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path: root/fs/xfs/xfs_reflink.c
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Diffstat (limited to 'fs/xfs/xfs_reflink.c')
-rw-r--r--fs/xfs/xfs_reflink.c63
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. */