diff options
| -rw-r--r-- | fs/direct-io.c | 24 | ||||
| -rw-r--r-- | fs/iomap.c | 12 | ||||
| -rw-r--r-- | include/linux/fs.h | 1 |
3 files changed, 34 insertions, 3 deletions
diff --git a/fs/direct-io.c b/fs/direct-io.c index 3aafb33..a0ca9e4 100644 --- a/fs/direct-io.c +++ b/fs/direct-io.c @@ -219,6 +219,27 @@ static inline struct page *dio_get_page(struct dio *dio, return dio->pages[sdio->head]; } +/* + * Warn about a page cache invalidation failure during a direct io write. + */ +void dio_warn_stale_pagecache(struct file *filp) +{ + static DEFINE_RATELIMIT_STATE(_rs, 86400 * HZ, DEFAULT_RATELIMIT_BURST); + char pathname[128]; + struct inode *inode = file_inode(filp); + char *path; + + errseq_set(&inode->i_mapping->wb_err, -EIO); + if (__ratelimit(&_rs)) { + path = file_path(filp, pathname, sizeof(pathname)); + if (IS_ERR(path)) + path = "(unknown)"; + pr_crit("Page cache invalidation failure on direct I/O. Possible data corruption due to collision with buffered I/O!\n"); + pr_crit("File: %s PID: %d Comm: %.20s\n", path, current->pid, + current->comm); + } +} + /** * dio_complete() - called when all DIO BIO I/O has been completed * @offset: the byte offset in the file of the completed operation @@ -290,7 +311,8 @@ static ssize_t dio_complete(struct dio *dio, ssize_t ret, unsigned int flags) err = invalidate_inode_pages2_range(dio->inode->i_mapping, offset >> PAGE_SHIFT, (offset + ret - 1) >> PAGE_SHIFT); - WARN_ON_ONCE(err); + if (err) + dio_warn_stale_pagecache(dio->iocb->ki_filp); } if (!(dio->flags & DIO_SKIP_DIO_COUNT)) @@ -753,7 +753,8 @@ static ssize_t iomap_dio_complete(struct iomap_dio *dio) err = invalidate_inode_pages2_range(inode->i_mapping, offset >> PAGE_SHIFT, (offset + dio->size - 1) >> PAGE_SHIFT); - WARN_ON_ONCE(err); + if (err) + dio_warn_stale_pagecache(iocb->ki_filp); } inode_dio_end(file_inode(iocb->ki_filp)); @@ -1018,9 +1019,16 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter, if (ret) goto out_free_dio; + /* + * Try to invalidate cache pages for the range we're direct + * writing. If this invalidation fails, tough, the write will + * still work, but racing two incompatible write paths is a + * pretty crazy thing to do, so we don't support it 100%. + */ ret = invalidate_inode_pages2_range(mapping, start >> PAGE_SHIFT, end >> PAGE_SHIFT); - WARN_ON_ONCE(ret); + if (ret) + dio_warn_stale_pagecache(iocb->ki_filp); ret = 0; if (iov_iter_rw(iter) == WRITE && !is_sync_kiocb(iocb) && diff --git a/include/linux/fs.h b/include/linux/fs.h index 511fbaa..7f8d96d 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2992,6 +2992,7 @@ enum { }; void dio_end_io(struct bio *bio); +void dio_warn_stale_pagecache(struct file *filp); ssize_t __blockdev_direct_IO(struct kiocb *iocb, struct inode *inode, struct block_device *bdev, struct iov_iter *iter, |
