/*
* This is called to unpin the buffer associated with the buf log
* item which was previously pinned with a call to xfs_buf_item_pin().
* Just call bunpin() on the buffer to do this.
*
* Also drop the reference to the buf item for the current transaction.
* If the XFS_BLI_STALE flag is set and we are the last reference,
* then free up the buf log item and unlock the buffer.
*/
void
xfs_buf_item_unpin(
xfs_buf_log_item_t *bip,
int stale)
{
xfs_mount_t *mp;
xfs_buf_t *bp;
int freed;
SPLDECL(s);
bp = bip->bli_buf;
ASSERT(bp != NULL);
ASSERT(XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *) == bip);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
xfs_buf_item_trace("UNPIN", bip);
xfs_buftrace("XFS_UNPIN", bp);
freed = atomic_dec_and_test(&bip->bli_refcount);
mp = bip->bli_item.li_mountp;
xfs_bunpin(bp);
if (freed && stale) {
ASSERT(bip->bli_flags & XFS_BLI_STALE);
ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
ASSERT(!(XFS_BUF_ISDELAYWRITE(bp)));
ASSERT(XFS_BUF_ISSTALE(bp));
ASSERT(bip->bli_format.blf_flags & XFS_BLI_CANCEL);
xfs_buf_item_trace("UNPIN STALE", bip);
xfs_buftrace("XFS_UNPIN STALE", bp);
/*
* If we get called here because of an IO error, we may
* or may not have the item on the AIL. xfs_trans_delete_ail()
* will take care of that situation.
* xfs_trans_delete_ail() drops the AIL lock.
*/
if (bip->bli_flags & XFS_BLI_STALE_INODE) {
xfs_buf_do_callbacks(bp, (xfs_log_item_t *)bip);
XFS_BUF_SET_FSPRIVATE(bp, NULL);
XFS_BUF_CLR_IODONE_FUNC(bp);
} else {
AIL_LOCK(mp,s);
xfs_trans_delete_ail(mp, (xfs_log_item_t *)bip, s);
xfs_buf_item_relse(bp);
ASSERT(XFS_BUF_FSPRIVATE(bp, void *) == NULL);
}
xfs_buf_relse(bp);
}
/*
* This is called to unpin the buffer associated with the buf log
* item which was previously pinned with a call to xfs_buf_item_pin().
*
* Also drop the reference to the buf item for the current transaction.
* If the XFS_BLI_STALE flag is set and we are the last reference,
* then free up the buf log item and unlock the buffer.
*
* If the remove flag is set we are called from uncommit in the
* forced-shutdown path. If that is true and the reference count on
* the log item is going to drop to zero we need to free the item's
* descriptor in the transaction.
*/
STATIC void
xfs_buf_item_unpin(
struct xfs_log_item *lip,
int remove)
{
struct xfs_buf_log_item *bip = BUF_ITEM(lip);
xfs_buf_t *bp = bip->bli_buf;
struct xfs_ail *ailp = lip->li_ailp;
int stale = bip->bli_flags & XFS_BLI_STALE;
int freed;
ASSERT(XFS_BUF_FSPRIVATE(bp, xfs_buf_log_item_t *) == bip);
ASSERT(atomic_read(&bip->bli_refcount) > 0);
trace_xfs_buf_item_unpin(bip);
freed = atomic_dec_and_test(&bip->bli_refcount);
if (atomic_dec_and_test(&bp->b_pin_count))
wake_up_all(&bp->b_waiters);
if (freed && stale) {
ASSERT(bip->bli_flags & XFS_BLI_STALE);
ASSERT(XFS_BUF_VALUSEMA(bp) <= 0);
ASSERT(!(XFS_BUF_ISDELAYWRITE(bp)));
ASSERT(XFS_BUF_ISSTALE(bp));
ASSERT(bip->bli_format.blf_flags & XFS_BLF_CANCEL);
trace_xfs_buf_item_unpin_stale(bip);
if (remove) {
/*
* If we are in a transaction context, we have to
* remove the log item from the transaction as we are
* about to release our reference to the buffer. If we
* don't, the unlock that occurs later in
* xfs_trans_uncommit() will try to reference the
* buffer which we no longer have a hold on.
*/
if (lip->li_desc)
xfs_trans_del_item(lip);
/*
* Since the transaction no longer refers to the buffer,
* the buffer should no longer refer to the transaction.
*/
XFS_BUF_SET_FSPRIVATE2(bp, NULL);
}
/*
* If we get called here because of an IO error, we may
* or may not have the item on the AIL. xfs_trans_ail_delete()
* will take care of that situation.
* xfs_trans_ail_delete() drops the AIL lock.
*/
if (bip->bli_flags & XFS_BLI_STALE_INODE) {
xfs_buf_do_callbacks(bp);
XFS_BUF_SET_FSPRIVATE(bp, NULL);
XFS_BUF_CLR_IODONE_FUNC(bp);
} else {
spin_lock(&ailp->xa_lock);
xfs_trans_ail_delete(ailp, (xfs_log_item_t *)bip);
xfs_buf_item_relse(bp);
ASSERT(XFS_BUF_FSPRIVATE(bp, void *) == NULL);
}
xfs_buf_relse(bp);
}
/*
* This is the inode flushing I/O completion routine. It is called
* from interrupt level when the buffer containing the inode is
* flushed to disk. It is responsible for removing the inode item
* from the AIL if it has not been re-logged, and unlocking the inode's
* flush lock.
*
* To reduce AIL lock traffic as much as possible, we scan the buffer log item
* list for other inodes that will run this function. We remove them from the
* buffer list so we can process all the inode IO completions in one AIL lock
* traversal.
*/
void
xfs_iflush_done(
struct xfs_buf *bp,
struct xfs_log_item *lip)
{
struct xfs_inode_log_item *iip;
struct xfs_log_item *blip;
struct xfs_log_item *next;
struct xfs_log_item *prev;
struct xfs_ail *ailp = lip->li_ailp;
int need_ail = 0;
/*
* Scan the buffer IO completions for other inodes being completed and
* attach them to the current inode log item.
*/
blip = XFS_BUF_FSPRIVATE(bp, xfs_log_item_t *);
prev = NULL;
while (blip != NULL) {
if (lip->li_cb != xfs_iflush_done) {
prev = blip;
blip = blip->li_bio_list;
continue;
}
/* remove from list */
next = blip->li_bio_list;
if (!prev) {
XFS_BUF_SET_FSPRIVATE(bp, next);
} else {
prev->li_bio_list = next;
}
/* add to current list */
blip->li_bio_list = lip->li_bio_list;
lip->li_bio_list = blip;
/*
* while we have the item, do the unlocked check for needing
* the AIL lock.
*/
iip = INODE_ITEM(blip);
if (iip->ili_logged && blip->li_lsn == iip->ili_flush_lsn)
need_ail++;
blip = next;
}
/* make sure we capture the state of the initial inode. */
iip = INODE_ITEM(lip);
if (iip->ili_logged && lip->li_lsn == iip->ili_flush_lsn)
need_ail++;
/*
* We only want to pull the item from the AIL if it is
* actually there and its location in the log has not
* changed since we started the flush. Thus, we only bother
* if the ili_logged flag is set and the inode's lsn has not
* changed. First we check the lsn outside
* the lock since it's cheaper, and then we recheck while
* holding the lock before removing the inode from the AIL.
*/
if (need_ail) {
struct xfs_log_item *log_items[need_ail];
int i = 0;
spin_lock(&ailp->xa_lock);
for (blip = lip; blip; blip = blip->li_bio_list) {
iip = INODE_ITEM(blip);
if (iip->ili_logged &&
blip->li_lsn == iip->ili_flush_lsn) {
log_items[i++] = blip;
}
ASSERT(i <= need_ail);
}
/* xfs_trans_ail_delete_bulk() drops the AIL lock. */
xfs_trans_ail_delete_bulk(ailp, log_items, i);
}
/*
* clean up and unlock the flush lock now we are done. We can clear the
* ili_last_fields bits now that we know that the data corresponding to
* them is safely on disk.
*/
for (blip = lip; blip; blip = next) {
next = blip->li_bio_list;
blip->li_bio_list = NULL;
iip = INODE_ITEM(blip);
iip->ili_logged = 0;
iip->ili_last_fields = 0;
xfs_ifunlock(iip->ili_inode);
}
}
