summaryrefslogtreecommitdiff
path: root/Documentation/filesystems
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2018-10-25 12:55:31 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2018-10-25 12:55:31 -0700
commit4ba9628fe5bf90e0125dbec847a0cf4f5553de14 (patch)
tree5dc0dd56eb05d834c8df575ba1b07d474f54c22c /Documentation/filesystems
parent06999fd59277afef07638453c695a500eb2a93c0 (diff)
parent1a16dbaf798c5b68ac767444eb045e6f3adaa16d (diff)
Merge branch 'work.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull more ->lookup() cleanups from Al Viro: "Some ->lookup() instances are still overcomplicating the life for themselves, open-coding the stuff that would be handled by d_splice_alias() just fine. Simplify a couple of such cases caught this cycle and document d_splice_alias() intended use" * 'work.lookup' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: Document d_splice_alias() calling conventions for ->lookup() users. simplify btrfs_lookup() clean erofs_lookup()
Diffstat (limited to 'Documentation/filesystems')
-rw-r--r--Documentation/filesystems/porting11
1 files changed, 11 insertions, 0 deletions
diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting
index 7b7b845c490a..321d74b73937 100644
--- a/Documentation/filesystems/porting
+++ b/Documentation/filesystems/porting
@@ -622,3 +622,14 @@ in your dentry operations instead.
alloc_file_clone(file, flags, ops) does not affect any caller's references.
On success you get a new struct file sharing the mount/dentry with the
original, on failure - ERR_PTR().
+--
+[recommended]
+ ->lookup() instances doing an equivalent of
+ if (IS_ERR(inode))
+ return ERR_CAST(inode);
+ return d_splice_alias(inode, dentry);
+ don't need to bother with the check - d_splice_alias() will do the
+ right thing when given ERR_PTR(...) as inode. Moreover, passing NULL
+ inode to d_splice_alias() will also do the right thing (equivalent of
+ d_add(dentry, NULL); return NULL;), so that kind of special cases
+ also doesn't need a separate treatment.