kernel/linux.git/fs/romfs/super.c, branch v6.6.131

romfs: check sb_set_blocksize() return value

2026-02-19T15:28:24+00:00

[ Upstream commit ab7ad7abb3660c58ffffdf07ff3bb976e7e0afa0 ] romfs_fill_super() ignores the return value of sb_set_blocksize(), which can fail if the requested block size is incompatible with the block device's configuration. This can be triggered by setting a loop device's block size larger than PAGE_SIZE using ioctl(LOOP_SET_BLOCK_SIZE, 32768), then mounting a romfs filesystem on that device. When sb_set_blocksize(sb, ROMBSIZE) is called with ROMBSIZE=4096 but the device has logical_block_size=32768, bdev_validate_blocksize() fails because the requested size is smaller than the device's logical block size. sb_set_blocksize() returns 0 (failure), but romfs ignores this and continues mounting. The superblock's block size remains at the device's logical block size (32768). Later, when sb_bread() attempts I/O with this oversized block size, it triggers a kernel BUG in folio_set_bh(): kernel BUG at fs/buffer.c:1582! BUG_ON(size > PAGE_SIZE); Fix by checking the return value of sb_set_blocksize() and failing the mount with -EINVAL if it returns 0. Reported-by: syzbot+9c4e33e12283d9437c25@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=9c4e33e12283d9437c25 Signed-off-by: Deepanshu Kartikey Link: https://patch.msgid.link/20260113084037.1167887-1-kartikey406@gmail.com Signed-off-by: Christian Brauner Signed-off-by: Sasha Levin

fs: Convert to bdev_open_by_dev()

2024-08-19T04:04:25+00:00

[ Upstream commit f4a48bc36cdfae7c603e8e3f2a51e2a283f3f365 ] Convert mount code to use bdev_open_by_dev() and propagate the handle around to bdev_release(). Acked-by: Christoph Hellwig Reviewed-by: Christian Brauner Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20230927093442.25915-19-jack@suse.cz Signed-off-by: Christian Brauner Stable-dep-of: 6306ff39a7fc ("jfs: fix log->bdev_handle null ptr deref in lbmStartIO") Signed-off-by: Sasha Levin

Merge tag 'v6.6-vfs.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2023-08-28T18:04:18+00:00

Pull superblock updates from Christian Brauner: "This contains the super rework that was ready for this cycle. The first part changes the order of how we open block devices and allocate superblocks, contains various cleanups, simplifications, and a new mechanism to wait on superblock state changes. This unblocks work to ultimately limit the number of writers to a block device. Jan has already scheduled follow-up work that will be ready for v6.7 and allows us to restrict the number of writers to a given block device. That series builds on this work right here. The second part contains filesystem freezing updates. Overview: The generic superblock changes are rougly organized as follows (ignoring additional minor cleanups): (1) Removal of the bd_super member from struct block_device. This was a very odd back pointer to struct super_block with unclear rules. For all relevant places we have other means to get the same information so just get rid of this. (2) Simplify rules for superblock cleanup. Roughly, everything that is allocated during fs_context initialization and that's stored in fs_context->s_fs_info needs to be cleaned up by the fs_context->free() implementation before the superblock allocation function has been called successfully. After sget_fc() returned fs_context->s_fs_info has been transferred to sb->s_fs_info at which point sb->kill_sb() if fully responsible for cleanup. Adhering to these rules means that cleanup of sb->s_fs_info in fill_super() is to be avoided as it's brittle and inconsistent. Cleanup shouldn't be duplicated between sb->put_super() as sb->put_super() is only called if sb->s_root has been set aka when the filesystem has been successfully born (SB_BORN). That complexity should be avoided. This also means that block devices are to be closed in sb->kill_sb() instead of sb->put_super(). More details in the lower section. (3) Make it possible to lookup or create a superblock before opening block devices There's a subtle dependency on (2) as some filesystems did rely on fill_super() to be called in order to correctly clean up sb->s_fs_info. All these filesystems have been fixed. (4) Switch most filesystem to follow the same logic as the generic mount code now does as outlined in (3). (5) Use the superblock as the holder of the block device. We can now easily go back from block device to owning superblock. (6) Export and extend the generic fs_holder_ops and use them as holder ops everywhere and remove the filesystem specific holder ops. (7) Call from the block layer up into the filesystem layer when the block device is removed, allowing to shut down the filesystem without risk of deadlocks. (8) Get rid of get_super(). We can now easily go back from the block device to owning superblock and can call up from the block layer into the filesystem layer when the device is removed. So no need to wade through all registered superblock to find the owning superblock anymore" Link: https://lore.kernel.org/lkml/20230824-prall-intakt-95dbffdee4a0@brauner/ * tag 'v6.6-vfs.super' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs: (47 commits) super: use higher-level helper for {freeze,thaw} super: wait until we passed kill super super: wait for nascent superblocks super: make locking naming consistent super: use locking helpers fs: simplify invalidate_inodes fs: remove get_super block: call into the file system for ioctl BLKFLSBUF block: call into the file system for bdev_mark_dead block: consolidate __invalidate_device and fsync_bdev block: drop the "busy inodes on changed media" log message dasd: also call __invalidate_device when setting the device offline amiflop: don't call fsync_bdev in FDFMTBEG floppy: call disk_force_media_change when changing the format block: simplify the disk_force_media_change interface nbd: call blk_mark_disk_dead in nbd_clear_sock_ioctl xfs use fs_holder_ops for the log and RT devices xfs: drop s_umount over opening the log and RT devices ext4: use fs_holder_ops for the log device ext4: drop s_umount over opening the log device ...

fs: use the super_block as holder when mounting file systems

2023-08-11T11:15:03+00:00

The file system type is not a very useful holder as it doesn't allow us to go back to the actual file system instance. Pass the super_block instead which is useful when passed back to the file system driver. Signed-off-by: Christoph Hellwig Reviewed-by: Jan Kara Reviewed-by: Christian Brauner Message-Id: <20230802154131.2221419-7-hch@lst.de> Signed-off-by: Christian Brauner

fs: open block device after superblock creation

2023-08-10T08:34:56+00:00

Currently get_tree_bdev and mount_bdev open the block device before committing to allocating a super block. That creates problems for restricting the number of writers to a device, and also leads to a unusual and not very helpful holder (the fs_type). Reorganize the super block code to first look whether the superblock for a particular device does already exist and open the block device only if it doesn't. [hch: port to before the bdev_handle changes, duplicate the bdev read-only check from blkdev_get_by_path, extend the fsfree_mutex coverage to protect against freezes, fix an open bdev leak when the bdev is frozen, use the bdev local variable more, rename the s variable to sb to be more descriptive] [brauner: remove references to mounts as they're mostly irrelevant] [brauner & hch: fold fixes for romfs and cramfs for syzbot+2faac0423fdc9692822b@syzkaller.appspotmail.com] Signed-off-by: Jan Kara Signed-off-by: Christoph Hellwig Message-Id: <20230724175145.201318-1-hch@lst.de> Signed-off-by: Christian Brauner

romfs: convert to ctime accessor functions

2023-07-24T08:30:04+00:00

In later patches, we're going to change how the inode's ctime field is used. Switch to using accessor functions instead of raw accesses of inode->i_ctime. Signed-off-by: Jeff Layton Message-Id: <20230705190309.579783-71-jlayton@kernel.org> Signed-off-by: Christian Brauner

romfs: Convert romfs to read_folio

2022-05-09T20:21:46+00:00

This is a "weak" conversion which converts straight back to using pages. A full conversion should be performed at some point, hopefully by someone familiar with the filesystem. Signed-off-by: Matthew Wilcox (Oracle)

fs: allocate inode by using alloc_inode_sb()

2022-03-22T22:57:03+00:00

The inode allocation is supposed to use alloc_inode_sb(), so convert kmem_cache_alloc() of all filesystems to alloc_inode_sb(). Link: https://lkml.kernel.org/r/20220228122126.37293-5-songmuchun@bytedance.com Signed-off-by: Muchun Song Acked-by: Theodore Ts'o [ext4] Acked-by: Roman Gushchin Cc: Alex Shi Cc: Anna Schumaker Cc: Chao Yu Cc: Dave Chinner Cc: Fam Zheng Cc: Jaegeuk Kim Cc: Johannes Weiner Cc: Kari Argillander Cc: Matthew Wilcox (Oracle) Cc: Michal Hocko Cc: Qi Zheng Cc: Shakeel Butt Cc: Trond Myklebust Cc: Vladimir Davydov Cc: Vlastimil Babka Cc: Wei Yang Cc: Xiongchun Duan Cc: Yang Shi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

Merge branch 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

2020-10-24T19:26:05+00:00

Pull misc vfs updates from Al Viro: "Assorted stuff all over the place (the largest group here is Christoph's stat cleanups)" * 'work.misc' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: fs: remove KSTAT_QUERY_FLAGS fs: remove vfs_stat_set_lookup_flags fs: move vfs_fstatat out of line fs: implement vfs_stat and vfs_lstat in terms of vfs_fstatat fs: remove vfs_statx_fd fs: omfs: use kmemdup() rather than kmalloc+memcpy [PATCH] reduce boilerplate in fsid handling fs: Remove duplicated flag O_NDELAY occurring twice in VALID_OPEN_FLAGS selftests: mount: add nosymfollow tests Add a "nosymfollow" mount option.

ROMFS: support inode blocks calculation

2020-10-16T18:11:22+00:00

When use 'stat' tool to display file status, the 'Blocks' field always in '0', this is not good for tool 'du'(e.g.: busybox 'du'), it always output '0' size for the files under ROMFS since such tool calculates number of 512B Blocks. This patch calculates approx. number of 512B blocks based on inode size. Signed-off-by: Libing Zhou Signed-off-by: Andrew Morton Cc: David Howells Cc: Al Viro Link: http://lkml.kernel.org/r/20200811052606.4243-1-libing.zhou@nokia-sbell.com Signed-off-by: Linus Torvalds