Attachment 6063 Details for Bug 7792 – patch - don't take extra tlink reference in cifs_initiate_search

[patch] patch - don't take extra tlink reference in cifs_initiate_search

0001-cifs-don-t-take-extra-tlink-reference-in-initiate_ci.patch (text/plain), 2.28 KB, created by Jeff Layton on 2010-11-11 13:32:20 UTC

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Creator: Jeff Layton

Created: 2010-11-11 13:32:20 UTC

Size: 2.28 KB

patch

obsolete

>From ca58a9c1c9d638dee4ee5f5c5961598b39e7ab9b Mon Sep 17 00:00:00 2001
>From: Jeff Layton <jlayton@redhat.com>
>Date: Thu, 11 Nov 2010 14:28:24 -0500
>Subject: [PATCH] cifs: don't take extra tlink reference in initiate_cifs_search
>
>It's possible for initiate_cifs_search to be called on a filp that
>already has private_data attached. If this happens, we'll end up
>calling cifs_sb_tlink, taking an extra reference to the tlink and
>attaching that to the cifsFileInfo. This leads to refcount leaks
>that manifest as a "stuck" cifsd at umount time.
>
>Fix this by only looking up the tlink for the cifsFile on the filp's
>first pass through this function. When called on a filp that already
>has cifsFileInfo associated with it, just use the tlink reference
>that it already owns.
>
>Signed-off-by: Jeff Layton <jlayton@redhat.com>
>---
> fs/cifs/readdir.c |   28 ++++++++++++++++------------
> 1 files changed, 16 insertions(+), 12 deletions(-)
>
>diff --git a/fs/cifs/readdir.c b/fs/cifs/readdir.c
>index c8961c5..0d8bf97 100644
>--- a/fs/cifs/readdir.c
>+++ b/fs/cifs/readdir.c
>@@ -227,26 +227,30 @@ static int initiate_cifs_search(const int xid, struct file *file)
> 	char *full_path = NULL;
> 	struct cifsFileInfo *cifsFile;
> 	struct cifs_sb_info *cifs_sb = CIFS_SB(file->f_path.dentry->d_sb);
>-	struct tcon_link *tlink;
>+	struct tcon_link *tlink = NULL;
> 	struct cifsTconInfo *pTcon;
> 
>-	tlink = cifs_sb_tlink(cifs_sb);
>-	if (IS_ERR(tlink))
>-		return PTR_ERR(tlink);
>-	pTcon = tlink_tcon(tlink);
>-
>-	if (file->private_data == NULL)
>-		file->private_data =
>-			kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
> 	if (file->private_data == NULL) {
>-		rc = -ENOMEM;
>-		goto error_exit;
>+		tlink = cifs_sb_tlink(cifs_sb);
>+		if (IS_ERR(tlink))
>+			return PTR_ERR(tlink);
>+
>+		cifsFile = kzalloc(sizeof(struct cifsFileInfo), GFP_KERNEL);
>+		if (cifsFile == NULL) {
>+			rc = -ENOMEM;
>+			goto error_exit;
>+		}
>+		file->private_data = cifsFile;
>+		cifsFile->tlink = cifs_get_tlink(tlink);
>+		pTcon = tlink_tcon(tlink);
>+	} else {
>+		cifsFile = file->private_data;
>+		pTcon = tlink_tcon(cifsFile->tlink);
> 	}
> 
> 	cifsFile = file->private_data;
> 	cifsFile->invalidHandle = true;
> 	cifsFile->srch_inf.endOfSearch = false;
>-	cifsFile->tlink = cifs_get_tlink(tlink);
> 
> 	full_path = build_path_from_dentry(file->f_path.dentry);
> 	if (full_path == NULL) {
>-- 
>1.7.2.3
>

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Attachments on bug 7792: 6058 | 6059 | 6060 | 6061 | 6063 | 6064