diff options
| author | Steve French <stfrench@microsoft.com> | 2024-05-14 01:02:05 +0300 |
|---|---|---|
| committer | Steve French <stfrench@microsoft.com> | 2024-05-14 01:02:05 +0300 |
| commit | 14b1cd25346b1d615616a9c2dfdad9b4e6581e0d (patch) | |
| tree | 509f7d1f8107d435be4e1991f63c3bec152c8c2b /fs | |
| parent | 29b4c7bb8565118e2c7e08709fce0dbe8bf61011 (diff) | |
| download | linux-14b1cd25346b1d615616a9c2dfdad9b4e6581e0d.tar.xz | |
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')
| -rw-r--r-- | fs/netfs/direct_read.c | 3 | ||||
| -rw-r--r-- | fs/smb/client/cifsglob.h | 1 | ||||
| -rw-r--r-- | fs/smb/client/file.c | 34 |
3 files changed, 28 insertions, 10 deletions
diff --git a/fs/netfs/direct_read.c b/fs/netfs/direct_read.c index ad4370b3935d..10a1e4da6bda 100644 --- a/fs/netfs/direct_read.c +++ b/fs/netfs/direct_read.c @@ -26,7 +26,7 @@ * * The caller must hold any appropriate locks. */ -static ssize_t netfs_unbuffered_read_iter_locked(struct kiocb *iocb, struct iov_iter *iter) +ssize_t netfs_unbuffered_read_iter_locked(struct kiocb *iocb, struct iov_iter *iter) { struct netfs_io_request *rreq; ssize_t ret; @@ -98,6 +98,7 @@ out: iov_iter_revert(iter, orig_count - iov_iter_count(iter)); return ret; } +EXPORT_SYMBOL(netfs_unbuffered_read_iter_locked); /** * netfs_unbuffered_read_iter - Perform an unbuffered or direct I/O read 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; } |