diff options
| author | Jeff Layton <jlayton@redhat.com> | 2012-07-25 14:59:54 -0400 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2012-08-09 08:22:54 -0700 |
| commit | a130e9e48f95bbec9cb9b8ac3f938e552760fbf6 (patch) | |
| tree | 58c684729ce73beeb9ace1817634a91a4bb0a71d /fs | |
| parent | 6f51cd3bb2b88c2da4666ff9a6f3a8d9b04875ad (diff) | |
cifs: ensure that we always do cifsFileInfo_get under the spinlock
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 <pshilovsky@samba.org>
Signed-off-by: Jeff Layton <jlayton@redhat.com>
Signed-off-by: Steve French <smfrench@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/cifs/cifsglob.h | 6 | ||||
| -rw-r--r-- | fs/cifs/file.c | 17 |
2 files changed, 15 insertions, 8 deletions
diff --git a/fs/cifs/cifsglob.h b/fs/cifs/cifsglob.h index 6df0cbe1cbc9..d86ba9f25193 100644 --- 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); /* diff --git a/fs/cifs/file.c b/fs/cifs/file.c index 513adbc211d7..2cbda4eb9e1e 100644 --- a/fs/cifs/file.c +++ b/fs/cifs/file.c @@ -284,6 +284,15 @@ cifs_new_fileinfo(__u16 fileHandle, struct file *file, 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(struct cifsInodeInfo *cifs_inode, 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 *file, struct address_space *mapping, 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; |