kernel/linux.git/fs/nilfs2/sufile.c, branch linux-7.1.y

nilfs2: Fix potential block overflow that cause system hang

2025-12-22T23:45:29+00:00

When a user executes the FITRIM command, an underflow can occur when calculating nblocks if end_block is too small. Since nblocks is of type sector_t, which is u64, a negative nblocks value will become a very large positive integer. This ultimately leads to the block layer function __blkdev_issue_discard() taking an excessively long time to process the bio chain, and the ns_segctor_sem lock remains held for a long period. This prevents other tasks from acquiring the ns_segctor_sem lock, resulting in the hang reported by syzbot in [1]. If the ending block is too small, typically if it is smaller than 4KiB range, depending on the usage of the segment 0, it may be possible to attempt a discard request beyond the device size causing the hang. Exiting successfully and assign the discarded size (0 in this case) to range->len. Although the start and len values in the user input range are too small, a conservative strategy is adopted here to safely ignore them, which is equivalent to a no-op; it will not perform any trimming and will not throw an error. [1] task:segctord state:D stack:28968 pid:6093 tgid:6093 ppid:2 task_flags:0x200040 flags:0x00080000 Call Trace: rwbase_write_lock+0x3dd/0x750 kernel/locking/rwbase_rt.c:272 nilfs_transaction_lock+0x253/0x4c0 fs/nilfs2/segment.c:357 nilfs_segctor_thread_construct fs/nilfs2/segment.c:2569 [inline] nilfs_segctor_thread+0x6ec/0xe00 fs/nilfs2/segment.c:2684 [ryusuke: corrected part of the commit message about the consequences] Fixes: 82e11e857be3 ("nilfs2: add nilfs_sufile_trim_fs to trim clean segs") Reported-by: syzbot+7eedce5eb281acd832f0@syzkaller.appspotmail.com Closes: https://syzkaller.appspot.com/bug?extid=7eedce5eb281acd832f0 Signed-off-by: Edward Adam Davis Signed-off-by: Ryusuke Konishi Cc: stable@vger.kernel.org Signed-off-by: Viacheslav Dubeyko

nilfs2: use the new ->i_state accessors

2025-10-20T18:22:27+00:00

Change generated with coccinelle and fixed up by hand as appropriate. Signed-off-by: Mateusz Guzik Signed-off-by: Christian Brauner

nilfs2: revise the return value description style for consistency.

2025-01-25T06:47:25+00:00

Also for comments that do not cause kernel-doc warnings (those that list multiple error codes), revise the return value description style to match Brian G.'s suggestion of "..., or one of the following negative error codes on failure:". Link: https://lkml.kernel.org/r/CAAq45aNh1qV8P6XgDhKeNstT=PvcPUaCXsAF-f9rvmzznsZL5A@mail.gmail.com Link: https://lkml.kernel.org/r/20250110010530.21872-8-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi Cc: "Brian G ." Signed-off-by: Andrew Morton

nilfs2: add missing return value kernel-doc descriptions

2025-01-25T06:47:25+00:00

There are a number of kernel-doc comments for functions that are missing return values, which also causes a number of warnings when the kernel-doc script is run with the "-Wall" option. Fix this issue by adding proper return value descriptions, and improve code maintainability. Link: https://lkml.kernel.org/r/20250110010530.21872-7-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi Cc: "Brian G ." Signed-off-by: Andrew Morton

nilfs2: correct return value kernel-doc descriptions for sufile

2025-01-25T06:47:25+00:00

Similar to the previous changes to fix return value descriptions, this fixes the format of the return value descriptions of functions for sufile-related functions, eliminating a dozen warnings emitted by the kernel-doc script. Link: https://lkml.kernel.org/r/20250110010530.21872-4-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi Cc: "Brian G ." Signed-off-by: Andrew Morton

nilfs2: convert segment usage file to be folio-based

2024-11-06T01:12:38+00:00

For the sufile, which is a metadata file that holds information about managing segments, convert the page-based implementation to a folio-based implementation. kmap_local_page() is changed to use kmap_local_folio(), and where offsets within a page are calculated using bh_offset(), are replaced with calculations using offset_in_folio() with an additional helper function nilfs_sufile_segment_usage_offset(). Link: https://lkml.kernel.org/r/20241024092602.13395-4-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi Cc: Matthew Wilcox (Oracle) Signed-off-by: Andrew Morton

nilfs2: do not propagate ENOENT error from nilfs_sufile_mark_dirty()

2024-09-02T03:43:40+00:00

nilfs_sufile_mark_dirty(), which marks a block in the sufile metadata file as dirty in preparation for log writing, returns -ENOENT to the caller if the block containing the segment usage of the specified segment is missing. This internal code can propagate through the log writer to system calls such as fsync. To prevent this, treat this case as a filesystem error and return -EIO instead. Link: https://lkml.kernel.org/r/20240821154627.11848-6-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton

nilfs2: treat missing sufile header block as metadata corruption

2024-09-02T03:43:39+00:00

Patch series "nilfs2: prevent unexpected ENOENT propagation". This series fixes potential issues where the result code -ENOENT, which is returned internally when a metadata file operation encouters a hole block, is exposed to user space without being properly handled. Several issues with the same cause leading to hangs or WARN_ON check failures have been reported by syzbot and fixed each time in the past. This collectively fixes the missing -ENOENT conversions that do not cause stability issues and are not covered by syzbot. This patch (of 5): The sufile, a metadata file that holds metadata for segment management, has statistical information in its first block, but if reading this block fails, it receives the internal code -ENOENT and returns it unchanged to the callers. To prevent this -ENOENT from being propagated to system calls, if reading the header block fails, return -EIO (or -EINVAL depending on the context) instead. Link: https://lkml.kernel.org/r/20240821154627.11848-1-konishi.ryusuke@gmail.com Link: https://lkml.kernel.org/r/20240821154627.11848-2-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton

nilfs2: fix missing initial short descriptions of kernel-doc comments

2024-09-02T03:43:37+00:00

Update some kernel-doc comments that are missing the initial short description and fix the following warnings output by the kernel-doc script: fs/nilfs2/bmap.c:353: warning: missing initial short description on line: * nilfs_bmap_lookup_dirty_buffers - fs/nilfs2/cpfile.c:708: warning: missing initial short description on line: * nilfs_cpfile_delete_checkpoint - fs/nilfs2/cpfile.c:972: warning: missing initial short description on line: * nilfs_cpfile_is_snapshot - fs/nilfs2/dat.c:275: warning: missing initial short description on line: * nilfs_dat_mark_dirty - fs/nilfs2/sufile.c:844: warning: missing initial short description on line: * nilfs_sufile_get_suinfo - Link: https://lkml.kernel.org/r/20240816074319.3253-9-konishi.ryusuke@gmail.com Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton

nilfs2: use div64_ul() instead of do_div()

2024-03-12T20:09:23+00:00

Fixes Coccinelle/coccicheck warnings reported by do_div.cocci. Compared to do_div(), div64_ul() does not implicitly cast the divisor and does not unnecessarily calculate the remainder. Link: https://lkml.kernel.org/r/20240229210456.63234-2-thorsten.blum@toblux.com Link: https://lkml.kernel.org/r/20240306142547.4612-1-konishi.ryusuke@gmail.com Signed-off-by: Thorsten Blum Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton