user/sven/linux.git/fs/buffer.c, branch v5.4.38

ext4: use non-movable memory for superblock readahead

2020-04-23T08:36:15Z

commit d87f639258a6a5980183f11876c884931ad93da2 upstream. Since commit a8ac900b8163 ("ext4: use non-movable memory for the superblock") buffers for ext4 superblock were allocated using the sb_bread_unmovable() helper which allocated buffer heads out of non-movable memory blocks. It was necessarily to not block page migrations and do not cause cma allocation failures. However commit 85c8f176a611 ("ext4: preload block group descriptors") broke this by introducing pre-reading of the ext4 superblock. The problem is that __breadahead() is using __getblk() underneath, which allocates buffer heads out of movable memory. It resulted in page migration failures I've seen on a machine with an ext4 partition and a preallocated cma area. Fix this by introducing sb_breadahead_unmovable() and __breadahead_gfp() helpers which use non-movable memory for buffer head allocations and use them for the ext4 superblock readahead. Reviewed-by: Andreas Dilger Fixes: 85c8f176a611 ("ext4: preload block group descriptors") Signed-off-by: Roman Gushchin Link: https://lore.kernel.org/r/20200229001411.128010-1-guro@fb.com Signed-off-by: Theodore Ts'o Signed-off-by: Greg Kroah-Hartman

fs: move guard_bio_eod() after bio_set_op_attrs

2020-01-17T18:48:21Z

commit 83c9c547168e8b914ea6398430473a4de68c52cc upstream. Commit 85a8ce62c2ea ("block: add bio_truncate to fix guard_bio_eod") adds bio_truncate() for handling bio EOD. However, bio_truncate() doesn't use the passed 'op' parameter from guard_bio_eod's callers. So bio_trunacate() may retrieve wrong 'op', and zering pages may not be done for READ bio. Fixes this issue by moving guard_bio_eod() after bio_set_op_attrs() in submit_bh_wbc() so that bio_truncate() can always retrieve correct op info. Meantime remove the 'op' parameter from guard_bio_eod() because it isn't used any more. Cc: Carlos Maiolino Cc: linux-fsdevel@vger.kernel.org Fixes: 85a8ce62c2ea ("block: add bio_truncate to fix guard_bio_eod") Signed-off-by: Ming Lei Signed-off-by: Greg Kroah-Hartman Fold in kerneldoc and bio_op() change. Signed-off-by: Jens Axboe

block: add bio_truncate to fix guard_bio_eod

2020-01-09T09:19:54Z

[ Upstream commit 85a8ce62c2eabe28b9d76ca4eecf37922402df93 ] Some filesystem, such as vfat, may send bio which crosses device boundary, and the worse thing is that the IO request starting within device boundaries can contain more than one segment past EOD. Commit dce30ca9e3b6 ("fs: fix guard_bio_eod to check for real EOD errors") tries to fix this issue by returning -EIO for this situation. However, this way lets fs user code lose chance to handle -EIO, then sync_inodes_sb() may hang for ever. Also the current truncating on last segment is dangerous by updating the last bvec, given bvec table becomes not immutable any more, and fs bio users may not retrieve the truncated pages via bio_for_each_segment_all() in its .end_io callback. Fixes this issue by supporting multi-segment truncating. And the approach is simpler: - just update bio size since block layer can make correct bvec with the updated bio size. Then bvec table becomes really immutable. - zero all truncated segments for read bio Cc: Carlos Maiolino Cc: linux-fsdevel@vger.kernel.org Fixed-by: dce30ca9e3b6 ("fs: fix guard_bio_eod to check for real EOD errors") Reported-by: syzbot+2b9e54155c8c25d8d165@syzkaller.appspotmail.com Signed-off-by: Ming Lei Signed-off-by: Jens Axboe Signed-off-by: Sasha Levin

Merge tag 'for-linus-20190715' of git://git.kernel.dk/linux-block

2019-07-16T04:20:52Z

Pull more block updates from Jens Axboe: "A later pull request with some followup items. I had some vacation coming up to the merge window, so certain things items were delayed a bit. This pull request also contains fixes that came in within the last few days of the merge window, which I didn't want to push right before sending you a pull request. This contains: - NVMe pull request, mostly fixes, but also a few minor items on the feature side that were timing constrained (Christoph et al) - Report zones fixes (Damien) - Removal of dead code (Damien) - Turn on cgroup psi memstall (Josef) - block cgroup MAINTAINERS entry (Konstantin) - Flush init fix (Josef) - blk-throttle low iops timing fix (Konstantin) - nbd resize fixes (Mike) - nbd 0 blocksize crash fix (Xiubo) - block integrity error leak fix (Wenwen) - blk-cgroup writeback and priority inheritance fixes (Tejun)" * tag 'for-linus-20190715' of git://git.kernel.dk/linux-block: (42 commits) MAINTAINERS: add entry for block io cgroup null_blk: fixup ->report_zones() for !CONFIG_BLK_DEV_ZONED block: Limit zone array allocation size sd_zbc: Fix report zones buffer allocation block: Kill gfp_t argument of blkdev_report_zones() block: Allow mapping of vmalloc-ed buffers block/bio-integrity: fix a memory leak bug nvme: fix NULL deref for fabrics options nbd: add netlink reconfigure resize support nbd: fix crash when the blksize is zero block: Disable write plugging for zoned block devices block: Fix elevator name declaration block: Remove unused definitions nvme: fix regression upon hot device removal and insertion blk-throttle: fix zero wait time for iops throttled group block: Fix potential overflow in blk_report_zones() blkcg: implement REQ_CGROUP_PUNT blkcg, writeback: Implement wbc_blkcg_css() blkcg, writeback: Add wbc->no_cgroup_owner blkcg, writeback: Rename wbc_account_io() to wbc_account_cgroup_owner() ...

blkcg, writeback: Rename wbc_account_io() to wbc_account_cgroup_owner()

2019-07-10T15:00:57Z

wbc_account_io() does a very specific job - try to see which cgroup is actually dirtying an inode and transfer its ownership to the majority dirtier if needed. The name is too generic and confusing. Let's rename it to something more specific. Reviewed-by: Jan Kara Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe

fs: fold __generic_write_end back into generic_write_end

2019-06-28T00:28:40Z

This effectively reverts a6d639da63ae ("fs: factor out a __generic_write_end helper") as we now open code what is left of that helper in iomap. Signed-off-by: Christoph Hellwig Signed-off-by: Andreas Gruenbacher Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong

treewide: Add SPDX license identifier for missed files

2019-05-21T08:50:45Z

Add SPDX license identifiers to all files which: - Have no license information of any form - Have EXPORT_.*_SYMBOL_GPL inside which was used in the initial scan/conversion to ignore the file These files fall under the project license, GPL v2 only. The resulting SPDX license identifier is: GPL-2.0-only Signed-off-by: Thomas Gleixner Signed-off-by: Greg Kroah-Hartman

iomap: Fix use-after-free error in page_done callback

2019-05-01T14:47:37Z

In iomap_write_end, we're not holding a page reference anymore when calling the page_done callback, but the callback needs that reference to access the page. To fix that, move the put_page call in __generic_write_end into the callers of __generic_write_end. Then, in iomap_write_end, put the page after calling the page_done callback. Reported-by: Jan Kara Fixes: 63899c6f8851 ("iomap: add a page_done callback") Signed-off-by: Andreas Gruenbacher Reviewed-by: Jan Kara Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong

fs: Turn __generic_write_end into a void function

2019-05-01T14:47:37Z

The VFS-internal __generic_write_end helper always returns the value of its @copied argument. This can be confusing, and it isn't very useful anyway, so turn __generic_write_end into a function returning void instead. Signed-off-by: Andreas Gruenbacher Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Darrick J. Wong

fs: fix guard_bio_eod to check for real EOD errors

2019-02-28T20:59:41Z

guard_bio_eod() can truncate a segment in bio to allow it to do IO on odd last sectors of a device. It already checks if the IO starts past EOD, but it does not consider the possibility of an IO request starting within device boundaries can contain more than one segment past EOD. In such cases, truncated_bytes can be bigger than PAGE_SIZE, and will underflow bvec->bv_len. Fix this by checking if truncated_bytes is lower than PAGE_SIZE. This situation has been found on filesystems such as isofs and vfat, which doesn't check the device size before mount, if the device is smaller than the filesystem itself, a readahead on such filesystem, which spans EOD, can trigger this situation, leading a call to zero_user() with a wrong size possibly corrupting memory. I didn't see any crash, or didn't let the system run long enough to check if memory corruption will be hit somewhere, but adding instrumentation to guard_bio_end() to check truncated_bytes size, was enough to see the error. The following script can trigger the error. MNT=/mnt IMG=./DISK.img DEV=/dev/loop0 mkfs.vfat $IMG mount $IMG $MNT cp -R /etc $MNT &> /dev/null umount $MNT losetup -D losetup --find --show --sizelimit 16247280 $IMG mount $DEV $MNT find $MNT -type f -exec cat {} + >/dev/null Kudos to Eric Sandeen for coming up with the reproducer above Reviewed-by: Ming Lei Signed-off-by: Carlos Maiolino Signed-off-by: Jens Axboe