diff options
| -rw-r--r-- | fs/xfs/linux-2.6/xfs_buf.c | 35 |
1 files changed, 16 insertions, 19 deletions
diff --git a/fs/xfs/linux-2.6/xfs_buf.c b/fs/xfs/linux-2.6/xfs_buf.c index aa1d353def29..4c5deb6e9e31 100644 --- a/fs/xfs/linux-2.6/xfs_buf.c +++ b/fs/xfs/linux-2.6/xfs_buf.c @@ -488,29 +488,16 @@ found: spin_unlock(&pag->pag_buf_lock); xfs_perag_put(pag); - /* Attempt to get the semaphore without sleeping, - * if this does not work then we need to drop the - * spinlock and do a hard attempt on the semaphore. - */ - if (down_trylock(&bp->b_sema)) { + if (xfs_buf_cond_lock(bp)) { + /* failed, so wait for the lock if requested. */ if (!(flags & XBF_TRYLOCK)) { - /* wait for buffer ownership */ xfs_buf_lock(bp); XFS_STATS_INC(xb_get_locked_waited); } else { - /* We asked for a trylock and failed, no need - * to look at file offset and length here, we - * know that this buffer at least overlaps our - * buffer and is locked, therefore our buffer - * either does not exist, or is this buffer. - */ xfs_buf_rele(bp); XFS_STATS_INC(xb_busy_locked); return NULL; } - } else { - /* trylock worked */ - XB_SET_OWNER(bp); } if (bp->b_flags & XBF_STALE) { @@ -876,10 +863,18 @@ xfs_buf_rele( */ /* - * Locks a buffer object, if it is not already locked. - * Note that this in no way locks the underlying pages, so it is only - * useful for synchronizing concurrent use of buffer objects, not for - * synchronizing independent access to the underlying pages. + * Locks a buffer object, if it is not already locked. Note that this in + * no way locks the underlying pages, so it is only useful for + * synchronizing concurrent use of buffer objects, not for synchronizing + * independent access to the underlying pages. + * + * If we come across a stale, pinned, locked buffer, we know that we are + * being asked to lock a buffer that has been reallocated. Because it is + * pinned, we know that the log has not been pushed to disk and hence it + * will still be locked. Rather than continuing to have trylock attempts + * fail until someone else pushes the log, push it ourselves before + * returning. This means that the xfsaild will not get stuck trying + * to push on stale inode buffers. */ int xfs_buf_cond_lock( @@ -890,6 +885,8 @@ xfs_buf_cond_lock( locked = down_trylock(&bp->b_sema) == 0; if (locked) XB_SET_OWNER(bp); + else if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) + xfs_log_force(bp->b_target->bt_mount, 0); trace_xfs_buf_cond_lock(bp, _RET_IP_); return locked ? 0 : -EBUSY; |