Attachment 635685 Details for Bug 867344 – cifs: Do not lookup hashed negative dentry in cifs_atomic_open

[patch] cifs: Do not lookup hashed negative dentry in cifs_atomic_open

0001-cifs-Do-not-lookup-hashed-negative-dentry-in-cifs_at.patch (text/plain), 1.15 KB, created by Sachin Prabhu on 2012-10-30 16:18:59 UTC

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Creator: Sachin Prabhu

Created: 2012-10-30 16:18:59 UTC

Size: 1.15 KB

patch

obsolete

>From ae1fea6432971c9e9ed0e775c858122bb65616eb Mon Sep 17 00:00:00 2001
>From: Sachin Prabhu <sprabhu@redhat.com>
>Date: Tue, 30 Oct 2012 15:42:08 +0000
>Subject: [PATCH] cifs: Do not lookup hashed negative dentry in
> cifs_atomic_open
>
>We do not need to lookup a hashed negative directory since we have
>already revalidated it before and have found it to be fine.
>
>This also prevents a crash in cifs_lookup() when it attempts to rehash
>the already hashed negative lookup dentry.
>
>Signed-off-by: Sachin Prabhu <sprabhu@redhat.com>
>---
> fs/cifs/dir.c | 6 ++++++
> 1 file changed, 6 insertions(+)
>
>diff --git a/fs/cifs/dir.c b/fs/cifs/dir.c
>index 7c0a812..e26d0a6 100644
>--- a/fs/cifs/dir.c
>+++ b/fs/cifs/dir.c
>@@ -398,6 +398,12 @@ cifs_atomic_open(struct inode *inode, struct dentry *direntry,
> 	 * in network traffic in the other paths.
> 	 */
> 	if (!(oflags & O_CREAT)) {
>+		/* Check for hashed negative dentry. We have already revalidated
>+		 * the dentry and it is fine. No need to perform another lookup.
>+		 */
>+		if (!d_unhashed(direntry))
>+			return -ENOENT;
>+
> 		struct dentry *res = cifs_lookup(inode, direntry, 0);
> 		if (IS_ERR(res))
> 			return PTR_ERR(res);
>-- 
>1.7.11.7
>

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Attachments on bug 867344: 629053 | 635685