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2020-05-14vfs: add faccessat2 syscallMiklos Szeredi2-9/+26
POSIX defines faccessat() as having a fourth "flags" argument, while the linux syscall doesn't have it. Glibc tries to emulate AT_EACCESS and AT_SYMLINK_NOFOLLOW, but AT_EACCESS emulation is broken. Add a new faccessat(2) syscall with the added flags argument and implement both flags. The value of AT_EACCESS is defined in glibc headers to be the same as AT_REMOVEDIR. Use this value for the kernel interface as well, together with the explanatory comment. Also add AT_EMPTY_PATH support, which is not documented by POSIX, but can be useful and is trivial to implement. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-14vfs: don't parse "silent" optionMiklos Szeredi1-1/+0
Parsing "silent" and clearing SB_SILENT makes zero sense. Parsing "silent" and setting SB_SILENT would make a bit more sense, but apparently nobody cares. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-05-14vfs: don't parse "posixacl" optionMiklos Szeredi1-1/+0
Unlike the others, this is _not_ a standard option accepted by mount(8). In fact SB_POSIXACL is an internal flag, and accepting MS_POSIXACL on the mount(2) interface is possibly a bug. The only filesystem that apparently wants to handle the "posixacl" option is 9p, but it has special handling of that option besides setting SB_POSIXACL. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-05-14vfs: don't parse forbidden flagsMiklos Szeredi1-28/+0
Makes little sense to keep this blacklist synced with what mount(8) parses and what it doesn't. E.g. it has various forms of "*atime" options, but not "atime"... Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-05-14statx: add mount_rootMiklos Szeredi1-0/+3
Determining whether a path or file descriptor refers to a mountpoint (or more precisely a mount root) is not trivial using current tools. Add a flag to statx that indicates whether the path or fd refers to the root of a mount or not. Cc: linux-api@vger.kernel.org Cc: linux-man@vger.kernel.org Reported-by: Lennart Poettering <mzxreary@0pointer.de> Reported-by: J. Bruce Fields <bfields@fieldses.org> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-05-14statx: add mount IDMiklos Szeredi1-0/+4
Systemd is hacking around to get it and it's trivial to add to statx, so... Cc: linux-api@vger.kernel.org Cc: linux-man@vger.kernel.org Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-05-14statx: don't clear STATX_ATIME on SB_RDONLYMiklos Szeredi1-1/+2
IS_NOATIME(inode) is defined as __IS_FLG(inode, SB_RDONLY|SB_NOATIME), so generic_fillattr() will clear STATX_ATIME from the result_mask if the super block is marked read only. This was probably not the intention, so fix to only clear STATX_ATIME if the fs doesn't support atime at all. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Acked-by: David Howells <dhowells@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-05-14uapi: deprecate STATX_ALLMiklos Szeredi1-1/+0
Constants of the *_ALL type can be actively harmful due to the fact that developers will usually fail to consider the possible effects of future changes to the definition. Deprecate STATX_ALL in the uapi, while no damage has been done yet. We could keep something like this around in the kernel, but there's actually no point, since all filesystems should be explicitly checking flags that they support and not rely on the VFS masking unknown ones out: a flag could be known to the VFS, yet not known to the filesystem. Cc: David Howells <dhowells@redhat.com> Cc: linux-api@vger.kernel.org Cc: linux-man@vger.kernel.org Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-05-14utimensat: AT_EMPTY_PATH supportMiklos Szeredi1-2/+4
This makes it possible to use utimensat on an O_PATH file (including symlinks). It supersedes the nonstandard utimensat(fd, NULL, ...) form. Cc: linux-api@vger.kernel.org Cc: linux-man@vger.kernel.org Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-05-14vfs: split out access_override_creds()Miklos Szeredi1-10/+24
Split out a helper that overrides the credentials in preparation for actually doing the access check. This prepares for the next patch that optionally disables the creds override. Suggested-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-14proc/mounts: add cursorMiklos Szeredi3-20/+87
If mounts are deleted after a read(2) call on /proc/self/mounts (or its kin), the subsequent read(2) could miss a mount that comes after the deleted one in the list. This is because the file position is interpreted as the number mount entries from the start of the list. E.g. first read gets entries #0 to #9; the seq file index will be 10. Then entry #5 is deleted, resulting in #10 becoming #9 and #11 becoming #10, etc... The next read will continue from entry #10, and #9 is missed. Solve this by adding a cursor entry for each open instance. Taking the global namespace_sem for write seems excessive, since we are only dealing with a per-namespace list. Instead add a per-namespace spinlock and use that together with namespace_sem taken for read to protect against concurrent modification of the mount list. This may reduce parallelism of is_local_mountpoint(), but it's hardly a big contention point. We could also use RCU freeing of cursors to make traversal not need additional locks, if that turns out to be neceesary. Only move the cursor once for each read (cursor is not added on open) to minimize cacheline invalidation. When EOF is reached, the cursor is taken off the list, in order to prevent an excessive number of cursors due to inactive open file descriptors. Reported-by: Karel Zak <kzak@redhat.com> Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-14aio: fix async fsync credsMiklos Szeredi1-0/+8
Avi Kivity reports that on fuse filesystems running in a user namespace asyncronous fsync fails with EOVERFLOW. The reason is that f_ops->fsync() is called with the creds of the kthread performing aio work instead of the creds of the process originally submitting IOCB_CMD_FSYNC. Fuse sends the creds of the caller in the request header and it needs to translate the uid and gid into the server's user namespace. Since the kthread is running in init_user_ns, the translation will fail and the operation returns an error. It can be argued that fsync doesn't actually need any creds, but just zeroing out those fields in the header (as with requests that currently don't take creds) is a backward compatibility risk. Instead of working around this issue in fuse, solve the core of the problem by calling the filesystem with the proper creds. Reported-by: Avi Kivity <avi@scylladb.com> Tested-by: Giuseppe Scrivano <gscrivan@redhat.com> Fixes: c9582eb0ff7d ("fuse: Fail all requests with invalid uids or gids") Cc: stable@vger.kernel.org # 4.18+ Signed-off-by: Miklos Szeredi <mszeredi@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de>
2020-05-14vfs: allow unprivileged whiteout creationMiklos Szeredi2-18/+6
Whiteouts, unlike real device node should not require privileges to create. The general concern with device nodes is that opening them can have side effects. The kernel already avoids zero major (see Documentation/admin-guide/devices.txt). To be on the safe side the patch explicitly forbids registering a char device with 0/0 number (see cdev_add()). This guarantees that a non-O_PATH open on a whiteout will fail with ENODEV; i.e. it won't have any side effect. Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
2020-05-03Merge tag 'for-5.7-rc3-tag' of ↵Linus Torvalds3-6/+52
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull more btrfs fixes from David Sterba: "A few more stability fixes, minor build warning fixes and git url fixup: - fix partial loss of prealloc extent past i_size after fsync - fix potential deadlock due to wrong transaction handle passing via journal_info - fix gcc 4.8 struct intialization warning - update git URL in MAINTAINERS entry" * tag 'for-5.7-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: MAINTAINERS: btrfs: fix git repo URL btrfs: fix gcc-4.8 build warning for struct initializer btrfs: transaction: Avoid deadlock due to bad initialization timing of fs_info::journal_info btrfs: fix partial loss of prealloc extent past i_size after fsync
2020-05-02Merge tag 'iomap-5.7-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linuxLinus Torvalds2-4/+9
Pull iomap fix from Darrick Wong: "Hoist the check for an unrepresentable FIBMAP return value into ioctl_fibmap. The internal kernel function can handle 64-bit values (and is needed to fix a regression on ext4 + jbd2). It is only the userspace ioctl that is so old that it cannot deal" * tag 'iomap-5.7-fixes-1' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: fibmap: Warn and return an error in case of block > INT_MAX
2020-05-02Merge tag 'nfs-for-5.7-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds4-16/+30
Pull NFS client bugfixes from Trond Myklebust: "Highlights include: Stable fixes: - fix handling of backchannel binding in BIND_CONN_TO_SESSION Bugfixes: - Fix a credential use-after-free issue in pnfs_roc() - Fix potential posix_acl refcnt leak in nfs3_set_acl - defer slow parts of rpc_free_client() to a workqueue - Fix an Oopsable race in __nfs_list_for_each_server() - Fix trace point use-after-free race - Regression: the RDMA client no longer responds to server disconnect requests - Fix return values of xdr_stream_encode_item_{present, absent} - _pnfs_return_layout() must always wait for layoutreturn completion Cleanups: - Remove unreachable error conditions" * tag 'nfs-for-5.7-4' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: NFS: Fix a race in __nfs_list_for_each_server() NFSv4.1: fix handling of backchannel binding in BIND_CONN_TO_SESSION SUNRPC: defer slow parts of rpc_free_client() to a workqueue. NFSv4: Remove unreachable error condition due to rpc_run_task() SUNRPC: Remove unreachable error condition xprtrdma: Fix use of xdr_stream_encode_item_{present, absent} xprtrdma: Fix trace point use-after-free race xprtrdma: Restore wake-up-all to rpcrdma_cm_event_handler() nfs: Fix potential posix_acl refcnt leak in nfs3_set_acl NFS/pnfs: Fix a credential use-after-free issue in pnfs_roc() NFS/pnfs: Ensure that _pnfs_return_layout() waits for layoutreturn completion
2020-05-01Merge tag 'io_uring-5.7-2020-05-01' of git://git.kernel.dk/linux-blockLinus Torvalds1-27/+31
Pull io_uring fixes from Jens Axboe: - Fix for statx not grabbing the file table, making AT_EMPTY_PATH fail - Cover a few cases where async poll can handle retry, eliminating the need for an async thread - fallback request busy/free fix (Bijan) - syzbot reported SQPOLL thread exit fix for non-preempt (Xiaoguang) - Fix extra put of req for sync_file_range (Pavel) - Always punt splice async. We'll improve this for 5.8, but wanted to eliminate the inode mutex lock from the non-blocking path for 5.7 (Pavel) * tag 'io_uring-5.7-2020-05-01' of git://git.kernel.dk/linux-block: io_uring: punt splice async because of inode mutex io_uring: check non-sync defer_list carefully io_uring: fix extra put in sync_file_range() io_uring: use cond_resched() in io_ring_ctx_wait_and_kill() io_uring: use proper references for fallback_req locking io_uring: only force async punt if poll based retry can't handle it io_uring: enable poll retry for any file with ->read_iter / ->write_iter io_uring: statx must grab the file table for valid fd
2020-05-01io_uring: punt splice async because of inode mutexPavel Begunkov1-14/+2
Nonblocking do_splice() still may wait for some time on an inode mutex. Let's play safe and always punt it async. Reported-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-01io_uring: check non-sync defer_list carefullyPavel Begunkov1-1/+1
io_req_defer() do double-checked locking. Use proper helpers for that, i.e. list_empty_careful(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-05-01io_uring: fix extra put in sync_file_range()Pavel Begunkov1-1/+1
[ 40.179474] refcount_t: underflow; use-after-free. [ 40.179499] WARNING: CPU: 6 PID: 1848 at lib/refcount.c:28 refcount_warn_saturate+0xae/0xf0 ... [ 40.179612] RIP: 0010:refcount_warn_saturate+0xae/0xf0 [ 40.179617] Code: 28 44 0a 01 01 e8 d7 01 c2 ff 0f 0b 5d c3 80 3d 15 44 0a 01 00 75 91 48 c7 c7 b8 f5 75 be c6 05 05 44 0a 01 01 e8 b7 01 c2 ff <0f> 0b 5d c3 80 3d f3 43 0a 01 00 0f 85 6d ff ff ff 48 c7 c7 10 f6 [ 40.179619] RSP: 0018:ffffb252423ebe18 EFLAGS: 00010286 [ 40.179623] RAX: 0000000000000000 RBX: ffff98d65e929400 RCX: 0000000000000000 [ 40.179625] RDX: 0000000000000001 RSI: 0000000000000086 RDI: 00000000ffffffff [ 40.179627] RBP: ffffb252423ebe18 R08: 0000000000000001 R09: 000000000000055d [ 40.179629] R10: 0000000000000c8c R11: 0000000000000001 R12: 0000000000000000 [ 40.179631] R13: ffff98d68c434400 R14: ffff98d6a9cbaa20 R15: ffff98d6a609ccb8 [ 40.179634] FS: 0000000000000000(0000) GS:ffff98d6af580000(0000) knlGS:0000000000000000 [ 40.179636] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [ 40.179638] CR2: 00000000033e3194 CR3: 000000006480a003 CR4: 00000000003606e0 [ 40.179641] Call Trace: [ 40.179652] io_put_req+0x36/0x40 [ 40.179657] io_free_work+0x15/0x20 [ 40.179661] io_worker_handle_work+0x2f5/0x480 [ 40.179667] io_wqe_worker+0x2a9/0x360 [ 40.179674] ? _raw_spin_unlock_irqrestore+0x24/0x40 [ 40.179681] kthread+0x12c/0x170 [ 40.179685] ? io_worker_handle_work+0x480/0x480 [ 40.179690] ? kthread_park+0x90/0x90 [ 40.179695] ret_from_fork+0x35/0x40 [ 40.179702] ---[ end trace 85027405f00110aa ]--- Opcode handler must never put submission ref, but that's what io_sync_file_range_finish() do. use io_steal_work() there. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-30io_uring: use cond_resched() in io_ring_ctx_wait_and_kill()Xiaoguang Wang1-1/+1
While working on to make io_uring sqpoll mode support syscalls that need struct files_struct, I got cpu soft lockup in io_ring_ctx_wait_and_kill(), while (ctx->sqo_thread && !wq_has_sleeper(&ctx->sqo_wait)) cpu_relax(); above loop never has an chance to exit, it's because preempt isn't enabled in the kernel, and the context calling io_ring_ctx_wait_and_kill() and io_sq_thread() run in the same cpu, if io_sq_thread calls a cond_resched() yield cpu and another context enters above loop, then io_sq_thread() will always in runqueue and never exit. Use cond_resched() can fix this issue. Reported-by: syzbot+66243bb7126c410cefe6@syzkaller.appspotmail.com Signed-off-by: Xiaoguang Wang <xiaoguang.wang@linux.alibaba.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-30io_uring: use proper references for fallback_req lockingBijan Mottahedeh1-2/+2
Use ctx->fallback_req address for test_and_set_bit_lock() and clear_bit_unlock(). Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-30io_uring: only force async punt if poll based retry can't handle itJens Axboe1-2/+4
We do blocking retry from our poll handler, if the file supports polled notifications. Only mark the request as needing an async worker if we can't poll for it. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-30io_uring: enable poll retry for any file with ->read_iter / ->write_iterJens Axboe1-7/+13
We can have files like eventfd where it's perfectly fine to do poll based retry on them, right now io_file_supports_async() doesn't take that into account. Pass in data direction and check the f_op instead of just always needing an async worker. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-30NFS: Fix a race in __nfs_list_for_each_server()Trond Myklebust1-1/+1
The struct nfs_server gets put on the cl_superblocks list before the server->super field has been initialised, in which case the call to nfs_sb_active() will Oops. Add a check to ensure that we skip such a list entry. Fixes: 3c9e502b59fb ("NFS: Add a helper nfs_client_for_each_server()") Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-04-30fibmap: Warn and return an error in case of block > INT_MAXRitesh Harjani2-4/+9
We better warn the fibmap user and not return a truncated and therefore an incorrect block map address if the bmap() returned block address is greater than INT_MAX (since user supplied integer pointer). It's better to pr_warn() all user of ioctl_fibmap() and return a proper error code rather than silently letting a FS corruption happen if the user tries to fiddle around with the returned block map address. We fix this by returning an error code of -ERANGE and returning 0 as the block mapping address in case if it is > INT_MAX. Now iomap_bmap() could be called from either of these two paths. Either when a user is calling an ioctl_fibmap() interface to get the block mapping address or by some filesystem via use of bmap() internal kernel API. bmap() kernel API is well equipped with handling of u64 addresses. WARN condition in iomap_bmap_actor() was mainly added to warn all the fibmap users. But now that we have directly added this warning for all fibmap users and also made sure to return 0 as block map address in case if addr > INT_MAX. So we can now remove this logic from iomap_bmap_actor(). Signed-off-by: Ritesh Harjani <riteshh@linux.ibm.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2020-04-30btrfs: fix gcc-4.8 build warning for struct initializerArnd Bergmann1-1/+1
Some older compilers like gcc-4.8 warn about mismatched curly braces in a initializer: fs/btrfs/backref.c: In function 'is_shared_data_backref': fs/btrfs/backref.c:394:9: error: missing braces around initializer [-Werror=missing-braces] struct prelim_ref target = {0}; ^ fs/btrfs/backref.c:394:9: error: (near initialization for 'target.rbnode') [-Werror=missing-braces] Use the GNU empty initializer extension to avoid this. Fixes: ed58f2e66e84 ("btrfs: backref, don't add refs from shared block when resolving normal backref") Reviewed-by: Qu Wenruo <wqu@suse.com> Signed-off-by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-04-28Merge branch 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfsLinus Torvalds2-20/+16
Pull vfs fixes from Al Viro: "Two old bugs..." * 'fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: propagate_one(): mnt_set_mountpoint() needs mount_lock dlmfs_file_write(): fix the bogosity in handling non-zero *ppos
2020-04-28Fix use after free in get_tree_bdev()David Howells1-1/+1
Commit 6fcf0c72e4b9, a fix to get_tree_bdev() put a missing blkdev_put() in the wrong place, before a warnf() that displays the bdev under consideration rather after it. This results in a silent lockup in printk("%pg") called via warnf() from get_tree_bdev() under some circumstances when there's a race with the blockdev being frozen. This can be caused by xfstests/tests/generic/085 in combination with Lukas Czerner's ext4 mount API conversion patchset. It looks like it ought to occur with other users of get_tree_bdev() such as XFS, but apparently doesn't. Fix this by switching the order of the lines. Fixes: 6fcf0c72e4b9 ("vfs: add missing blkdev_put() in get_tree_bdev()") Reported-by: Lukas Czerner <lczerner@redhat.com> Signed-off-by: David Howells <dhowells@redhat.com> cc: Ian Kent <raven@themaw.net> cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2020-04-28NFSv4.1: fix handling of backchannel binding in BIND_CONN_TO_SESSIONOlga Kornievskaia1-0/+8
Currently, if the client sends BIND_CONN_TO_SESSION with NFS4_CDFC4_FORE_OR_BOTH but only gets NFS4_CDFS4_FORE back it ignores that it wasn't able to enable a backchannel. To make sure, the client sends BIND_CONN_TO_SESSION as the first operation on the connections (ie., no other session compounds haven't been sent before), and if the client's request to bind the backchannel is not satisfied, then reset the connection and retry. Cc: stable@vger.kernel.org Signed-off-by: Olga Kornievskaia <kolga@netapp.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-04-27Merge tag 'for-5.7-rc3-tag' of ↵Linus Torvalds4-11/+48
git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux Pull btrfs fixes from David Sterba: - regression fixes: - transaction leak when deleting unused block group - log cleanup after transaction abort - fix block group leak when removing fails - transaction leak if relocation recovery fails - fix SPDX header * tag 'for-5.7-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: btrfs: fix transaction leak in btrfs_recover_relocation btrfs: fix block group leak when removing fails btrfs: drop logs when we've aborted a transaction btrfs: fix memory leak of transaction when deleting unused block group btrfs: discard: Use the correct style for SPDX License Identifier
2020-04-27io_uring: statx must grab the file table for valid fdJens Axboe1-2/+10
Clay reports that OP_STATX fails for a test case with a valid fd and empty path: -- Test 0: statx:fd 3: SUCCEED, file mode 100755 -- Test 1: statx:path ./uring_statx: SUCCEED, file mode 100755 -- Test 2: io_uring_statx:fd 3: FAIL, errno 9: Bad file descriptor -- Test 3: io_uring_statx:path ./uring_statx: SUCCEED, file mode 100755 This is due to statx not grabbing the process file table, hence we can't lookup the fd in async context. If the fd is valid, ensure that we grab the file table so we can grab the file from async context. Cc: stable@vger.kernel.org # v5.6 Reported-by: Clay Harris <bugs@claycon.org> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2020-04-27btrfs: transaction: Avoid deadlock due to bad initialization timing of ↵Qu Wenruo1-2/+11
fs_info::journal_info [BUG] One run of btrfs/063 triggered the following lockdep warning: ============================================ WARNING: possible recursive locking detected 5.6.0-rc7-custom+ #48 Not tainted -------------------------------------------- kworker/u24:0/7 is trying to acquire lock: ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs] but task is already holding lock: ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs] other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(sb_internal#2); lock(sb_internal#2); *** DEADLOCK *** May be due to missing lock nesting notation 4 locks held by kworker/u24:0/7: #0: ffff88817b495948 ((wq_completion)btrfs-endio-write){+.+.}, at: process_one_work+0x557/0xb80 #1: ffff888189ea7db8 ((work_completion)(&work->normal_work)){+.+.}, at: process_one_work+0x557/0xb80 #2: ffff88817d3a46e0 (sb_internal#2){.+.+}, at: start_transaction+0x66c/0x890 [btrfs] #3: ffff888174ca4da8 (&fs_info->reloc_mutex){+.+.}, at: btrfs_record_root_in_trans+0x83/0xd0 [btrfs] stack backtrace: CPU: 0 PID: 7 Comm: kworker/u24:0 Not tainted 5.6.0-rc7-custom+ #48 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015 Workqueue: btrfs-endio-write btrfs_work_helper [btrfs] Call Trace: dump_stack+0xc2/0x11a __lock_acquire.cold+0xce/0x214 lock_acquire+0xe6/0x210 __sb_start_write+0x14e/0x290 start_transaction+0x66c/0x890 [btrfs] btrfs_join_transaction+0x1d/0x20 [btrfs] find_free_extent+0x1504/0x1a50 [btrfs] btrfs_reserve_extent+0xd5/0x1f0 [btrfs] btrfs_alloc_tree_block+0x1ac/0x570 [btrfs] btrfs_copy_root+0x213/0x580 [btrfs] create_reloc_root+0x3bd/0x470 [btrfs] btrfs_init_reloc_root+0x2d2/0x310 [btrfs] record_root_in_trans+0x191/0x1d0 [btrfs] btrfs_record_root_in_trans+0x90/0xd0 [btrfs] start_transaction+0x16e/0x890 [btrfs] btrfs_join_transaction+0x1d/0x20 [btrfs] btrfs_finish_ordered_io+0x55d/0xcd0 [btrfs] finish_ordered_fn+0x15/0x20 [btrfs] btrfs_work_helper+0x116/0x9a0 [btrfs] process_one_work+0x632/0xb80 worker_thread+0x80/0x690 kthread+0x1a3/0x1f0 ret_from_fork+0x27/0x50 It's pretty hard to reproduce, only one hit so far. [CAUSE] This is because we're calling btrfs_join_transaction() without re-using the current running one: btrfs_finish_ordered_io() |- btrfs_join_transaction() <<< Call #1 |- btrfs_record_root_in_trans() |- btrfs_reserve_extent() |- btrfs_join_transaction() <<< Call #2 Normally such btrfs_join_transaction() call should re-use the existing one, without trying to re-start a transaction. But the problem is, in btrfs_join_transaction() call #1, we call btrfs_record_root_in_trans() before initializing current::journal_info. And in btrfs_join_transaction() call #2, we're relying on current::journal_info to avoid such deadlock. [FIX] Call btrfs_record_root_in_trans() after we have initialized current::journal_info. CC: stable@vger.kernel.org # 4.4+ Signed-off-by: Qu Wenruo <wqu@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-04-27btrfs: fix partial loss of prealloc extent past i_size after fsyncFilipe Manana1-3/+40
When we have an inode with a prealloc extent that starts at an offset lower than the i_size and there is another prealloc extent that starts at an offset beyond i_size, we can end up losing part of the first prealloc extent (the part that starts at i_size) and have an implicit hole if we fsync the file and then have a power failure. Consider the following example with comments explaining how and why it happens. $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt # Create our test file with 2 consecutive prealloc extents, each with a # size of 128Kb, and covering the range from 0 to 256Kb, with a file # size of 0. $ xfs_io -f -c "falloc -k 0 128K" /mnt/foo $ xfs_io -c "falloc -k 128K 128K" /mnt/foo # Fsync the file to record both extents in the log tree. $ xfs_io -c "fsync" /mnt/foo # Now do a redudant extent allocation for the range from 0 to 64Kb. # This will merely increase the file size from 0 to 64Kb. Instead we # could also do a truncate to set the file size to 64Kb. $ xfs_io -c "falloc 0 64K" /mnt/foo # Fsync the file, so we update the inode item in the log tree with the # new file size (64Kb). This also ends up setting the number of bytes # for the first prealloc extent to 64Kb. This is done by the truncation # at btrfs_log_prealloc_extents(). # This means that if a power failure happens after this, a write into # the file range 64Kb to 128Kb will not use the prealloc extent and # will result in allocation of a new extent. $ xfs_io -c "fsync" /mnt/foo # Now set the file size to 256K with a truncate and then fsync the file. # Since no changes happened to the extents, the fsync only updates the # i_size in the inode item at the log tree. This results in an implicit # hole for the file range from 64Kb to 128Kb, something which fsck will # complain when not using the NO_HOLES feature if we replay the log # after a power failure. $ xfs_io -c "truncate 256K" -c "fsync" /mnt/foo So instead of always truncating the log to the inode's current i_size at btrfs_log_prealloc_extents(), check first if there's a prealloc extent that starts at an offset lower than the i_size and with a length that crosses the i_size - if there is one, just make sure we truncate to a size that corresponds to the end offset of that prealloc extent, so that we don't lose the part of that extent that starts at i_size if a power failure happens. A test case for fstests follows soon. Fixes: 31d11b83b96f ("Btrfs: fix duplicate extents after fsync of file with prealloc extents") CC: stable@vger.kernel.org # 4.14+ Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
2020-04-27propagate_one(): mnt_set_mountpoint() needs mount_lockAl Viro1-5/+4
... to protect the modification of mp->m_count done by it. Most of the places that modify that thing also have namespace_lock held, but not all of them can do so, so we really need mount_lock here. Kudos to Piotr Krysiuk <piotras@gmail.com>, who'd spotted a related bug in pivot_root(2) (fixed unnoticed in 5.3); search for other similar turds has caught out this one. Cc: stable@kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-04-26Merge tag '5.7-rc2-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds4-18/+78
Pull cifs fixes from Steve French: "Five cifs/smb3 fixes:two for DFS reconnect failover, one lease fix for stable and the others to fix a missing spinlock during reconnect" * tag '5.7-rc2-smb3-fixes' of git://git.samba.org/sfrench/cifs-2.6: cifs: fix uninitialised lease_key in open_shroot() cifs: ensure correct super block for DFS reconnect cifs: do not share tcons with DFS cifs: minor update to comments around the cifs_tcp_ses_lock mutex cifs: protect updating server->dstaddr with a spinlock
2020-04-26Merge tag 'driver-core-5.7-rc3' of ↵Linus Torvalds1-12/+3
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core Pull driver core fixes from Greg KH: "Here are some small firmware/driver core/debugfs fixes for 5.7-rc3. The debugfs change is now possible as now the last users of debugfs_create_u32() have been fixed up in the different trees that got merged into 5.7-rc1, and I don't want it creeping back in. The firmware changes did cause a regression in linux-next, so the final patch here reverts part of that, re-exporting the symbol to resolve that issue. All of these patches, with the exception of the final one, have been in linux-next with only that one reported issue" * tag 'driver-core-5.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/driver-core: firmware_loader: revert removal of the fw_fallback_config export debugfs: remove return value of debugfs_create_u32() firmware_loader: remove unused exports firmware: imx: fix compile-testing
2020-04-25Merge branch 'for-linus' of ↵Linus Torvalds1-1/+0
git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace Pull pid leak fix from Eric Biederman: "Oleg noticed that put_pid(thread_pid) was not getting called when proc was not compiled in. Let's get that fixed before 5.7 is released and causes problems for anyone" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/ebiederm/user-namespace: proc: Put thread_pid in release_task not proc_flush_pid
2020-04-25NFSv4: Remove unreachable error condition due to rpc_run_task()Xiyu Yang1-2/+1
nfs4_proc_layoutget() invokes rpc_run_task(), which return the value to "task". Since rpc_run_task() is impossible to return an ERR pointer, there is no need to add the IS_ERR() condition on "task" here. So we need to remove it. Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
2020-04-24proc: Put thread_pid in release_task not proc_flush_pidEric W. Biederman1-1/+0
Oleg pointed out that in the unlikely event the kernel is compiled with CONFIG_PROC_FS unset that release_task will now leak the pid. Move the put_pid out of proc_flush_pid into release_task to fix this and to guarantee I don't make that mistake again. When possible it makes sense to keep get and put in the same function so it can easily been seen how they pair up. Fixes: 7bc3e6e55acf ("proc: Use a list of inodes to flush from proc") Reported-by: Oleg Nesterov <oleg@redhat.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
2020-04-24Merge tag 'io_uring-5.7-2020-04-24' of git://git.kernel.dk/linux-blockLinus Torvalds1-5/+5
Pull io_uring fix from Jens Axboe: "Single fixup for a change that went into -rc2" * tag 'io_uring-5.7-2020-04-24' of git://git.kernel.dk/linux-block: io_uring: only restore req->work for req that needs do completion
2020-04-24Merge tag 'block-5.7-2020-04-24' of git://git.kernel.dk/linux-blockLinus Torvalds2-2/+11
Pull block fixes from Jens Axboe: "A few fixes/changes that should go into this release: - null_blk zoned fixes (Damien) - blkdev_close() sync improvement (Douglas) - Fix regression in blk-iocost that impacted (at least) systemtap (Waiman) - Comment fix, header removal (Zhiqiang, Jianpeng)" * tag 'block-5.7-2020-04-24' of git://git.kernel.dk/linux-block: null_blk: Cleanup zoned device initialization null_blk: Fix zoned command handling block: remove unused header blk-iocost: Fix error on iocost_ioc_vrate_adj bdev: Reduce time holding bd_mutex in sync in blkdev_close() buffer: remove useless comment and WB_REASON_FREE_MORE_MEM, reason.
2020-04-24Merge tag 'afs-fixes-20200424' of ↵Linus Torvalds7-21/+15
git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs Pull misc AFS fixes from David Howells: "Three miscellaneous fixes to the afs filesystem: - Remove some struct members that aren't used, aren't set or aren't read, plus a wake up that nothing ever waits for. - Actually set the AFS_SERVER_FL_HAVE_EPOCH flag so that the code that depends on it can work. - Make a couple of waits uninterruptible if they're done for an operation that isn't supposed to be interruptible" * tag 'afs-fixes-20200424' of git://git.kernel.org/pub/scm/linux/kernel/git/dhowells/linux-fs: afs: Make record checking use TASK_UNINTERRUPTIBLE when appropriate afs: Fix to actually set AFS_SERVER_FL_HAVE_EPOCH afs: Remove some unused bits
2020-04-24afs: Make record checking use TASK_UNINTERRUPTIBLE when appropriateDavid Howells4-12/+11
When an operation is meant to be done uninterruptibly (such as FS.StoreData), we should not be allowing volume and server record checking to be interrupted. Fixes: d2ddc776a458 ("afs: Overhaul volume and server record caching and fileserver rotation") Signed-off-by: David Howells <dhowells@redhat.com>
2020-04-24afs: Fix to actually set AFS_SERVER_FL_HAVE_EPOCHDavid Howells1-1/+1
AFS keeps track of the epoch value from the rxrpc protocol to note (a) when a fileserver appears to have restarted and (b) when different endpoints of a fileserver do not appear to be associated with the same fileserver (ie. all probes back from a fileserver from all of its interfaces should carry the same epoch). However, the AFS_SERVER_FL_HAVE_EPOCH flag that indicates that we've received the server's epoch is never set, though it is used. Fix this to set the flag when we first receive an epoch value from a probe sent to the filesystem client from the fileserver. Fixes: 3bf0fb6f33dd ("afs: Probe multiple fileservers simultaneously") Signed-off-by: David Howells <dhowells@redhat.com>
2020-04-24afs: Remove some unused bitsDavid Howells3-8/+3
Remove three bits: (1) afs_server::no_epoch is neither set nor used. (2) afs_server::have_result is set and a wakeup is applied to it, but nothing looks at it or waits on it. (3) afs_vl_dump_edestaddrreq() prints afs_addr_list::probed, but nothing sets it for VL servers. Signed-off-by: David Howells <dhowells@redhat.com>
2020-04-23dlmfs_file_write(): fix the bogosity in handling non-zero *pposAl Viro1-15/+12
'count' is how much you want written, not the final position. Moreover, it can legitimately be less than the current position... Cc: stable@vger.kernel.org Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2020-04-23Merge tag 'nfsd-5.7-rc-1' of git://git.linux-nfs.org/projects/cel/cel-2.6Linus Torvalds2-1/+5
Pull nfsd fixes from Chuck Lever: "The first set of 5.7-rc fixes for NFS server issues. These were all unresolved at the time the 5.7 window opened, and needed some additional time to ensure they were correctly addressed. They are ready now. At the moment I know of one more urgent issue regarding the NFS server. A fix has been tested and is under review. I expect to send one more pull request, containing this fix (which now consists of 3 patches). Fixes: - Address several use-after-free and memory leak bugs - Prevent a backchannel livelock" * tag 'nfsd-5.7-rc-1' of git://git.linux-nfs.org/projects/cel/cel-2.6: svcrdma: Fix leak of svc_rdma_recv_ctxt objects svcrdma: Fix trace point use-after-free race SUNRPC: Fix backchannel RPC soft lockups SUNRPC/cache: Fix unsafe traverse caused double-free in cache_purge nfsd: memory corruption in nfsd4_lock()
2020-04-23Merge tag 'for-5.7-rc3' of ↵Linus Torvalds6-35/+45
git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat Pull exfat fixes from Namjae Jeon: - several bug fixes(broken mount discard option, remount failure, memory leak) - add missing MODULE_ALIAS_FS for automatically loading exfat module. - set s_time_gran and truncate atime with exfat timestamp granularity. * tag 'for-5.7-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/linkinjeon/exfat: exfat: truncate atimes to 2s granularity exfat: properly set s_time_gran exfat: remove 'bps' mount-option exfat: Unify access to the boot sector exfat: add missing MODULE_ALIAS_FS() exfat: Fix discard support
2020-04-23btrfs: fix transaction leak in btrfs_recover_relocationXiyu Yang1-0/+1
btrfs_recover_relocation() invokes btrfs_join_transaction(), which joins a btrfs_trans_handle object into transactions and returns a reference of it with increased refcount to "trans". When btrfs_recover_relocation() returns, "trans" becomes invalid, so the refcount should be decreased to keep refcount balanced. The reference counting issue happens in one exception handling path of btrfs_recover_relocation(). When read_fs_root() failed, the refcnt increased by btrfs_join_transaction() is not decreased, causing a refcnt leak. Fix this issue by calling btrfs_end_transaction() on this error path when read_fs_root() failed. Fixes: 79787eaab461 ("btrfs: replace many BUG_ONs with proper error handling") CC: stable@vger.kernel.org # 4.4+ Reviewed-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: Xiyu Yang <xiyuyang19@fudan.edu.cn> Signed-off-by: Xin Tan <tanxin.ctf@gmail.com> Signed-off-by: David Sterba <dsterba@suse.com>