kernel/fs/sysv/itree.c, branch linux-rolling-stable

sysv: Remove the filesystem

2025-02-21T09:32:47Z

Since 2002 (change "Replace BKL for chain locking with sysvfs-private rwlock") the sysv filesystem was doing IO under a rwlock in its get_block() function (yes, a non-sleepable lock hold over a function used to read inode metadata for all reads and writes). Nobody noticed until syzbot in 2023 [1]. This shows nobody is using the filesystem. Just drop it. [1] https://lore.kernel.org/all/0000000000000ccf9a05ee84f5b0@google.com/ Signed-off-by: Jan Kara Link: https://lore.kernel.org/r/20250220163940.10155-2-jack@suse.cz Reviewed-by: Jeff Layton Reviewed-by: "Darrick J. Wong" Signed-off-by: Christian Brauner

buffer: Convert __block_write_begin() to take a folio

2024-08-07T09:33:36Z

Almost all callers have a folio now, so change __block_write_begin() to take a folio and remove a call to compound_head(). Reviewed-by: Josef Bacik Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Christian Brauner

fs: Convert aops->write_begin to take a folio

2024-08-07T09:33:21Z

Convert all callers from working on a page to working on one page of a folio (support for working on an entire folio can come later). Removes a lot of folio->page->folio conversions. Reviewed-by: Josef Bacik Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Christian Brauner

sysv: Convert sysv_prepare_chunk() to take a folio

2024-08-07T09:31:54Z

All callers now have a folio, so convert sysv_prepare_chunk() to take one. Reviewed-by: Josef Bacik Signed-off-by: Matthew Wilcox (Oracle) Signed-off-by: Christian Brauner

sysv: don't call sb_bread() with pointers_lock held

2024-02-02T12:11:49Z

syzbot is reporting sleep in atomic context in SysV filesystem [1], for sb_bread() is called with rw_spinlock held. A "write_lock(&pointers_lock) => read_lock(&pointers_lock) deadlock" bug and a "sb_bread() with write_lock(&pointers_lock)" bug were introduced by "Replace BKL for chain locking with sysvfs-private rwlock" in Linux 2.5.12. Then, "[PATCH] err1-40: sysvfs locking fix" in Linux 2.6.8 fixed the former bug by moving pointers_lock lock to the callers, but instead introduced a "sb_bread() with read_lock(&pointers_lock)" bug (which made this problem easier to hit). Al Viro suggested that why not to do like get_branch()/get_block()/ find_shared() in Minix filesystem does. And doing like that is almost a revert of "[PATCH] err1-40: sysvfs locking fix" except that get_branch() from with find_shared() is called without write_lock(&pointers_lock). Reported-by: syzbot Link: https://syzkaller.appspot.com/bug?extid=69b40dc5fd40f32c199f Suggested-by: Al Viro Signed-off-by: Tetsuo Handa Link: https://lore.kernel.org/r/0d195f93-a22a-49a2-0020-103534d6f7f6@I-love.SAKURA.ne.jp Signed-off-by: Christian Brauner

sysv: remove writepage implementation

2023-12-29T19:58:35Z

If the filesystem implements migrate_folio and writepages, there is no need for a writepage implementation. Link: https://lkml.kernel.org/r/20231215200245.748418-12-willy@infradead.org Signed-off-by: Matthew Wilcox (Oracle) Reviewed-by: Jens Axboe Cc: Christoph Hellwig Signed-off-by: Andrew Morton

sysv: convert to new timestamp accessors

2023-10-18T12:08:28Z

Convert to using the new inode timestamp accessor functions. Signed-off-by: Jeff Layton Link: https://lore.kernel.org/r/20231004185347.80880-69-jlayton@kernel.org Signed-off-by: Christian Brauner

fs: pass the request_mask to generic_fillattr

2023-08-09T06:56:36Z

generic_fillattr just fills in the entire stat struct indiscriminately today, copying data from the inode. There is at least one attribute (STATX_CHANGE_COOKIE) that can have side effects when it is reported, and we're looking at adding more with the addition of multigrain timestamps. Add a request_mask argument to generic_fillattr and have most callers just pass in the value that is passed to getattr. Have other callers (e.g. ksmbd) just pass in STATX_BASIC_STATS. Also move the setting of STATX_CHANGE_COOKIE into generic_fillattr. Acked-by: Joseph Qi Reviewed-by: Xiubo Li Reviewed-by: "Paulo Alcantara (SUSE)" Reviewed-by: Jan Kara Signed-off-by: Jeff Layton Message-Id: <20230807-mgctime-v7-2-d1dec143a704@kernel.org> Signed-off-by: Christian Brauner

sysv: convert to ctime accessor functions

2023-07-24T08:30:05Z

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 Reviewed-by: Jan Kara Message-Id: <20230705190309.579783-74-jlayton@kernel.org> Signed-off-by: Christian Brauner

fs/sysv: Null check to prevent null-ptr-deref bug

2023-06-01T07:51:06Z

sb_getblk(inode->i_sb, parent) return a null ptr and taking lock on that leads to the null-ptr-deref bug. Reported-by: syzbot+aad58150cbc64ba41bdc@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=aad58150cbc64ba41bdc Signed-off-by: Prince Kumar Maurya Message-Id: <20230531013141.19487-1-princekumarmaurya06@gmail.com> Signed-off-by: Christian Brauner