocb->ki_pos += num_written; |
| } |
| out: |
| btrfs_inode_unlock(BTRFS_I(inode), ilock_flags); |
| return num_written ? num_written : ret; |
| } |
| |
| static ssize_t btrfs_encoded_write(struct kiocb *iocb, struct iov_iter *from, |
| const struct btrfs_ioctl_encoded_io_args *encoded) |
| { |
| struct file *file = iocb->ki_filp; |
| struct inode *inode = file_inode(file); |
| loff_t count; |
| ssize_t ret; |
| |
| btrfs_inode_lock(BTRFS_I(inode), 0); |
| count = encoded->len; |
| ret = generic_write_checks_count(iocb, &count); |
| if (ret == 0 && count != encoded->len) { |
| /* |
| * The write got truncated by generic_write_checks_count(). We |
| * can't do a partial encoded write. |
| */ |
| ret = -EFBIG; |
| } |
| if (ret || encoded->len == 0) |
| goto out; |
| |
| ret = btrfs_write_check(iocb, from, encoded->len); |
| if (ret < 0) |
| goto out; |
| |
| ret = btrfs_do_encoded_write(iocb, from, encoded); |
| out: |
| btrfs_inode_unlock(BTRFS_I(inode), 0); |
| return ret; |
| } |
| |
| ssize_t btrfs_do_write_iter(struct kiocb *iocb, struct iov_iter *from, |
| const struct btrfs_ioctl_encoded_io_args *encoded) |
| { |
| struct file *file = iocb->ki_filp; |
| struct btrfs_inode *inode = BTRFS_I(file_inode(file)); |
| ssize_t num_written, num_sync; |
| |
| /* |
| * If the fs flips readonly due to some impossible error, although we |
| * have opened a file as writable, we have to stop this write operation |
| * to ensure consistency. |
| */ |
| if (BTRFS_FS_ERROR(inode->root->fs_info)) |
| return -EROFS; |
| |
| if (encoded && (iocb->ki_flags & IOCB_NOWAIT)) |
| return -EOPNOTSUPP; |
| |
| if (encoded) { |
| num_written = btrfs_encoded_write(iocb, from, encoded); |
| num_sync = encoded->len; |
| } else if (iocb->ki_flags & IOCB_DIRECT) { |
| num_written = btrfs_direct_write(iocb, from); |
| num_sync = num_written; |
| } else { |
| num_written = btrfs_buffered_write(iocb, from); |
| num_sync = num_written; |
| } |
| |
| btrfs_set_inode_last_sub_trans(inode); |
| |
| if (num_sync > 0) { |
| num_sync = generic_write_sync(iocb, num_sync); |
| if (num_sync < 0) |
| num_written = num_sync; |
| } |
| |
| return num_written; |
| } |
| |
| static ssize_t btrfs_file_write_iter(struct kiocb *iocb, struct iov_iter *from) |
| { |
| return btrfs_do_write_iter(iocb, from, NULL); |
| } |
| |
| int btrfs_release_file(struct inode *inode, struct file *filp) |
| { |
| struct btrfs_file_private *private = filp->private_data; |
| |
| if (private) { |
| kfree(private->filldir_buf); |
| free_extent_state(private->llseek_cached_state); |
| kfree(private); |
| filp->private_data = NULL; |
| } |
| |
| /* |
| * Set by setattr when we are about to truncate a file from a non-zero |
| * size to a zero size. This tries to flush down new bytes that may |
| * have been written if the application were using truncate to replace |
| * a file in place. |
| */ |
| if (test_and_clear_bit(BTRFS_INODE_FLUSH_ON_CLOSE, |
| &BTRFS_I(inode)->runtime_flags)) |
| filemap_flush(inode->i_mapping); |
| return 0; |
| } |
| |
| static int start_ordered_ops(struct btrfs_inode *inode, loff_t start, loff_t end) |
| { |
| int ret; |
| struct blk_plug plug; |
| |
| /* |
| * This is only called in fsync, which would do synchronous writes, so |
| * a plug can merge adjacent IOs as much as possible. Esp. in case of |
| * multiple disks using raid profile, a large IO can be split to |
| * several segments of stripe length (currently 64K). |
| */ |
| blk_start_plug(&plug); |
| ret = btrfs_fdatawrite_range(inode, start, end); |
| blk_finish_plug(&plug); |
| |
| return ret; |
| } |
| |
| static inline bool skip_inode_logging(const struct btrfs_log_ctx *ctx) |
| { |
| struct btrfs_inode *inode = ctx->inode; |
| struct btrfs_fs_info *fs_info = inode->root->fs_info; |
| |
| if (btrfs_inode_in_log(inode, btrfs_get_fs_generation(fs_info)) && |
| list_empty(&ctx->ordered_extents)) |
| return true; |
| |
| /* |
| * If we are doing a fast fsync we can not bail out if the inode's |
| * last_trans is <= then the last committed transaction, because we only |
| * update the last_trans of the inode during ordered extent completion, |
| * and for a fast fsync we don't wait for that, we only wait for the |
| * writeback to complete. |
| */ |
| if (inode->last_trans <= btrfs_get_last_trans_committed(fs_info) && |
| (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags) || |
| list_empty(&ctx->ordered_extents))) |
| return true; |
| |
| return false; |
| } |
| |
| /* |
| * fsync call for both files and directories. This logs the inode into |
| * the tree log instead of forcing full commits whenever possible. |
| * |
| * It needs to call filemap_fdatawait so that all ordered extent updates are |
| * in the metadata btree are up to date for copying to the log. |
| * |
| * It drops the inode mutex before doing the tree log commit. This is an |
| * important optimization for directories because holding the mutex prevents |
| * new operations on the dir while we write to disk. |
| */ |
| int btrfs_sync_file(struct file *file, loff_t start, loff_t end, int datasync) |
| { |
| struct dentry *dentry = file_dentry(file); |
| struct btrfs_inode *inode = BTRFS_I(d_inode(dentry)); |
| struct btrfs_root *root = inode->root; |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| struct btrfs_trans_handle *trans; |
| struct btrfs_log_ctx ctx; |
| int ret = 0, err; |
| u64 len; |
| bool full_sync; |
| |
| trace_btrfs_sync_file(file, datasync); |
| |
| btrfs_init_log_ctx(&ctx, inode); |
| |
| /* |
| * Always set the range to a full range, otherwise we can get into |
| * several problems, from missing file extent items to represent holes |
| * when not using the NO_HOLES feature, to log tree corruption due to |
| * races between hole detection during logging and completion of ordered |
| * extents outside the range, to missing checksums due to ordered extents |
| * for which we flushed only a subset of their pages. |
| */ |
| start = 0; |
| end = LLONG_MAX; |
| len = (u64)LLONG_MAX + 1; |
| |
| /* |
| * We write the dirty pages in the range and wait until they complete |
| * out of the ->i_mutex. If so, we can flush the dirty pages by |
| * multi-task, and make the performance up. See |
| * btrfs_wait_ordered_range for an explanation of the ASYNC check. |
| */ |
| ret = start_ordered_ops(inode, start, end); |
| if (ret) |
| goto out; |
| |
| btrfs_inode_lock(inode, BTRFS_ILOCK_MMAP); |
| |
| atomic_inc(&root->log_batch); |
| |
| /* |
| * Before we acquired the inode's lock and the mmap lock, someone may |
| * have dirtied more pages in the target range. We need to make sure |
| * that writeback for any such pages does not start while we are logging |
| * the inode, because if it does, any of the following might happen when |
| * we are not doing a full inode sync: |
| * |
| * 1) We log an extent after its writeback finishes but before its |
| * checksums are added to the csum tree, leading to -EIO errors |
| * when attempting to read the extent after a log replay. |
| * |
| * 2) We can end up logging an extent before its writeback finishes. |
| * Therefore after the log replay we will have a file extent item |
| * pointing to an unwritten extent (and no data checksums as well). |
| * |
| * So trigger writeback for any eventual new dirty pages and then we |
| * wait for all ordered extents to complete below. |
| */ |
| ret = start_ordered_ops(inode, start, end); |
| if (ret) { |
| btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP); |
| goto out; |
| } |
| |
| /* |
| * Always check for the full sync flag while holding the inode's lock, |
| * to avoid races with other tasks. The flag must be either set all the |
| * time during logging or always off all the time while logging. |
| * We check the flag here after starting delalloc above, because when |
| * running delalloc the full sync flag may be set if we need to drop |
| * extra extent map ranges due to temporary memory allocation failures. |
| */ |
| full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags); |
| |
| /* |
| * We have to do this here to avoid the priority inversion of waiting on |
| * IO of a lower priority task while holding a transaction open. |
| * |
| * For a full fsync we wait for the ordered extents to complete while |
| * for a fast fsync we wait just for writeback to complete, and then |
| * attach the ordered extents to the transaction so that a transaction |
| * commit waits for their completion, to avoid data loss if we fsync, |
| * the current transaction commits before the ordered extents complete |
| * and a power failure happens right after that. |
| * |
| * For zoned filesystem, if a write IO uses a ZONE_APPEND command, the |
| * logical address recorded in the ordered extent may change. We need |
| * to wait for the IO to stabilize the logical address. |
| */ |
| if (full_sync || btrfs_is_zoned(fs_info)) { |
| ret = btrfs_wait_ordered_range(inode, start, len); |
| clear_bit(BTRFS_INODE_COW_WRITE_ERROR, &inode->runtime_flags); |
| } else { |
| /* |
| * Get our ordered extents as soon as possible to avoid doing |
| * checksum lookups in the csum tree, and use instead the |
| * checksums attached to the ordered extents. |
| */ |
| btrfs_get_ordered_extents_for_logging(inode, &ctx.ordered_extents); |
| ret = filemap_fdatawait_range(inode->vfs_inode.i_mapping, start, end); |
| if (ret) |
| goto out_release_extents; |
| |
| /* |
| * Check and clear the BTRFS_INODE_COW_WRITE_ERROR now after |
| * starting and waiting for writeback, because for buffered IO |
| * it may have been set during the end IO callback |
| * (end_bbio_data_write() -> btrfs_finish_ordered_extent()) in |
| * case an error happened and we need to wait for ordered |
| * extents to complete so that any extent maps that point to |
| * unwritten locations are dropped and we don't log them. |
| */ |
| if (test_and_clear_bit(BTRFS_INODE_COW_WRITE_ERROR, &inode->runtime_flags)) |
| ret = btrfs_wait_ordered_range(inode, start, len); |
| } |
| |
| if (ret) |
| goto out_release_extents; |
| |
| atomic_inc(&root->log_batch); |
| |
| if (skip_inode_logging(&ctx)) { |
| /* |
| * We've had everything committed since the last time we were |
| * modified so clear this flag in case it was set for whatever |
| * reason, it's no longer relevant. |
| */ |
| clear_bit(BTRFS_INODE_NEEDS_FULL_SYNC, &inode->runtime_flags); |
| /* |
| * An ordered extent might have started before and completed |
| * already with io errors, in which case the inode was not |
| * updated and we end up here. So check the inode's mapping |
| * for any errors that might have happened since we last |
| * checked called fsync. |
| */ |
| ret = filemap_check_wb_err(inode->vfs_inode.i_mapping, file->f_wb_err); |
| goto out_release_extents; |
| } |
| |
| btrfs_init_log_ctx_scratch_eb(&ctx); |
| |
| /* |
| * We use start here because we will need to wait on the IO to complete |
| * in btrfs_sync_log, which could require joining a transaction (for |
| * example checking cross references in the nocow path). If we use join |
| * here we could get into a situation where we're waiting on IO to |
| * happen that is blocked on a transaction trying to commit. With start |
| * we inc the extwriter counter, so we wait for all extwriters to exit |
| * before we start blocking joiners. This comment is to keep somebody |
| * from thinking they are super smart and changing this to |
| * btrfs_join_transaction *cough*Josef*cough*. |
| */ |
| trans = btrfs_start_transaction(root, 0); |
| if (IS_ERR(trans)) { |
| ret = PTR_ERR(trans); |
| goto out_release_extents; |
| } |
| trans->in_fsync = true; |
| |
| ret = btrfs_log_dentry_safe(trans, dentry, &ctx); |
| /* |
| * Scratch eb no longer needed, release before syncing log or commit |
| * transaction, to avoid holding unnecessary memory during such long |
| * operations. |
| */ |
| if (ctx.scratch_eb) { |
| free_extent_buffer(ctx.scratch_eb); |
| ctx.scratch_eb = NULL; |
| } |
| btrfs_release_log_ctx_extents(&ctx); |
| if (ret < 0) { |
| /* Fallthrough and commit/free transaction. */ |
| ret = BTRFS_LOG_FORCE_COMMIT; |
| } |
| |
| /* we've logged all the items and now have a consistent |
| * version of the file in the log. It is possible that |
| * someone will come in and modify the file, but that's |
| * fine because the log is consistent on disk, and we |
| * have references to all of the file's extents |
| * |
| * It is possible that someone will come in and log the |
| * file again, but that will end up using the synchronization |
| * inside btrfs_sync_log to keep things safe. |
| */ |
| btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP); |
| |
| if (ret == BTRFS_NO_LOG_SYNC) { |
| ret = btrfs_end_transaction(trans); |
| goto out; |
| } |
| |
| /* We successfully logged the inode, attempt to sync the log. */ |
| if (!ret) { |
| ret = btrfs_sync_log(trans, root, &ctx); |
| if (!ret) { |
| ret = btrfs_end_transaction(trans); |
| goto out; |
| } |
| } |
| |
| /* |
| * At this point we need to commit the transaction because we had |
| * btrfs_need_log_full_commit() or some other error. |
| * |
| * If we didn't do a full sync we have to stop the trans handle, wait on |
| * the ordered extents, start it again and commit the transaction. If |
| * we attempt to wait on the ordered extents here we could deadlock with |
| * something like fallocate() that is holding the extent lock trying to |
| * start a transaction while some other thread is trying to commit the |
| * transaction while we (fsync) are currently holding the transaction |
| * open. |
| */ |
| if (!full_sync) { |
| ret = btrfs_end_transaction(trans); |
| if (ret) |
| goto out; |
| ret = btrfs_wait_ordered_range(inode, start, len); |
| if (ret) |
| goto out; |
| |
| /* |
| * This is safe to use here because we're only interested in |
| * making sure the transaction that had the ordered extents is |
| * committed. We aren't waiting on anything past this point, |
| * we're purely getting the transaction and committing it. |
| */ |
| trans = btrfs_attach_transaction_barrier(root); |
| if (IS_ERR(trans)) { |
| ret = PTR_ERR(trans); |
| |
| /* |
| * We committed the transaction and there's no currently |
| * running transaction, this means everything we care |
| * about made it to disk and we are done. |
| */ |
| if (ret == -ENOENT) |
| ret = 0; |
| goto out; |
| } |
| } |
| |
| ret = btrfs_commit_transaction(trans); |
| out: |
| free_extent_buffer(ctx.scratch_eb); |
| ASSERT(list_empty(&ctx.list)); |
| ASSERT(list_empty(&ctx.conflict_inodes)); |
| err = file_check_and_advance_wb_err(file); |
| if (!ret) |
| ret = err; |
| return ret > 0 ? -EIO : ret; |
| |
| out_release_extents: |
| btrfs_release_log_ctx_extents(&ctx); |
| btrfs_inode_unlock(inode, BTRFS_ILOCK_MMAP); |
| goto out; |
| } |
| |
| /* |
| * btrfs_page_mkwrite() is not allowed to change the file size as it gets |
| * called from a page fault handler when a page is first dirtied. Hence we must |
| * be careful to check for EOF conditions here. We set the page up correctly |
| * for a written page which means we get ENOSPC checking when writing into |
| * holes and correct delalloc and unwritten extent mapping on filesystems that |
| * support these features. |
| * |
| * We are not allowed to take the i_mutex here so we have to play games to |
| * protect against truncate races as the page could now be beyond EOF. Because |
| * truncate_setsize() writes the inode size before removing pages, once we have |
| * the page lock we can determine safely if the page is beyond EOF. If it is not |
| * beyond EOF, then the page is guaranteed safe against truncation until we |
| * unlock the page. |
| */ |
| static vm_fault_t btrfs_page_mkwrite(struct vm_fault *vmf) |
| { |
| struct page *page = vmf->page; |
| struct folio *folio = page_folio(page); |
| struct inode *inode = file_inode(vmf->vma->vm_file); |
| struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); |
| struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; |
| struct btrfs_ordered_extent *ordered; |
| struct extent_state *cached_state = NULL; |
| struct extent_changeset *data_reserved = NULL; |
| unsigned long zero_start; |
| loff_t size; |
| vm_fault_t ret; |
| int ret2; |
| int reserved = 0; |
| u64 reserved_space; |
| u64 page_start; |
| u64 page_end; |
| u64 end; |
| |
| ASSERT(folio_order(folio) == 0); |
| |
| reserved_space = PAGE_SIZE; |
| |
| sb_start_pagefault(inode->i_sb); |
| page_start = page_offset(page); |
| page_end = page_start + PAGE_SIZE - 1; |
| end = page_end; |
| |
| /* |
| * Reserving delalloc space after obtaining the page lock can lead to |
| * deadlock. For example, if a dirty page is locked by this function |
| * and the call to btrfs_delalloc_reserve_space() ends up triggering |
| * dirty page write out, then the btrfs_writepages() function could |
| * end up waiting indefinitely to get a lock on the page currently |
| * being processed by btrfs_page_mkwrite() function. |
| */ |
| ret2 = btrfs_delalloc_reserve_space(BTRFS_I(inode), &data_reserved, |
| page_start, reserved_space); |
| if (!ret2) { |
| ret2 = file_update_time(vmf->vma->vm_file); |
| reserved = 1; |
| } |
| if (ret2) { |
| ret = vmf_error(ret2); |
| if (reserved) |
| goto out; |
| goto out_noreserve; |
| } |
| |
| /* Make the VM retry the fault. */ |
| ret = VM_FAULT_NOPAGE; |
| again: |
| down_read(&BTRFS_I(inode)->i_mmap_lock); |
| lock_page(page); |
| size = i_size_read(inode); |
| |
| if ((page->mapping != inode->i_mapping) || |
| (page_start >= size)) { |
| /* Page got truncated out from underneath us. */ |
| goto out_unlock; |
| } |
| wait_on_page_writeback(page); |
| |
| lock_extent(io_tree, page_start, page_end, &cached_state); |
| ret2 = set_page_extent_mapped(page); |
| if (ret2 < 0) { |
| ret = vmf_error(ret2); |
| unlock_extent(io_tree, page_start, page_end, &cached_state); |
| goto out_unlock; |
| } |
| |
| /* |
| * We can't set the delalloc bits if there are pending ordered |
| * extents. Drop our locks and wait for them to finish. |
| */ |
| ordered = btrfs_lookup_ordered_range(BTRFS_I(inode), page_start, PAGE_SIZE); |
| if (ordered) { |
| unlock_extent(io_tree, page_start, page_end, &cached_state); |
| unlock_page(page); |
| up_read(&BTRFS_I(inode)->i_mmap_lock); |
| btrfs_start_ordered_extent(ordered); |
| btrfs_put_ordered_extent(ordered); |
| goto again; |
| } |
| |
| if (page->index == ((size - 1) >> PAGE_SHIFT)) { |
| reserved_space = round_up(size - page_start, fs_info->sectorsize); |
| if (reserved_space < PAGE_SIZE) { |
| end = page_start + reserved_space - 1; |
| btrfs_delalloc_release_space(BTRFS_I(inode), |
| data_reserved, page_start, |
| PAGE_SIZE - reserved_space, true); |
| } |
| } |
| |
| /* |
| * page_mkwrite gets called when the page is firstly dirtied after it's |
| * faulted in, but write(2) could also dirty a page and set delalloc |
| * bits, thus in this case for space account reason, we still need to |
| * clear any delalloc bits within this page range since we have to |
| * reserve data&meta space before lock_page() (see above comments). |
| */ |
| clear_extent_bit(&BTRFS_I(inode)->io_tree, page_start, end, |
| EXTENT_DELALLOC | EXTENT_DO_ACCOUNTING | |
| EXTENT_DEFRAG, &cached_state); |
| |
| ret2 = btrfs_set_extent_delalloc(BTRFS_I(inode), page_start, end, 0, |
| &cached_state); |
| if (ret2) { |
| unlock_extent(io_tree, page_start, page_end, &cached_state); |
| ret = VM_FAULT_SIGBUS; |
| goto out_unlock; |
| } |
| |
| /* Page is wholly or partially inside EOF. */ |
| if (page_start + PAGE_SIZE > size) |
| zero_start = offset_in_page(size); |
| else |
| zero_start = PAGE_SIZE; |
| |
| if (zero_start != PAGE_SIZE) |
| memzero_page(page, zero_start, PAGE_SIZE - zero_start); |
| |
| btrfs_folio_clear_checked(fs_info, folio, page_start, PAGE_SIZE); |
| btrfs_folio_set_dirty(fs_info, folio, page_start, end + 1 - page_start); |
| btrfs_folio_set_uptodate(fs_info, folio, page_start, end + 1 - page_start); |
| |
| btrfs_set_inode_last_sub_trans(BTRFS_I(inode)); |
| |
| unlock_extent(io_tree, page_start, page_end, &cached_state); |
| up_read(&BTRFS_I(inode)->i_mmap_lock); |
| |
| btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE); |
| sb_end_pagefault(inode->i_sb); |
| extent_changeset_free(data_reserved); |
| return VM_FAULT_LOCKED; |
| |
| out_unlock: |
| unlock_page(page); |
| up_read(&BTRFS_I(inode)->i_mmap_lock); |
| out: |
| btrfs_delalloc_release_extents(BTRFS_I(inode), PAGE_SIZE); |
| btrfs_delalloc_release_space(BTRFS_I(inode), data_reserved, page_start, |
| reserved_space, (ret != 0)); |
| out_noreserve: |
| sb_end_pagefault(inode->i_sb); |
| extent_changeset_free(data_reserved); |
| return ret; |
| } |
| |
| static const struct vm_operations_struct btrfs_file_vm_ops = { |
| .fault = filemap_fault, |
| .map_pages = filemap_map_pages, |
| .page_mkwrite = btrfs_page_mkwrite, |
| }; |
| |
| static int btrfs_file_mmap(struct file *filp, struct vm_area_struct *vma) |
| { |
| struct address_space *mapping = filp->f_mapping; |
| |
| if (!mapping->a_ops->read_folio) |
| return -ENOEXEC; |
| |
| file_accessed(filp); |
| vma->vm_ops = &btrfs_file_vm_ops; |
| |
| return 0; |
| } |
| |
| static int hole_mergeable(struct btrfs_inode *inode, struct extent_buffer *leaf, |
| int slot, u64 start, u64 end) |
| { |
| struct btrfs_file_extent_item *fi; |
| struct btrfs_key key; |
| |
| if (slot < 0 || slot >= btrfs_header_nritems(leaf)) |
| return 0; |
| |
| btrfs_item_key_to_cpu(leaf, &key, slot); |
| if (key.objectid != btrfs_ino(inode) || |
| key.type != BTRFS_EXTENT_DATA_KEY) |
| return 0; |
| |
| fi = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); |
| |
| if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG) |
| return 0; |
| |
| if (btrfs_file_extent_disk_bytenr(leaf, fi)) |
| return 0; |
| |
| if (key.offset == end) |
| return 1; |
| if (key.offset + btrfs_file_extent_num_bytes(leaf, fi) == start) |
| return 1; |
| return 0; |
| } |
| |
| static int fill_holes(struct btrfs_trans_handle *trans, |
| struct btrfs_inode *inode, |
| struct btrfs_path *path, u64 offset, u64 end) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_root *root = inode->root; |
| struct extent_buffer *leaf; |
| struct btrfs_file_extent_item *fi; |
| struct extent_map *hole_em; |
| struct btrfs_key key; |
| int ret; |
| |
| if (btrfs_fs_incompat(fs_info, NO_HOLES)) |
| goto out; |
| |
| key.objectid = btrfs_ino(inode); |
| key.type = BTRFS_EXTENT_DATA_KEY; |
| key.offset = offset; |
| |
| ret = btrfs_search_slot(trans, root, &key, path, 0, 1); |
| if (ret <= 0) { |
| /* |
| * We should have dropped this offset, so if we find it then |
| * something has gone horribly wrong. |
| */ |
| if (ret == 0) |
| ret = -EINVAL; |
| return ret; |
| } |
| |
| leaf = path->nodes[0]; |
| if (hole_mergeable(inode, leaf, path->slots[0] - 1, offset, end)) { |
| u64 num_bytes; |
| |
| path->slots[0]--; |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + |
| end - offset; |
| btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); |
| btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes); |
| btrfs_set_file_extent_offset(leaf, fi, 0); |
| btrfs_set_file_extent_generation(leaf, fi, trans->transid); |
| btrfs_mark_buffer_dirty(trans, leaf); |
| goto out; |
| } |
| |
| if (hole_mergeable(inode, leaf, path->slots[0], offset, end)) { |
| u64 num_bytes; |
| |
| key.offset = offset; |
| btrfs_set_item_key_safe(trans, path, &key); |
| fi = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_file_extent_item); |
| num_bytes = btrfs_file_extent_num_bytes(leaf, fi) + end - |
| offset; |
| btrfs_set_file_extent_num_bytes(leaf, fi, num_bytes); |
| btrfs_set_file_extent_ram_bytes(leaf, fi, num_bytes); |
| btrfs_set_file_extent_offset(leaf, fi, 0); |
| btrfs_set_file_extent_generation(leaf, fi, trans->transid); |
| btrfs_mark_buffer_dirty(trans, leaf); |
| goto out; |
| } |
| btrfs_release_path(path); |
| |
| ret = btrfs_insert_hole_extent(trans, root, btrfs_ino(inode), offset, |
| end - offset); |
| if (ret) |
| return ret; |
| |
| out: |
| btrfs_release_path(path); |
| |
| hole_em = alloc_extent_map(); |
| if (!hole_em) { |
| btrfs_drop_extent_map_range(inode, offset, end - 1, false); |
| btrfs_set_inode_full_sync(inode); |
| } else { |
| hole_em->start = offset; |
| hole_em->len = end - offset; |
| hole_em->ram_bytes = hole_em->len; |
| |
| hole_em->disk_bytenr = EXTENT_MAP_HOLE; |
| hole_em->disk_num_bytes = 0; |
| hole_em->generation = trans->transid; |
| |
| ret = btrfs_replace_extent_map_range(inode, hole_em, true); |
| free_extent_map(hole_em); |
| if (ret) |
| btrfs_set_inode_full_sync(inode); |
| } |
| |
| return 0; |
| } |
| |
| /* |
| * Find a hole extent on given inode and change start/len to the end of hole |
| * extent.(hole/vacuum extent whose em->start <= start && |
| * em->start + em->len > start) |
| * When a hole extent is found, return 1 and modify start/len. |
| */ |
| static int find_first_non_hole(struct btrfs_inode *inode, u64 *start, u64 *len) |
| { |
| struct btrfs_fs_info *fs_info = inode->root->fs_info; |
| struct extent_map *em; |
| int ret = 0; |
| |
| em = btrfs_get_extent(inode, NULL, |
| round_down(*start, fs_info->sectorsize), |
| round_up(*len, fs_info->sectorsize)); |
| if (IS_ERR(em)) |
| return PTR_ERR(em); |
| |
| /* Hole or vacuum extent(only exists in no-hole mode) */ |
| if (em->disk_bytenr == EXTENT_MAP_HOLE) { |
| ret = 1; |
| *len = em->start + em->len > *start + *len ? |
| 0 : *start + *len - em->start - em->len; |
| *start = em->start + em->len; |
| } |
| free_extent_map(em); |
| return ret; |
| } |
| |
| static void btrfs_punch_hole_lock_range(struct inode *inode, |
| const u64 lockstart, |
| const u64 lockend, |
| struct extent_state **cached_state) |
| { |
| /* |
| * For subpage case, if the range is not at page boundary, we could |
| * have pages at the leading/tailing part of the range. |
| * This could lead to dead loop since filemap_range_has_page() |
| * will always return true. |
| * So here we need to do extra page alignment for |
| * filemap_range_has_page(). |
| */ |
| const u64 page_lockstart = round_up(lockstart, PAGE_SIZE); |
| const u64 page_lockend = round_down(lockend + 1, PAGE_SIZE) - 1; |
| |
| while (1) { |
| truncate_pagecache_range(inode, lockstart, lockend); |
| |
| lock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend, |
| cached_state); |
| /* |
| * We can't have ordered extents in the range, nor dirty/writeback |
| * pages, because we have locked the inode's VFS lock in exclusive |
| * mode, we have locked the inode's i_mmap_lock in exclusive mode, |
| * we have flushed all delalloc in the range and we have waited |
| * for any ordered extents in the range to complete. |
| * We can race with anyone reading pages from this range, so after |
| * locking the range check if we have pages in the range, and if |
| * we do, unlock the range and retry. |
| */ |
| if (!filemap_range_has_page(inode->i_mapping, page_lockstart, |
| page_lockend)) |
| break; |
| |
| unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend, |
| cached_state); |
| } |
| |
| btrfs_assert_inode_range_clean(BTRFS_I(inode), lockstart, lockend); |
| } |
| |
| static int btrfs_insert_replace_extent(struct btrfs_trans_handle *trans, |
| struct btrfs_inode *inode, |
| struct btrfs_path *path, |
| struct btrfs_replace_extent_info *extent_info, |
| const u64 replace_len, |
| const u64 bytes_to_drop) |
| { |
| struct btrfs_fs_info *fs_info = trans->fs_info; |
| struct btrfs_root *root = inode->root; |
| struct btrfs_file_extent_item *extent; |
| struct extent_buffer *leaf; |
| struct btrfs_key key; |
| int slot; |
| int ret; |
| |
| if (replace_len == 0) |
| return 0; |
| |
| if (extent_info->disk_offset == 0 && |
| btrfs_fs_incompat(fs_info, NO_HOLES)) { |
| btrfs_update_inode_bytes(inode, 0, bytes_to_drop); |
| return 0; |
| } |
| |
| key.objectid = btrfs_ino(inode); |
| key.type = BTRFS_EXTENT_DATA_KEY; |
| key.offset = extent_info->file_offset; |
| ret = btrfs_insert_empty_item(trans, root, path, &key, |
| sizeof(struct btrfs_file_extent_item)); |
| if (ret) |
| return ret; |
| leaf = path->nodes[0]; |
| slot = path->slots[0]; |
| write_extent_buffer(leaf, extent_info->extent_buf, |
| btrfs_item_ptr_offset(leaf, slot), |
| sizeof(struct btrfs_file_extent_item)); |
| extent = btrfs_item_ptr(leaf, slot, struct btrfs_file_extent_item); |
| ASSERT(btrfs_file_extent_type(leaf, extent) != BTRFS_FILE_EXTENT_INLINE); |
| btrfs_set_file_extent_offset(leaf, extent, extent_info->data_offset); |
| btrfs_set_file_extent_num_bytes(leaf, extent, replace_len); |
| if (extent_info->is_new_extent) |
| btrfs_set_file_extent_generation(leaf, extent, trans->transid); |
| btrfs_mark_buffer_dirty(trans, leaf); |
| btrfs_release_path(path); |
| |
| ret = btrfs_inode_set_file_extent_range(inode, extent_info->file_offset, |
| replace_len); |
| if (ret) |
| return ret; |
| |
| /* If it's a hole, nothing more needs to be done. */ |
| if (extent_info->disk_offset == 0) { |
| btrfs_update_inode_bytes(inode, 0, bytes_to_drop); |
| return 0; |
| } |
| |
| btrfs_update_inode_bytes(inode, replace_len, bytes_to_drop); |
| |
| if (extent_info->is_new_extent && extent_info->insertions == 0) { |
| key.objectid = extent_info->disk_offset; |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| key.offset = extent_info->disk_len; |
| ret = btrfs_alloc_reserved_file_extent(trans, root, |
| btrfs_ino(inode), |
| extent_info->file_offset, |
| extent_info->qgroup_reserved, |
| &key); |
| } else { |
| struct btrfs_ref ref = { |
| .action = BTRFS_ADD_DELAYED_REF, |
| .bytenr = extent_info->disk_offset, |
| .num_bytes = extent_info->disk_len, |
| .owning_root = btrfs_root_id(root), |
| .ref_root = btrfs_root_id(root), |
| }; |
| u64 ref_offset; |
| |
| ref_offset = extent_info->file_offset - extent_info->data_offset; |
| btrfs_init_data_ref(&ref, btrfs_ino(inode), ref_offset, 0, false); |
| ret = btrfs_inc_extent_ref(trans, &ref); |
| } |
| |
| extent_info->insertions++; |
| |
| return ret; |
| } |
| |
| /* |
| * The respective range must have been previously locked, as well as the inode. |
| * The end offset is inclusive (last byte of the range). |
| * @extent_info is NULL for fallocate's hole punching and non-NULL when replacing |
| * the file range with an extent. |
| * When not punching a hole, we don't want to end up in a state where we dropped |
| * extents without inserting a new one, so we must abort the transaction to avoid |
| * a corruption. |
| */ |
| int btrfs_replace_file_extents(struct btrfs_inode *inode, |
| struct btrfs_path *path, const u64 start, |
| const u64 end, |
| struct btrfs_replace_extent_info *extent_info, |
| struct btrfs_trans_handle **trans_out) |
| { |
| struct btrfs_drop_extents_args drop_args = { 0 }; |
| struct btrfs_root *root = inode->root; |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| u64 min_size = btrfs_calc_insert_metadata_size(fs_info, 1); |
| u64 ino_size = round_up(inode->vfs_inode.i_size, fs_info->sectorsize); |
| struct btrfs_trans_handle *trans = NULL; |
| struct btrfs_block_rsv *rsv; |
| unsigned int rsv_count; |
| u64 cur_offset; |
| u64 len = end - start; |
| int ret = 0; |
| |
| if (end <= start) |
| return -EINVAL; |
| |
| rsv = btrfs_alloc_block_rsv(fs_info, BTRFS_BLOCK_RSV_TEMP); |
| if (!rsv) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| rsv->size = btrfs_calc_insert_metadata_size(fs_info, 1); |
| rsv->failfast = true; |
| |
| /* |
| * 1 - update the inode |
| * 1 - removing the extents in the range |
| * 1 - adding the hole extent if no_holes isn't set or if we are |
| * replacing the range with a new extent |
| */ |
| if (!btrfs_fs_incompat(fs_info, NO_HOLES) || extent_info) |
| rsv_count = 3; |
| else |
| rsv_count = 2; |
| |
| trans = btrfs_start_transaction(root, rsv_count); |
| if (IS_ERR(trans)) { |
| ret = PTR_ERR(trans); |
| trans = NULL; |
| goto out_free; |
| } |
| |
| ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, rsv, |
| min_size, false); |
| if (WARN_ON(ret)) |
| goto out_trans; |
| trans->block_rsv = rsv; |
| |
| cur_offset = start; |
| drop_args.path = path; |
| drop_args.end = end + 1; |
| drop_args.drop_cache = true; |
| while (cur_offset < end) { |
| drop_args.start = cur_offset; |
| ret = btrfs_drop_extents(trans, root, inode, &drop_args); |
| /* If we are punching a hole decrement the inode's byte count */ |
| if (!extent_info) |
| btrfs_update_inode_bytes(inode, 0, |
| drop_args.bytes_found); |
| if (ret != -ENOSPC) { |
| /* |
| * The only time we don't want to abort is if we are |
| * attempting to clone a partial inline extent, in which |
| * case we'll get EOPNOTSUPP. However if we aren't |
| * clone we need to abort no matter what, because if we |
| * got EOPNOTSUPP via prealloc then we messed up and |
| * need to abort. |
| */ |
| if (ret && |
| (ret != -EOPNOTSUPP || |
| (extent_info && extent_info->is_new_extent))) |
| btrfs_abort_transaction(trans, ret); |
| break; |
| } |
| |
| trans->block_rsv = &fs_info->trans_block_rsv; |
| |
| if (!extent_info && cur_offset < drop_args.drop_end && |
| cur_offset < ino_size) { |
| ret = fill_holes(trans, inode, path, cur_offset, |
| drop_args.drop_end); |
| if (ret) { |
| /* |
| * If we failed then we didn't insert our hole |
| * entries for the area we dropped, so now the |
| * fs is corrupted, so we must abort the |
| * transaction. |
| */ |
| btrfs_abort_transaction(trans, ret); |
| break; |
| } |
| } else if (!extent_info && cur_offset < drop_args.drop_end) { |
| /* |
| * We are past the i_size here, but since we didn't |
| * insert holes we need to clear the mapped area so we |
| * know to not set disk_i_size in this area until a new |
| * file extent is inserted here. |
| */ |
| ret = btrfs_inode_clear_file_extent_range(inode, |
| cur_offset, |
| drop_args.drop_end - cur_offset); |
| if (ret) { |
| /* |
| * We couldn't clear our area, so we could |
| * presumably adjust up and corrupt the fs, so |
| * we need to abort. |
| */ |
| btrfs_abort_transaction(trans, ret); |
| break; |
| } |
| } |
| |
| if (extent_info && |
| drop_args.drop_end > extent_info->file_offset) { |
| u64 replace_len = drop_args.drop_end - |
| extent_info->file_offset; |
| |
| ret = btrfs_insert_replace_extent(trans, inode, path, |
| extent_info, replace_len, |
| drop_args.bytes_found); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| break; |
| } |
| extent_info->data_len -= replace_len; |
| extent_info->data_offset += replace_len; |
| extent_info->file_offset += replace_len; |
| } |
| |
| /* |
| * We are releasing our handle on the transaction, balance the |
| * dirty pages of the btree inode and flush delayed items, and |
| * then get a new transaction handle, which may now point to a |
| * new transaction in case someone else may have committed the |
| * transaction we used to replace/drop file extent items. So |
| * bump the inode's iversion and update mtime and ctime except |
| * if we are called from a dedupe context. This is because a |
| * power failure/crash may happen after the transaction is |
| * committed and before we finish replacing/dropping all the |
| * file extent items we need. |
| */ |
| inode_inc_iversion(&inode->vfs_inode); |
| |
| if (!extent_info || extent_info->update_times) |
| inode_set_mtime_to_ts(&inode->vfs_inode, |
| inode_set_ctime_current(&inode->vfs_inode)); |
| |
| ret = btrfs_update_inode(trans, inode); |
| if (ret) |
| break; |
| |
| btrfs_end_transaction(trans); |
| btrfs_btree_balance_dirty(fs_info); |
| |
| trans = btrfs_start_transaction(root, rsv_count); |
| if (IS_ERR(trans)) { |
| ret = PTR_ERR(trans); |
| trans = NULL; |
| break; |
| } |
| |
| ret = btrfs_block_rsv_migrate(&fs_info->trans_block_rsv, |
| rsv, min_size, false); |
| if (WARN_ON(ret)) |
| break; |
| trans->block_rsv = rsv; |
| |
| cur_offset = drop_args.drop_end; |
| len = end - cur_offset; |
| if (!extent_info && len) { |
| ret = find_first_non_hole(inode, &cur_offset, &len); |
| if (unlikely(ret < 0)) |
| break; |
| if (ret && !len) { |
| ret = 0; |
| break; |
| } |
| } |
| } |
| |
| /* |
| * If we were cloning, force the next fsync to be a full one since we |
| * we replaced (or just dropped in the case of cloning holes when |
| * NO_HOLES is enabled) file extent items and did not setup new extent |
| * maps for the replacement extents (or holes). |
| */ |
| if (extent_info && !extent_info->is_new_extent) |
| btrfs_set_inode_full_sync(inode); |
| |
| if (ret) |
| goto out_trans; |
| |
| trans->block_rsv = &fs_info->trans_block_rsv; |
| /* |
| * If we are using the NO_HOLES feature we might have had already an |
| * hole that overlaps a part of the region [lockstart, lockend] and |
| * ends at (or beyond) lockend. Since we have no file extent items to |
| * represent holes, drop_end can be less than lockend and so we must |
| * make sure we have an extent map representing the existing hole (the |
| * call to __btrfs_drop_extents() might have dropped the existing extent |
| * map representing the existing hole), otherwise the fast fsync path |
| * will not record the existence of the hole region |
| * [existing_hole_start, lockend]. |
| */ |
| if (drop_args.drop_end <= end) |
| drop_args.drop_end = end + 1; |
| /* |
| * Don't insert file hole extent item if it's for a range beyond eof |
| * (because it's useless) or if it represents a 0 bytes range (when |
| * cur_offset == drop_end). |
| */ |
| if (!extent_info && cur_offset < ino_size && |
| cur_offset < drop_args.drop_end) { |
| ret = fill_holes(trans, inode, path, cur_offset, |
| drop_args.drop_end); |
| if (ret) { |
| /* Same comment as above. */ |
| btrfs_abort_transaction(trans, ret); |
| goto out_trans; |
| } |
| } else if (!extent_info && cur_offset < drop_args.drop_end) { |
| /* See the comment in the loop above for the reasoning here. */ |
| ret = btrfs_inode_clear_file_extent_range(inode, cur_offset, |
| drop_args.drop_end - cur_offset); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto out_trans; |
| } |
| |
| } |
| if (extent_info) { |
| ret = btrfs_insert_replace_extent(trans, inode, path, |
| extent_info, extent_info->data_len, |
| drop_args.bytes_found); |
| if (ret) { |
| btrfs_abort_transaction(trans, ret); |
| goto out_trans; |
| } |
| } |
| |
| out_trans: |
| if (!trans) |
| goto out_free; |
| |
| trans->block_rsv = &fs_info->trans_block_rsv; |
| if (ret) |
| btrfs_end_transaction(trans); |
| else |
| *trans_out = trans; |
| out_free: |
| btrfs_free_block_rsv(fs_info, rsv); |
| out: |
| return ret; |
| } |
| |
| static int btrfs_punch_hole(struct file *file, loff_t offset, loff_t len) |
| { |
| struct inode *inode = file_inode(file); |
| struct btrfs_fs_info *fs_info = inode_to_fs_info(inode); |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct extent_state *cached_state = NULL; |
| struct btrfs_path *path; |
| struct btrfs_trans_handle *trans = NULL; |
| u64 lockstart; |
| u64 lockend; |
| u64 tail_start; |
| u64 tail_len; |
| u64 orig_start = offset; |
| int ret = 0; |
| bool same_block; |
| u64 ino_size; |
| bool truncated_block = false; |
| bool updated_inode = false; |
| |
| btrfs_inode_lock(BTRFS_I(inode), BTRFS_ILOCK_MMAP); |
| |
| ret = btrfs_wait_ordered_range(BTRFS_I(inode), offset, len); |
| if (ret) |
| goto out_only_mutex; |
| |
| ino_size = round_up(inode->i_size, fs_info->sectorsize); |
| ret = find_first_non_hole(BTRFS_I(inode), &offset, &len); |
| if (ret < 0) |
| goto out_only_mutex; |
| if (ret && !len) { |
| /* Already in a large hole */ |
| ret = 0; |
| goto out_only_mutex; |
| } |
| |
| ret = file_modified(file); |
| if (ret) |
| goto out_only_mutex; |
| |
| lockstart = round_up(offset, fs_info->sectorsize); |
| lockend = round_down(offset + len, fs_info->sectorsize) - 1; |
| same_block = (BTRFS_BYTES_TO_BLKS(fs_info, offset)) |
| == (BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1)); |
| /* |
| * We needn't truncate any block which is beyond the end of the file |
| * because we are sure there is no data there. |
| */ |
| /* |
| * Only do this if we are in the same block and we aren't doing the |
| * entire block. |
| */ |
| if (same_block && len < fs_info->sectorsize) { |
| if (offset < ino_size) { |
| truncated_block = true; |
| ret = btrfs_truncate_block(BTRFS_I(inode), offset, len, |
| 0); |
| } else { |
| ret = 0; |
| } |
| goto out_only_mutex; |
| } |
| |
| /* zero back part of the first block */ |
| if (offset < ino_size) { |
| truncated_block = true; |
| ret = btrfs_truncate_block(BTRFS_I(inode), offset, 0, 0); |
| if (ret) { |
| btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_MMAP); |
| return ret; |
| } |
| } |
| |
| /* Check the aligned pages after the first unaligned page, |
| * if offset != orig_start, which means the first unaligned page |
| * including several following pages are already in holes, |
| * the extra check can be skipped */ |
| if (offset == orig_start) { |
| /* after truncate page, check hole again */ |
| len = offset + len - lockstart; |
| offset = lockstart; |
| ret = find_first_non_hole(BTRFS_I(inode), &offset, &len); |
| if (ret < 0) |
| goto out_only_mutex; |
| if (ret && !len) { |
| ret = 0; |
| goto out_only_mutex; |
| } |
| lockstart = offset; |
| } |
| |
| /* Check the tail unaligned part is in a hole */ |
| tail_start = lockend + 1; |
| tail_len = offset + len - tail_start; |
| if (tail_len) { |
| ret = find_first_non_hole(BTRFS_I(inode), &tail_start, &tail_len); |
| if (unlikely(ret < 0)) |
| goto out_only_mutex; |
| if (!ret) { |
| /* zero the front end of the last page */ |
| if (tail_start + tail_len < ino_size) { |
| truncated_block = true; |
| ret = btrfs_truncate_block(BTRFS_I(inode), |
| tail_start + tail_len, |
| 0, 1); |
| if (ret) |
| goto out_only_mutex; |
| } |
| } |
| } |
| |
| if (lockend < lockstart) { |
| ret = 0; |
| goto out_only_mutex; |
| } |
| |
| btrfs_punch_hole_lock_range(inode, lockstart, lockend, &cached_state); |
| |
| path = btrfs_alloc_path(); |
| if (!path) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| ret = btrfs_replace_file_extents(BTRFS_I(inode), path, lockstart, |
| lockend, NULL, &trans); |
| btrfs_free_path(path); |
| if (ret) |
| goto out; |
| |
| ASSERT(trans != NULL); |
| inode_inc_iversion(inode); |
| inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); |
| ret = btrfs_update_inode(trans, BTRFS_I(inode)); |
| updated_inode = true; |
| btrfs_end_transaction(trans); |
| btrfs_btree_balance_dirty(fs_info); |
| out: |
| unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend, |
| &cached_state); |
| out_only_mutex: |
| if (!updated_inode && truncated_block && !ret) { |
| /* |
| * If we only end up zeroing part of a page, we still need to |
| * update the inode item, so that all the time fields are |
| * updated as well as the necessary btrfs inode in memory fields |
| * for detecting, at fsync time, if the inode isn't yet in the |
| * log tree or it's there but not up to date. |
| */ |
| struct timespec64 now = inode_set_ctime_current(inode); |
| |
| inode_inc_iversion(inode); |
| inode_set_mtime_to_ts(inode, now); |
| trans = btrfs_start_transaction(root, 1); |
| if (IS_ERR(trans)) { |
| ret = PTR_ERR(trans); |
| } else { |
| int ret2; |
| |
| ret = btrfs_update_inode(trans, BTRFS_I(inode)); |
| ret2 = btrfs_end_transaction(trans); |
| if (!ret) |
| ret = ret2; |
| } |
| } |
| btrfs_inode_unlock(BTRFS_I(inode), BTRFS_ILOCK_MMAP); |
| return ret; |
| } |
| |
| /* Helper structure to record which range is already reserved */ |
| struct falloc_range { |
| struct list_head list; |
| u64 start; |
| u64 len; |
| }; |
| |
| /* |
| * Helper function to add falloc range |
| * |
| * Caller should have locked the larger range of extent containing |
| * [start, len) |
| */ |
| static int add_falloc_range(struct list_head *head, u64 start, u64 len) |
| { |
| struct falloc_range *range = NULL; |
| |
| if (!list_empty(head)) { |
| /* |
| * As fallocate iterates by bytenr order, we only need to check |
| * the last range. |
| */ |
| range = list_last_entry(head, struct falloc_range, list); |
| if (range->start + range->len == start) { |
| range->len += len; |
| return 0; |
| } |
| } |
| |
| range = kmalloc(sizeof(*range), GFP_KERNEL); |
| if (!range) |
| return -ENOMEM; |
| range->start = start; |
| range->len = len; |
| list_add_tail(&range->list, head); |
| return 0; |
| } |
| |
| static int btrfs_fallocate_update_isize(struct inode *inode, |
| const u64 end, |
| const int mode) |
| { |
| struct btrfs_trans_handle *trans; |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| int ret; |
| int ret2; |
| |
| if (mode & FALLOC_FL_KEEP_SIZE || end <= i_size_read(inode)) |
| return 0; |
| |
| trans = btrfs_start_transaction(root, 1); |
| if (IS_ERR(trans)) |
| return PTR_ERR(trans); |
| |
| inode_set_ctime_current(inode); |
| i_size_write(inode, end); |
| btrfs_inode_safe_disk_i_size_write(BTRFS_I(inode), 0); |
| ret = btrfs_update_inode(trans, BTRFS_I(inode)); |
| ret2 = btrfs_end_transaction(trans); |
| |
| return ret ? ret : ret2; |
| } |
| |
| enum { |
| RANGE_BOUNDARY_WRITTEN_EXTENT, |
| RANGE_BOUNDARY_PREALLOC_EXTENT, |
| RANGE_BOUNDARY_HOLE, |
| }; |
| |
| static int btrfs_zero_range_check_range_boundary(struct btrfs_inode *inode, |
| u64 offset) |
| { |
| const u64 sectorsize = inode->root->fs_info->sectorsize; |
| struct extent_map *em; |
| int ret; |
| |
| offset = round_down(offset, sectorsize); |
| em = btrfs_get_extent(inode, NULL, offset, sectorsize); |
| if (IS_ERR(em)) |
| return PTR_ERR(em); |
| |
| if (em->disk_bytenr == EXTENT_MAP_HOLE) |
| ret = RANGE_BOUNDARY_HOLE; |
| else if (em->flags & EXTENT_FLAG_PREALLOC) |
| ret = RANGE_BOUNDARY_PREALLOC_EXTENT; |
| else |
| ret = RANGE_BOUNDARY_WRITTEN_EXTENT; |
| |
| free_extent_map(em); |
| return ret; |
| } |
| |
| static int btrfs_zero_range(struct inode *inode, |
| loff_t offset, |
| loff_t len, |
| const int mode) |
| { |
| struct btrfs_fs_info *fs_info = BTRFS_I(inode)->root->fs_info; |
| struct extent_map *em; |
| struct extent_changeset *data_reserved = NULL; |
| int ret; |
| u64 alloc_hint = 0; |
| const u64 sectorsize = fs_info->sectorsize; |
| u64 alloc_start = round_down(offset, sectorsize); |
| u64 alloc_end = round_up(offset + len, sectorsize); |
| u64 bytes_to_reserve = 0; |
| bool space_reserved = false; |
| |
| em = btrfs_get_extent(BTRFS_I(inode), NULL, alloc_start, |
| alloc_end - alloc_start); |
| if (IS_ERR(em)) { |
| ret = PTR_ERR(em); |
| goto out; |
| } |
| |
| /* |
| * Avoid hole punching and extent allocation for some cases. More cases |
| * could be considered, but these are unlikely common and we keep things |
| * as simple as possible for now. Also, intentionally, if the target |
| * range contains one or more prealloc extents together with regular |
| * extents and holes, we drop all the existing extents and allocate a |
| * new prealloc extent, so that we get a larger contiguous disk extent. |
| */ |
| if (em->start <= alloc_start && (em->flags & EXTENT_FLAG_PREALLOC)) { |
| const u64 em_end = em->start + em->len; |
| |
| if (em_end >= offset + len) { |
| /* |
| * The whole range is already a prealloc extent, |
| * do nothing except updating the inode's i_size if |
| * needed. |
| */ |
| free_extent_map(em); |
| ret = btrfs_fallocate_update_isize(inode, offset + len, |
| mode); |
| goto out; |
| } |
| /* |
| * Part of the range is already a prealloc extent, so operate |
| * only on the remaining part of the range. |
| */ |
| alloc_start = em_end; |
| ASSERT(IS_ALIGNED(alloc_start, sectorsize)); |
| len = offset + len - alloc_start; |
| offset = alloc_start; |
| alloc_hint = extent_map_block_start(em) + em->len; |
| } |
| free_extent_map(em); |
| |
| if (BTRFS_BYTES_TO_BLKS(fs_info, offset) == |
| BTRFS_BYTES_TO_BLKS(fs_info, offset + len - 1)) { |
| em = btrfs_get_extent(BTRFS_I(inode), NULL, alloc_start, sectorsize); |
| if (IS_ERR(em)) { |
| ret = PTR_ERR(em); |
| goto out; |
| } |
| |
| if (em->flags & EXTENT_FLAG_PREALLOC) { |
| free_extent_map(em); |
| ret = btrfs_fallocate_update_isize(inode, offset + len, |
| mode); |
| goto out; |
| } |
| if (len < sectorsize && em->disk_bytenr != EXTENT_MAP_HOLE) { |
| free_extent_map(em); |
| ret = btrfs_truncate_block(BTRFS_I(inode), offset, len, |
| 0); |
| if (!ret) |
| ret = btrfs_fallocate_update_isize(inode, |
| offset + len, |
| mode); |
| return ret; |
| } |
| free_extent_map(em); |
| alloc_start = round_down(offset, sectorsize); |
| alloc_end = alloc_start + sectorsize; |
| goto reserve_space; |
| } |
| |
| alloc_start = round_up(offset, sectorsize); |
| alloc_end = round_down(offset + len, sectorsize); |
| |
| /* |
| * For unaligned ranges, check the pages at the boundaries, they might |
| * map to an extent, in which case we need to partially zero them, or |
| * they might map to a hole, in which case we need our allocation range |
| * to cover them. |
| */ |
| if (!IS_ALIGNED(offset, sectorsize)) { |
| ret = btrfs_zero_range_check_range_boundary(BTRFS_I(inode), |
| offset); |
| if (ret < 0) |
| goto out; |
| if (ret == RANGE_BOUNDARY_HOLE) { |
| alloc_start = round_down(offset, sectorsize); |
| ret = 0; |
| } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) { |
| ret = btrfs_truncate_block(BTRFS_I(inode), offset, 0, 0); |
| if (ret) |
| goto out; |
| } else { |
| ret = 0; |
| } |
| } |
| |
| if (!IS_ALIGNED(offset + len, sectorsize)) { |
| ret = btrfs_zero_range_check_range_boundary(BTRFS_I(inode), |
| offset + len); |
| if (ret < 0) |
| goto out; |
| if (ret == RANGE_BOUNDARY_HOLE) { |
| alloc_end = round_up(offset + len, sectorsize); |
| ret = 0; |
| } else if (ret == RANGE_BOUNDARY_WRITTEN_EXTENT) { |
| ret = btrfs_truncate_block(BTRFS_I(inode), offset + len, |
| 0, 1); |
| if (ret) |
| goto out; |
| } else { |
| ret = 0; |
| } |
| } |
| |
| reserve_space: |
| if (alloc_start < alloc_end) { |
| struct extent_state *cached_state = NULL; |
| const u64 lockstart = alloc_start; |
| const u64 lockend = alloc_end - 1; |
| |
| bytes_to_reserve = alloc_end - alloc_start; |
| ret = btrfs_alloc_data_chunk_ondemand(BTRFS_I(inode), |
| bytes_to_reserve); |
| if (ret < 0) |
| goto out; |
| space_reserved = true; |
| btrfs_punch_hole_lock_range(inode, lockstart, lockend, |
| &cached_state); |
| ret = btrfs_qgroup_reserve_data(BTRFS_I(inode), &data_reserved, |
| alloc_start, bytes_to_reserve); |
| if (ret) { |
| unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, |
| lockend, &cached_state); |
| goto out; |
| } |
| ret = btrfs_prealloc_file_range(inode, mode, alloc_start, |
| alloc_end - alloc_start, |
| fs_info->sectorsize, |
| offset + len, &alloc_hint); |
| unlock_extent(&BTRFS_I(inode)->io_tree, lockstart, lockend, |
| &cached_state); |
| /* btrfs_prealloc_file_range releases reserved space on error */ |
| if (ret) { |
| space_reserved = false; |
| goto out; |
| } |
| } |
| ret = btrfs_fallocate_update_isize(inode, offset + len, mode); |
| out: |
| if (ret && space_reserved) |
| btrfs_free_reserved_data_space(BTRFS_I(inode), data_reserved, |
| alloc_start, bytes_to_reserve); |
| extent_changeset_free(data_reserved); |
| |
| return ret; |
| } |
| |
| static long btrfs_fallocate(struct file *file, int mode, |
| loff_t offset, loff_t len) |
| { |
| struct inode *inode = file_inode(file); |
| struct extent_state *cached_state = NULL; |
| struct extent_changeset *data_reserved = NULL; |
| struct falloc_range *range; |
| struct falloc_range *tmp; |
| LIST_HEAD(reserve_list); |
| u64 cur_offset; |
| u64 last_byte; |
| u64 alloc_start; |
| u64 alloc_end; |
| u64 alloc_hint = 0; |
| u64 locked_end; |
| u64 actual_end = 0; |
| u64 data_space_needed = 0; |
| u64 data_space_reserved = 0; |
| u64 qgroup_reserved = 0; |
| struct extent_map *em; |
| int blocksize = BTRFS_I(inode)->root->fs_info->sectorsize; |
| int ret; |
| |
| /* Do not allow fallocate in ZONED mode */ |
| if (btrfs_is_zoned(inode_to_fs_info(inode))) |
| return -EOPNOTSUPP; |
| |
| alloc_start = round_down(offset, blocksize); |
| alloc_end = round_up(offset + len, blocksize); |
| cur_offset = alloc_start; |
| |
| /* Make sure we aren't being give some crap mode */ |
| if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | |
| FALLOC_FL_ZERO_RANGE)) |
| return -EOPNOTSUPP; |
| |
| if (mode & FALLOC_FL_PUNCH_HOLE) |
| return btrfs_punch_hole(file, offset, len); |
| |
| btrfs_inode_lock(BTRFS_I(inode), BTRFS_ILOCK_MMAP); |
| |
| if (!(mode & FALLOC_FL_KEEP_SIZE) && offset + len > inode->i_size) { |
| ret = inode_newsize_ok(inode, offset + len); |
| if (ret) |
| goto out; |
| } |
| |
| ret = file_modified(file); |
| if (ret) |
| goto out; |
| |
| /* |
| * TODO: Move these two operations after we have checked |
| * accurate reserved space, or fallocate can still fail but |
| * with page truncated or size expanded. |
| * |
| * But that's a minor problem and won't do much harm BTW. |
| */ |
| |