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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
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()
-rw-r--r--Documentation/filesystems/porting11
-rw-r--r--drivers/staging/erofs/namei.c19
-rw-r--r--fs/btrfs/inode.c12
3 files changed, 21 insertions, 21 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.
diff --git a/drivers/staging/erofs/namei.c b/drivers/staging/erofs/namei.c
index 546a47156101..8cf0617d4ea0 100644
--- a/drivers/staging/erofs/namei.c
+++ b/drivers/staging/erofs/namei.c
@@ -223,18 +223,13 @@ static struct dentry *erofs_lookup(struct inode *dir,
if (err == -ENOENT) {
/* negative dentry */
inode = NULL;
- goto negative_out;
- } else if (unlikely(err))
- return ERR_PTR(err);
-
- debugln("%s, %s (nid %llu) found, d_type %u", __func__,
- dentry->d_name.name, nid, d_type);
-
- inode = erofs_iget(dir->i_sb, nid, d_type == EROFS_FT_DIR);
- if (IS_ERR(inode))
- return ERR_CAST(inode);
-
-negative_out:
+ } else if (unlikely(err)) {
+ inode = ERR_PTR(err);
+ } else {
+ debugln("%s, %s (nid %llu) found, d_type %u", __func__,
+ dentry->d_name.name, nid, d_type);
+ inode = erofs_iget(dir->i_sb, nid, d_type == EROFS_FT_DIR);
+ }
return d_splice_alias(inode, dentry);
}
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index f22f77172c5f..181c58b23110 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -5764,16 +5764,10 @@ static int btrfs_dentry_delete(const struct dentry *dentry)
static struct dentry *btrfs_lookup(struct inode *dir, struct dentry *dentry,
unsigned int flags)
{
- struct inode *inode;
-
- inode = btrfs_lookup_dentry(dir, dentry);
- if (IS_ERR(inode)) {
- if (PTR_ERR(inode) == -ENOENT)
- inode = NULL;
- else
- return ERR_CAST(inode);
- }
+ struct inode *inode = btrfs_lookup_dentry(dir, dentry);
+ if (inode == ERR_PTR(-ENOENT))
+ inode = NULL;
return d_splice_alias(inode, dentry);
}