This is a note to let you know that I've just added the patch titled
cifs: ensure that we always do cifsFileInfo_get under the spinlock
to the 3.5-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary
The filename of the patch is:
cifs-ensure-that-we-always-do-cifsfileinfo_get-under-the-spinlock.patch
and it can be found in the queue-3.5 subdirectory.
If you, or anyone else, feels it should not be added to the stable tree,
please let <[email protected]> know about it.
>From 764a1b1acecedfe204cb2e80d8e2cc7c6df1b0b8 Mon Sep 17 00:00:00 2001
From: Jeff Layton <[email protected]>
Date: Wed, 25 Jul 2012 14:59:54 -0400
Subject: cifs: ensure that we always do cifsFileInfo_get under the spinlock
From: Jeff Layton <[email protected]>
commit 764a1b1acecedfe204cb2e80d8e2cc7c6df1b0b8 upstream.
The readpages bug is a regression that was introduced in 6993f74a5.
This also fixes a couple of similar bugs in the uncached read and write
codepaths.
Also, prevent this sort of thing in the future by having cifsFileInfo_get
take the spinlock itself, and adding a _locked variant for use in places
that are already holding the lock. The _put code has always done that
so this makes for a less confusing interface.
Reviewed-by: Pavel Shilovsky <[email protected]>
Signed-off-by: Jeff Layton <[email protected]>
Signed-off-by: Steve French <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>
---
fs/cifs/cifsglob.h | 6 +++---
fs/cifs/file.c | 17 ++++++++++++-----
2 files changed, 15 insertions(+), 8 deletions(-)
--- a/fs/cifs/cifsglob.h
+++ b/fs/cifs/cifsglob.h
@@ -657,13 +657,13 @@ struct cifs_io_parms {
* Take a reference on the file private data. Must be called with
* cifs_file_list_lock held.
*/
-static inline
-struct cifsFileInfo *cifsFileInfo_get(struct cifsFileInfo *cifs_file)
+static inline void
+cifsFileInfo_get_locked(struct cifsFileInfo *cifs_file)
{
++cifs_file->count;
- return cifs_file;
}
+struct cifsFileInfo *cifsFileInfo_get(struct cifsFileInfo *cifs_file);
void cifsFileInfo_put(struct cifsFileInfo *cifs_file);
/*
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -284,6 +284,15 @@ cifs_new_fileinfo(__u16 fileHandle, stru
static void cifs_del_lock_waiters(struct cifsLockInfo *lock);
+struct cifsFileInfo *
+cifsFileInfo_get(struct cifsFileInfo *cifs_file)
+{
+ spin_lock(&cifs_file_list_lock);
+ cifsFileInfo_get_locked(cifs_file);
+ spin_unlock(&cifs_file_list_lock);
+ return cifs_file;
+}
+
/*
* Release a reference on the file private data. This may involve closing
* the filehandle out on the server. Must be called without holding
@@ -1563,7 +1572,7 @@ struct cifsFileInfo *find_readable_file(
if (!open_file->invalidHandle) {
/* found a good file */
/* lock it so it will not be closed on us */
- cifsFileInfo_get(open_file);
+ cifsFileInfo_get_locked(open_file);
spin_unlock(&cifs_file_list_lock);
return open_file;
} /* else might as well continue, and look for
@@ -1615,7 +1624,7 @@ refind_writable:
if (OPEN_FMODE(open_file->f_flags) & FMODE_WRITE) {
if (!open_file->invalidHandle) {
/* found a good writable file */
- cifsFileInfo_get(open_file);
+ cifsFileInfo_get_locked(open_file);
spin_unlock(&cifs_file_list_lock);
return open_file;
} else {
@@ -1632,7 +1641,7 @@ refind_writable:
if (inv_file) {
any_available = false;
- cifsFileInfo_get(inv_file);
+ cifsFileInfo_get_locked(inv_file);
}
spin_unlock(&cifs_file_list_lock);
@@ -3082,8 +3091,6 @@ static int cifs_readpages(struct file *f
break;
}
- spin_lock(&cifs_file_list_lock);
- spin_unlock(&cifs_file_list_lock);
rdata->cfile = cifsFileInfo_get(open_file);
rdata->mapping = mapping;
rdata->offset = offset;
Patches currently in stable-queue which might be from [email protected] are
queue-3.5/cifs-ensure-that-we-always-do-cifsfileinfo_get-under-the-spinlock.patch
queue-3.5/cifs-reinstate-sec-ntlmv2-mount-option.patch
--
To unsubscribe from this list: send the line "unsubscribe stable" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
