projects / ipfire-2.x.git / blame
| Commit | Line | Data |
|---|---|---|
| 2cb7cef9 BS |
1 | From: mason@suse.de |
| 2 | Subject: make sure O_SYNC writes properly return -EIO | |
| 3 | References: bnc#58622 | |
| 4 | ||
| 5 | Make sure to honor the error status of synchronous writeback during | |
| 6 | O_SYNC writes | |
| 7 | ||
| 8 | Acked-by: Jeff Mahoney <jeffm@suse.com> | |
| 9 | ||
| 10 | --- | |
| 11 | mm/filemap.c | 17 +++++++++++++++-- | |
| 12 | 1 file changed, 15 insertions(+), 2 deletions(-) | |
| 13 | ||
| 14 | --- a/mm/filemap.c | |
| 15 | +++ b/mm/filemap.c | |
| 16 | @@ -2498,7 +2498,7 @@ generic_file_buffered_write(struct kiocb | |
| 17 | ||
| 18 | if (likely(status >= 0)) { | |
| 19 | written += status; | |
| 20 | - *ppos = pos + status; | |
| 21 | + pos += status; | |
| 22 | ||
| 23 | /* | |
| 24 | * For now, when the user asks for O_SYNC, we'll actually give | |
| 25 | @@ -2516,10 +2516,23 @@ generic_file_buffered_write(struct kiocb | |
| 26 | * to buffered writes (block instantiation inside i_size). So we sync | |
| 27 | * the file data here, to try to honour O_DIRECT expectations. | |
| 28 | */ | |
| 29 | - if (unlikely(file->f_flags & O_DIRECT) && written) | |
| 30 | + if (unlikely(file->f_flags & O_DIRECT) && status >= 0 && written) | |
| 31 | status = filemap_write_and_wait_range(mapping, | |
| 32 | pos, pos + written - 1); | |
| 33 | ||
| 34 | + /* | |
| 35 | + * We must let know userspace if something hasn't been written | |
| 36 | + * correctly. If we got an I/O error it means we got an hardware | |
| 37 | + * failure, anything can be happening to the on-disk data, | |
| 38 | + * letting know userspace that a bit of data might have been | |
| 39 | + * written correctly on disk is a very low priority, compared | |
| 40 | + * to letting know userspace that some data has _not_ been | |
| 41 | + * written at all. | |
| 42 | + */ | |
| 43 | + if (unlikely(status == -EIO)) | |
| 44 | + return status; | |
| 45 | + *ppos = pos; | |
| 46 | + | |
| 47 | return written ? written : status; | |
| 48 | } | |
| 49 | EXPORT_SYMBOL(generic_file_buffered_write); |