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path: root/fs/xfs/xfs_buf_item.c
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Diffstat (limited to 'fs/xfs/xfs_buf_item.c')
-rw-r--r--fs/xfs/xfs_buf_item.c64
1 files changed, 35 insertions, 29 deletions
diff --git a/fs/xfs/xfs_buf_item.c b/fs/xfs/xfs_buf_item.c
index e0a11583ce5a..f3c49e69eab9 100644
--- a/fs/xfs/xfs_buf_item.c
+++ b/fs/xfs/xfs_buf_item.c
@@ -467,8 +467,10 @@ xfs_buf_item_unpin_remove(
/*
* This is called to attempt to lock the buffer associated with this
* buf log item. Don't sleep on the buffer lock. If we can't get
- * the lock right away, return 0. If we can get the lock, pull the
- * buffer from the free list, mark it busy, and return 1.
+ * the lock right away, return 0. If we can get the lock, take a
+ * reference to the buffer. If this is a delayed write buffer that
+ * needs AIL help to be written back, invoke the pushbuf routine
+ * rather than the normal success path.
*/
STATIC uint
xfs_buf_item_trylock(
@@ -477,24 +479,18 @@ xfs_buf_item_trylock(
xfs_buf_t *bp;
bp = bip->bli_buf;
-
- if (XFS_BUF_ISPINNED(bp)) {
+ if (XFS_BUF_ISPINNED(bp))
return XFS_ITEM_PINNED;
- }
-
- if (!XFS_BUF_CPSEMA(bp)) {
+ if (!XFS_BUF_CPSEMA(bp))
return XFS_ITEM_LOCKED;
- }
- /*
- * Remove the buffer from the free list. Only do this
- * if it's on the free list. Private buffers like the
- * superblock buffer are not.
- */
+ /* take a reference to the buffer. */
XFS_BUF_HOLD(bp);
ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
trace_xfs_buf_item_trylock(bip);
+ if (XFS_BUF_ISDELAYWRITE(bp))
+ return XFS_ITEM_PUSHBUF;
return XFS_ITEM_SUCCESS;
}
@@ -626,11 +622,9 @@ xfs_buf_item_committed(
}
/*
- * This is called to asynchronously write the buffer associated with this
- * buf log item out to disk. The buffer will already have been locked by
- * a successful call to xfs_buf_item_trylock(). If the buffer still has
- * B_DELWRI set, then get it going out to disk with a call to bawrite().
- * If not, then just release the buffer.
+ * The buffer is locked, but is not a delayed write buffer. This happens
+ * if we race with IO completion and hence we don't want to try to write it
+ * again. Just release the buffer.
*/
STATIC void
xfs_buf_item_push(
@@ -642,17 +636,29 @@ xfs_buf_item_push(
trace_xfs_buf_item_push(bip);
bp = bip->bli_buf;
+ ASSERT(!XFS_BUF_ISDELAYWRITE(bp));
+ xfs_buf_relse(bp);
+}
- if (XFS_BUF_ISDELAYWRITE(bp)) {
- int error;
- error = xfs_bawrite(bip->bli_item.li_mountp, bp);
- if (error)
- xfs_fs_cmn_err(CE_WARN, bip->bli_item.li_mountp,
- "xfs_buf_item_push: pushbuf error %d on bip %p, bp %p",
- error, bip, bp);
- } else {
- xfs_buf_relse(bp);
- }
+/*
+ * The buffer is locked and is a delayed write buffer. Promote the buffer
+ * in the delayed write queue as the caller knows that they must invoke
+ * the xfsbufd to get this buffer written. We have to unlock the buffer
+ * to allow the xfsbufd to write it, too.
+ */
+STATIC void
+xfs_buf_item_pushbuf(
+ xfs_buf_log_item_t *bip)
+{
+ xfs_buf_t *bp;
+
+ ASSERT(!(bip->bli_flags & XFS_BLI_STALE));
+ trace_xfs_buf_item_pushbuf(bip);
+
+ bp = bip->bli_buf;
+ ASSERT(XFS_BUF_ISDELAYWRITE(bp));
+ xfs_buf_delwri_promote(bp);
+ xfs_buf_relse(bp);
}
/* ARGSUSED */
@@ -677,7 +683,7 @@ static struct xfs_item_ops xfs_buf_item_ops = {
.iop_committed = (xfs_lsn_t(*)(xfs_log_item_t*, xfs_lsn_t))
xfs_buf_item_committed,
.iop_push = (void(*)(xfs_log_item_t*))xfs_buf_item_push,
- .iop_pushbuf = NULL,
+ .iop_pushbuf = (void(*)(xfs_log_item_t*))xfs_buf_item_pushbuf,
.iop_committing = (void(*)(xfs_log_item_t*, xfs_lsn_t))
xfs_buf_item_committing
};