| Message ID | 20230420014734.302304-1-sarthakkukreti@chromium.org |
|---|---|
| State | New |
| Headers | show |
| Series | [v5-fix,1/5] block: Don't invalidate pagecache for invalid falloc modes | expand |
On Wed, Apr 19 2023 at 9:47P -0400, Sarthak Kukreti <sarthakkukreti@chromium.org> wrote: > Only call truncate_bdev_range() if the fallocate mode is > supported. This fixes a bug where data in the pagecache > could be invalidated if the fallocate() was called on the > block device with an invalid mode. > > Fixes: 25f4c41415e5 ("block: implement (some of) fallocate for block devices") You should add: Cc: stable@vger.kernel.org Reported-by: Darrick J. Wong <djwong@kernel.org> > Signed-off-by: Sarthak Kukreti <sarthakkukreti@chromium.org> > --- > block/fops.c | 37 ++++++++++++++++++++++++------------- > 1 file changed, 24 insertions(+), 13 deletions(-) > > diff --git a/block/fops.c b/block/fops.c > index d2e6be4e3d1c..d359254c645d 100644 > --- a/block/fops.c > +++ b/block/fops.c > @@ -648,26 +648,37 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start, > > filemap_invalidate_lock(inode->i_mapping); > > - /* Invalidate the page cache, including dirty pages. */ > - error = truncate_bdev_range(bdev, file->f_mode, start, end); > - if (error) > - goto fail; > - You remove the only user of the 'fail' label. But I think it'd be cleaner to keep using it below (reduces indentation churn too). > + /* > + * Invalidate the page cache, including dirty pages, for valid > + * de-allocate mode calls to fallocate(). > + */ > switch (mode) { > case FALLOC_FL_ZERO_RANGE: > case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE: > - error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, > - len >> SECTOR_SHIFT, GFP_KERNEL, > - BLKDEV_ZERO_NOUNMAP); > + error = truncate_bdev_range(bdev, file->f_mode, start, end); > + if (!error) > + error = blkdev_issue_zeroout(bdev, > + start >> SECTOR_SHIFT, > + len >> SECTOR_SHIFT, > + GFP_KERNEL, > + BLKDEV_ZERO_NOUNMAP); > break; So: error = truncate_bdev_range(bdev, file->f_mode, start, end); if (error) goto fail; ... > case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE: > - error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, > - len >> SECTOR_SHIFT, GFP_KERNEL, > - BLKDEV_ZERO_NOFALLBACK); > + error = truncate_bdev_range(bdev, file->f_mode, start, end); > + if (!error) > + error = blkdev_issue_zeroout(bdev, > + start >> SECTOR_SHIFT, > + len >> SECTOR_SHIFT, > + GFP_KERNEL, > + BLKDEV_ZERO_NOFALLBACK); > break; Same. > case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE: > - error = blkdev_issue_discard(bdev, start >> SECTOR_SHIFT, > - len >> SECTOR_SHIFT, GFP_KERNEL); > + error = truncate_bdev_range(bdev, file->f_mode, start, end); > + if (!error) > + error = blkdev_issue_discard(bdev, > + start >> SECTOR_SHIFT, > + len >> SECTOR_SHIFT, > + GFP_KERNEL); > break; Same.
diff --git a/block/fops.c b/block/fops.c index d2e6be4e3d1c..d359254c645d 100644 --- a/block/fops.c +++ b/block/fops.c @@ -648,26 +648,37 @@ static long blkdev_fallocate(struct file *file, int mode, loff_t start, filemap_invalidate_lock(inode->i_mapping); - /* Invalidate the page cache, including dirty pages. */ - error = truncate_bdev_range(bdev, file->f_mode, start, end); - if (error) - goto fail; - + /* + * Invalidate the page cache, including dirty pages, for valid + * de-allocate mode calls to fallocate(). + */ switch (mode) { case FALLOC_FL_ZERO_RANGE: case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE: - error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, - len >> SECTOR_SHIFT, GFP_KERNEL, - BLKDEV_ZERO_NOUNMAP); + error = truncate_bdev_range(bdev, file->f_mode, start, end); + if (!error) + error = blkdev_issue_zeroout(bdev, + start >> SECTOR_SHIFT, + len >> SECTOR_SHIFT, + GFP_KERNEL, + BLKDEV_ZERO_NOUNMAP); break; case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE: - error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, - len >> SECTOR_SHIFT, GFP_KERNEL, - BLKDEV_ZERO_NOFALLBACK); + error = truncate_bdev_range(bdev, file->f_mode, start, end); + if (!error) + error = blkdev_issue_zeroout(bdev, + start >> SECTOR_SHIFT, + len >> SECTOR_SHIFT, + GFP_KERNEL, + BLKDEV_ZERO_NOFALLBACK); break; case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE: - error = blkdev_issue_discard(bdev, start >> SECTOR_SHIFT, - len >> SECTOR_SHIFT, GFP_KERNEL); + error = truncate_bdev_range(bdev, file->f_mode, start, end); + if (!error) + error = blkdev_issue_discard(bdev, + start >> SECTOR_SHIFT, + len >> SECTOR_SHIFT, + GFP_KERNEL); break; default: error = -EOPNOTSUPP;
Only call truncate_bdev_range() if the fallocate mode is supported. This fixes a bug where data in the pagecache could be invalidated if the fallocate() was called on the block device with an invalid mode. Fixes: 25f4c41415e5 ("block: implement (some of) fallocate for block devices") Signed-off-by: Sarthak Kukreti <sarthakkukreti@chromium.org> --- block/fops.c | 37 ++++++++++++++++++++++++------------- 1 file changed, 24 insertions(+), 13 deletions(-)