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5e0829c0 GKH |
1 | From 6dfbd84684700cb58b34e8602c01c12f3d2595c8 Mon Sep 17 00:00:00 2001 |
2 | From: Pavel Shilovsky <piastryyy@gmail.com> | |
3 | Date: Mon, 4 Mar 2019 17:48:01 -0800 | |
4 | Subject: CIFS: Fix read after write for files with read caching | |
5 | ||
6 | From: Pavel Shilovsky <piastryyy@gmail.com> | |
7 | ||
8 | commit 6dfbd84684700cb58b34e8602c01c12f3d2595c8 upstream. | |
9 | ||
10 | When we have a READ lease for a file and have just issued a write | |
11 | operation to the server we need to purge the cache and set oplock/lease | |
12 | level to NONE to avoid reading stale data. Currently we do that | |
13 | only if a write operation succedeed thus not covering cases when | |
14 | a request was sent to the server but a negative error code was | |
15 | returned later for some other reasons (e.g. -EIOCBQUEUED or -EINTR). | |
16 | Fix this by turning off caching regardless of the error code being | |
17 | returned. | |
18 | ||
19 | The patches fixes generic tests 075 and 112 from the xfs-tests. | |
20 | ||
21 | Cc: <stable@vger.kernel.org> | |
22 | Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> | |
23 | Signed-off-by: Steve French <stfrench@microsoft.com> | |
24 | Reviewed-by: Ronnie Sahlberg <lsahlber@redhat.com> | |
25 | Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org> | |
26 | ||
27 | --- | |
28 | fs/cifs/file.c | 12 +++++++----- | |
29 | 1 file changed, 7 insertions(+), 5 deletions(-) | |
30 | ||
31 | --- a/fs/cifs/file.c | |
32 | +++ b/fs/cifs/file.c | |
33 | @@ -2772,14 +2772,16 @@ cifs_strict_writev(struct kiocb *iocb, s | |
34 | * these pages but not on the region from pos to ppos+len-1. | |
35 | */ | |
36 | written = cifs_user_writev(iocb, from); | |
37 | - if (written > 0 && CIFS_CACHE_READ(cinode)) { | |
38 | + if (CIFS_CACHE_READ(cinode)) { | |
39 | /* | |
40 | - * Windows 7 server can delay breaking level2 oplock if a write | |
41 | - * request comes - break it on the client to prevent reading | |
42 | - * an old data. | |
43 | + * We have read level caching and we have just sent a write | |
44 | + * request to the server thus making data in the cache stale. | |
45 | + * Zap the cache and set oplock/lease level to NONE to avoid | |
46 | + * reading stale data from the cache. All subsequent read | |
47 | + * operations will read new data from the server. | |
48 | */ | |
49 | cifs_zap_mapping(inode); | |
50 | - cifs_dbg(FYI, "Set no oplock for inode=%p after a write operation\n", | |
51 | + cifs_dbg(FYI, "Set Oplock/Lease to NONE for inode=%p after write\n", | |
52 | inode); | |
53 | cinode->oplock = 0; | |
54 | } |