From: Darrick J. Wong <djwong@xxxxxxxxxx>
Quite a few patches from now, we're going to change the parent pointer
xattr format to encode as much of the dirent name in the xattr name as
fits, and spill the rest of it to the xattr value. To make this work
correctly, we'll be adding the ability to look up xattrs based on name
/and/ value.
Internally, the xattr data structure supports attributes with a zero
length value, which is how we're going to store parent pointers for
short dirent names. The parent pointer repair code uses xfs_attr_set to
add missing and remove dangling parent pointers, so that interface must
be capable of setting an xattr with args->value == NULL.
The userspace API doesn't support this, so xfs_attr_set currently treats
a NULL args->value as a request to remove an attr. However, that's a
quirk of the existing callers and the interface. Make the callers of
xfs_attr_set to declare explicitly that they want to remove an xattr.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
fs/xfs/libxfs/xfs_attr.c | 9 +++++----
fs/xfs/xfs_xattr.c | 5 +++++
2 files changed, 10 insertions(+), 4 deletions(-)
diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c
index e28d93d232de..1518b786cdaa 100644
--- a/fs/xfs/libxfs/xfs_attr.c
+++ b/fs/xfs/libxfs/xfs_attr.c
@@ -967,6 +967,7 @@ xfs_attr_set(
struct xfs_mount *mp = dp->i_mount;
struct xfs_trans_res tres;
bool rsvd = (args->attr_filter & XFS_ATTR_ROOT);
+ bool is_remove = args->op_flags & XFS_DA_OP_REMOVE;
int error, local;
int rmt_blks = 0;
unsigned int total;
@@ -991,7 +992,7 @@ xfs_attr_set(
args->op_flags = XFS_DA_OP_OKNOENT |
(args->op_flags & XFS_DA_OP_LOGGED);
- if (args->value) {
+ if (!is_remove) {
XFS_STATS_INC(mp, xs_attr_set);
args->total = xfs_attr_calc_size(args, &local);
@@ -1025,7 +1026,7 @@ xfs_attr_set(
if (error)
return error;
- if (args->value || xfs_inode_hasattr(dp)) {
+ if (!is_remove || xfs_inode_hasattr(dp)) {
error = xfs_iext_count_may_overflow(dp, XFS_ATTR_FORK,
XFS_IEXT_ATTR_MANIP_CNT(rmt_blks));
if (error == -EFBIG)
@@ -1039,7 +1040,7 @@ xfs_attr_set(
switch (error) {
case -EEXIST:
/* if no value, we are performing a remove operation */
- if (!args->value) {
+ if (is_remove) {
error = xfs_attr_defer_remove(args);
break;
}
@@ -1051,7 +1052,7 @@ xfs_attr_set(
break;
case -ENOATTR:
/* Can't remove what isn't there. */
- if (!args->value)
+ if (is_remove)
goto out_trans_cancel;
/* Pure replace fails if no existing attr to replace. */
diff --git a/fs/xfs/xfs_xattr.c b/fs/xfs/xfs_xattr.c
index 7b9a0ed1b11f..61779d92295f 100644
--- a/fs/xfs/xfs_xattr.c
+++ b/fs/xfs/xfs_xattr.c
@@ -103,6 +103,11 @@ xfs_attr_change(
use_logging = true;
}
+ if (args->value)
+ args->op_flags &= ~XFS_DA_OP_REMOVE;
+ else
+ args->op_flags |= XFS_DA_OP_REMOVE;
+
error = xfs_attr_set(args);
if (use_logging)
