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Commit 7f5d38141e30 ("new primitive: __fs_parse()")
taking p_log instead of fs_context.
So, update that comment to refer to p_log instead
Signed-off-by: Chen Hanxiao <chenhx.fnst@fujitsu.com>
Link: https://lore.kernel.org/r/20240202072042.906-1-chenhx.fnst@fujitsu.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Use the new KMEM_CACHE() macro instead of direct kmem_cache_create
to simplify the creation of SLAB caches.
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Link: https://lore.kernel.org/r/20240201093426.207932-1-chentao@kylinos.cn
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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commit 0a31bd5f2bbb ("KMEM_CACHE(): simplify slab cache creation")
introduces a new macro.
Use the new KMEM_CACHE() macro instead of direct kmem_cache_create
to simplify the creation of SLAB caches.
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Link: https://lore.kernel.org/r/20240131070941.135178-1-chentao@kylinos.cn
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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The mix of int, unsigned int, and unsigned long used by struct
poll_list::len, todo, len, and j meant that the signed overflow
sanitizer got worried it needed to instrument several places where
arithmetic happens between these variables. Since all of the variables
are always positive and bounded by unsigned int, use a single type in
all places. Additionally expand the zero-test into an explicit range
check before updating "todo".
This keeps sanitizer instrumentation[1] out of a UACCESS path:
vmlinux.o: warning: objtool: do_sys_poll+0x285: call to __ubsan_handle_sub_overflow() with UACCESS enabled
Link: https://github.com/KSPP/linux/issues/26 [1]
Cc: Christian Brauner <brauner@kernel.org>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jan Kara <jack@suse.cz>
Cc: <linux-fsdevel@vger.kernel.org>
Signed-off-by: Kees Cook <keescook@chromium.org>
Link: https://lore.kernel.org/r/20240129184014.work.593-kees@kernel.org
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Let's use file_mnt_idmap() as we do that across the tree.
No functional impact.
Cc: Christian Brauner <brauner@kernel.org>
Cc: Konstantin Komarov <almaz.alexandrovich@paragon-software.com>
Cc: <ntfs3@lists.linux.dev>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
Link: https://lore.kernel.org/r/20240129180024.219766-1-aleksandr.mikhalitsyn@canonical.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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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 <syzbot+69b40dc5fd40f32c199f@syzkaller.appspotmail.com>
Link: https://syzkaller.appspot.com/bug?extid=69b40dc5fd40f32c199f
Suggested-by: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Link: https://lore.kernel.org/r/0d195f93-a22a-49a2-0020-103534d6f7f6@I-love.SAKURA.ne.jp
Signed-off-by: Christian Brauner <brauner@kernel.org>
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*_lock_nested() is fundamentally broken; lockdep needs to check lock
ordering, but we cannot device a total ordering on an unbounded number
of elements with only a few subclasses.
the replacement is to define lock ordering with a proper comparison
function.
fs/pipe.c was already doing everything correctly otherwise, nothing
much changes here.
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jan Kara <jack@suse.cz>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
Link: https://lore.kernel.org/r/20240127020111.487218-2-kent.overstreet@linux.dev
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/cel/linux
Merge exportfs fixes from Chuck Lever:
* tag 'exportfs-6.9' of ssh://gitolite.kernel.org/pub/scm/linux/kernel/git/cel/linux:
fs: Create a generic is_dot_dotdot() utility
exportfs: fix the fallback implementation of the get_name export operation
Link: https://lore.kernel.org/r/BDC2AEB4-7085-4A7C-8DE8-A659FE1DBA6A@oracle.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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When printing eventfd->count, interrupts will be disabled and a spinlock
will be obtained, competing with eventfd_write(). By moving the
"eventfd-count" print out of the spinlock and merging multiple
seq_printf() into one, it could improve a bit, just like timerfd_show().
Signed-off-by: Wen Yang <wenyang.linux@foxmail.com>
Link: https://lore.kernel.org/r/tencent_B0B3D2BD9861FD009E03AB18A81783322709@qq.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dylan Yudaken <dylany@fb.com>
Cc: David Woodhouse <dwmw@amazon.co.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Eric Biggers <ebiggers@google.com>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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De-duplicate the same functionality in several places by hoisting
the is_dot_dotdot() utility function into linux/fs.h.
Suggested-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Reviewed-by: Amir Goldstein <amir73il@gmail.com>
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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The fallback implementation for the get_name export operation uses
readdir() to try to match the inode number to a filename. That filename
is then used together with lookup_one() to produce a dentry.
A problem arises when we match the '.' or '..' entries, since that
causes lookup_one() to fail. This has sometimes been seen to occur for
filesystems that violate POSIX requirements around uniqueness of inode
numbers, something that is common for snapshot directories.
This patch just ensures that we skip '.' and '..' rather than allowing a
match.
Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
Reviewed-by: Jeff Layton <jlayton@kernel.org>
Acked-by: Amir Goldstein <amir73il@gmail.com>
Link: https://lore.kernel.org/linux-nfs/CAOQ4uxiOZobN76OKB-VBNXWeFKVwLW_eK5QtthGyYzWU9mjb7Q@mail.gmail.com/
Acked-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
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syzbot identified a kernel information leak vulnerability in
do_sys_name_to_handle() and issued the following report [1].
[1]
"BUG: KMSAN: kernel-infoleak in instrument_copy_to_user include/linux/instrumented.h:114 [inline]
BUG: KMSAN: kernel-infoleak in _copy_to_user+0xbc/0x100 lib/usercopy.c:40
instrument_copy_to_user include/linux/instrumented.h:114 [inline]
_copy_to_user+0xbc/0x100 lib/usercopy.c:40
copy_to_user include/linux/uaccess.h:191 [inline]
do_sys_name_to_handle fs/fhandle.c:73 [inline]
__do_sys_name_to_handle_at fs/fhandle.c:112 [inline]
__se_sys_name_to_handle_at+0x949/0xb10 fs/fhandle.c:94
__x64_sys_name_to_handle_at+0xe4/0x140 fs/fhandle.c:94
...
Uninit was created at:
slab_post_alloc_hook+0x129/0xa70 mm/slab.h:768
slab_alloc_node mm/slub.c:3478 [inline]
__kmem_cache_alloc_node+0x5c9/0x970 mm/slub.c:3517
__do_kmalloc_node mm/slab_common.c:1006 [inline]
__kmalloc+0x121/0x3c0 mm/slab_common.c:1020
kmalloc include/linux/slab.h:604 [inline]
do_sys_name_to_handle fs/fhandle.c:39 [inline]
__do_sys_name_to_handle_at fs/fhandle.c:112 [inline]
__se_sys_name_to_handle_at+0x441/0xb10 fs/fhandle.c:94
__x64_sys_name_to_handle_at+0xe4/0x140 fs/fhandle.c:94
...
Bytes 18-19 of 20 are uninitialized
Memory access of size 20 starts at ffff888128a46380
Data copied to user address 0000000020000240"
Per Chuck Lever's suggestion, use kzalloc() instead of kmalloc() to
solve the problem.
Fixes: 990d6c2d7aee ("vfs: Add name to file handle conversion support")
Suggested-by: Chuck Lever III <chuck.lever@oracle.com>
Reported-and-tested-by: <syzbot+09b349b3066c2e0b1e96@syzkaller.appspotmail.com>
Signed-off-by: Nikita Zhandarovich <n.zhandarovich@fintech.ru>
Link: https://lore.kernel.org/r/20240119153906.4367-1-n.zhandarovich@fintech.ru
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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The wb_wakeup_delayed is only used in fs-writeback.c. Move it to
fs-writeback.c after defination of wb_wakeup and make it static.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20240118203339.764093-1-shikemeng@huaweicloud.com
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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We met a kernel crash issue when running stress-ng testing, and the
system crashes when printing the dentry name in dump_mapping().
Unable to handle kernel NULL pointer dereference at virtual address 0000000000000000
pc : dentry_name+0xd8/0x224
lr : pointer+0x22c/0x370
sp : ffff800025f134c0
......
Call trace:
dentry_name+0xd8/0x224
pointer+0x22c/0x370
vsnprintf+0x1ec/0x730
vscnprintf+0x2c/0x60
vprintk_store+0x70/0x234
vprintk_emit+0xe0/0x24c
vprintk_default+0x3c/0x44
vprintk_func+0x84/0x2d0
printk+0x64/0x88
__dump_page+0x52c/0x530
dump_page+0x14/0x20
set_migratetype_isolate+0x110/0x224
start_isolate_page_range+0xc4/0x20c
offline_pages+0x124/0x474
memory_block_offline+0x44/0xf4
memory_subsys_offline+0x3c/0x70
device_offline+0xf0/0x120
......
The root cause is that, one thread is doing page migration, and we will
use the target page's ->mapping field to save 'anon_vma' pointer between
page unmap and page move, and now the target page is locked and refcount
is 1.
Currently, there is another stress-ng thread performing memory hotplug,
attempting to offline the target page that is being migrated. It discovers
that the refcount of this target page is 1, preventing the offline operation,
thus proceeding to dump the page. However, page_mapping() of the target
page may return an incorrect file mapping to crash the system in dump_mapping(),
since the target page->mapping only saves 'anon_vma' pointer without setting
PAGE_MAPPING_ANON flag.
The page migration issue has been fixed by commit d1adb25df711 ("mm: migrate:
fix getting incorrect page mapping during page migration"). In addition,
Matthew suggested we should also improve dump_mapping()'s robustness to
resilient against the kernel crash [1].
With checking the 'dentry.parent' and 'dentry.d_name.name' used by
dentry_name(), I can see dump_mapping() will output the invalid dentry
instead of crashing the system when this issue is reproduced again.
[12211.189128] page:fffff7de047741c0 refcount:1 mapcount:0 mapping:ffff989117f55ea0 index:0x1 pfn:0x211dd07
[12211.189144] aops:0x0 ino:1 invalid dentry:74786574206e6870
[12211.189148] flags: 0x57ffffc0000001(locked|node=1|zone=2|lastcpupid=0x1fffff)
[12211.189150] page_type: 0xffffffff()
[12211.189153] raw: 0057ffffc0000001 0000000000000000 dead000000000122 ffff989117f55ea0
[12211.189154] raw: 0000000000000001 0000000000000001 00000001ffffffff 0000000000000000
[12211.189155] page dumped because: unmovable page
[1] https://lore.kernel.org/all/ZXxn%2F0oixJxxAnpF@casper.infradead.org/
Suggested-by: Matthew Wilcox <willy@infradead.org>
Signed-off-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Link: https://lore.kernel.org/r/937ab1f87328516821d39be672b6bc18861d9d3e.1705391420.git.baolin.wang@linux.alibaba.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Use the new KMEM_CACHE() macro instead of direct kmem_cache_create
to simplify the creation of SLAB caches.
Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Link: https://lore.kernel.org/r/20240116091137.92375-1-chentao@kylinos.cn
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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and the uapi
introduce a BUILD_BUG_ON to check that the EFD_SEMAPHORE is equal to its
definition in the uapi file, just like EFD_CLOEXEC and EFD_NONBLOCK.
Signed-off-by: Wen Yang <wenyang.linux@foxmail.com>
Link: https://lore.kernel.org/r/tencent_0BAA2DEAF9208D49987457E6583F9BE79507@qq.com
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Jan Kara <jack@suse.cz>
Cc: <linux-fsdevel@vger.kernel.org>
Cc: <linux-kernel@vger.kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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This comment refers to function mark_buffer_inode_dirty(), but the
function is actually called mark_buffer_dirty_inode(), so fix the
comment.
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
Link: https://lore.kernel.org/r/20240108172040.178173-1-agruenba@redhat.com
Reviewed-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>
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The word "filesytem" should be "filesystem"
Signed-off-by: Jay <merqqcury@gmail.com>
Link: https://lore.kernel.org/r/20240109072927.29626-1-merqqcury@gmail.com
Signed-off-by: Christian Brauner <brauner@kernel.org>
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Pull more bcachefs updates from Kent Overstreet:
"Some fixes, Some refactoring, some minor features:
- Assorted prep work for disk space accounting rewrite
- BTREE_TRIGGER_ATOMIC: after combining our trigger callbacks, this
makes our trigger context more explicit
- A few fixes to avoid excessive transaction restarts on
multithreaded workloads: fstests (in addition to ktest tests) are
now checking slowpath counters, and that's shaking out a few bugs
- Assorted tracepoint improvements
- Starting to break up bcachefs_format.h and move on disk types so
they're with the code they belong to; this will make room to start
documenting the on disk format better.
- A few minor fixes"
* tag 'bcachefs-2024-01-21' of https://evilpiepirate.org/git/bcachefs: (46 commits)
bcachefs: Improve inode_to_text()
bcachefs: logged_ops_format.h
bcachefs: reflink_format.h
bcachefs; extents_format.h
bcachefs: ec_format.h
bcachefs: subvolume_format.h
bcachefs: snapshot_format.h
bcachefs: alloc_background_format.h
bcachefs: xattr_format.h
bcachefs: dirent_format.h
bcachefs: inode_format.h
bcachefs; quota_format.h
bcachefs: sb-counters_format.h
bcachefs: counters.c -> sb-counters.c
bcachefs: comment bch_subvolume
bcachefs: bch_snapshot::btime
bcachefs: add missing __GFP_NOWARN
bcachefs: opts->compression can now also be applied in the background
bcachefs: Prep work for variable size btree node buffers
bcachefs: grab s_umount only if snapshotting
...
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Add line breaks - inode_to_text() is now much easier to read.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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bcachefs_format.h has gotten too big; let's do some organizing.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Add a field to bch_snapshot for creation time; this will be important
when we start exposing the snapshot tree to userspace.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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The "apply this compression method in the background" paths now use the
compression option if background_compression is not set; this means that
setting or changing the compression option will cause existing data to
be compressed accordingly in the background.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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bcachefs btree nodes are big - typically 256k - and btree roots are
pinned in memory. As we're now up to 18 btrees, we now have significant
memory overhead in mostly empty btree roots.
And in the future we're going to start enforcing that certain btree node
boundaries exist, to solve lock contention issues - analagous to XFS's
AGIs.
Thus, we need to start allocating smaller btree node buffers when we
can. This patch changes code that refers to the filesystem constant
c->opts.btree_node_size to refer to the btree node buffer size -
btree_buf_bytes() - where appropriate.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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When I was testing mongodb over bcachefs with compression,
there is a lockdep warning when snapshotting mongodb data volume.
$ cat test.sh
prog=bcachefs
$prog subvolume create /mnt/data
$prog subvolume create /mnt/data/snapshots
while true;do
$prog subvolume snapshot /mnt/data /mnt/data/snapshots/$(date +%s)
sleep 1s
done
$ cat /etc/mongodb.conf
systemLog:
destination: file
logAppend: true
path: /mnt/data/mongod.log
storage:
dbPath: /mnt/data/
lockdep reports:
[ 3437.452330] ======================================================
[ 3437.452750] WARNING: possible circular locking dependency detected
[ 3437.453168] 6.7.0-rc7-custom+ #85 Tainted: G E
[ 3437.453562] ------------------------------------------------------
[ 3437.453981] bcachefs/35533 is trying to acquire lock:
[ 3437.454325] ffffa0a02b2b1418 (sb_writers#10){.+.+}-{0:0}, at: filename_create+0x62/0x190
[ 3437.454875]
but task is already holding lock:
[ 3437.455268] ffffa0a02b2b10e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: bch2_fs_file_ioctl+0x232/0xc90 [bcachefs]
[ 3437.456009]
which lock already depends on the new lock.
[ 3437.456553]
the existing dependency chain (in reverse order) is:
[ 3437.457054]
-> #3 (&type->s_umount_key#48){.+.+}-{3:3}:
[ 3437.457507] down_read+0x3e/0x170
[ 3437.457772] bch2_fs_file_ioctl+0x232/0xc90 [bcachefs]
[ 3437.458206] __x64_sys_ioctl+0x93/0xd0
[ 3437.458498] do_syscall_64+0x42/0xf0
[ 3437.458779] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 3437.459155]
-> #2 (&c->snapshot_create_lock){++++}-{3:3}:
[ 3437.459615] down_read+0x3e/0x170
[ 3437.459878] bch2_truncate+0x82/0x110 [bcachefs]
[ 3437.460276] bchfs_truncate+0x254/0x3c0 [bcachefs]
[ 3437.460686] notify_change+0x1f1/0x4a0
[ 3437.461283] do_truncate+0x7f/0xd0
[ 3437.461555] path_openat+0xa57/0xce0
[ 3437.461836] do_filp_open+0xb4/0x160
[ 3437.462116] do_sys_openat2+0x91/0xc0
[ 3437.462402] __x64_sys_openat+0x53/0xa0
[ 3437.462701] do_syscall_64+0x42/0xf0
[ 3437.462982] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 3437.463359]
-> #1 (&sb->s_type->i_mutex_key#15){+.+.}-{3:3}:
[ 3437.463843] down_write+0x3b/0xc0
[ 3437.464223] bch2_write_iter+0x5b/0xcc0 [bcachefs]
[ 3437.464493] vfs_write+0x21b/0x4c0
[ 3437.464653] ksys_write+0x69/0xf0
[ 3437.464839] do_syscall_64+0x42/0xf0
[ 3437.465009] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 3437.465231]
-> #0 (sb_writers#10){.+.+}-{0:0}:
[ 3437.465471] __lock_acquire+0x1455/0x21b0
[ 3437.465656] lock_acquire+0xc6/0x2b0
[ 3437.465822] mnt_want_write+0x46/0x1a0
[ 3437.465996] filename_create+0x62/0x190
[ 3437.466175] user_path_create+0x2d/0x50
[ 3437.466352] bch2_fs_file_ioctl+0x2ec/0xc90 [bcachefs]
[ 3437.466617] __x64_sys_ioctl+0x93/0xd0
[ 3437.466791] do_syscall_64+0x42/0xf0
[ 3437.466957] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 3437.467180]
other info that might help us debug this:
[ 3437.469670] 2 locks held by bcachefs/35533:
other info that might help us debug this:
[ 3437.467507] Chain exists of:
sb_writers#10 --> &c->snapshot_create_lock --> &type->s_umount_key#48
[ 3437.467979] Possible unsafe locking scenario:
[ 3437.468223] CPU0 CPU1
[ 3437.468405] ---- ----
[ 3437.468585] rlock(&type->s_umount_key#48);
[ 3437.468758] lock(&c->snapshot_create_lock);
[ 3437.469030] lock(&type->s_umount_key#48);
[ 3437.469291] rlock(sb_writers#10);
[ 3437.469434]
*** DEADLOCK ***
[ 3437.469670] 2 locks held by bcachefs/35533:
[ 3437.469838] #0: ffffa0a02ce00a88 (&c->snapshot_create_lock){++++}-{3:3}, at: bch2_fs_file_ioctl+0x1e3/0xc90 [bcachefs]
[ 3437.470294] #1: ffffa0a02b2b10e0 (&type->s_umount_key#48){.+.+}-{3:3}, at: bch2_fs_file_ioctl+0x232/0xc90 [bcachefs]
[ 3437.470744]
stack backtrace:
[ 3437.470922] CPU: 7 PID: 35533 Comm: bcachefs Kdump: loaded Tainted: G E 6.7.0-rc7-custom+ #85
[ 3437.471313] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
[ 3437.471694] Call Trace:
[ 3437.471795] <TASK>
[ 3437.471884] dump_stack_lvl+0x57/0x90
[ 3437.472035] check_noncircular+0x132/0x150
[ 3437.472202] __lock_acquire+0x1455/0x21b0
[ 3437.472369] lock_acquire+0xc6/0x2b0
[ 3437.472518] ? filename_create+0x62/0x190
[ 3437.472683] ? lock_is_held_type+0x97/0x110
[ 3437.472856] mnt_want_write+0x46/0x1a0
[ 3437.473025] ? filename_create+0x62/0x190
[ 3437.473204] filename_create+0x62/0x190
[ 3437.473380] user_path_create+0x2d/0x50
[ 3437.473555] bch2_fs_file_ioctl+0x2ec/0xc90 [bcachefs]
[ 3437.473819] ? lock_acquire+0xc6/0x2b0
[ 3437.474002] ? __fget_files+0x2a/0x190
[ 3437.474195] ? __fget_files+0xbc/0x190
[ 3437.474380] ? lock_release+0xc5/0x270
[ 3437.474567] ? __x64_sys_ioctl+0x93/0xd0
[ 3437.474764] ? __pfx_bch2_fs_file_ioctl+0x10/0x10 [bcachefs]
[ 3437.475090] __x64_sys_ioctl+0x93/0xd0
[ 3437.475277] do_syscall_64+0x42/0xf0
[ 3437.475454] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 3437.475691] RIP: 0033:0x7f2743c313af
======================================================
In __bch2_ioctl_subvolume_create(), we grab s_umount unconditionally
and unlock it at the end of the function. There is a comment
"why do we need this lock?" about the lock coming from
commit 42d237320e98 ("bcachefs: Snapshot creation, deletion")
The reason is that __bch2_ioctl_subvolume_create() calls
sync_inodes_sb() which enforce locked s_umount to writeback all dirty
nodes before doing snapshot works.
Fix it by read locking s_umount for snapshotting only and unlocking
s_umount after sync_inodes_sb().
Signed-off-by: Su Yue <glass.su@suse.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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bch_fs::snapshots is allocated by kvzalloc in __snapshot_t_mut.
It should be freed by kvfree not kfree.
Or umount will triger:
[ 406.829178 ] BUG: unable to handle page fault for address: ffffe7b487148008
[ 406.830676 ] #PF: supervisor read access in kernel mode
[ 406.831643 ] #PF: error_code(0x0000) - not-present page
[ 406.832487 ] PGD 0 P4D 0
[ 406.832898 ] Oops: 0000 [#1] PREEMPT SMP PTI
[ 406.833512 ] CPU: 2 PID: 1754 Comm: umount Kdump: loaded Tainted: G OE 6.7.0-rc7-custom+ #90
[ 406.834746 ] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Arch Linux 1.16.3-1-1 04/01/2014
[ 406.835796 ] RIP: 0010:kfree+0x62/0x140
[ 406.836197 ] Code: 80 48 01 d8 0f 82 e9 00 00 00 48 c7 c2 00 00 00 80 48 2b 15 78 9f 1f 01 48 01 d0 48 c1 e8 0c 48 c1 e0 06 48 03 05 56 9f 1f 01 <48> 8b 50 08 48 89 c7 f6 c2 01 0f 85 b0 00 00 00 66 90 48 8b 07 f6
[ 406.837810 ] RSP: 0018:ffffb9d641607e48 EFLAGS: 00010286
[ 406.838213 ] RAX: ffffe7b487148000 RBX: ffffb9d645200000 RCX: ffffb9d641607dc4
[ 406.838738 ] RDX: 000065bb00000000 RSI: ffffffffc0d88b84 RDI: ffffb9d645200000
[ 406.839217 ] RBP: ffff9a4625d00068 R08: 0000000000000001 R09: 0000000000000001
[ 406.839650 ] R10: 0000000000000001 R11: 000000000000001f R12: ffff9a4625d4da80
[ 406.840055 ] R13: ffff9a4625d00000 R14: ffffffffc0e2eb20 R15: 0000000000000000
[ 406.840451 ] FS: 00007f0a264ffb80(0000) GS:ffff9a4e2d500000(0000) knlGS:0000000000000000
[ 406.840851 ] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 406.841125 ] CR2: ffffe7b487148008 CR3: 000000018c4d2000 CR4: 00000000000006f0
[ 406.841464 ] Call Trace:
[ 406.841583 ] <TASK>
[ 406.841682 ] ? __die+0x1f/0x70
[ 406.841828 ] ? page_fault_oops+0x159/0x470
[ 406.842014 ] ? fixup_exception+0x22/0x310
[ 406.842198 ] ? exc_page_fault+0x1ed/0x200
[ 406.842382 ] ? asm_exc_page_fault+0x22/0x30
[ 406.842574 ] ? bch2_fs_release+0x54/0x280 [bcachefs]
[ 406.842842 ] ? kfree+0x62/0x140
[ 406.842988 ] ? kfree+0x104/0x140
[ 406.843138 ] bch2_fs_release+0x54/0x280 [bcachefs]
[ 406.843390 ] kobject_put+0xb7/0x170
[ 406.843552 ] deactivate_locked_super+0x2f/0xa0
[ 406.843756 ] cleanup_mnt+0xba/0x150
[ 406.843917 ] task_work_run+0x59/0xa0
[ 406.844083 ] exit_to_user_mode_prepare+0x197/0x1a0
[ 406.844302 ] syscall_exit_to_user_mode+0x16/0x40
[ 406.844510 ] do_syscall_64+0x4e/0xf0
[ 406.844675 ] entry_SYSCALL_64_after_hwframe+0x6e/0x76
[ 406.844907 ] RIP: 0033:0x7f0a2664e4fb
Signed-off-by: Su Yue <glass.su@suse.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Fixes: 023f9ac9f70f bcachefs: Delete dio read alignment check
Reported-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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The variable tmp is being assigned a value but it isn't being
read afterwards. The assignment is redundant and so tmp can be
removed.
Cleans up clang scan build warning:
warning: Although the value stored to 'ret' is used in the enclosing
expression, the value is never actually read from 'ret'
[deadcode.DeadStores]
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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drop_locks_do() should not be used in a fastpath without first trying
the do in nonblocking mode - the unlock and relock will cause excessive
transaction restarts and potentially livelocking with other threads that
are contending for the same locks.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Factor out bch2_journal_bufs_to_text(), and use it in the
journal_entry_full() tracepoint; when we can't get a journal reservation
we need to know the outstanding journal entry sizes to know if the
problem is due to excessive flushing.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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When issuing discards, we may need to flush the journal if there's too
many buckets that can't be discarded until a journal flush.
But the heuristic was bad; we should be comparing the number of buckets
that need to flushes against the number of free buckets, not the number
of buckets we saw.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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Also print out the data_opts, so that we can see what specifically is
being done to an extent.
Signed-off-by: Kent Overstreet <kent.overstreet@linux.dev>
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