diff options
Diffstat (limited to 'fs/xfs/xfs_reflink.c')
| -rw-r--r-- | fs/xfs/xfs_reflink.c | 63 |
1 files changed, 37 insertions, 26 deletions
diff --git a/fs/xfs/xfs_reflink.c b/fs/xfs/xfs_reflink.c index c4ec7afd1170..edbe37b7f636 100644 --- a/fs/xfs/xfs_reflink.c +++ b/fs/xfs/xfs_reflink.c @@ -1190,11 +1190,11 @@ xfs_reflink_remap_blocks( } /* - * Grab the exclusive iolock for a data copy from src to dest, making - * sure to abide vfs locking order (lowest pointer value goes first) and - * breaking the pnfs layout leases on dest before proceeding. The loop - * is needed because we cannot call the blocking break_layout() with the - * src iolock held, and therefore have to back out both locks. + * Grab the exclusive iolock for a data copy from src to dest, making sure to + * abide vfs locking order (lowest pointer value goes first) and breaking the + * layout leases before proceeding. The loop is needed because we cannot call + * the blocking break_layout() with the iolocks held, and therefore have to + * back out both locks. */ static int xfs_iolock_two_inodes_and_break_layout( @@ -1203,33 +1203,44 @@ xfs_iolock_two_inodes_and_break_layout( { int error; -retry: - if (src < dest) { - inode_lock_shared(src); - inode_lock_nested(dest, I_MUTEX_NONDIR2); - } else { - /* src >= dest */ - inode_lock(dest); - } + if (src > dest) + swap(src, dest); - error = break_layout(dest, false); - if (error == -EWOULDBLOCK) { - inode_unlock(dest); - if (src < dest) - inode_unlock_shared(src); +retry: + /* Wait to break both inodes' layouts before we start locking. */ + error = break_layout(src, true); + if (error) + return error; + if (src != dest) { error = break_layout(dest, true); if (error) return error; - goto retry; } + + /* Lock one inode and make sure nobody got in and leased it. */ + inode_lock(src); + error = break_layout(src, false); if (error) { + inode_unlock(src); + if (error == -EWOULDBLOCK) + goto retry; + return error; + } + + if (src == dest) + return 0; + + /* Lock the other inode and make sure nobody got in and leased it. */ + inode_lock_nested(dest, I_MUTEX_NONDIR2); + error = break_layout(dest, false); + if (error) { + inode_unlock(src); inode_unlock(dest); - if (src < dest) - inode_unlock_shared(src); + if (error == -EWOULDBLOCK) + goto retry; return error; } - if (src > dest) - inode_lock_shared_nested(src, I_MUTEX_NONDIR2); + return 0; } @@ -1247,10 +1258,10 @@ xfs_reflink_remap_unlock( xfs_iunlock(dest, XFS_MMAPLOCK_EXCL); if (!same_inode) - xfs_iunlock(src, XFS_MMAPLOCK_SHARED); + xfs_iunlock(src, XFS_MMAPLOCK_EXCL); inode_unlock(inode_out); if (!same_inode) - inode_unlock_shared(inode_in); + inode_unlock(inode_in); } /* @@ -1325,7 +1336,7 @@ xfs_reflink_remap_prep( if (same_inode) xfs_ilock(src, XFS_MMAPLOCK_EXCL); else - xfs_lock_two_inodes(src, XFS_MMAPLOCK_SHARED, dest, + xfs_lock_two_inodes(src, XFS_MMAPLOCK_EXCL, dest, XFS_MMAPLOCK_EXCL); /* Check file eligibility and prepare for block sharing. */ |