[CIFS] Fix hang in find_writable_file
Caused by unneeded reopen during reconnect while spinlock held.
Fixes kernel bugzilla bug #7903
Thanks to Lin Feng Shen for testing this, and Amit Arora for
some nice problem determination to narrow this down.
Acked-by: Dave Kleikamp <shaggy@us.ibm.com>
Signed-off-by: Steve French <sfrench@us.ibm.com>
diff --git a/fs/cifs/file.c b/fs/cifs/file.c
index e13592a..894b1f7 100644
--- a/fs/cifs/file.c
+++ b/fs/cifs/file.c
@@ -1904,6 +1904,25 @@
return rc;
}
+static int is_inode_writable(struct cifsInodeInfo *cifs_inode)
+{
+ struct cifsFileInfo *open_file;
+
+ read_lock(&GlobalSMBSeslock);
+ list_for_each_entry(open_file, &cifs_inode->openFileList, flist) {
+ if (open_file->closePend)
+ continue;
+ if (open_file->pfile &&
+ ((open_file->pfile->f_flags & O_RDWR) ||
+ (open_file->pfile->f_flags & O_WRONLY))) {
+ read_unlock(&GlobalSMBSeslock);
+ return 1;
+ }
+ }
+ read_unlock(&GlobalSMBSeslock);
+ return 0;
+}
+
/* We do not want to update the file size from server for inodes
open for write - to avoid races with writepage extending
the file - in the future we could consider allowing
@@ -1912,19 +1931,13 @@
page caching in the current Linux kernel design */
int is_size_safe_to_change(struct cifsInodeInfo *cifsInode, __u64 end_of_file)
{
- struct cifsFileInfo *open_file = NULL;
+ if (!cifsInode)
+ return 1;
- if (cifsInode)
- open_file = find_writable_file(cifsInode);
-
- if (open_file) {
+ if (is_inode_writable(cifsInode)) {
+ /* This inode is open for write at least once */
struct cifs_sb_info *cifs_sb;
- /* there is not actually a write pending so let
- this handle go free and allow it to
- be closable if needed */
- atomic_dec(&open_file->wrtPending);
-
cifs_sb = CIFS_SB(cifsInode->vfs_inode.i_sb);
if ( cifs_sb->mnt_cifs_flags & CIFS_MOUNT_DIRECT_IO ) {
/* since no page cache to corrupt on directio