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android-kvm / linux / e850301f0981741c47f5ee423380a2a963fce563 / . / fs / xfs / xfs_icache.c
blob: d806d3bfa89361f1893015a8f09c3d443bf98ebc [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0
/*
* Copyright (c) 2000-2005 Silicon Graphics, Inc.
* All Rights Reserved.
*/
#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_shared.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_sb.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_trans_priv.h"
#include "xfs_inode_item.h"
#include "xfs_quota.h"
#include "xfs_trace.h"
#include "xfs_icache.h"
#include "xfs_bmap_util.h"
#include "xfs_dquot_item.h"
#include "xfs_dquot.h"
#include "xfs_reflink.h"
#include "xfs_ialloc.h"
#include <linux/iversion.h>
/*
* Allocate and initialise an xfs_inode.
*/
struct xfs_inode *
xfs_inode_alloc(
struct xfs_mount *mp,
xfs_ino_t ino)
{
struct xfs_inode *ip;
/*
* if this didn't occur in transactions, we could use
* KM_MAYFAIL and return NULL here on ENOMEM. Set the
* code up to do this anyway.
*/
ip = kmem_zone_alloc(xfs_inode_zone, 0);
if (!ip)
return NULL;
if (inode_init_always(mp->m_super, VFS_I(ip))) {
kmem_cache_free(xfs_inode_zone, ip);
return NULL;
}
/* VFS doesn't initialise i_mode! */
VFS_I(ip)->i_mode = 0;
XFS_STATS_INC(mp, vn_active);
ASSERT(atomic_read(&ip->i_pincount) == 0);
ASSERT(!xfs_isiflocked(ip));
ASSERT(ip->i_ino == 0);
/* initialise the xfs inode */
ip->i_ino = ino;
ip->i_mount = mp;
memset(&ip->i_imap, 0, sizeof(struct xfs_imap));
ip->i_afp = NULL;
ip->i_cowfp = NULL;
memset(&ip->i_df, 0, sizeof(ip->i_df));
ip->i_flags = 0;
ip->i_delayed_blks = 0;
memset(&ip->i_d, 0, sizeof(ip->i_d));
ip->i_sick = 0;
ip->i_checked = 0;
INIT_WORK(&ip->i_ioend_work, xfs_end_io);
INIT_LIST_HEAD(&ip->i_ioend_list);
spin_lock_init(&ip->i_ioend_lock);
return ip;
}
STATIC void
xfs_inode_free_callback(
struct rcu_head *head)
{
struct inode *inode = container_of(head, struct inode, i_rcu);
struct xfs_inode *ip = XFS_I(inode);
switch (VFS_I(ip)->i_mode & S_IFMT) {
case S_IFREG:
case S_IFDIR:
case S_IFLNK:
xfs_idestroy_fork(&ip->i_df);
break;
}
if (ip->i_afp) {
xfs_idestroy_fork(ip->i_afp);
kmem_cache_free(xfs_ifork_zone, ip->i_afp);
}
if (ip->i_cowfp) {
xfs_idestroy_fork(ip->i_cowfp);
kmem_cache_free(xfs_ifork_zone, ip->i_cowfp);
}
if (ip->i_itemp) {
ASSERT(!test_bit(XFS_LI_IN_AIL,
&ip->i_itemp->ili_item.li_flags));
xfs_inode_item_destroy(ip);
ip->i_itemp = NULL;
}
kmem_cache_free(xfs_inode_zone, ip);
}
static void
__xfs_inode_free(
struct xfs_inode *ip)
{
/* asserts to verify all state is correct here */
ASSERT(atomic_read(&ip->i_pincount) == 0);
XFS_STATS_DEC(ip->i_mount, vn_active);
call_rcu(&VFS_I(ip)->i_rcu, xfs_inode_free_callback);
}
void
xfs_inode_free(
struct xfs_inode *ip)
{
ASSERT(!xfs_isiflocked(ip));
/*
* Because we use RCU freeing we need to ensure the inode always
* appears to be reclaimed with an invalid inode number when in the
* free state. The ip->i_flags_lock provides the barrier against lookup
* races.
*/
spin_lock(&ip->i_flags_lock);
ip->i_flags = XFS_IRECLAIM;
ip->i_ino = 0;
spin_unlock(&ip->i_flags_lock);
__xfs_inode_free(ip);
}
/*
* Queue a new inode reclaim pass if there are reclaimable inodes and there
* isn't a reclaim pass already in progress. By default it runs every 5s based
* on the xfs periodic sync default of 30s. Perhaps this should have it's own
* tunable, but that can be done if this method proves to be ineffective or too
* aggressive.
*/
static void
xfs_reclaim_work_queue(
struct xfs_mount *mp)
{
rcu_read_lock();
if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_RECLAIM_TAG)) {
queue_delayed_work(mp->m_reclaim_workqueue, &mp->m_reclaim_work,
msecs_to_jiffies(xfs_syncd_centisecs / 6 * 10));
}
rcu_read_unlock();
}
/*
* This is a fast pass over the inode cache to try to get reclaim moving on as
* many inodes as possible in a short period of time. It kicks itself every few
* seconds, as well as being kicked by the inode cache shrinker when memory
* goes low. It scans as quickly as possible avoiding locked inodes or those
* already being flushed, and once done schedules a future pass.
*/
void
xfs_reclaim_worker(
struct work_struct *work)
{
struct xfs_mount *mp = container_of(to_delayed_work(work),
struct xfs_mount, m_reclaim_work);
xfs_reclaim_inodes(mp, SYNC_TRYLOCK);
xfs_reclaim_work_queue(mp);
}
static void
xfs_perag_set_reclaim_tag(
struct xfs_perag *pag)
{
struct xfs_mount *mp = pag->pag_mount;
lockdep_assert_held(&pag->pag_ici_lock);
if (pag->pag_ici_reclaimable++)
return;
/* propagate the reclaim tag up into the perag radix tree */
spin_lock(&mp->m_perag_lock);
radix_tree_tag_set(&mp->m_perag_tree, pag->pag_agno,
XFS_ICI_RECLAIM_TAG);
spin_unlock(&mp->m_perag_lock);
/* schedule periodic background inode reclaim */
xfs_reclaim_work_queue(mp);
trace_xfs_perag_set_reclaim(mp, pag->pag_agno, -1, _RET_IP_);
}
static void
xfs_perag_clear_reclaim_tag(
struct xfs_perag *pag)
{
struct xfs_mount *mp = pag->pag_mount;
lockdep_assert_held(&pag->pag_ici_lock);
if (--pag->pag_ici_reclaimable)
return;
/* clear the reclaim tag from the perag radix tree */
spin_lock(&mp->m_perag_lock);
radix_tree_tag_clear(&mp->m_perag_tree, pag->pag_agno,
XFS_ICI_RECLAIM_TAG);
spin_unlock(&mp->m_perag_lock);
trace_xfs_perag_clear_reclaim(mp, pag->pag_agno, -1, _RET_IP_);
}
/*
* We set the inode flag atomically with the radix tree tag.
* Once we get tag lookups on the radix tree, this inode flag
* can go away.
*/
void
xfs_inode_set_reclaim_tag(
struct xfs_inode *ip)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_perag *pag;
pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
spin_lock(&pag->pag_ici_lock);
spin_lock(&ip->i_flags_lock);
radix_tree_tag_set(&pag->pag_ici_root, XFS_INO_TO_AGINO(mp, ip->i_ino),
XFS_ICI_RECLAIM_TAG);
xfs_perag_set_reclaim_tag(pag);
__xfs_iflags_set(ip, XFS_IRECLAIMABLE);
spin_unlock(&ip->i_flags_lock);
spin_unlock(&pag->pag_ici_lock);
xfs_perag_put(pag);
}
STATIC void
xfs_inode_clear_reclaim_tag(
struct xfs_perag *pag,
xfs_ino_t ino)
{
radix_tree_tag_clear(&pag->pag_ici_root,
XFS_INO_TO_AGINO(pag->pag_mount, ino),
XFS_ICI_RECLAIM_TAG);
xfs_perag_clear_reclaim_tag(pag);
}
static void
xfs_inew_wait(
struct xfs_inode *ip)
{
wait_queue_head_t *wq = bit_waitqueue(&ip->i_flags, __XFS_INEW_BIT);
DEFINE_WAIT_BIT(wait, &ip->i_flags, __XFS_INEW_BIT);
do {
prepare_to_wait(wq, &wait.wq_entry, TASK_UNINTERRUPTIBLE);
if (!xfs_iflags_test(ip, XFS_INEW))
break;
schedule();
} while (true);
finish_wait(wq, &wait.wq_entry);
}
/*
* When we recycle a reclaimable inode, we need to re-initialise the VFS inode
* part of the structure. This is made more complex by the fact we store
* information about the on-disk values in the VFS inode and so we can't just
* overwrite the values unconditionally. Hence we save the parameters we
* need to retain across reinitialisation, and rewrite them into the VFS inode
* after reinitialisation even if it fails.
*/
static int
xfs_reinit_inode(
struct xfs_mount *mp,
struct inode *inode)
{
int error;
uint32_t nlink = inode->i_nlink;
uint32_t generation = inode->i_generation;
uint64_t version = inode_peek_iversion(inode);
umode_t mode = inode->i_mode;
dev_t dev = inode->i_rdev;
kuid_t uid = inode->i_uid;
kgid_t gid = inode->i_gid;
error = inode_init_always(mp->m_super, inode);
set_nlink(inode, nlink);
inode->i_generation = generation;
inode_set_iversion_queried(inode, version);
inode->i_mode = mode;
inode->i_rdev = dev;
inode->i_uid = uid;
inode->i_gid = gid;
return error;
}
/*
* If we are allocating a new inode, then check what was returned is
* actually a free, empty inode. If we are not allocating an inode,
* then check we didn't find a free inode.
*
* Returns:
* 0 if the inode free state matches the lookup context
* -ENOENT if the inode is free and we are not allocating
* -EFSCORRUPTED if there is any state mismatch at all
*/
static int
xfs_iget_check_free_state(
struct xfs_inode *ip,
int flags)
{
if (flags & XFS_IGET_CREATE) {
/* should be a free inode */
if (VFS_I(ip)->i_mode != 0) {
xfs_warn(ip->i_mount,
"Corruption detected! Free inode 0x%llx not marked free! (mode 0x%x)",
ip->i_ino, VFS_I(ip)->i_mode);
return -EFSCORRUPTED;
}
if (ip->i_d.di_nblocks != 0) {
xfs_warn(ip->i_mount,
"Corruption detected! Free inode 0x%llx has blocks allocated!",
ip->i_ino);
return -EFSCORRUPTED;
}
return 0;
}
/* should be an allocated inode */
if (VFS_I(ip)->i_mode == 0)
return -ENOENT;
return 0;
}
/*
* Check the validity of the inode we just found it the cache
*/
static int
xfs_iget_cache_hit(
struct xfs_perag *pag,
struct xfs_inode *ip,
xfs_ino_t ino,
int flags,
int lock_flags) __releases(RCU)
{
struct inode *inode = VFS_I(ip);
struct xfs_mount *mp = ip->i_mount;
int error;
/*
* check for re-use of an inode within an RCU grace period due to the
* radix tree nodes not being updated yet. We monitor for this by
* setting the inode number to zero before freeing the inode structure.
* If the inode has been reallocated and set up, then the inode number
* will not match, so check for that, too.
*/
spin_lock(&ip->i_flags_lock);
if (ip->i_ino != ino) {
trace_xfs_iget_skip(ip);
XFS_STATS_INC(mp, xs_ig_frecycle);
error = -EAGAIN;
goto out_error;
}
/*
* If we are racing with another cache hit that is currently
* instantiating this inode or currently recycling it out of
* reclaimabe state, wait for the initialisation to complete
* before continuing.
*
* XXX(hch): eventually we should do something equivalent to
* wait_on_inode to wait for these flags to be cleared
* instead of polling for it.
*/
if (ip->i_flags & (XFS_INEW|XFS_IRECLAIM)) {
trace_xfs_iget_skip(ip);
XFS_STATS_INC(mp, xs_ig_frecycle);
error = -EAGAIN;
goto out_error;
}
/*
* Check the inode free state is valid. This also detects lookup
* racing with unlinks.
*/
error = xfs_iget_check_free_state(ip, flags);
if (error)
goto out_error;
/*
* If IRECLAIMABLE is set, we've torn down the VFS inode already.
* Need to carefully get it back into useable state.
*/
if (ip->i_flags & XFS_IRECLAIMABLE) {
trace_xfs_iget_reclaim(ip);
if (flags & XFS_IGET_INCORE) {
error = -EAGAIN;
goto out_error;
}
/*
* We need to set XFS_IRECLAIM to prevent xfs_reclaim_inode
* from stomping over us while we recycle the inode. We can't
* clear the radix tree reclaimable tag yet as it requires
* pag_ici_lock to be held exclusive.
*/
ip->i_flags |= XFS_IRECLAIM;
spin_unlock(&ip->i_flags_lock);
rcu_read_unlock();
ASSERT(!rwsem_is_locked(&inode->i_rwsem));
error = xfs_reinit_inode(mp, inode);
if (error) {
bool wake;
/*
* Re-initializing the inode failed, and we are in deep
* trouble. Try to re-add it to the reclaim list.
*/
rcu_read_lock();
spin_lock(&ip->i_flags_lock);
wake = !!__xfs_iflags_test(ip, XFS_INEW);
ip->i_flags &= ~(XFS_INEW | XFS_IRECLAIM);
if (wake)
wake_up_bit(&ip->i_flags, __XFS_INEW_BIT);
ASSERT(ip->i_flags & XFS_IRECLAIMABLE);
trace_xfs_iget_reclaim_fail(ip);
goto out_error;
}
spin_lock(&pag->pag_ici_lock);
spin_lock(&ip->i_flags_lock);
/*
* Clear the per-lifetime state in the inode as we are now
* effectively a new inode and need to return to the initial
* state before reuse occurs.
*/
ip->i_flags &= ~XFS_IRECLAIM_RESET_FLAGS;
ip->i_flags |= XFS_INEW;
xfs_inode_clear_reclaim_tag(pag, ip->i_ino);
inode->i_state = I_NEW;
ip->i_sick = 0;
ip->i_checked = 0;
spin_unlock(&ip->i_flags_lock);
spin_unlock(&pag->pag_ici_lock);
} else {
/* If the VFS inode is being torn down, pause and try again. */
if (!igrab(inode)) {
trace_xfs_iget_skip(ip);
error = -EAGAIN;
goto out_error;
}
/* We've got a live one. */
spin_unlock(&ip->i_flags_lock);
rcu_read_unlock();
trace_xfs_iget_hit(ip);
}
if (lock_flags != 0)
xfs_ilock(ip, lock_flags);
if (!(flags & XFS_IGET_INCORE))
xfs_iflags_clear(ip, XFS_ISTALE | XFS_IDONTCACHE);
XFS_STATS_INC(mp, xs_ig_found);
return 0;
out_error:
spin_unlock(&ip->i_flags_lock);
rcu_read_unlock();
return error;
}
static int
xfs_iget_cache_miss(
struct xfs_mount *mp,
struct xfs_perag *pag,
xfs_trans_t *tp,
xfs_ino_t ino,
struct xfs_inode **ipp,
int flags,
int lock_flags)
{
struct xfs_inode *ip;
int error;
xfs_agino_t agino = XFS_INO_TO_AGINO(mp, ino);
int iflags;
ip = xfs_inode_alloc(mp, ino);
if (!ip)
return -ENOMEM;
error = xfs_imap(mp, tp, ip->i_ino, &ip->i_imap, flags);
if (error)
goto out_destroy;
/*
* For version 5 superblocks, if we are initialising a new inode and we
* are not utilising the XFS_MOUNT_IKEEP inode cluster mode, we can
* simply build the new inode core with a random generation number.
*
* For version 4 (and older) superblocks, log recovery is dependent on
* the di_flushiter field being initialised from the current on-disk
* value and hence we must also read the inode off disk even when
* initializing new inodes.
*/
if (xfs_sb_version_has_v3inode(&mp->m_sb) &&
(flags & XFS_IGET_CREATE) && !(mp->m_flags & XFS_MOUNT_IKEEP)) {
VFS_I(ip)->i_generation = prandom_u32();
} else {
struct xfs_dinode *dip;
struct xfs_buf *bp;
error = xfs_imap_to_bp(mp, tp, &ip->i_imap, &dip, &bp, 0);
if (error)
goto out_destroy;
error = xfs_inode_from_disk(ip, dip);
if (!error)
xfs_buf_set_ref(bp, XFS_INO_REF);
xfs_trans_brelse(tp, bp);
if (error)
goto out_destroy;
}
trace_xfs_iget_miss(ip);
/*
* Check the inode free state is valid. This also detects lookup
* racing with unlinks.
*/
error = xfs_iget_check_free_state(ip, flags);
if (error)
goto out_destroy;
/*
* Preload the radix tree so we can insert safely under the
* write spinlock. Note that we cannot sleep inside the preload
* region. Since we can be called from transaction context, don't
* recurse into the file system.
*/
if (radix_tree_preload(GFP_NOFS)) {
error = -EAGAIN;
goto out_destroy;
}
/*
* Because the inode hasn't been added to the radix-tree yet it can't
* be found by another thread, so we can do the non-sleeping lock here.
*/
if (lock_flags) {
if (!xfs_ilock_nowait(ip, lock_flags))
BUG();
}
/*
* These values must be set before inserting the inode into the radix
* tree as the moment it is inserted a concurrent lookup (allowed by the
* RCU locking mechanism) can find it and that lookup must see that this
* is an inode currently under construction (i.e. that XFS_INEW is set).
* The ip->i_flags_lock that protects the XFS_INEW flag forms the
* memory barrier that ensures this detection works correctly at lookup
* time.
*/
iflags = XFS_INEW;
if (flags & XFS_IGET_DONTCACHE)
iflags |= XFS_IDONTCACHE;
ip->i_udquot = NULL;
ip->i_gdquot = NULL;
ip->i_pdquot = NULL;
xfs_iflags_set(ip, iflags);
/* insert the new inode */
spin_lock(&pag->pag_ici_lock);
error = radix_tree_insert(&pag->pag_ici_root, agino, ip);
if (unlikely(error)) {
WARN_ON(error != -EEXIST);
XFS_STATS_INC(mp, xs_ig_dup);
error = -EAGAIN;
goto out_preload_end;
}
spin_unlock(&pag->pag_ici_lock);
radix_tree_preload_end();
*ipp = ip;
return 0;
out_preload_end:
spin_unlock(&pag->pag_ici_lock);
radix_tree_preload_end();
if (lock_flags)
xfs_iunlock(ip, lock_flags);
out_destroy:
__destroy_inode(VFS_I(ip));
xfs_inode_free(ip);
return error;
}
/*
* Look up an inode by number in the given file system.
* The inode is looked up in the cache held in each AG.
* If the inode is found in the cache, initialise the vfs inode
* if necessary.
*
* If it is not in core, read it in from the file system's device,
* add it to the cache and initialise the vfs inode.
*
* The inode is locked according to the value of the lock_flags parameter.
* This flag parameter indicates how and if the inode's IO lock and inode lock
* should be taken.
*
* mp -- the mount point structure for the current file system. It points
* to the inode hash table.
* tp -- a pointer to the current transaction if there is one. This is
* simply passed through to the xfs_iread() call.
* ino -- the number of the inode desired. This is the unique identifier
* within the file system for the inode being requested.
* lock_flags -- flags indicating how to lock the inode. See the comment
* for xfs_ilock() for a list of valid values.
*/
int
xfs_iget(
xfs_mount_t *mp,
xfs_trans_t *tp,
xfs_ino_t ino,
uint flags,
uint lock_flags,
xfs_inode_t **ipp)
{
xfs_inode_t *ip;
int error;
xfs_perag_t *pag;
xfs_agino_t agino;
/*
* xfs_reclaim_inode() uses the ILOCK to ensure an inode
* doesn't get freed while it's being referenced during a
* radix tree traversal here. It assumes this function
* aqcuires only the ILOCK (and therefore it has no need to
* involve the IOLOCK in this synchronization).
*/
ASSERT((lock_flags & (XFS_IOLOCK_EXCL | XFS_IOLOCK_SHARED)) == 0);
/* reject inode numbers outside existing AGs */
if (!ino || XFS_INO_TO_AGNO(mp, ino) >= mp->m_sb.sb_agcount)
return -EINVAL;
XFS_STATS_INC(mp, xs_ig_attempts);
/* get the perag structure and ensure that it's inode capable */
pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ino));
agino = XFS_INO_TO_AGINO(mp, ino);
again:
error = 0;
rcu_read_lock();
ip = radix_tree_lookup(&pag->pag_ici_root, agino);
if (ip) {
error = xfs_iget_cache_hit(pag, ip, ino, flags, lock_flags);
if (error)
goto out_error_or_again;
} else {
rcu_read_unlock();
if (flags & XFS_IGET_INCORE) {
error = -ENODATA;
goto out_error_or_again;
}
XFS_STATS_INC(mp, xs_ig_missed);
error = xfs_iget_cache_miss(mp, pag, tp, ino, &ip,
flags, lock_flags);
if (error)
goto out_error_or_again;
}
xfs_perag_put(pag);
*ipp = ip;
/*
* If we have a real type for an on-disk inode, we can setup the inode
* now. If it's a new inode being created, xfs_ialloc will handle it.
*/
if (xfs_iflags_test(ip, XFS_INEW) && VFS_I(ip)->i_mode != 0)
xfs_setup_existing_inode(ip);
return 0;
out_error_or_again:
if (!(flags & XFS_IGET_INCORE) && error == -EAGAIN) {
delay(1);
goto again;
}
xfs_perag_put(pag);
return error;
}
/*
* "Is this a cached inode that's also allocated?"
*
* Look up an inode by number in the given file system. If the inode is
* in cache and isn't in purgatory, return 1 if the inode is allocated
* and 0 if it is not. For all other cases (not in cache, being torn
* down, etc.), return a negative error code.
*
* The caller has to prevent inode allocation and freeing activity,
* presumably by locking the AGI buffer. This is to ensure that an
* inode cannot transition from allocated to freed until the caller is
* ready to allow that. If the inode is in an intermediate state (new,
* reclaimable, or being reclaimed), -EAGAIN will be returned; if the
* inode is not in the cache, -ENOENT will be returned. The caller must
* deal with these scenarios appropriately.
*
* This is a specialized use case for the online scrubber; if you're
* reading this, you probably want xfs_iget.
*/
int
xfs_icache_inode_is_allocated(
struct xfs_mount *mp,
struct xfs_trans *tp,
xfs_ino_t ino,
bool *inuse)
{
struct xfs_inode *ip;
int error;
error = xfs_iget(mp, tp, ino, XFS_IGET_INCORE, 0, &ip);
if (error)
return error;
*inuse = !!(VFS_I(ip)->i_mode);
xfs_irele(ip);
return 0;
}
/*
* The inode lookup is done in batches to keep the amount of lock traffic and
* radix tree lookups to a minimum. The batch size is a trade off between
* lookup reduction and stack usage. This is in the reclaim path, so we can't
* be too greedy.
*/
#define XFS_LOOKUP_BATCH 32
STATIC int
xfs_inode_ag_walk_grab(
struct xfs_inode *ip,
int flags)
{
struct inode *inode = VFS_I(ip);
bool newinos = !!(flags & XFS_AGITER_INEW_WAIT);
ASSERT(rcu_read_lock_held());
/*
* check for stale RCU freed inode
*
* If the inode has been reallocated, it doesn't matter if it's not in
* the AG we are walking - we are walking for writeback, so if it
* passes all the "valid inode" checks and is dirty, then we'll write
* it back anyway. If it has been reallocated and still being
* initialised, the XFS_INEW check below will catch it.
*/
spin_lock(&ip->i_flags_lock);
if (!ip->i_ino)
goto out_unlock_noent;
/* avoid new or reclaimable inodes. Leave for reclaim code to flush */
if ((!newinos && __xfs_iflags_test(ip, XFS_INEW)) ||
__xfs_iflags_test(ip, XFS_IRECLAIMABLE | XFS_IRECLAIM))
goto out_unlock_noent;
spin_unlock(&ip->i_flags_lock);
/* nothing to sync during shutdown */
if (XFS_FORCED_SHUTDOWN(ip->i_mount))
return -EFSCORRUPTED;
/* If we can't grab the inode, it must on it's way to reclaim. */
if (!igrab(inode))
return -ENOENT;
/* inode is valid */
return 0;
out_unlock_noent:
spin_unlock(&ip->i_flags_lock);
return -ENOENT;
}
STATIC int
xfs_inode_ag_walk(
struct xfs_mount *mp,
struct xfs_perag *pag,
int (*execute)(struct xfs_inode *ip, int flags,
void *args),
int flags,
void *args,
int tag,
int iter_flags)
{
uint32_t first_index;
int last_error = 0;
int skipped;
int done;
int nr_found;
restart:
done = 0;
skipped = 0;
first_index = 0;
nr_found = 0;
do {
struct xfs_inode *batch[XFS_LOOKUP_BATCH];
int error = 0;
int i;
rcu_read_lock();
if (tag == -1)
nr_found = radix_tree_gang_lookup(&pag->pag_ici_root,
(void **)batch, first_index,
XFS_LOOKUP_BATCH);
else
nr_found = radix_tree_gang_lookup_tag(
&pag->pag_ici_root,
(void **) batch, first_index,
XFS_LOOKUP_BATCH, tag);
if (!nr_found) {
rcu_read_unlock();
break;
}
/*
* Grab the inodes before we drop the lock. if we found
* nothing, nr == 0 and the loop will be skipped.
*/
for (i = 0; i < nr_found; i++) {
struct xfs_inode *ip = batch[i];
if (done || xfs_inode_ag_walk_grab(ip, iter_flags))
batch[i] = NULL;
/*
* Update the index for the next lookup. Catch
* overflows into the next AG range which can occur if
* we have inodes in the last block of the AG and we
* are currently pointing to the last inode.
*
* Because we may see inodes that are from the wrong AG
* due to RCU freeing and reallocation, only update the
* index if it lies in this AG. It was a race that lead
* us to see this inode, so another lookup from the
* same index will not find it again.
*/
if (XFS_INO_TO_AGNO(mp, ip->i_ino) != pag->pag_agno)
continue;
first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
done = 1;
}
/* unlock now we've grabbed the inodes. */
rcu_read_unlock();
for (i = 0; i < nr_found; i++) {
if (!batch[i])
continue;
if ((iter_flags & XFS_AGITER_INEW_WAIT) &&
xfs_iflags_test(batch[i], XFS_INEW))
xfs_inew_wait(batch[i]);
error = execute(batch[i], flags, args);
xfs_irele(batch[i]);
if (error == -EAGAIN) {
skipped++;
continue;
}
if (error && last_error != -EFSCORRUPTED)
last_error = error;
}
/* bail out if the filesystem is corrupted. */
if (error == -EFSCORRUPTED)
break;
cond_resched();
} while (nr_found && !done);
if (skipped) {
delay(1);
goto restart;
}
return last_error;
}
/*
* Background scanning to trim post-EOF preallocated space. This is queued
* based on the 'speculative_prealloc_lifetime' tunable (5m by default).
*/
void
xfs_queue_eofblocks(
struct xfs_mount *mp)
{
rcu_read_lock();
if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_EOFBLOCKS_TAG))
queue_delayed_work(mp->m_eofblocks_workqueue,
&mp->m_eofblocks_work,
msecs_to_jiffies(xfs_eofb_secs * 1000));
rcu_read_unlock();
}
void
xfs_eofblocks_worker(
struct work_struct *work)
{
struct xfs_mount *mp = container_of(to_delayed_work(work),
struct xfs_mount, m_eofblocks_work);
if (!sb_start_write_trylock(mp->m_super))
return;
xfs_icache_free_eofblocks(mp, NULL);
sb_end_write(mp->m_super);
xfs_queue_eofblocks(mp);
}
/*
* Background scanning to trim preallocated CoW space. This is queued
* based on the 'speculative_cow_prealloc_lifetime' tunable (5m by default).
* (We'll just piggyback on the post-EOF prealloc space workqueue.)
*/
void
xfs_queue_cowblocks(
struct xfs_mount *mp)
{
rcu_read_lock();
if (radix_tree_tagged(&mp->m_perag_tree, XFS_ICI_COWBLOCKS_TAG))
queue_delayed_work(mp->m_eofblocks_workqueue,
&mp->m_cowblocks_work,
msecs_to_jiffies(xfs_cowb_secs * 1000));
rcu_read_unlock();
}
void
xfs_cowblocks_worker(
struct work_struct *work)
{
struct xfs_mount *mp = container_of(to_delayed_work(work),
struct xfs_mount, m_cowblocks_work);
if (!sb_start_write_trylock(mp->m_super))
return;
xfs_icache_free_cowblocks(mp, NULL);
sb_end_write(mp->m_super);
xfs_queue_cowblocks(mp);
}
int
xfs_inode_ag_iterator_flags(
struct xfs_mount *mp,
int (*execute)(struct xfs_inode *ip, int flags,
void *args),
int flags,
void *args,
int iter_flags)
{
struct xfs_perag *pag;
int error = 0;
int last_error = 0;
xfs_agnumber_t ag;
ag = 0;
while ((pag = xfs_perag_get(mp, ag))) {
ag = pag->pag_agno + 1;
error = xfs_inode_ag_walk(mp, pag, execute, flags, args, -1,
iter_flags);
xfs_perag_put(pag);
if (error) {
last_error = error;
if (error == -EFSCORRUPTED)
break;
}
}
return last_error;
}
int
xfs_inode_ag_iterator(
struct xfs_mount *mp,
int (*execute)(struct xfs_inode *ip, int flags,
void *args),
int flags,
void *args)
{
return xfs_inode_ag_iterator_flags(mp, execute, flags, args, 0);
}
int
xfs_inode_ag_iterator_tag(
struct xfs_mount *mp,
int (*execute)(struct xfs_inode *ip, int flags,
void *args),
int flags,
void *args,
int tag)
{
struct xfs_perag *pag;
int error = 0;
int last_error = 0;
xfs_agnumber_t ag;
ag = 0;
while ((pag = xfs_perag_get_tag(mp, ag, tag))) {
ag = pag->pag_agno + 1;
error = xfs_inode_ag_walk(mp, pag, execute, flags, args, tag,
0);
xfs_perag_put(pag);
if (error) {
last_error = error;
if (error == -EFSCORRUPTED)
break;
}
}
return last_error;
}
/*
* Grab the inode for reclaim exclusively.
* Return 0 if we grabbed it, non-zero otherwise.
*/
STATIC int
xfs_reclaim_inode_grab(
struct xfs_inode *ip,
int flags)
{
ASSERT(rcu_read_lock_held());
/* quick check for stale RCU freed inode */
if (!ip->i_ino)
return 1;
/*
* If we are asked for non-blocking operation, do unlocked checks to
* see if the inode already is being flushed or in reclaim to avoid
* lock traffic.
*/
if ((flags & SYNC_TRYLOCK) &&
__xfs_iflags_test(ip, XFS_IFLOCK | XFS_IRECLAIM))
return 1;
/*
* The radix tree lock here protects a thread in xfs_iget from racing
* with us starting reclaim on the inode. Once we have the
* XFS_IRECLAIM flag set it will not touch us.
*
* Due to RCU lookup, we may find inodes that have been freed and only
* have XFS_IRECLAIM set. Indeed, we may see reallocated inodes that
* aren't candidates for reclaim at all, so we must check the
* XFS_IRECLAIMABLE is set first before proceeding to reclaim.
*/
spin_lock(&ip->i_flags_lock);
if (!__xfs_iflags_test(ip, XFS_IRECLAIMABLE) ||
__xfs_iflags_test(ip, XFS_IRECLAIM)) {
/* not a reclaim candidate. */
spin_unlock(&ip->i_flags_lock);
return 1;
}
__xfs_iflags_set(ip, XFS_IRECLAIM);
spin_unlock(&ip->i_flags_lock);
return 0;
}
/*
* Inodes in different states need to be treated differently. The following
* table lists the inode states and the reclaim actions necessary:
*
* inode state iflush ret required action
* --------------- ---------- ---------------
* bad - reclaim
* shutdown EIO unpin and reclaim
* clean, unpinned 0 reclaim
* stale, unpinned 0 reclaim
* clean, pinned(*) 0 requeue
* stale, pinned EAGAIN requeue
* dirty, async - requeue
* dirty, sync 0 reclaim
*
* (*) dgc: I don't think the clean, pinned state is possible but it gets
* handled anyway given the order of checks implemented.
*
* Also, because we get the flush lock first, we know that any inode that has
* been flushed delwri has had the flush completed by the time we check that
* the inode is clean.
*
* Note that because the inode is flushed delayed write by AIL pushing, the
* flush lock may already be held here and waiting on it can result in very
* long latencies. Hence for sync reclaims, where we wait on the flush lock,
* the caller should push the AIL first before trying to reclaim inodes to
* minimise the amount of time spent waiting. For background relaim, we only
* bother to reclaim clean inodes anyway.
*
* Hence the order of actions after gaining the locks should be:
* bad => reclaim
* shutdown => unpin and reclaim
* pinned, async => requeue
* pinned, sync => unpin
* stale => reclaim
* clean => reclaim
* dirty, async => requeue
* dirty, sync => flush, wait and reclaim
*/
STATIC int
xfs_reclaim_inode(
struct xfs_inode *ip,
struct xfs_perag *pag,
int sync_mode)
{
struct xfs_buf *bp = NULL;
xfs_ino_t ino = ip->i_ino; /* for radix_tree_delete */
int error;
restart:
error = 0;
xfs_ilock(ip, XFS_ILOCK_EXCL);
if (!xfs_iflock_nowait(ip)) {
if (!(sync_mode & SYNC_WAIT))
goto out;
xfs_iflock(ip);
}
if (XFS_FORCED_SHUTDOWN(ip->i_mount)) {
xfs_iunpin_wait(ip);
/* xfs_iflush_abort() drops the flush lock */
xfs_iflush_abort(ip);
goto reclaim;
}
if (xfs_ipincount(ip)) {
if (!(sync_mode & SYNC_WAIT))
goto out_ifunlock;
xfs_iunpin_wait(ip);
}
if (xfs_iflags_test(ip, XFS_ISTALE) || xfs_inode_clean(ip)) {
xfs_ifunlock(ip);
goto reclaim;
}
/*
* Never flush out dirty data during non-blocking reclaim, as it would
* just contend with AIL pushing trying to do the same job.
*/
if (!(sync_mode & SYNC_WAIT))
goto out_ifunlock;
/*
* Now we have an inode that needs flushing.
*
* Note that xfs_iflush will never block on the inode buffer lock, as
* xfs_ifree_cluster() can lock the inode buffer before it locks the
* ip->i_lock, and we are doing the exact opposite here. As a result,
* doing a blocking xfs_imap_to_bp() to get the cluster buffer would
* result in an ABBA deadlock with xfs_ifree_cluster().
*
* As xfs_ifree_cluser() must gather all inodes that are active in the
* cache to mark them stale, if we hit this case we don't actually want
* to do IO here - we want the inode marked stale so we can simply
* reclaim it. Hence if we get an EAGAIN error here, just unlock the
* inode, back off and try again. Hopefully the next pass through will
* see the stale flag set on the inode.
*/
error = xfs_iflush(ip, &bp);
if (error == -EAGAIN) {
xfs_iunlock(ip, XFS_ILOCK_EXCL);
/* backoff longer than in xfs_ifree_cluster */
delay(2);
goto restart;
}
if (!error) {
error = xfs_bwrite(bp);
xfs_buf_relse(bp);
}
reclaim:
ASSERT(!xfs_isiflocked(ip));
/*
* Because we use RCU freeing we need to ensure the inode always appears
* to be reclaimed with an invalid inode number when in the free state.
* We do this as early as possible under the ILOCK so that
* xfs_iflush_cluster() and xfs_ifree_cluster() can be guaranteed to
* detect races with us here. By doing this, we guarantee that once
* xfs_iflush_cluster() or xfs_ifree_cluster() has locked XFS_ILOCK that
* it will see either a valid inode that will serialise correctly, or it
* will see an invalid inode that it can skip.
*/
spin_lock(&ip->i_flags_lock);
ip->i_flags = XFS_IRECLAIM;
ip->i_ino = 0;
spin_unlock(&ip->i_flags_lock);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
XFS_STATS_INC(ip->i_mount, xs_ig_reclaims);
/*
* Remove the inode from the per-AG radix tree.
*
* Because radix_tree_delete won't complain even if the item was never
* added to the tree assert that it's been there before to catch
* problems with the inode life time early on.
*/
spin_lock(&pag->pag_ici_lock);
if (!radix_tree_delete(&pag->pag_ici_root,
XFS_INO_TO_AGINO(ip->i_mount, ino)))
ASSERT(0);
xfs_perag_clear_reclaim_tag(pag);
spin_unlock(&pag->pag_ici_lock);
/*
* Here we do an (almost) spurious inode lock in order to coordinate
* with inode cache radix tree lookups. This is because the lookup
* can reference the inodes in the cache without taking references.
*
* We make that OK here by ensuring that we wait until the inode is
* unlocked after the lookup before we go ahead and free it.
*/
xfs_ilock(ip, XFS_ILOCK_EXCL);
xfs_qm_dqdetach(ip);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
__xfs_inode_free(ip);
return error;
out_ifunlock:
xfs_ifunlock(ip);
out:
xfs_iflags_clear(ip, XFS_IRECLAIM);
xfs_iunlock(ip, XFS_ILOCK_EXCL);
/*
* We could return -EAGAIN here to make reclaim rescan the inode tree in
* a short while. However, this just burns CPU time scanning the tree
* waiting for IO to complete and the reclaim work never goes back to
* the idle state. Instead, return 0 to let the next scheduled
* background reclaim attempt to reclaim the inode again.
*/
return 0;
}
/*
* Walk the AGs and reclaim the inodes in them. Even if the filesystem is
* corrupted, we still want to try to reclaim all the inodes. If we don't,
* then a shut down during filesystem unmount reclaim walk leak all the
* unreclaimed inodes.
*/
STATIC int
xfs_reclaim_inodes_ag(
struct xfs_mount *mp,
int flags,
int *nr_to_scan)
{
struct xfs_perag *pag;
int error = 0;
int last_error = 0;
xfs_agnumber_t ag;
int trylock = flags & SYNC_TRYLOCK;
int skipped;
restart:
ag = 0;
skipped = 0;
while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
unsigned long first_index = 0;
int done = 0;
int nr_found = 0;
ag = pag->pag_agno + 1;
if (trylock) {
if (!mutex_trylock(&pag->pag_ici_reclaim_lock)) {
skipped++;
xfs_perag_put(pag);
continue;
}
first_index = pag->pag_ici_reclaim_cursor;
} else
mutex_lock(&pag->pag_ici_reclaim_lock);
do {
struct xfs_inode *batch[XFS_LOOKUP_BATCH];
int i;
rcu_read_lock();
nr_found = radix_tree_gang_lookup_tag(
&pag->pag_ici_root,
(void **)batch, first_index,
XFS_LOOKUP_BATCH,
XFS_ICI_RECLAIM_TAG);
if (!nr_found) {
done = 1;
rcu_read_unlock();
break;
}
/*
* Grab the inodes before we drop the lock. if we found
* nothing, nr == 0 and the loop will be skipped.
*/
for (i = 0; i < nr_found; i++) {
struct xfs_inode *ip = batch[i];
if (done || xfs_reclaim_inode_grab(ip, flags))
batch[i] = NULL;
/*
* Update the index for the next lookup. Catch
* overflows into the next AG range which can
* occur if we have inodes in the last block of
* the AG and we are currently pointing to the
* last inode.
*
* Because we may see inodes that are from the
* wrong AG due to RCU freeing and
* reallocation, only update the index if it
* lies in this AG. It was a race that lead us
* to see this inode, so another lookup from
* the same index will not find it again.
*/
if (XFS_INO_TO_AGNO(mp, ip->i_ino) !=
pag->pag_agno)
continue;
first_index = XFS_INO_TO_AGINO(mp, ip->i_ino + 1);
if (first_index < XFS_INO_TO_AGINO(mp, ip->i_ino))
done = 1;
}
/* unlock now we've grabbed the inodes. */
rcu_read_unlock();
for (i = 0; i < nr_found; i++) {
if (!batch[i])
continue;
error = xfs_reclaim_inode(batch[i], pag, flags);
if (error && last_error != -EFSCORRUPTED)
last_error = error;
}
*nr_to_scan -= XFS_LOOKUP_BATCH;
cond_resched();
} while (nr_found && !done && *nr_to_scan > 0);
if (trylock && !done)
pag->pag_ici_reclaim_cursor = first_index;
else
pag->pag_ici_reclaim_cursor = 0;
mutex_unlock(&pag->pag_ici_reclaim_lock);
xfs_perag_put(pag);
}
/*
* if we skipped any AG, and we still have scan count remaining, do
* another pass this time using blocking reclaim semantics (i.e
* waiting on the reclaim locks and ignoring the reclaim cursors). This
* ensure that when we get more reclaimers than AGs we block rather
* than spin trying to execute reclaim.
*/
if (skipped && (flags & SYNC_WAIT) && *nr_to_scan > 0) {
trylock = 0;
goto restart;
}
return last_error;
}
int
xfs_reclaim_inodes(
xfs_mount_t *mp,
int mode)
{
int nr_to_scan = INT_MAX;
return xfs_reclaim_inodes_ag(mp, mode, &nr_to_scan);
}
/*
* Scan a certain number of inodes for reclaim.
*
* When called we make sure that there is a background (fast) inode reclaim in
* progress, while we will throttle the speed of reclaim via doing synchronous
* reclaim of inodes. That means if we come across dirty inodes, we wait for
* them to be cleaned, which we hope will not be very long due to the
* background walker having already kicked the IO off on those dirty inodes.
*/
long
xfs_reclaim_inodes_nr(
struct xfs_mount *mp,
int nr_to_scan)
{
/* kick background reclaimer and push the AIL */
xfs_reclaim_work_queue(mp);
xfs_ail_push_all(mp->m_ail);
return xfs_reclaim_inodes_ag(mp, SYNC_TRYLOCK | SYNC_WAIT, &nr_to_scan);
}
/*
* Return the number of reclaimable inodes in the filesystem for
* the shrinker to determine how much to reclaim.
*/
int
xfs_reclaim_inodes_count(
struct xfs_mount *mp)
{
struct xfs_perag *pag;
xfs_agnumber_t ag = 0;
int reclaimable = 0;
while ((pag = xfs_perag_get_tag(mp, ag, XFS_ICI_RECLAIM_TAG))) {
ag = pag->pag_agno + 1;
reclaimable += pag->pag_ici_reclaimable;
xfs_perag_put(pag);
}
return reclaimable;
}
STATIC int
xfs_inode_match_id(
struct xfs_inode *ip,
struct xfs_eofblocks *eofb)
{
if ((eofb->eof_flags & XFS_EOF_FLAGS_UID) &&
!uid_eq(VFS_I(ip)->i_uid, eofb->eof_uid))
return 0;
if ((eofb->eof_flags & XFS_EOF_FLAGS_GID) &&
!gid_eq(VFS_I(ip)->i_gid, eofb->eof_gid))
return 0;
if ((eofb->eof_flags & XFS_EOF_FLAGS_PRID) &&
ip->i_d.di_projid != eofb->eof_prid)
return 0;
return 1;
}
/*
* A union-based inode filtering algorithm. Process the inode if any of the
* criteria match. This is for global/internal scans only.
*/
STATIC int
xfs_inode_match_id_union(
struct xfs_inode *ip,
struct xfs_eofblocks *eofb)
{
if ((eofb->eof_flags & XFS_EOF_FLAGS_UID) &&
uid_eq(VFS_I(ip)->i_uid, eofb->eof_uid))
return 1;
if ((eofb->eof_flags & XFS_EOF_FLAGS_GID) &&
gid_eq(VFS_I(ip)->i_gid, eofb->eof_gid))
return 1;
if ((eofb->eof_flags & XFS_EOF_FLAGS_PRID) &&
ip->i_d.di_projid == eofb->eof_prid)
return 1;
return 0;
}
STATIC int
xfs_inode_free_eofblocks(
struct xfs_inode *ip,
int flags,
void *args)
{
int ret = 0;
struct xfs_eofblocks *eofb = args;
int match;
if (!xfs_can_free_eofblocks(ip, false)) {
/* inode could be preallocated or append-only */
trace_xfs_inode_free_eofblocks_invalid(ip);
xfs_inode_clear_eofblocks_tag(ip);
return 0;
}
/*
* If the mapping is dirty the operation can block and wait for some
* time. Unless we are waiting, skip it.
*/
if (!(flags & SYNC_WAIT) &&
mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_DIRTY))
return 0;
if (eofb) {
if (eofb->eof_flags & XFS_EOF_FLAGS_UNION)
match = xfs_inode_match_id_union(ip, eofb);
else
match = xfs_inode_match_id(ip, eofb);
if (!match)
return 0;
/* skip the inode if the file size is too small */
if (eofb->eof_flags & XFS_EOF_FLAGS_MINFILESIZE &&
XFS_ISIZE(ip) < eofb->eof_min_file_size)
return 0;
}
/*
* If the caller is waiting, return -EAGAIN to keep the background
* scanner moving and revisit the inode in a subsequent pass.
*/
if (!xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
if (flags & SYNC_WAIT)
ret = -EAGAIN;
return ret;
}
ret = xfs_free_eofblocks(ip);
xfs_iunlock(ip, XFS_IOLOCK_EXCL);
return ret;
}
static int
__xfs_icache_free_eofblocks(
struct xfs_mount *mp,
struct xfs_eofblocks *eofb,
int (*execute)(struct xfs_inode *ip, int flags,
void *args),
int tag)
{
int flags = SYNC_TRYLOCK;
if (eofb && (eofb->eof_flags & XFS_EOF_FLAGS_SYNC))
flags = SYNC_WAIT;
return xfs_inode_ag_iterator_tag(mp, execute, flags,
eofb, tag);
}
int
xfs_icache_free_eofblocks(
struct xfs_mount *mp,
struct xfs_eofblocks *eofb)
{
return __xfs_icache_free_eofblocks(mp, eofb, xfs_inode_free_eofblocks,
XFS_ICI_EOFBLOCKS_TAG);
}
/*
* Run eofblocks scans on the quotas applicable to the inode. For inodes with
* multiple quotas, we don't know exactly which quota caused an allocation
* failure. We make a best effort by including each quota under low free space
* conditions (less than 1% free space) in the scan.
*/
static int
__xfs_inode_free_quota_eofblocks(
struct xfs_inode *ip,
int (*execute)(struct xfs_mount *mp,
struct xfs_eofblocks *eofb))
{
int scan = 0;
struct xfs_eofblocks eofb = {0};
struct xfs_dquot *dq;
/*
* Run a sync scan to increase effectiveness and use the union filter to
* cover all applicable quotas in a single scan.
*/
eofb.eof_flags = XFS_EOF_FLAGS_UNION|XFS_EOF_FLAGS_SYNC;
if (XFS_IS_UQUOTA_ENFORCED(ip->i_mount)) {
dq = xfs_inode_dquot(ip, XFS_DQ_USER);
if (dq && xfs_dquot_lowsp(dq)) {
eofb.eof_uid = VFS_I(ip)->i_uid;
eofb.eof_flags |= XFS_EOF_FLAGS_UID;
scan = 1;
}
}
if (XFS_IS_GQUOTA_ENFORCED(ip->i_mount)) {
dq = xfs_inode_dquot(ip, XFS_DQ_GROUP);
if (dq && xfs_dquot_lowsp(dq)) {
eofb.eof_gid = VFS_I(ip)->i_gid;
eofb.eof_flags |= XFS_EOF_FLAGS_GID;
scan = 1;
}
}
if (scan)
execute(ip->i_mount, &eofb);
return scan;
}
int
xfs_inode_free_quota_eofblocks(
struct xfs_inode *ip)
{
return __xfs_inode_free_quota_eofblocks(ip, xfs_icache_free_eofblocks);
}
static inline unsigned long
xfs_iflag_for_tag(
int tag)
{
switch (tag) {
case XFS_ICI_EOFBLOCKS_TAG:
return XFS_IEOFBLOCKS;
case XFS_ICI_COWBLOCKS_TAG:
return XFS_ICOWBLOCKS;
default:
ASSERT(0);
return 0;
}
}
static void
__xfs_inode_set_blocks_tag(
xfs_inode_t *ip,
void (*execute)(struct xfs_mount *mp),
void (*set_tp)(struct xfs_mount *mp, xfs_agnumber_t agno,
int error, unsigned long caller_ip),
int tag)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_perag *pag;
int tagged;
/*
* Don't bother locking the AG and looking up in the radix trees
* if we already know that we have the tag set.
*/
if (ip->i_flags & xfs_iflag_for_tag(tag))
return;
spin_lock(&ip->i_flags_lock);
ip->i_flags |= xfs_iflag_for_tag(tag);
spin_unlock(&ip->i_flags_lock);
pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
spin_lock(&pag->pag_ici_lock);
tagged = radix_tree_tagged(&pag->pag_ici_root, tag);
radix_tree_tag_set(&pag->pag_ici_root,
XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino), tag);
if (!tagged) {
/* propagate the eofblocks tag up into the perag radix tree */
spin_lock(&ip->i_mount->m_perag_lock);
radix_tree_tag_set(&ip->i_mount->m_perag_tree,
XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
tag);
spin_unlock(&ip->i_mount->m_perag_lock);
/* kick off background trimming */
execute(ip->i_mount);
set_tp(ip->i_mount, pag->pag_agno, -1, _RET_IP_);
}
spin_unlock(&pag->pag_ici_lock);
xfs_perag_put(pag);
}
void
xfs_inode_set_eofblocks_tag(
xfs_inode_t *ip)
{
trace_xfs_inode_set_eofblocks_tag(ip);
return __xfs_inode_set_blocks_tag(ip, xfs_queue_eofblocks,
trace_xfs_perag_set_eofblocks,
XFS_ICI_EOFBLOCKS_TAG);
}
static void
__xfs_inode_clear_blocks_tag(
xfs_inode_t *ip,
void (*clear_tp)(struct xfs_mount *mp, xfs_agnumber_t agno,
int error, unsigned long caller_ip),
int tag)
{
struct xfs_mount *mp = ip->i_mount;
struct xfs_perag *pag;
spin_lock(&ip->i_flags_lock);
ip->i_flags &= ~xfs_iflag_for_tag(tag);
spin_unlock(&ip->i_flags_lock);
pag = xfs_perag_get(mp, XFS_INO_TO_AGNO(mp, ip->i_ino));
spin_lock(&pag->pag_ici_lock);
radix_tree_tag_clear(&pag->pag_ici_root,
XFS_INO_TO_AGINO(ip->i_mount, ip->i_ino), tag);
if (!radix_tree_tagged(&pag->pag_ici_root, tag)) {
/* clear the eofblocks tag from the perag radix tree */
spin_lock(&ip->i_mount->m_perag_lock);
radix_tree_tag_clear(&ip->i_mount->m_perag_tree,
XFS_INO_TO_AGNO(ip->i_mount, ip->i_ino),
tag);
spin_unlock(&ip->i_mount->m_perag_lock);
clear_tp(ip->i_mount, pag->pag_agno, -1, _RET_IP_);
}
spin_unlock(&pag->pag_ici_lock);
xfs_perag_put(pag);
}
void
xfs_inode_clear_eofblocks_tag(
xfs_inode_t *ip)
{
trace_xfs_inode_clear_eofblocks_tag(ip);
return __xfs_inode_clear_blocks_tag(ip,
trace_xfs_perag_clear_eofblocks, XFS_ICI_EOFBLOCKS_TAG);
}
/*
* Set ourselves up to free CoW blocks from this file. If it's already clean
* then we can bail out quickly, but otherwise we must back off if the file
* is undergoing some kind of write.
*/
static bool
xfs_prep_free_cowblocks(
struct xfs_inode *ip)
{
/*
* Just clear the tag if we have an empty cow fork or none at all. It's
* possible the inode was fully unshared since it was originally tagged.
*/
if (!xfs_inode_has_cow_data(ip)) {
trace_xfs_inode_free_cowblocks_invalid(ip);
xfs_inode_clear_cowblocks_tag(ip);
return false;
}
/*
* If the mapping is dirty or under writeback we cannot touch the
* CoW fork. Leave it alone if we're in the midst of a directio.
*/
if ((VFS_I(ip)->i_state & I_DIRTY_PAGES) ||
mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_DIRTY) ||
mapping_tagged(VFS_I(ip)->i_mapping, PAGECACHE_TAG_WRITEBACK) ||
atomic_read(&VFS_I(ip)->i_dio_count))
return false;
return true;
}
/*
* Automatic CoW Reservation Freeing
*
* These functions automatically garbage collect leftover CoW reservations
* that were made on behalf of a cowextsize hint when we start to run out
* of quota or when the reservations sit around for too long. If the file
* has dirty pages or is undergoing writeback, its CoW reservations will
* be retained.
*
* The actual garbage collection piggybacks off the same code that runs
* the speculative EOF preallocation garbage collector.
*/
STATIC int
xfs_inode_free_cowblocks(
struct xfs_inode *ip,
int flags,
void *args)
{
struct xfs_eofblocks *eofb = args;
int match;
int ret = 0;
if (!xfs_prep_free_cowblocks(ip))
return 0;
if (eofb) {
if (eofb->eof_flags & XFS_EOF_FLAGS_UNION)
match = xfs_inode_match_id_union(ip, eofb);
else
match = xfs_inode_match_id(ip, eofb);
if (!match)
return 0;
/* skip the inode if the file size is too small */
if (eofb->eof_flags & XFS_EOF_FLAGS_MINFILESIZE &&
XFS_ISIZE(ip) < eofb->eof_min_file_size)
return 0;
}
/* Free the CoW blocks */
xfs_ilock(ip, XFS_IOLOCK_EXCL);
xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
/*
* Check again, nobody else should be able to dirty blocks or change
* the reflink iflag now that we have the first two locks held.
*/
if (xfs_prep_free_cowblocks(ip))
ret = xfs_reflink_cancel_cow_range(ip, 0, NULLFILEOFF, false);
xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
xfs_iunlock(ip, XFS_IOLOCK_EXCL);
return ret;
}
int
xfs_icache_free_cowblocks(
struct xfs_mount *mp,
struct xfs_eofblocks *eofb)
{
return __xfs_icache_free_eofblocks(mp, eofb, xfs_inode_free_cowblocks,
XFS_ICI_COWBLOCKS_TAG);
}
int
xfs_inode_free_quota_cowblocks(
struct xfs_inode *ip)
{
return __xfs_inode_free_quota_eofblocks(ip, xfs_icache_free_cowblocks);
}
void
xfs_inode_set_cowblocks_tag(
xfs_inode_t *ip)
{
trace_xfs_inode_set_cowblocks_tag(ip);
return __xfs_inode_set_blocks_tag(ip, xfs_queue_cowblocks,
trace_xfs_perag_set_cowblocks,
XFS_ICI_COWBLOCKS_TAG);
}
void
xfs_inode_clear_cowblocks_tag(
xfs_inode_t *ip)
{
trace_xfs_inode_clear_cowblocks_tag(ip);
return __xfs_inode_clear_blocks_tag(ip,
trace_xfs_perag_clear_cowblocks, XFS_ICI_COWBLOCKS_TAG);
}
/* Disable post-EOF and CoW block auto-reclamation. */
void
xfs_stop_block_reaping(
struct xfs_mount *mp)
{
cancel_delayed_work_sync(&mp->m_eofblocks_work);
cancel_delayed_work_sync(&mp->m_cowblocks_work);
}
/* Enable post-EOF and CoW block auto-reclamation. */
void
xfs_start_block_reaping(
struct xfs_mount *mp)
{
xfs_queue_eofblocks(mp);
xfs_queue_cowblocks(mp);
}