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authorGravatar Steve French <stfrench@microsoft.com> 2024-05-13 17:02:05 -0500
committerGravatar Steve French <stfrench@microsoft.com> 2024-05-13 17:02:05 -0500
commit14b1cd25346b1d615616a9c2dfdad9b4e6581e0d (patch)
tree509f7d1f8107d435be4e1991f63c3bec152c8c2b /fs/smb
parentcifs: Change from mempool_destroy to mempool_exit for request pools (diff)
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cifs: Fix locking in cifs_strict_readv()
Fix to take the i_rwsem (through the netfs locking wrappers) before taking cinode->lock_sem. Fixes: 3ee1a1fc3981 ("cifs: Cut over to using netfslib") Reported-by: Enzo Matsumiya <ematsumiya@suse.de> Signed-off-by: David Howells <dhowells@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>
Diffstat (limited to 'fs/smb')
-rw-r--r--fs/smb/client/cifsglob.h1
-rw-r--r--fs/smb/client/file.c34
2 files changed, 26 insertions, 9 deletions
diff --git a/fs/smb/client/cifsglob.h b/fs/smb/client/cifsglob.h
index 65574e69ba4f..73482734a8d8 100644
--- a/fs/smb/client/cifsglob.h
+++ b/fs/smb/client/cifsglob.h
@@ -1995,6 +1995,7 @@ require use of the stronger protocol */
* ->chans_need_reconnect
* ->chans_in_reconnect
* cifs_tcon->tc_lock (anything that is not protected by another lock and can change)
+ * inode->i_rwsem, taken by fs/netfs/locking.c e.g. should be taken before cifsInodeInfo locks
* cifsInodeInfo->open_file_lock cifsInodeInfo->openFileList cifs_alloc_inode
* cifsInodeInfo->writers_lock cifsInodeInfo->writers cifsInodeInfo_alloc
* cifsInodeInfo->lock_sem cifsInodeInfo->llist cifs_init_once
diff --git a/fs/smb/client/file.c b/fs/smb/client/file.c
index 4c981ce89f8a..9d38294a7e68 100644
--- a/fs/smb/client/file.c
+++ b/fs/smb/client/file.c
@@ -2916,16 +2916,32 @@ cifs_strict_readv(struct kiocb *iocb, struct iov_iter *to)
* We need to hold the sem to be sure nobody modifies lock list
* with a brlock that prevents reading.
*/
- down_read(&cinode->lock_sem);
- if (!cifs_find_lock_conflict(cfile, iocb->ki_pos, iov_iter_count(to),
- tcon->ses->server->vals->shared_lock_type,
- 0, NULL, CIFS_READ_OP)) {
- if (iocb->ki_flags & IOCB_DIRECT)
- rc = netfs_unbuffered_read_iter(iocb, to);
- else
- rc = netfs_buffered_read_iter(iocb, to);
+ if (iocb->ki_flags & IOCB_DIRECT) {
+ rc = netfs_start_io_direct(inode);
+ if (rc < 0)
+ goto out;
+ down_read(&cinode->lock_sem);
+ if (!cifs_find_lock_conflict(
+ cfile, iocb->ki_pos, iov_iter_count(to),
+ tcon->ses->server->vals->shared_lock_type,
+ 0, NULL, CIFS_READ_OP))
+ rc = netfs_unbuffered_read_iter_locked(iocb, to);
+ up_read(&cinode->lock_sem);
+ netfs_end_io_direct(inode);
+ } else {
+ rc = netfs_start_io_read(inode);
+ if (rc < 0)
+ goto out;
+ down_read(&cinode->lock_sem);
+ if (!cifs_find_lock_conflict(
+ cfile, iocb->ki_pos, iov_iter_count(to),
+ tcon->ses->server->vals->shared_lock_type,
+ 0, NULL, CIFS_READ_OP))
+ rc = filemap_read(iocb, to, 0);
+ up_read(&cinode->lock_sem);
+ netfs_end_io_read(inode);
}
- up_read(&cinode->lock_sem);
+out:
return rc;
}