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author | Dave Chinner <dchinner@redhat.com> | 2022-05-11 10:02:23 +0300 |
---|---|---|
committer | Dave Chinner <david@fromorbit.com> | 2022-05-11 10:02:23 +0300 |
commit | a4b8917b06c71a4ea61ac45b6e979eb7676417f8 (patch) | |
tree | 83c98132158949a5af15781b1929225cb42cdd8c /fs/xfs/libxfs | |
parent | c5218a7cd97349c53bc64e447778a07e49364d40 (diff) | |
download | linux-a4b8917b06c71a4ea61ac45b6e979eb7676417f8.tar.xz |
xfs: avoid empty xattr transaction when attrs are inline
generic/642 triggered a reproducable assert failure in
xlog_cil_commit() that resulted from a xfs_attr_set() committing
an empty but dirty transaction. When the CIL is empty and this
occurs, xlog_cil_commit() tries a background push and this triggers
a "pushing an empty CIL" assert.
XFS: Assertion failed: !list_empty(&cil->xc_cil), file: fs/xfs/xfs_log_cil.c, line: 1274
Call Trace:
<TASK>
xlog_cil_commit+0xa5a/0xad0
__xfs_trans_commit+0xb8/0x330
xfs_trans_commit+0x10/0x20
xfs_attr_set+0x3e2/0x4c0
xfs_xattr_set+0x8d/0xe0
__vfs_setxattr+0x6b/0x90
__vfs_setxattr_noperm+0x76/0x220
__vfs_setxattr_locked+0xdf/0x100
vfs_setxattr+0x94/0x170
setxattr+0x110/0x200
path_setxattr+0xbf/0xe0
__x64_sys_setxattr+0x2b/0x30
do_syscall_64+0x35/0x80
The problem is related to the breakdown of attribute addition in
xfs_attr_set_iter() and how it is called from deferred operations.
When we have a pure leaf xattr insert, we add the xattr to the leaf
and set the next state to XFS_DAS_FOUND_LBLK and return -EAGAIN.
This requeues the xattr defered work, rolls the transaction and
runs xfs_attr_set_iter() again. This then checks the xattr for
being remote (it's not) and whether a replace op is being done (this
is a create op) and if neither are true it returns without having
done anything.
xfs_xattri_finish_update() then unconditionally sets the transaction
dirty, and the deferops finishes and returns to __xfs_trans_commit()
which sees the transaction dirty and tries to commit it by calling
xlog_cil_commit(). The transaction is empty, and then the assert
fires if this happens when the CIL is empty.
This patch addresses the structure of xfs_attr_set_iter() that
requires re-entry on leaf add even when nothing will be done. This
gets rid of the trailing empty transaction and so doesn't trigger
the XFS_TRANS_DIRTY assignment in xfs_xattri_finish_update()
incorrectly. Addressing that is for a different patch.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Allison Henderson<allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Dave Chinner <david@fromorbit.com>
Diffstat (limited to 'fs/xfs/libxfs')
-rw-r--r-- | fs/xfs/libxfs/xfs_attr.c | 39 |
1 files changed, 19 insertions, 20 deletions
diff --git a/fs/xfs/libxfs/xfs_attr.c b/fs/xfs/libxfs/xfs_attr.c index 3a5f22eae607..98a2a2f89664 100644 --- a/fs/xfs/libxfs/xfs_attr.c +++ b/fs/xfs/libxfs/xfs_attr.c @@ -314,6 +314,7 @@ xfs_attr_leaf_addname( { struct xfs_da_args *args = attr->xattri_da_args; struct xfs_inode *dp = args->dp; + enum xfs_delattr_state next_state = XFS_DAS_UNINIT; int error; if (xfs_attr_is_leaf(dp)) { @@ -334,37 +335,35 @@ xfs_attr_leaf_addname( * when we come back, we'll be a node, so we'll fall * down into the node handling code below */ - trace_xfs_attr_set_iter_return( - attr->xattri_dela_state, args->dp); - return -EAGAIN; + error = -EAGAIN; + goto out; } - - if (error) - return error; - - attr->xattri_dela_state = XFS_DAS_FOUND_LBLK; + next_state = XFS_DAS_FOUND_LBLK; } else { error = xfs_attr_node_addname_find_attr(attr); if (error) return error; + next_state = XFS_DAS_FOUND_NBLK; error = xfs_attr_node_addname(attr); - if (error) - return error; - - /* - * If addname was successful, and we dont need to alloc or - * remove anymore blks, we're done. - */ - if (!args->rmtblkno && - !(args->op_flags & XFS_DA_OP_RENAME)) - return 0; + } + if (error) + return error; - attr->xattri_dela_state = XFS_DAS_FOUND_NBLK; + /* + * We need to commit and roll if we need to allocate remote xattr blocks + * or perform more xattr manipulations. Otherwise there is nothing more + * to do and we can return success. + */ + if (args->rmtblkno || + (args->op_flags & XFS_DA_OP_RENAME)) { + attr->xattri_dela_state = next_state; + error = -EAGAIN; } +out: trace_xfs_attr_leaf_addname_return(attr->xattri_dela_state, args->dp); - return -EAGAIN; + return error; } /* |