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autofs4: eliminate d_unhashed in path walk checks

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We unhash the dentry (in a subsequent patch) in ->d_revalidate() in order
to send mount requests to ->lookup().  But then we can not rely on
d_unhased() to give reliable results because it may be called at any time
by any code path.  The d_unhashed() function is used by __simple_empty()
in the path walking callbacks but autofs mount point dentrys should have
no directories at all so a list_empty() on d_subdirs should be (and is)
sufficient.

Signed-off-by: Ian Kent <raven@themaw.net>
Cc: Sage Weil <sage@newdream.net>
Cc: Al Viro <viro@ZenIV.linux.org.uk>
Cc: Andreas Dilger <adilger@sun.com>
Cc: Christoph Hellwig <hch@infradead.org>
Cc: Yehuda Saheh <yehuda@newdream.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
This commit is contained in:
Ian Kent 2009-12-15 16:45:48 -08:00 committed by Linus Torvalds
parent 6510c9d859
commit c42c7f7e69
1 changed files with 3 additions and 4 deletions
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7
fs/autofs4/root.c
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@ -133,7 +133,7 @@ static int autofs4_dir_open(struct inode *inode, struct file *file)
* it.
*/
spin_lock(&dcache_lock);
if (!d_mountpoint(dentry) && __simple_empty(dentry)) {
if (!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
spin_unlock(&dcache_lock);
return -ENOENT;
}
@ -257,7 +257,7 @@ static void *autofs4_follow_link(struct dentry *dentry, struct nameidata *nd)
* mount it again.
*/
if (ino->flags & AUTOFS_INF_PENDING ||
(!d_mountpoint(dentry) && __simple_empty(dentry))) {
(!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs))) {
spin_unlock(&dcache_lock);
spin_unlock(&sbi->fs_lock);
@ -340,8 +340,7 @@ static int autofs4_revalidate(struct dentry *dentry, struct nameidata *nd)
/* Check for a non-mountpoint directory with no contents */
spin_lock(&dcache_lock);
if (S_ISDIR(dentry->d_inode->i_mode) &&
!d_mountpoint(dentry) &&
__simple_empty(dentry)) {
!d_mountpoint(dentry) && list_empty(&dentry->d_subdirs)) {
DPRINTK("dentry=%p %.*s, emptydir",
dentry, dentry->d_name.len, dentry->d_name.name);
spin_unlock(&dcache_lock);