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2021-09-07Merge tag 'fuse-update-5.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse Pull fuse updates from Miklos Szeredi: - Allow mounting an active fuse device. Previously the fuse device would always be mounted during initialization, and sharing a fuse superblock was only possible through mount or namespace cloning - Fix data flushing in syncfs (virtiofs only) - Fix data flushing in copy_file_range() - Fix a possible deadlock in atomic O_TRUNC - Misc fixes and cleanups * tag 'fuse-update-5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/mszeredi/fuse: fuse: remove unused arg in fuse_write_file_get() fuse: wait for writepages in syncfs fuse: flush extending writes fuse: truncate pagecache on atomic_o_trunc fuse: allow sharing existing sb fuse: move fget() to fuse_get_tree() fuse: move option checking into fuse_fill_super() fuse: name fs_context consistently fuse: fix use after free in fuse_read_interrupt()
2021-09-07Revert "memcg: enable accounting for pollfd and select bits arrays"Linus Torvalds
This reverts commit b655843444152c0a14b749308e4cb35d91cbcf0b. Just like with the memcg lock accounting, the kernel test robot reports a sizeable performance regression for this commit, and while it clearly does the rigth thing in theory, we'll need to look at just how to avoid or minimize the performance overhead of the memcg accounting. People already have suggestions on how to do that, but it's "future work". So revert it for now. [ Note: the first link below is for this same commit but a different commit ID, because it's the kernel test robot ended up noticing it in Andrew Morton's patch queue ] Link: https://lore.kernel.org/lkml/20210905132732.GC15026@xsang-OptiPlex-9020/ Link: https://lore.kernel.org/lkml/20210907150757.GE17617@xsang-OptiPlex-9020/ Acked-by: Jens Axboe <axboe@kernel.dk> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Roman Gushchin <guro@fb.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-07Revert "memcg: enable accounting for file lock caches"Linus Torvalds
This reverts commit 0f12156dff2862ac54235fc72703f18770769042. The kernel test robot reports a sizeable performance regression for this commit, and while it clearly does the rigth thing in theory, we'll need to look at just how to avoid or minimize the performance overhead of the memcg accounting. People already have suggestions on how to do that, but it's "future work". So revert it for now. Link: https://lore.kernel.org/lkml/20210907150757.GE17617@xsang-OptiPlex-9020/ Acked-by: Jens Axboe <axboe@kernel.dk> Acked-by: Shakeel Butt <shakeelb@google.com> Acked-by: Roman Gushchin <guro@fb.com> Cc: Tejun Heo <tj@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-07Revert "mm/gup: remove try_get_page(), call try_get_compound_head() directly"Linus Torvalds
This reverts commit 9857a17f206ff374aea78bccfb687f145368be2e. That commit was completely broken, and I should have caught on to it earlier. But happily, the kernel test robot noticed the breakage fairly quickly. The breakage is because "try_get_page()" is about avoiding the page reference count overflow case, but is otherwise the exact same as a plain "get_page()". In contrast, "try_get_compound_head()" is an entirely different beast, and uses __page_cache_add_speculative() because it's not just about the page reference count, but also about possibly racing with the underlying page going away. So all the commentary about how "try_get_page() has fallen a little behind in terms of maintenance, try_get_compound_head() handles speculative page references more thoroughly" was just completely wrong: yes, try_get_compound_head() handles speculative page references, but the point is that try_get_page() does not, and must not. So there's no lack of maintainance - there are fundamentally different semantics. A speculative page reference would be entirely wrong in "get_page()", and it's entirely wrong in "try_get_page()". It's not about speculation, it's purely about "uhhuh, you can't get this page because you've tried to increment the reference count too much already". The reason the kernel test robot noticed this bug was that it hit the VM_BUG_ON() in __page_cache_add_speculative(), which is all about verifying that the context of any speculative page access is correct. But since that isn't what try_get_page() is all about, the VM_BUG_ON() tests things that are not correct to test for try_get_page(). Reported-by: kernel test robot <oliver.sang@intel.com> Cc: John Hubbard <jhubbard@nvidia.com> Cc: Christoph Hellwig <hch@lst.de> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-07block: move fs/block_dev.c to block/bdev.cChristoph Hellwig
Move it together with the rest of the block layer. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210907141303.1371844-3-hch@lst.de Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-07block: split out operations on block special filesChristoph Hellwig
Add a new block/fops.c for all the file and address_space operations that provide the block special file support. Signed-off-by: Christoph Hellwig <hch@lst.de> Link: https://lore.kernel.org/r/20210907141303.1371844-2-hch@lst.de [axboe: correct trailing whitespace while at it] Signed-off-by: Jens Axboe <axboe@kernel.dk>
2021-09-07btrfs: zoned: fix double counting of split ordered extentNaohiro Aota
btrfs_add_ordered_extent_*() add num_bytes to fs_info->ordered_bytes. Then, splitting an ordered extent will call btrfs_add_ordered_extent_*() again for split extents, leading to double counting of the region of a split extent. These leaked bytes are finally reported at unmount time as follow: BTRFS info (device dm-1): at unmount dio bytes count 364544 Fix the double counting by subtracting split extent's size from fs_info->ordered_bytes. Fixes: d22002fd37bd ("btrfs: zoned: split ordered extent when bio is sent") CC: stable@vger.kernel.org # 5.12+ Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Signed-off-by: Naohiro Aota <naohiro.aota@wdc.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-09-07btrfs: fix lockdep warning while mounting sprout fsAnand Jain
Following test case reproduces lockdep warning. Test case: $ mkfs.btrfs -f <dev1> $ btrfstune -S 1 <dev1> $ mount <dev1> <mnt> $ btrfs device add <dev2> <mnt> -f $ umount <mnt> $ mount <dev2> <mnt> $ umount <mnt> The warning claims a possible ABBA deadlock between the threads initiated by [#1] btrfs device add and [#0] the mount. [ 540.743122] WARNING: possible circular locking dependency detected [ 540.743129] 5.11.0-rc7+ #5 Not tainted [ 540.743135] ------------------------------------------------------ [ 540.743142] mount/2515 is trying to acquire lock: [ 540.743149] ffffa0c5544c2ce0 (&fs_devs->device_list_mutex){+.+.}-{4:4}, at: clone_fs_devices+0x6d/0x210 [btrfs] [ 540.743458] but task is already holding lock: [ 540.743461] ffffa0c54a7932b8 (btrfs-chunk-00){++++}-{4:4}, at: __btrfs_tree_read_lock+0x32/0x200 [btrfs] [ 540.743541] which lock already depends on the new lock. [ 540.743543] the existing dependency chain (in reverse order) is: [ 540.743546] -> #1 (btrfs-chunk-00){++++}-{4:4}: [ 540.743566] down_read_nested+0x48/0x2b0 [ 540.743585] __btrfs_tree_read_lock+0x32/0x200 [btrfs] [ 540.743650] btrfs_read_lock_root_node+0x70/0x200 [btrfs] [ 540.743733] btrfs_search_slot+0x6c6/0xe00 [btrfs] [ 540.743785] btrfs_update_device+0x83/0x260 [btrfs] [ 540.743849] btrfs_finish_chunk_alloc+0x13f/0x660 [btrfs] <--- device_list_mutex [ 540.743911] btrfs_create_pending_block_groups+0x18d/0x3f0 [btrfs] [ 540.743982] btrfs_commit_transaction+0x86/0x1260 [btrfs] [ 540.744037] btrfs_init_new_device+0x1600/0x1dd0 [btrfs] [ 540.744101] btrfs_ioctl+0x1c77/0x24c0 [btrfs] [ 540.744166] __x64_sys_ioctl+0xe4/0x140 [ 540.744170] do_syscall_64+0x4b/0x80 [ 540.744174] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 540.744180] -> #0 (&fs_devs->device_list_mutex){+.+.}-{4:4}: [ 540.744184] __lock_acquire+0x155f/0x2360 [ 540.744188] lock_acquire+0x10b/0x5c0 [ 540.744190] __mutex_lock+0xb1/0xf80 [ 540.744193] mutex_lock_nested+0x27/0x30 [ 540.744196] clone_fs_devices+0x6d/0x210 [btrfs] [ 540.744270] btrfs_read_chunk_tree+0x3c7/0xbb0 [btrfs] [ 540.744336] open_ctree+0xf6e/0x2074 [btrfs] [ 540.744406] btrfs_mount_root.cold.72+0x16/0x127 [btrfs] [ 540.744472] legacy_get_tree+0x38/0x90 [ 540.744475] vfs_get_tree+0x30/0x140 [ 540.744478] fc_mount+0x16/0x60 [ 540.744482] vfs_kern_mount+0x91/0x100 [ 540.744484] btrfs_mount+0x1e6/0x670 [btrfs] [ 540.744536] legacy_get_tree+0x38/0x90 [ 540.744537] vfs_get_tree+0x30/0x140 [ 540.744539] path_mount+0x8d8/0x1070 [ 540.744541] do_mount+0x8d/0xc0 [ 540.744543] __x64_sys_mount+0x125/0x160 [ 540.744545] do_syscall_64+0x4b/0x80 [ 540.744547] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 540.744551] other info that might help us debug this: [ 540.744552] Possible unsafe locking scenario: [ 540.744553] CPU0 CPU1 [ 540.744554] ---- ---- [ 540.744555] lock(btrfs-chunk-00); [ 540.744557] lock(&fs_devs->device_list_mutex); [ 540.744560] lock(btrfs-chunk-00); [ 540.744562] lock(&fs_devs->device_list_mutex); [ 540.744564] *** DEADLOCK *** [ 540.744565] 3 locks held by mount/2515: [ 540.744567] #0: ffffa0c56bf7a0e0 (&type->s_umount_key#42/1){+.+.}-{4:4}, at: alloc_super.isra.16+0xdf/0x450 [ 540.744574] #1: ffffffffc05a9628 (uuid_mutex){+.+.}-{4:4}, at: btrfs_read_chunk_tree+0x63/0xbb0 [btrfs] [ 540.744640] #2: ffffa0c54a7932b8 (btrfs-chunk-00){++++}-{4:4}, at: __btrfs_tree_read_lock+0x32/0x200 [btrfs] [ 540.744708] stack backtrace: [ 540.744712] CPU: 2 PID: 2515 Comm: mount Not tainted 5.11.0-rc7+ #5 But the device_list_mutex in clone_fs_devices() is redundant, as explained below. Two threads [1] and [2] (below) could lead to clone_fs_device(). [1] open_ctree <== mount sprout fs btrfs_read_chunk_tree() mutex_lock(&uuid_mutex) <== global lock read_one_dev() open_seed_devices() clone_fs_devices() <== seed fs_devices mutex_lock(&orig->device_list_mutex) <== seed fs_devices [2] btrfs_init_new_device() <== sprouting mutex_lock(&uuid_mutex); <== global lock btrfs_prepare_sprout() lockdep_assert_held(&uuid_mutex) clone_fs_devices(seed_fs_device) <== seed fs_devices Both of these threads hold uuid_mutex which is sufficient to protect getting the seed device(s) freed while we are trying to clone it for sprouting [2] or mounting a sprout [1] (as above). A mounted seed device can not free/write/replace because it is read-only. An unmounted seed device can be freed by btrfs_free_stale_devices(), but it needs uuid_mutex. So this patch removes the unnecessary device_list_mutex in clone_fs_devices(). And adds a lockdep_assert_held(&uuid_mutex) in clone_fs_devices(). Reported-by: Su Yue <l@damenly.su> Tested-by: Su Yue <l@damenly.su> Signed-off-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-09-07btrfs: delay blkdev_put until after the device removeJosef Bacik
When removing the device we call blkdev_put() on the device once we've removed it, and because we have an EXCL open we need to take the ->open_mutex on the block device to clean it up. Unfortunately during device remove we are holding the sb writers lock, which results in the following lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc2+ #407 Not tainted ------------------------------------------------------ losetup/11595 is trying to acquire lock: ffff973ac35dd138 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0 but task is already holding lock: ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&lo->lo_mutex){+.+.}-{3:3}: __mutex_lock+0x7d/0x750 lo_open+0x28/0x60 [loop] blkdev_get_whole+0x25/0xf0 blkdev_get_by_dev.part.0+0x168/0x3c0 blkdev_open+0xd2/0xe0 do_dentry_open+0x161/0x390 path_openat+0x3cc/0xa20 do_filp_open+0x96/0x120 do_sys_openat2+0x7b/0x130 __x64_sys_openat+0x46/0x70 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #3 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock+0x7d/0x750 blkdev_put+0x3a/0x220 btrfs_rm_device.cold+0x62/0xe5 btrfs_ioctl+0x2a31/0x2e70 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #2 (sb_writers#12){.+.+}-{0:0}: lo_write_bvec+0xc2/0x240 [loop] loop_process_work+0x238/0xd00 [loop] process_one_work+0x26b/0x560 worker_thread+0x55/0x3c0 kthread+0x140/0x160 ret_from_fork+0x1f/0x30 -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}: process_one_work+0x245/0x560 worker_thread+0x55/0x3c0 kthread+0x140/0x160 ret_from_fork+0x1f/0x30 -> #0 ((wq_completion)loop0){+.+.}-{0:0}: __lock_acquire+0x10ea/0x1d90 lock_acquire+0xb5/0x2b0 flush_workqueue+0x91/0x5e0 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x660 [loop] block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&lo->lo_mutex); lock(&disk->open_mutex); lock(&lo->lo_mutex); lock((wq_completion)loop0); *** DEADLOCK *** 1 lock held by losetup/11595: #0: ffff973ac9812c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop] stack backtrace: CPU: 0 PID: 11595 Comm: losetup Not tainted 5.14.0-rc2+ #407 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: dump_stack_lvl+0x57/0x72 check_noncircular+0xcf/0xf0 ? stack_trace_save+0x3b/0x50 __lock_acquire+0x10ea/0x1d90 lock_acquire+0xb5/0x2b0 ? flush_workqueue+0x67/0x5e0 ? lockdep_init_map_type+0x47/0x220 flush_workqueue+0x91/0x5e0 ? flush_workqueue+0x67/0x5e0 ? verify_cpu+0xf0/0x100 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x660 [loop] ? blkdev_ioctl+0x8d/0x2a0 block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae RIP: 0033:0x7fc21255d4cb So instead save the bdev and do the put once we've dropped the sb writers lock in order to avoid the lockdep recursion. Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-09-07btrfs: update the bdev time directly when closingJosef Bacik
We update the ctime/mtime of a block device when we remove it so that blkid knows the device changed. However we do this by re-opening the block device and calling filp_update_time. This is more correct because it'll call the inode->i_op->update_time if it exists, but the block dev inodes do not do this. Instead call generic_update_time() on the bd_inode in order to avoid the blkdev_open path and get rid of the following lockdep splat: ====================================================== WARNING: possible circular locking dependency detected 5.14.0-rc2+ #406 Not tainted ------------------------------------------------------ losetup/11596 is trying to acquire lock: ffff939640d2f538 ((wq_completion)loop0){+.+.}-{0:0}, at: flush_workqueue+0x67/0x5e0 but task is already holding lock: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop] which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #4 (&lo->lo_mutex){+.+.}-{3:3}: __mutex_lock+0x7d/0x750 lo_open+0x28/0x60 [loop] blkdev_get_whole+0x25/0xf0 blkdev_get_by_dev.part.0+0x168/0x3c0 blkdev_open+0xd2/0xe0 do_dentry_open+0x161/0x390 path_openat+0x3cc/0xa20 do_filp_open+0x96/0x120 do_sys_openat2+0x7b/0x130 __x64_sys_openat+0x46/0x70 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #3 (&disk->open_mutex){+.+.}-{3:3}: __mutex_lock+0x7d/0x750 blkdev_get_by_dev.part.0+0x56/0x3c0 blkdev_open+0xd2/0xe0 do_dentry_open+0x161/0x390 path_openat+0x3cc/0xa20 do_filp_open+0x96/0x120 file_open_name+0xc7/0x170 filp_open+0x2c/0x50 btrfs_scratch_superblocks.part.0+0x10f/0x170 btrfs_rm_device.cold+0xe8/0xed btrfs_ioctl+0x2a31/0x2e70 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae -> #2 (sb_writers#12){.+.+}-{0:0}: lo_write_bvec+0xc2/0x240 [loop] loop_process_work+0x238/0xd00 [loop] process_one_work+0x26b/0x560 worker_thread+0x55/0x3c0 kthread+0x140/0x160 ret_from_fork+0x1f/0x30 -> #1 ((work_completion)(&lo->rootcg_work)){+.+.}-{0:0}: process_one_work+0x245/0x560 worker_thread+0x55/0x3c0 kthread+0x140/0x160 ret_from_fork+0x1f/0x30 -> #0 ((wq_completion)loop0){+.+.}-{0:0}: __lock_acquire+0x10ea/0x1d90 lock_acquire+0xb5/0x2b0 flush_workqueue+0x91/0x5e0 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x660 [loop] block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae other info that might help us debug this: Chain exists of: (wq_completion)loop0 --> &disk->open_mutex --> &lo->lo_mutex Possible unsafe locking scenario: CPU0 CPU1 ---- ---- lock(&lo->lo_mutex); lock(&disk->open_mutex); lock(&lo->lo_mutex); lock((wq_completion)loop0); *** DEADLOCK *** 1 lock held by losetup/11596: #0: ffff939655510c68 (&lo->lo_mutex){+.+.}-{3:3}, at: __loop_clr_fd+0x41/0x660 [loop] stack backtrace: CPU: 1 PID: 11596 Comm: losetup Not tainted 5.14.0-rc2+ #406 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.13.0-2.fc32 04/01/2014 Call Trace: dump_stack_lvl+0x57/0x72 check_noncircular+0xcf/0xf0 ? stack_trace_save+0x3b/0x50 __lock_acquire+0x10ea/0x1d90 lock_acquire+0xb5/0x2b0 ? flush_workqueue+0x67/0x5e0 ? lockdep_init_map_type+0x47/0x220 flush_workqueue+0x91/0x5e0 ? flush_workqueue+0x67/0x5e0 ? verify_cpu+0xf0/0x100 drain_workqueue+0xa0/0x110 destroy_workqueue+0x36/0x250 __loop_clr_fd+0x9a/0x660 [loop] ? blkdev_ioctl+0x8d/0x2a0 block_ioctl+0x3f/0x50 __x64_sys_ioctl+0x80/0xb0 do_syscall_64+0x38/0x90 entry_SYSCALL_64_after_hwframe+0x44/0xae Reviewed-by: Anand Jain <anand.jain@oracle.com> Signed-off-by: Josef Bacik <josef@toxicpanda.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-09-07btrfs: use correct header for div_u64 in misc.hKari Argillander
asm/do_div.h is for div_u64, but it is found in math64.h. This change will make compiler job easier and prevent compiler errors in situation where compiler will not find math64.h from another paths. Signed-off-by: Kari Argillander <kari.argillander@gmail.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-09-07btrfs: fix upper limit for max_inline for page size 64KAnand Jain
The mount option max_inline ranges from 0 to the sectorsize (which is now equal to page size). But we parse the mount options too early and before the actual sectorsize is read from the superblock. So the upper limit of max_inline is unaware of the actual sectorsize and is limited by the temporary sectorsize 4096, even on a system where the default sectorsize is 64K. Fix this by reading the superblock sectorsize before the mount option parse. Reported-by: Alexander Tsvetkov <alexander.tsvetkov@oracle.com> CC: stable@vger.kernel.org # 5.4+ Signed-off-by: Anand Jain <anand.jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2021-09-06Merge tag 'for-5.15/io_uring-2021-09-04' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull io_uring fixes from Jens Axboe: "As sometimes happens, two reports came in around the merge window open that led to some fixes. Hence this one is a bit bigger than usual followup fixes, but most of it will be going towards stable, outside of the fixes that are addressing regressions from this merge window. In detail: - postgres is a heavy user of signals between tasks, and if we're unlucky this can interfere with io-wq worker creation. Make sure we're resilient against unrelated signal handling. This set of changes also includes hardening against allocation failures, which could previously had led to stalls. - Some use cases that end up having a mix of bounded and unbounded work would have starvation issues related to that. Split the pending work lists to handle that better. - Completion trace int -> unsigned -> long fix - Fix issue with REGISTER_IOWQ_MAX_WORKERS and SQPOLL - Fix regression with hash wait lock in this merge window - Fix retry issued on block devices (Ming) - Fix regression with links in this merge window (Pavel) - Fix race with multi-shot poll and completions (Xiaoguang) - Ensure regular file IO doesn't inadvertently skip completion batching (Pavel) - Ensure submissions are flushed after running task_work (Pavel)" * tag 'for-5.15/io_uring-2021-09-04' of git://git.kernel.dk/linux-block: io_uring: io_uring_complete() trace should take an integer io_uring: fix possible poll event lost in multi shot mode io_uring: prolong tctx_task_work() with flushing io_uring: don't disable kiocb_done() CQE batching io_uring: ensure IORING_REGISTER_IOWQ_MAX_WORKERS works with SQPOLL io-wq: make worker creation resilient against signals io-wq: get rid of FIXED worker flag io-wq: only exit on fatal signals io-wq: split bounded and unbounded work into separate lists io-wq: fix queue stalling race io_uring: don't submit half-prepared drain request io_uring: fix queueing half-created requests io-wq: ensure that hash wait lock is IRQ disabling io_uring: retry in case of short read on block device io_uring: IORING_OP_WRITE needs hash_reg_file set io-wq: fix race between adding work and activating a free worker
2021-09-06fuse: remove unused arg in fuse_write_file_get()Miklos Szeredi
The struct fuse_conn argument is not used and can be removed. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-09-06fuse: wait for writepages in syncfsMiklos Szeredi
In case of fuse the MM subsystem doesn't guarantee that page writeback completes by the time ->sync_fs() is called. This is because fuse completes page writeback immediately to prevent DoS of memory reclaim by the userspace file server. This means that fuse itself must ensure that writes are synced before sending the SYNCFS request to the server. Introduce sync buckets, that hold a counter for the number of outstanding write requests. On syncfs replace the current bucket with a new one and wait until the old bucket's counter goes down to zero. It is possible to have multiple syncfs calls in parallel, in which case there could be more than one waited-on buckets. Descendant buckets must not complete until the parent completes. Add a count to the child (new) bucket until the (parent) old bucket completes. Use RCU protection to dereference the current bucket and to wake up an emptied bucket. Use fc->lock to protect against parallel assignments to the current bucket. This leaves just the counter to be a possible scalability issue. The fc->num_waiting counter has a similar issue, so both should be addressed at the same time. Reported-by: Amir Goldstein <amir73il@gmail.com> Fixes: 2d82ab251ef0 ("virtiofs: propagate sync() to file server") Cc: <stable@vger.kernel.org> # v5.14 Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2021-09-06file: Export receive_fd() to modulesXie Yongji
Export receive_fd() so that some modules can use it to pass file descriptor between processes without missing any security stuffs. Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Acked-by: Jason Wang <jasowang@redhat.com> Link: https://lore.kernel.org/r/20210831103634.33-4-xieyongji@bytedance.com Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-09-06eventfd: Export eventfd_wake_count to modulesXie Yongji
Export eventfd_wake_count so that some modules can use the eventfd_signal_count() to check whether the eventfd_signal() call should be deferred to a safe context. NB(mst): this patch is not needed in Linus tree since there eventfd_signal_count() has been superseded by an already exported eventfd_signal_allowed(). Signed-off-by: Xie Yongji <xieyongji@bytedance.com> Link: https://lore.kernel.org/r/20210831103634.33-3-xieyongji@bytedance.com Acked-by: Jason Wang <jasowang@redhat.com> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
2021-09-05binfmt: a.out: Fix bogus semicolonGeert Uytterhoeven
fs/binfmt_aout.c: In function ‘load_aout_library’: fs/binfmt_aout.c:311:27: error: expected ‘)’ before ‘;’ token 311 | MAP_FIXED | MAP_PRIVATE; | ^ fs/binfmt_aout.c:309:10: error: too few arguments to function ‘vm_mmap’ 309 | error = vm_mmap(file, start_addr, ex.a_text + ex.a_data, | ^~~~~~~ In file included from fs/binfmt_aout.c:12: include/linux/mm.h:2626:35: note: declared here 2626 | extern unsigned long __must_check vm_mmap(struct file *, unsigned long, | ^~~~~~~ Fix this by reverting the accidental replacement of a comma by a semicolon. Fixes: 42be8b42535183f8 ("binfmt: don't use MAP_DENYWRITE when loading shared libraries via uselib()") Reported-by: noreply@ellerman.id.au Reported-by: Guenter Roeck <linux@roeck-us.net> Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-04Merge tag 'denywrite-for-5.15' of git://github.com/davidhildenbrand/linuxLinus Torvalds
Pull MAP_DENYWRITE removal from David Hildenbrand: "Remove all in-tree usage of MAP_DENYWRITE from the kernel and remove VM_DENYWRITE. There are some (minor) user-visible changes: - We no longer deny write access to shared libaries loaded via legacy uselib(); this behavior matches modern user space e.g. dlopen(). - We no longer deny write access to the elf interpreter after exec completed, treating it just like shared libraries (which it often is). - We always deny write access to the file linked via /proc/pid/exe: sys_prctl(PR_SET_MM_MAP/EXE_FILE) will fail if write access to the file cannot be denied, and write access to the file will remain denied until the link is effectivel gone (exec, termination, sys_prctl(PR_SET_MM_MAP/EXE_FILE)) -- just as if exec'ing the file. Cross-compiled for a bunch of architectures (alpha, microblaze, i386, s390x, ...) and verified via ltp that especially the relevant tests (i.e., creat07 and execve04) continue working as expected" * tag 'denywrite-for-5.15' of git://github.com/davidhildenbrand/linux: fs: update documentation of get_write_access() and friends mm: ignore MAP_DENYWRITE in ksys_mmap_pgoff() mm: remove VM_DENYWRITE binfmt: remove in-tree usage of MAP_DENYWRITE kernel/fork: always deny write access to current MM exe_file kernel/fork: factor out replacing the current MM exe_file binfmt: don't use MAP_DENYWRITE when loading shared libraries via uselib()
2021-09-04Merge git://github.com/Paragon-Software-Group/linux-ntfs3Linus Torvalds
Merge NTFSv3 filesystem from Konstantin Komarov: "This patch adds NTFS Read-Write driver to fs/ntfs3. Having decades of expertise in commercial file systems development and huge test coverage, we at Paragon Software GmbH want to make our contribution to the Open Source Community by providing implementation of NTFS Read-Write driver for the Linux Kernel. This is fully functional NTFS Read-Write driver. Current version works with NTFS (including v3.1) and normal/compressed/sparse files and supports journal replaying. We plan to support this version after the codebase once merged, and add new features and fix bugs. For example, full journaling support over JBD will be added in later updates" Link: https://lore.kernel.org/lkml/20210729134943.778917-1-almaz.alexandrovich@paragon-software.com/ Link: https://lore.kernel.org/lkml/aa4aa155-b9b2-9099-b7a2-349d8d9d8fbd@paragon-software.com/ * git://github.com/Paragon-Software-Group/linux-ntfs3: (35 commits) fs/ntfs3: Change how module init/info messages are displayed fs/ntfs3: Remove GPL boilerplates from decompress lib files fs/ntfs3: Remove unnecessary condition checking from ntfs_file_read_iter fs/ntfs3: Fix integer overflow in ni_fiemap with fiemap_prep() fs/ntfs3: Restyle comments to better align with kernel-doc fs/ntfs3: Rework file operations fs/ntfs3: Remove fat ioctl's from ntfs3 driver for now fs/ntfs3: Restyle comments to better align with kernel-doc fs/ntfs3: Fix error handling in indx_insert_into_root() fs/ntfs3: Potential NULL dereference in hdr_find_split() fs/ntfs3: Fix error code in indx_add_allocate() fs/ntfs3: fix an error code in ntfs_get_acl_ex() fs/ntfs3: add checks for allocation failure fs/ntfs3: Use kcalloc/kmalloc_array over kzalloc/kmalloc fs/ntfs3: Do not use driver own alloc wrappers fs/ntfs3: Use kernel ALIGN macros over driver specific fs/ntfs3: Restyle comment block in ni_parse_reparse() fs/ntfs3: Remove unused including <linux/version.h> fs/ntfs3: Fix fall-through warnings for Clang fs/ntfs3: Fix one none utf8 char in source file ...
2021-09-04Merge tag 'f2fs-for-5.15-rc1' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs Pull f2fs updates from Jaegeuk Kim: "In this cycle, we've addressed some performance issues such as lock contention, misbehaving compress_cache, allowing extent_cache for compressed files, and new sysfs to adjust ra_size for fadvise. In order to diagnose the performance issues quickly, we also added an iostat which shows the IO latencies periodically. On the stability side, we've found two memory leakage cases in the error path in compression flow. And, we've also fixed various corner cases in fiemap, quota, checkpoint=disable, zstd, and so on. Enhancements: - avoid long checkpoint latency by releasing nat_tree_lock - collect and show iostats periodically - support extent_cache for compressed files - add a sysfs entry to manage ra_size given fadvise(POSIX_FADV_SEQUENTIAL) - report f2fs GC status via sysfs - add discard_unit=%s in mount option to handle zoned device Bug fixes: - fix two memory leakages when an error happens in the compressed IO flow - fix commpress_cache to get the right LBA - fix fiemap to deal with compressed case correctly - fix wrong EIO returns due to SBI_NEED_FSCK - fix missing writes when enabling checkpoint back - fix quota deadlock - fix zstd level mount option In addition to the above major updates, we've cleaned up several code paths such as dio, unnecessary operations, debugfs/f2fs/status, sanity check, and typos" * tag 'f2fs-for-5.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/jaegeuk/f2fs: (46 commits) f2fs: should put a page beyond EOF when preparing a write f2fs: deallocate compressed pages when error happens f2fs: enable realtime discard iff device supports discard f2fs: guarantee to write dirty data when enabling checkpoint back f2fs: fix to unmap pages from userspace process in punch_hole() f2fs: fix unexpected ENOENT comes from f2fs_map_blocks() f2fs: fix to account missing .skipped_gc_rwsem f2fs: adjust unlock order for cleanup f2fs: Don't create discard thread when device doesn't support realtime discard f2fs: rebuild nat_bits during umount f2fs: introduce periodic iostat io latency traces f2fs: separate out iostat feature f2fs: compress: do sanity check on cluster f2fs: fix description about main_blkaddr node f2fs: convert S_IRUGO to 0444 f2fs: fix to keep compatibility of fault injection interface f2fs: support fault injection for f2fs_kmem_cache_alloc() f2fs: compress: allow write compress released file after truncate to zero f2fs: correct comment in segment.h f2fs: improve sbi status info in debugfs/f2fs/status ...
2021-09-04Merge tag 'nfs-for-5.15-1' of git://git.linux-nfs.org/projects/anna/linux-nfsLinus Torvalds
Pull NFS client updates from Anna Schumaker: "New Features: - Better client responsiveness when server isn't replying - Use refcount_t in sunrpc rpc_client refcount tracking - Add srcaddr and dst_port to the sunrpc sysfs info files - Add basic support for connection sharing between servers with multiple NICs` Bugfixes and Cleanups: - Sunrpc tracepoint cleanups - Disconnect after ib_post_send() errors to avoid deadlocks - Fix for tearing down rpcrdma_reps - Fix a potential pNFS layoutget livelock loop - pNFS layout barrier fixes - Fix a potential memory corruption in rpc_wake_up_queued_task_set_status() - Fix reconnection locking - Fix return value of get_srcport() - Remove rpcrdma_post_sends() - Remove pNFS dead code - Remove copy size restriction for inter-server copies - Overhaul the NFS callback service - Clean up sunrpc TCP socket shutdowns - Always provide aligned buffers to RPC read layers" * tag 'nfs-for-5.15-1' of git://git.linux-nfs.org/projects/anna/linux-nfs: (39 commits) NFS: Always provide aligned buffers to the RPC read layers NFSv4.1 add network transport when session trunking is detected SUNRPC enforce creation of no more than max_connect xprts NFSv4 introduce max_connect mount options SUNRPC add xps_nunique_destaddr_xprts to xprt_switch_info in sysfs SUNRPC keep track of number of transports to unique addresses NFSv3: Delete duplicate judgement in nfs3_async_handle_jukebox SUNRPC: Tweak TCP socket shutdown in the RPC client SUNRPC: Simplify socket shutdown when not reusing TCP ports NFSv4.2: remove restriction of copy size for inter-server copy. NFS: Clean up the synopsis of callback process_op() NFS: Extract the xdr_init_encode/decode() calls from decode_compound NFS: Remove unused callback void decoder NFS: Add a private local dispatcher for NFSv4 callback operations SUNRPC: Eliminate the RQ_AUTHERR flag SUNRPC: Set rq_auth_stat in the pg_authenticate() callout SUNRPC: Add svc_rqst::rq_auth_stat SUNRPC: Add dst_port to the sysfs xprt info file SUNRPC: Add srcaddr as a file in sysfs sunrpc: Fix return value of get_srcport() ...
2021-09-03ksmbd: add validation for ndr read/write functionsNamjae Jeon
If ndr->length is smaller than expected size, ksmbd can access invalid access in ndr->data. This patch add validation to check ndr->offset is over ndr->length. and added exception handling to check return value of ndr read/write function. Cc: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03ksmbd: remove unused ksmbd_file_table_flush functionNamjae Jeon
ksmbd_file_table_flush is a leftover from SMB1. This function is no longer needed as SMB1 has been removed from ksmbd. Reported-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03ksmbd: smbd: fix dma mapping error in smb_direct_post_send_dataHyunchul Lee
Becase smb direct header is mapped and msg->num_sge already is incremented, the decrement should be removed from the condition. Signed-off-by: Hyunchul Lee <hyc.lee@gmail.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03ksmbd: Reduce error log 'speed is unknown' to debugPer Forlin
This log happens on servers with a network bridge since the bridge does not have a specified link speed. This is not a real error so change the error log to debug instead. Signed-off-by: Per Forlin <perfn@axis.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03ksmbd: defer notify_change() callChristian Brauner
When ownership is changed we might in certain scenarios loose the ability to alter the inode after we changed ownership. This can e.g. happen when we are on an idmapped mount where uid 0 is mapped to uid 1000 and uid 1000 is mapped to uid 0. A caller with fs*id 1000 will be able to create files as *id 1000 on disk. They will also be able to change ownership of files owned by *id 0 to *id 1000 but they won't be able to change ownership in the other direction. This means acl operations following notify_change() would fail. Move the notify_change() call after the acls have been updated. This guarantees that we don't end up with spurious "hash value diff" warnings later on because we managed to change ownership but didn't manage to alter acls. Cc: Steve French <stfrench@microsoft.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Hyunchul Lee <hyc.lee@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: linux-cifs@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03ksmbd: remove setattr preparations in set_file_basic_info()Christian Brauner
Permission checking and copying over ownership information is the task of the underlying filesystem not ksmbd. The order is also wrong here. This modifies the inode before notify_change(). If notify_change() fails this will have changed ownership nonetheless. All of this is unnecessary though since the underlying filesystem's ->setattr handler will do all this (if required) by itself. Cc: Steve French <stfrench@microsoft.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Hyunchul Lee <hyc.lee@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: linux-cifs@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03ksmbd: ensure error is surfaced in set_file_basic_info()Christian Brauner
It seems the error was accidently ignored until now. Make sure it is surfaced. Cc: Steve French <stfrench@microsoft.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Hyunchul Lee <hyc.lee@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: linux-cifs@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03ndr: fix translation in ndr_encode_posix_acl()Christian Brauner
The sid_to_id() helper encodes raw ownership information suitable for s*id handling. This is conceptually equivalent to reporting ownership information via stat to userspace. In this case the consumer is ksmbd instead of a regular user. So when encoding raw ownership information suitable for s*id handling later we need to map the id up according to the user namespace of ksmbd itself taking any idmapped mounts into account. Cc: Steve French <stfrench@microsoft.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Hyunchul Lee <hyc.lee@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: linux-cifs@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03ksmbd: fix translation in sid_to_id()Christian Brauner
The sid_to_id() functions is relevant when changing ownership of filesystem objects based on acl information. In this case we need to first translate the relevant s*ids into k*ids in ksmbd's user namespace and account for any idmapped mounts. Requesting a change in ownership requires the inverse translation to be applied when we would report ownership to userspace. So k*id_from_mnt() must be used here. Cc: Steve French <stfrench@microsoft.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Hyunchul Lee <hyc.lee@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: linux-cifs@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03ksmbd: fix subauth 0 handling in sid_to_id()Christian Brauner
It's not obvious why subauth 0 would be excluded from translation. This would lead to wrong results whenever a non-identity idmapping is used. Cc: Steve French <stfrench@microsoft.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Hyunchul Lee <hyc.lee@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: linux-cifs@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03ksmbd: fix translation in acl entriesChristian Brauner
The ksmbd server performs translation of posix acls to smb acls. Currently the translation is wrong since the idmapping of the mount is used to map the ids into raw userspace ids but what is relevant is the user namespace of ksmbd itself. The user namespace of ksmbd itself which is the initial user namespace. The operation is similar to asking "What *ids would a userspace process see given that k*id in the relevant user namespace?". Before the final translation we need to apply the idmapping of the mount in case any is used. Add two simple helpers for ksmbd. Cc: Steve French <stfrench@microsoft.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Hyunchul Lee <hyc.lee@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: linux-cifs@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03ksmbd: fix translation in ksmbd_acls_fattr()Christian Brauner
When creating new filesystem objects ksmbd translates between k*ids and s*ids. For this it often uses struct smb_fattr and stashes the k*ids in cf_uid and cf_gid. Let cf_uid and cf_gid always contain the final information taking any potential idmapped mounts into account. When finally translation cf_*id into s*ids translate them into the user namespace of ksmbd since that is the relevant user namespace here. Cc: Steve French <stfrench@microsoft.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Hyunchul Lee <hyc.lee@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: linux-cifs@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03ksmbd: fix translation in create_posix_rsp_buf()Christian Brauner
When transferring ownership information to the client the k*ids are translated into raw *ids before they are sent over the wire. The function currently erroneously translates the k*ids according to the mount's idmapping. Instead, reporting the owning *ids to userspace the underlying k*ids need to be mapped up in the caller's user namespace. This is how stat() works. The caller in this instance is ksmbd itself and ksmbd always runs in the initial user namespace. Translate according to that taking any potential idmapped mounts into account. Switch to from_k*id_munged() which ensures that the overflow*id is returned instead of the (*id_t)-1 when the k*id can't be translated. Cc: Steve French <stfrench@microsoft.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Hyunchul Lee <hyc.lee@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: linux-cifs@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03ksmbd: fix translation in smb2_populate_readdir_entry()Christian Brauner
When transferring ownership information to the client the k*ids are translated into raw *ids before they are sent over the wire. The function currently erroneously translates the k*ids according to the mount's idmapping. Instead, reporting the owning *ids to userspace the underlying k*ids need to be mapped up in the caller's user namespace. This is how stat() works. The caller in this instance is ksmbd itself and ksmbd always runs in the initial user namespace. Translate according to that. The idmapping of the mount is already taken into account by the lower filesystem and so kstat->*id will contain the mapped k*ids. Switch to from_k*id_munged() which ensures that the overflow*id is returned instead of the (*id_t)-1 when the k*id can't be translated. Cc: Steve French <stfrench@microsoft.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Hyunchul Lee <hyc.lee@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: linux-cifs@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03ksmbd: fix lookup on idmapped mountsChristian Brauner
It's great that the new in-kernel ksmbd server will support idmapped mounts out of the box! However, lookup is currently broken. Lookup helpers such as lookup_one_len() call inode_permission() internally to ensure that the caller is privileged over the inode of the base dentry they are trying to lookup under. So the permission checking here is currently wrong. Linux v5.15 will gain a new lookup helper lookup_one() that does take idmappings into account. I've added it as part of my patch series to make btrfs support idmapped mounts. The new helper is in linux-next as part of David's (Sterba) btrfs for-next branch as commit c972214c133b ("namei: add mapping aware lookup helper"). I've said it before during one of my first reviews: I would very much recommend adding fstests to [1]. It already seems to have very rudimentary cifs support. There is a completely generic idmapped mount testsuite that supports idmapped mounts. [1]: https://git.kernel.org/pub/scm/fs/xfs/xfsprogs-dev.git/ Cc: Colin Ian King <colin.king@canonical.com> Cc: Steve French <stfrench@microsoft.com> Cc: Christoph Hellwig <hch@infradead.org> Cc: Namjae Jeon <namjae.jeon@samsung.com> Cc: Hyunchul Lee <hyc.lee@gmail.com> Cc: Sergey Senozhatsky <senozhatsky@chromium.org> Cc: David Sterba <dsterba@suse.com> Cc: linux-cifs@vger.kernel.org Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com> Signed-off-by: Namjae Jeon <linkinjeon@kernel.org> Signed-off-by: Steve French <stfrench@microsoft.com>
2021-09-03io_uring: reexpand under-reexpanded itersPavel Begunkov
[ 74.211232] BUG: KASAN: stack-out-of-bounds in iov_iter_revert+0x809/0x900 [ 74.212778] Read of size 8 at addr ffff888025dc78b8 by task syz-executor.0/828 [ 74.214756] CPU: 0 PID: 828 Comm: syz-executor.0 Not tainted 5.14.0-rc3-next-20210730 #1 [ 74.216525] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.14.0-0-g155821a1990b-prebuilt.qemu.org 04/01/2014 [ 74.219033] Call Trace: [ 74.219683] dump_stack_lvl+0x8b/0xb3 [ 74.220706] print_address_description.constprop.0+0x1f/0x140 [ 74.224226] kasan_report.cold+0x7f/0x11b [ 74.226085] iov_iter_revert+0x809/0x900 [ 74.227960] io_write+0x57d/0xe40 [ 74.232647] io_issue_sqe+0x4da/0x6a80 [ 74.242578] __io_queue_sqe+0x1ac/0xe60 [ 74.245358] io_submit_sqes+0x3f6e/0x76a0 [ 74.248207] __do_sys_io_uring_enter+0x90c/0x1a20 [ 74.257167] do_syscall_64+0x3b/0x90 [ 74.257984] entry_SYSCALL_64_after_hwframe+0x44/0xae old_size = iov_iter_count(); ... iov_iter_revert(old_size - iov_iter_count()); If iov_iter_revert() is done base on the initial size as above, and the iter is truncated and not reexpanded in the middle, it miscalculates borders causing problems. This trace is due to no one reexpanding after generic_write_checks(). Now iters store how many bytes has been truncated, so reexpand them to the initial state right before reverting. Cc: stable@vger.kernel.org Reported-by: Palash Oswal <oswalpalash@gmail.com> Reported-by: Sudip Mukherjee <sudipm.mukherjee@gmail.com> Reported-and-tested-by: syzbot+9671693590ef5aad8953@syzkaller.appspotmail.com Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2021-09-03Merge tag 'kbuild-v5.15' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild Pull Kbuild updates from Masahiro Yamada: - Add -s option (strict mode) to merge_config.sh to make it fail when any symbol is redefined. - Show a warning if a different compiler is used for building external modules. - Infer --target from ARCH for CC=clang to let you cross-compile the kernel without CROSS_COMPILE. - Make the integrated assembler default (LLVM_IAS=1) for CC=clang. - Add <linux/stdarg.h> to the kernel source instead of borrowing <stdarg.h> from the compiler. - Add Nick Desaulniers as a Kbuild reviewer. - Drop stale cc-option tests. - Fix the combination of CONFIG_TRIM_UNUSED_KSYMS and CONFIG_LTO_CLANG to handle symbols in inline assembly. - Show a warning if 'FORCE' is missing for if_changed rules. - Various cleanups * tag 'kbuild-v5.15' of git://git.kernel.org/pub/scm/linux/kernel/git/masahiroy/linux-kbuild: (39 commits) kbuild: redo fake deps at include/ksym/*.h kbuild: clean up objtool_args slightly modpost: get the *.mod file path more simply checkkconfigsymbols.py: Fix the '--ignore' option kbuild: merge vmlinux_link() between ARCH=um and other architectures kbuild: do not remove 'linux' link in scripts/link-vmlinux.sh kbuild: merge vmlinux_link() between the ordinary link and Clang LTO kbuild: remove stale *.symversions kbuild: remove unused quiet_cmd_update_lto_symversions gen_compile_commands: extract compiler command from a series of commands x86: remove cc-option-yn test for -mtune= arc: replace cc-option-yn uses with cc-option s390: replace cc-option-yn uses with cc-option ia64: move core-y in arch/ia64/Makefile to arch/ia64/Kbuild sparc: move the install rule to arch/sparc/Makefile security: remove unneeded subdir-$(CONFIG_...) kbuild: sh: remove unused install script kbuild: Fix 'no symbols' warning when CONFIG_TRIM_UNUSD_KSYMS=y kbuild: Switch to 'f' variants of integrated assembler flag kbuild: Shuffle blank line to improve comment meaning ...
2021-09-03Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge misc updates from Andrew Morton: "173 patches. Subsystems affected by this series: ia64, ocfs2, block, and mm (debug, pagecache, gup, swap, shmem, memcg, selftests, pagemap, mremap, bootmem, sparsemem, vmalloc, kasan, pagealloc, memory-failure, hugetlb, userfaultfd, vmscan, compaction, mempolicy, memblock, oom-kill, migration, ksm, percpu, vmstat, and madvise)" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (173 commits) mm/madvise: add MADV_WILLNEED to process_madvise() mm/vmstat: remove unneeded return value mm/vmstat: simplify the array size calculation mm/vmstat: correct some wrong comments mm/percpu,c: remove obsolete comments of pcpu_chunk_populated() selftests: vm: add COW time test for KSM pages selftests: vm: add KSM merging time test mm: KSM: fix data type selftests: vm: add KSM merging across nodes test selftests: vm: add KSM zero page merging test selftests: vm: add KSM unmerge test selftests: vm: add KSM merge test mm/migrate: correct kernel-doc notation mm: wire up syscall process_mrelease mm: introduce process_mrelease system call memblock: make memblock_find_in_range method private mm/mempolicy.c: use in_task() in mempolicy_slab_node() mm/mempolicy: unify the create() func for bind/interleave/prefer-many policies mm/mempolicy: advertise new MPOL_PREFERRED_MANY mm/hugetlb: add support for mempolicy MPOL_PREFERRED_MANY ...
2021-09-03userfaultfd: prevent concurrent API initializationNadav Amit
userfaultfd assumes that the enabled features are set once and never changed after UFFDIO_API ioctl succeeded. However, currently, UFFDIO_API can be called concurrently from two different threads, succeed on both threads and leave userfaultfd's features in non-deterministic state. Theoretically, other uffd operations (ioctl's and page-faults) can be dispatched while adversely affected by such changes of features. Moreover, the writes to ctx->state and ctx->features are not ordered, which can - theoretically, again - let userfaultfd_ioctl() think that userfaultfd API completed, while the features are still not initialized. To avoid races, it is arguably best to get rid of ctx->state. Since there are only 2 states, record the API initialization in ctx->features as the uppermost bit and remove ctx->state. Link: https://lkml.kernel.org/r/20210808020724.1022515-3-namit@vmware.com Fixes: 9cd75c3cd4c3d ("userfaultfd: non-cooperative: add ability to report non-PF events from uffd descriptor") Signed-off-by: Nadav Amit <namit@vmware.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Jens Axboe <axboe@kernel.dk> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Peter Xu <peterx@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03userfaultfd: change mmap_changing to atomicNadav Amit
Patch series "userfaultfd: minor bug fixes". Three unrelated bug fixes. The first two addresses possible issues (not too theoretical ones), but I did not encounter them in practice. The third patch addresses a test bug that causes the test to fail on my system. It has been sent before as part of a bigger RFC. This patch (of 3): mmap_changing is currently a boolean variable, which is set and cleared without any lock that protects against concurrent modifications. mmap_changing is supposed to mark whether userfaultfd page-faults handling should be retried since mappings are undergoing a change. However, concurrent calls, for instance to madvise(MADV_DONTNEED), might cause mmap_changing to be false, although the remove event was still not read (hence acknowledged) by the user. Change mmap_changing to atomic_t and increase/decrease appropriately. Add a debug assertion to see whether mmap_changing is negative. Link: https://lkml.kernel.org/r/20210808020724.1022515-1-namit@vmware.com Link: https://lkml.kernel.org/r/20210808020724.1022515-2-namit@vmware.com Fixes: df2cc96e77011 ("userfaultfd: prevent non-cooperative events vs mcopy_atomic races") Signed-off-by: Nadav Amit <namit@vmware.com> Cc: Mike Rapoport <rppt@linux.vnet.ibm.com> Cc: Peter Xu <peterx@redhat.com> Cc: Axel Rasmussen <axelrasmussen@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Andrea Arcangeli <aarcange@redhat.com> Cc: Jens Axboe <axboe@kernel.dk> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03mm/pagemap: add mmap_assert_locked() annotations to find_vma*()Luigi Rizzo
find_vma() and variants need protection when used. This patch adds mmap_assert_lock() calls in the functions. To make sure the invariant is satisfied, we also need to add a mmap_read_lock() around the get_user_pages_remote() call in get_arg_page(). The lock is not strictly necessary because the mm has been newly created, but the extra cost is limited because the same mutex was also acquired shortly before in __bprm_mm_init(), so it is hot and uncontended. [penguin-kernel@i-love.sakura.ne.jp: TOMOYO needs the same protection which get_arg_page() needs] Link: https://lkml.kernel.org/r/58bb6bf7-a57e-8a40-e74b-39584b415152@i-love.sakura.ne.jp Link: https://lkml.kernel.org/r/20210731175341.3458608-1-lrizzo@google.com Signed-off-by: Luigi Rizzo <lrizzo@google.com> Cc: David Rientjes <rientjes@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03mm: remove flush_kernel_dcache_pageChristoph Hellwig
flush_kernel_dcache_page is a rather confusing interface that implements a subset of flush_dcache_page by not being able to properly handle page cache mapped pages. The only callers left are in the exec code as all other previous callers were incorrect as they could have dealt with page cache pages. Replace the calls to flush_kernel_dcache_page with calls to flush_dcache_page, which for all architectures does either exactly the same thing, can contains one or more of the following: 1) an optimization to defer the cache flush for page cache pages not mapped into userspace 2) additional flushing for mapped page cache pages if cache aliases are possible Link: https://lkml.kernel.org/r/20210712060928.4161649-7-hch@lst.de Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Linus Torvalds <torvalds@linux-foundation.org> Reviewed-by: Ira Weiny <ira.weiny@intel.com> Cc: Alex Shi <alexs@kernel.org> Cc: Geoff Levand <geoff@infradead.org> Cc: Greentime Hu <green.hu@gmail.com> Cc: Guo Ren <guoren@kernel.org> Cc: Helge Deller <deller@gmx.de> Cc: "James E.J. Bottomley" <James.Bottomley@HansenPartnership.com> Cc: Nick Hu <nickhu@andestech.com> Cc: Paul Cercueil <paul@crapouillou.net> Cc: Rich Felker <dalias@libc.org> Cc: Russell King <linux@armlinux.org.uk> Cc: Thomas Bogendoerfer <tsbogend@alpha.franken.de> Cc: Ulf Hansson <ulf.hansson@linaro.org> Cc: Vincent Chen <deanbo422@gmail.com> Cc: Yoshinori Sato <ysato@users.osdn.me> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03memcg: enable accounting for new namesapces and struct nsproxyVasily Averin
Container admin can create new namespaces and force kernel to allocate up to several pages of memory for the namespaces and its associated structures. Net and uts namespaces have enabled accounting for such allocations. It makes sense to account for rest ones to restrict the host's memory consumption from inside the memcg-limited container. Link: https://lkml.kernel.org/r/5525bcbf-533e-da27-79b7-158686c64e13@virtuozzo.com Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Acked-by: Serge Hallyn <serge@hallyn.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Acked-by: Kirill Tkhai <ktkhai@virtuozzo.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrei Vagin <avagin@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roman Gushchin <guro@fb.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Yutian Yang <nglaive@gmail.com> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03memcg: enable accounting for fasync_cacheVasily Averin
fasync_struct is used by almost all character device drivers to set up the fasync queue, and for regular files by the file lease code. This structure is quite small but long-living and it can be assigned for any open file. It makes sense to account for its allocations to restrict the host's memory consumption from inside the memcg-limited container. Link: https://lkml.kernel.org/r/1b408625-d71c-0b26-b0b6-9baf00f93e69@virtuozzo.com Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrei Vagin <avagin@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roman Gushchin <guro@fb.com> Cc: Serge Hallyn <serge@hallyn.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Yutian Yang <nglaive@gmail.com> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03memcg: enable accounting for file lock cachesVasily Averin
User can create file locks for each open file and force kernel to allocate small but long-living objects per each open file. It makes sense to account for these objects to limit the host's memory consumption from inside the memcg-limited container. Link: https://lkml.kernel.org/r/b009f4c7-f0ab-c0ec-8e83-918f47d677da@virtuozzo.com Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrei Vagin <avagin@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roman Gushchin <guro@fb.com> Cc: Serge Hallyn <serge@hallyn.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Yutian Yang <nglaive@gmail.com> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03memcg: enable accounting for pollfd and select bits arraysVasily Averin
User can call select/poll system calls with a large number of assigned file descriptors and force kernel to allocate up to several pages of memory till end of these sleeping system calls. We have here long-living unaccounted per-task allocations. It makes sense to account for these allocations to restrict the host's memory consumption from inside the memcg-limited container. Link: https://lkml.kernel.org/r/56e31cb5-6e1e-bdba-d7ca-be64b9842363@virtuozzo.com Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrei Vagin <avagin@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Borislav Petkov <bp@suse.de> Cc: Christian Brauner <christian.brauner@ubuntu.com> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Roman Gushchin <guro@fb.com> Cc: Serge Hallyn <serge@hallyn.com> Cc: Tejun Heo <tj@kernel.org> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Yutian Yang <nglaive@gmail.com> Cc: Zefan Li <lizefan.x@bytedance.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03memcg: enable accounting for mnt_cache entriesVasily Averin
Patch series "memcg accounting from OpenVZ", v7. OpenVZ uses memory accounting 20+ years since v2.2.x linux kernels. Initially we used our own accounting subsystem, then partially committed it to upstream, and a few years ago switched to cgroups v1. Now we're rebasing again, revising our old patches and trying to push them upstream. We try to protect the host system from any misuse of kernel memory allocation triggered by untrusted users inside the containers. Patch-set is addressed mostly to cgroups maintainers and cgroups@ mailing list, though I would be very grateful for any comments from maintainersi of affected subsystems or other people added in cc: Compared to the upstream, we additionally account the following kernel objects: - network devices and its Tx/Rx queues - ipv4/v6 addresses and routing-related objects - inet_bind_bucket cache objects - VLAN group arrays - ipv6/sit: ip_tunnel_prl - scm_fp_list objects used by SCM_RIGHTS messages of Unix sockets - nsproxy and namespace objects itself - IPC objects: semaphores, message queues and share memory segments - mounts - pollfd and select bits arrays - signals and posix timers - file lock - fasync_struct used by the file lease code and driver's fasync queues - tty objects - per-mm LDT We have an incorrect/incomplete/obsoleted accounting for few other kernel objects: sk_filter, af_packets, netlink and xt_counters for iptables. They require rework and probably will be dropped at all. Also we're going to add an accounting for nft, however it is not ready yet. We have not tested performance on upstream, however, our performance team compares our current RHEL7-based production kernel and reports that they are at least not worse as the according original RHEL7 kernel. This patch (of 10): The kernel allocates ~400 bytes of 'struct mount' for any new mount. Creating a new mount namespace clones most of the parent mounts, and this can be repeated many times. Additionally, each mount allocates up to PATH_MAX=4096 bytes for mnt->mnt_devname. It makes sense to account for these allocations to restrict the host's memory consumption from inside the memcg-limited container. Link: https://lkml.kernel.org/r/045db11f-4a45-7c9b-2664-5b32c2b44943@virtuozzo.com Signed-off-by: Vasily Averin <vvs@virtuozzo.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Acked-by: Christian Brauner <christian.brauner@ubuntu.com> Cc: Tejun Heo <tj@kernel.org> Cc: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: Roman Gushchin <guro@fb.com> Cc: Yutian Yang <nglaive@gmail.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Alexey Dobriyan <adobriyan@gmail.com> Cc: Andrei Vagin <avagin@gmail.com> Cc: Borislav Petkov <bp@alien8.de> Cc: Dmitry Safonov <0x7f454c46@gmail.com> Cc: "Eric W. Biederman" <ebiederm@xmission.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Cc: "H. Peter Anvin" <hpa@zytor.com> Cc: Ingo Molnar <mingo@redhat.com> Cc: "J. Bruce Fields" <bfields@fieldses.org> Cc: Jeff Layton <jlayton@kernel.org> Cc: Jens Axboe <axboe@kernel.dk> Cc: Jiri Slaby <jirislaby@kernel.org> Cc: Kirill Tkhai <ktkhai@virtuozzo.com> Cc: Oleg Nesterov <oleg@redhat.com> Cc: Serge Hallyn <serge@hallyn.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Zefan Li <lizefan.x@bytedance.com> Cc: Borislav Petkov <bp@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2021-09-03memcg: charge fs_context and legacy_fs_contextYutian Yang
This patch adds accounting flags to fs_context and legacy_fs_context allocation sites so that kernel could correctly charge these objects. We have written a PoC to demonstrate the effect of the missing-charging bugs. The PoC takes around 1,200MB unaccounted memory, while it is charged for only 362MB memory usage. We evaluate the PoC on QEMU x86_64 v5.2.90 + Linux kernel v5.10.19 + Debian buster. All the limitations including ulimits and sysctl variables are set as default. Specifically, the hard NOFILE limit and nr_open in sysctl are both 1,048,576. /*------------------------- POC code ----------------------------*/ #define _GNU_SOURCE #include <sys/types.h> #include <sys/file.h> #include <time.h> #include <sys/wait.h> #include <stdint.h> #include <stdlib.h> #include <unistd.h> #include <stdio.h> #include <signal.h> #include <sched.h> #include <fcntl.h> #include <linux/mount.h> #define errExit(msg) do { perror(msg); exit(EXIT_FAILURE); \ } while (0) #define STACK_SIZE (8 * 1024) #ifndef __NR_fsopen #define __NR_fsopen 430 #endif static inline int fsopen(const char *fs_name, unsigned int flags) { return syscall(__NR_fsopen, fs_name, flags); } static char thread_stack[512][STACK_SIZE]; int thread_fn(void* arg) { for (int i = 0; i< 800000; ++i) { int fsfd = fsopen("nfs", FSOPEN_CLOEXEC); if (fsfd == -1) { errExit("fsopen"); } } while(1); return 0; } int main(int argc, char *argv[]) { int thread_pid; for (int i = 0; i < 1; ++i) { thread_pid = clone(thread_fn, thread_stack[i] + STACK_SIZE, \ SIGCHLD, NULL); } while(1); return 0; } /*-------------------------- end --------------------------------*/ Link: https://lkml.kernel.org/r/1626517201-24086-1-git-send-email-nglaive@gmail.com Signed-off-by: Yutian Yang <nglaive@gmail.com> Reviewed-by: Shakeel Butt <shakeelb@google.com> Cc: Michal Hocko <mhocko@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Vladimir Davydov <vdavydov.dev@gmail.com> Cc: <shenwenbo@zju.edu.cn> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>