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2019-11-25io_uring: simplify io_req_link_next()Pavel Begunkov1-10/+1
"if (nxt)" is always true, as it was checked in the while's condition. io_wq_current_is_worker() is unnecessary, as non-async callers don't pass nxt, so io_queue_async_work() will be called for them anyway. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: pass only !null to io_req_find_next()Pavel Begunkov1-2/+7
Make io_req_find_next() and io_req_link_next() to accept only non-null nxt, and handle it in callers. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: remove io_free_req_find_next()Pavel Begunkov1-7/+2
There is only one one-liner user of io_free_req_find_next(). Inline it. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: add likely/unlikely in io_get_sqring()Pavel Begunkov1-2/+2
The number of SQEs to submit is specified by a user, so io_get_sqring() in most of the cases succeeds. Hint compilers about that. Checking ASM genereted by gcc 9.2.0 for x64, there is one branch misprediction. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: rename __io_submit_sqe()Pavel Begunkov1-4/+4
__io_submit_sqe() is issuing requests, so call it as such. Moreover, it ends by calling io_iopoll_req_issued(). Rename it and make terminology clearer. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: improve trace_io_uring_defer() trace pointJens Axboe1-1/+1
We don't have shadow requests anymore, so get rid of the shadow argument. Add the user_data argument, as that's often useful to easily match up requests, instead of having to look at request pointers. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: drain next sqe instead of shadowingPavel Begunkov1-68/+18
There's an issue with the shadow drain logic in that we drop the completion lock after deciding to defer a request, then re-grab it later and assume that the state is still the same. In the mean time, someone else completing a request could have found and issued it. This can cause a stall in the queue, by having a shadow request inserted that nobody is going to drain. Additionally, if we fail allocating the shadow request, we simply ignore the drain. Instead of using a shadow request, defer the next request/link instead. This also has the following advantages: - removes semi-duplicated code - doesn't allocate memory for shadows - works better if only the head marked for drain - doesn't need complex synchronisation On the flip side, it removes the shadow->seq == last_drain_in_in_link->seq optimization. That shouldn't be a common case, and can always be added back, if needed. Fixes: 4fe2c963154c ("io_uring: add support for link with drain") Cc: Jackie Liu <liuyun01@kylinos.cn> Reported-by: Jens Axboe <axboe@kernel.dk> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: close lookup gap for dependent next workJens Axboe3-3/+22
When we find new work to process within the work handler, we queue the linked timeout before we have issued the new work. This can be problematic for very short timeouts, as we have a window where the new work isn't visible. Allow the work handler to store a callback function for this in the work item, and flag it with IO_WQ_WORK_CB if the caller has done so. If that is set, then io-wq will call the callback when it has setup the new work item. Reported-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: allow finding next link independent of req reference countJens Axboe1-5/+15
We currently try and start the next link when we put the request, and only if we were going to free it. This means that the optimization to continue executing requests from the same context often fails, as we're not putting the final reference. Add REQ_F_LINK_NEXT to keep track of this, and allow io_uring to find the next request more efficiently. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: io_allocate_scq_urings() should return a sane stateJens Axboe1-2/+8
We currently rely on the ring destroy on cleaning things up in case of failure, but io_allocate_scq_urings() can leave things half initialized if only parts of it fails. Be nice and return with either everything setup in success, or return an error with things nicely cleaned up. Reported-by: syzbot+0d818c0d39399188f393@syzkaller.appspotmail.com Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: Always REQ_F_FREE_SQE for allocated sqePavel Begunkov1-27/+22
Always mark requests with allocated sqe and deallocate it in __io_free_req(). It's easier to follow and doesn't add edge cases. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: io_fail_links() should only consider first linked timeoutJens Axboe1-3/+4
We currently clear the linked timeout field if we cancel such a timeout, but we should only attempt to cancel if it's the first one we see. Others should simply be freed like other requests, as they haven't been started yet. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: Fix leaking linked timeoutsPavel Begunkov1-0/+1
let have a dependant link: REQ -> LINK_TIMEOUT -> LINK_TIMEOUT 1. submission stage: submission references for REQ and LINK_TIMEOUT are dropped. So, references respectively (1,1,2) 2. io_put(REQ) + FAIL_LINKS stage: calls io_fail_links(), which for all linked timeouts will call cancel_timeout() and drop 1 reference. So, references after: (0,0,1). That's a leak. Make it treat only the first linked timeout as such, and pass others through __io_double_put_req(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: remove redundant checkPavel Begunkov1-4/+0
Pass any IORING_OP_LINK_TIMEOUT request further, where it will eventually fail in io_issue_sqe(). Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: break links for failed deferPavel Begunkov1-0/+4
If io_req_defer() failed, it needs to cancel a dependant link. Signed-off-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io-wq: remove extra space charactersDan Carpenter1-3/+3
These lines are indented an extra space character. Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io-wq: wait for io_wq_create() to setup necessary workersJens Axboe1-15/+35
We currently have a race where if setup is really slow, we can be calling io_wq_destroy() before we're done setting up. This will cause the caller to get stuck waiting for the manager to set things up, but the manager already exited. Fix this by doing a sync setup of the manager. This also fixes the case where if we failed creating workers, we'd also get stuck. In practice this race window was really small, as we already wait for the manager to start. Hence someone would have to call io_wq_destroy() after the task has started, but before it started the first loop. The reported test case forked tons of these, which is why it became an issue. Reported-by: syzbot+0f1cc17f85154f400465@syzkaller.appspotmail.com Fixes: 771b53d033e8 ("io-wq: small threadpool implementation for io_uring") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: request cancellations should break linksJens Axboe1-0/+6
We currently don't explicitly break links if a request is cancelled, but we should. Add explicitly link breakage for all types of request cancellations that we support. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: correct poll cancel and linked timeout expiration completionJens Axboe1-11/+22
Currently a poll request fills a completion entry of 0, even if it got cancelled. This is odd, and it makes it harder to support with chains. Ensure that it returns -ECANCELED in the completions events if it got cancelled, and furthermore ensure that the linked timeout that triggered it completes with -ETIME if we did indeed trigger the completions through a timeout. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: remove dead REQ_F_SEQ_PREV flagJens Axboe1-1/+0
With the conversion to io-wq, we no longer use that flag. Kill it. Fixes: 561fb04a6a22 ("io_uring: replace workqueue usage with io-wq") Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: fix sequencing issues with linked timeoutsJens Axboe1-41/+61
We have an issue with timeout links that are deeper in the submit chain, because we only handle it upfront, not from later submissions. Move the prep + issue of the timeout link to the async work prep handler, and do it normally for non-async queue. If we validate and prepare the timeout links upfront when we first see them, there's nothing stopping us from supporting any sort of nesting. Fixes: 2665abfd757f ("io_uring: add support for linked SQE timeouts") Reported-by: Pavel Begunkov <asml.silence@gmail.com> Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: make req->timeout be dynamically allocatedJens Axboe1-59/+70
There are a few reasons for this: - As a prep to improving the linked timeout logic - io_timeout is the biggest member in the io_kiocb opcode union This also enables a few cleanups, like unifying the timer setup between IORING_OP_TIMEOUT and IORING_OP_LINK_TIMEOUT, and not needing multiple arguments to the link/prep helpers. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: make io_double_put_req() use normal completion pathJens Axboe1-2/+14
If we don't use the normal completion path, we may skip killing links that should be errored and freed. Add __io_double_put_req() for use within the completion path itself, other calls should just use io_double_put_req(). Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: cleanup return values from the queueing functionsJens Axboe1-16/+12
__io_queue_sqe(), io_queue_sqe(), io_queue_link_head() all return 0/err, but the caller doesn't care since the errors are handled inline. Clean these up and just make them void. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25io_uring: io_async_cancel() should pass in 'nxt' request pointerJens Axboe1-1/+1
If we have a linked request, this enables us to pass it back directly without having to go through async context. Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-11-25Merge tag 'linux-kselftest-5.5-rc1-kunit' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftestLinus Torvalds3-0/+290
Pull kselftest KUnit support gtom Shuah Khan: "This adds KUnit, a lightweight unit testing and mocking framework for the Linux kernel from Brendan Higgins. KUnit is not an end-to-end testing framework. It is currently supported on UML and sub-systems can write unit tests and run them in UML env. KUnit documentation is included in this update. In addition, this Kunit update adds 3 new kunit tests: - proc sysctl test from Iurii Zaikin - the 'list' doubly linked list test from David Gow - ext4 tests for decoding extended timestamps from Iurii Zaikin In the future KUnit will be linked to Kselftest framework to provide a way to trigger KUnit tests from user-space" * tag 'linux-kselftest-5.5-rc1-kunit' of git://git.kernel.org/pub/scm/linux/kernel/git/shuah/linux-kselftest: (23 commits) lib/list-test: add a test for the 'list' doubly linked list ext4: add kunit test for decoding extended timestamps Documentation: kunit: Fix verification command kunit: Fix '--build_dir' option kunit: fix failure to build without printk MAINTAINERS: add proc sysctl KUnit test to PROC SYSCTL section kernel/sysctl-test: Add null pointer test for sysctl.c:proc_dointvec() MAINTAINERS: add entry for KUnit the unit testing framework Documentation: kunit: add documentation for KUnit kunit: defconfig: add defconfigs for building KUnit tests kunit: tool: add Python wrappers for running KUnit tests kunit: test: add tests for KUnit managed resources kunit: test: add the concept of assertions kunit: test: add tests for kunit test abort kunit: test: add support for test abort objtool: add kunit_try_catch_throw to the noreturn list kunit: test: add initial tests lib: enable building KUnit in lib/ kunit: test: add the concept of expectations kunit: test: add assertion printing library ...
2019-11-25Merge tag 'fsverity-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscryptLinus Torvalds2-2/+8
Pull fsverity updates from Eric Biggers: "Expose the fs-verity bit through statx()" * tag 'fsverity-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt: docs: fs-verity: mention statx() support f2fs: support STATX_ATTR_VERITY ext4: support STATX_ATTR_VERITY statx: define STATX_ATTR_VERITY docs: fs-verity: document first supported kernel version
2019-11-25Merge tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscryptLinus Torvalds10-271/+158
Pull fscrypt updates from Eric Biggers: - Add the IV_INO_LBLK_64 encryption policy flag which modifies the encryption to be optimized for UFS inline encryption hardware. - For AES-128-CBC, use the crypto API's implementation of ESSIV (which was added in 5.4) rather than doing ESSIV manually. - A few other cleanups. * tag 'fscrypt-for-linus' of git://git.kernel.org/pub/scm/fs/fscrypt/fscrypt: f2fs: add support for IV_INO_LBLK_64 encryption policies ext4: add support for IV_INO_LBLK_64 encryption policies fscrypt: add support for IV_INO_LBLK_64 policies fscrypt: avoid data race on fscrypt_mode::logged_impl_name docs: ioctl-number: document fscrypt ioctl numbers fscrypt: zeroize fscrypt_info before freeing fscrypt: remove struct fscrypt_ctx fscrypt: invoke crypto API for ESSIV handling
2019-11-25Merge tag 'affs-for-5.5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linuxLinus Torvalds2-16/+10
Pull AFFS updates from David Sterba: "A minor bugfix and cleanup for AFFS" * tag 'affs-for-5.5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: affs: fix a memory leak in affs_remount affs: Replace binary semaphores with mutexes
2019-11-25Merge tag 'for-5.5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linuxLinus Torvalds63-2546/+2694
Pull btrfs updates from David Sterba: "User visible changes: - new block group profiles: RAID1 with 3- and 4- copies - RAID1 in btrfs has always 2 copies, now add support for 3 and 4 - this is an incompat feature (named RAID1C34) - recommended use of RAID1C3 is replacement of RAID6 profile on metadata, this brings a more reliable resiliency against 2 device loss/damage - support for new checksums - per-filesystem, set at mkfs time - fast hash (crc32c successor): xxhash, 64bit digest - strong hashes (both 256bit): sha256 (slower, FIPS), blake2b (faster) - the blake2b module goes via the crypto tree, btrfs.ko has a soft dependency - speed up lseek, don't take inode locks unnecessarily, this can speed up parallel SEEK_CUR/SEEK_SET/SEEK_END by 80% - send: - allow clone operations within the same file - limit maximum number of sent clone references to avoid slow backref walking - error message improvements: device scan prints process name and PID Core changes: - cleanups - remove unique workqueue helpers, used to provide a way to avoid deadlocks in the workqueue code, now done in a simpler way - remove lots of indirect function calls in compression code - extent IO tree code moved out of extent_io.c - cleanup backup superblock handling at mount time - transaction life cycle documentation and cleanups - locking code cleanups, annotations and documentation - add more cold, const, pure function attributes - removal of unused or redundant struct members or variables - new tree-checker sanity tests - try to detect missing INODE_ITEM, cross-reference checks of DIR_ITEM, DIR_INDEX, INODE_REF, and XATTR_* items - remove own bio scheduling code (used to avoid checksum submissions being stuck behind other IO), replaced by cgroup controller-based code to allow better control and avoid priority inversions in cases where the custom and cgroup scheduling disagreed Fixes: - avoid getting stuck during cyclic writebacks - fix trimming of ranges crossing block group boundaries - fix rename exchange on subvolumes, all involved subvolumes need to be recorded in the transaction" * tag 'for-5.5-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (137 commits) btrfs: drop bdev argument from submit_extent_page btrfs: remove extent_map::bdev btrfs: drop bio_set_dev where not needed btrfs: get bdev directly from fs_devices in submit_extent_page btrfs: record all roots for rename exchange on a subvol Btrfs: fix block group remaining RO forever after error during device replace btrfs: scrub: Don't check free space before marking a block group RO btrfs: change btrfs_fs_devices::rotating to bool btrfs: change btrfs_fs_devices::seeding to bool btrfs: rename btrfs_block_group_cache btrfs: block-group: Reuse the item key from caller of read_one_block_group() btrfs: block-group: Refactor btrfs_read_block_groups() btrfs: document extent buffer locking btrfs: access eb::blocking_writers according to ACCESS_ONCE policies btrfs: set blocking_writers directly, no increment or decrement btrfs: merge blocking_writers branches in btrfs_tree_read_lock btrfs: drop incompat bit for raid1c34 after last block group is gone btrfs: add incompat for raid1 with 3, 4 copies btrfs: add support for 4-copy replication (raid1c4) btrfs: add support for 3-copy replication (raid1c3) ...
2019-11-25Merge tag 'for-5.5/disk-revalidate-20191122' of git://git.kernel.dk/linux-blockLinus Torvalds1-11/+37
Pull disk revalidation updates from Jens Axboe: "This continues the work that Jan Kara started to thoroughly cleanup and consolidate how we handle rescans and revalidations" * tag 'for-5.5/disk-revalidate-20191122' of git://git.kernel.dk/linux-block: block: move clearing bd_invalidated into check_disk_size_change block: remove (__)blkdev_reread_part as an exported API block: fix bdev_disk_changed for non-partitioned devices block: move rescan_partitions to fs/block_dev.c block: merge invalidate_partitions into rescan_partitions block: refactor rescan_partitions
2019-11-25Merge tag 'for-5.5/zoned-20191122' of git://git.kernel.dk/linux-blockLinus Torvalds1-35/+16
Pull zoned block device update from Jens Axboe: "Enhancements and improvements to the zoned device support" * tag 'for-5.5/zoned-20191122' of git://git.kernel.dk/linux-block: scsi: sd_zbc: Remove set but not used variable 'buflen' block: rework zone reporting scsi: sd_zbc: Cleanup sd_zbc_alloc_report_buffer() null_blk: Add zone_nr_conv to features null_blk: clean up report zones null_blk: clean up the block device operations block: Remove partition support for zoned block devices block: Simplify report zones execution block: cleanup the !zoned case in blk_revalidate_disk_zones block: Enhance blk_revalidate_disk_zones()
2019-11-25Merge tag 'for-5.5/block-20191121' of git://git.kernel.dk/linux-blockLinus Torvalds3-19/+23
Pull core block updates from Jens Axboe: "Due to more granular branches, this one is small and will be followed with other core branches that add specific features. I meant to just have a core and drivers branch, but external dependencies we ended up adding a few more that are also core. The changes are: - Fixes and improvements for the zoned device support (Ajay, Damien) - sed-opal table writing and datastore UID (Revanth) - blk-cgroup (and bfq) blk-cgroup stat fixes (Tejun) - Improvements to the block stats tracking (Pavel) - Fix for overruning sysfs buffer for large number of CPUs (Ming) - Optimization for small IO (Ming, Christoph) - Fix typo in RWH lifetime hint (Eugene) - Dead code removal and documentation (Bart) - Reduction in memory usage for queue and tag set (Bart) - Kerneldoc header documentation (André) - Device/partition revalidation fixes (Jan) - Stats tracking for flush requests (Konstantin) - Various other little fixes here and there (et al)" * tag 'for-5.5/block-20191121' of git://git.kernel.dk/linux-block: (48 commits) Revert "block: split bio if the only bvec's length is > SZ_4K" block: add iostat counters for flush requests block,bfq: Skip tracing hooks if possible block: sed-opal: Introduce SUM_SET_LIST parameter and append it using 'add_token_u64' blk-cgroup: cgroup_rstat_updated() shouldn't be called on cgroup1 block: Don't disable interrupts in trigger_softirq() sbitmap: Delete sbitmap_any_bit_clear() blk-mq: Delete blk_mq_has_free_tags() and blk_mq_can_queue() block: split bio if the only bvec's length is > SZ_4K block: still try to split bio if the bvec crosses pages blk-cgroup: separate out blkg_rwstat under CONFIG_BLK_CGROUP_RWSTAT blk-cgroup: reimplement basic IO stats using cgroup rstat blk-cgroup: remove now unused blkg_print_stat_{bytes|ios}_recursive() blk-throtl: stop using blkg->stat_bytes and ->stat_ios bfq-iosched: stop using blkg->stat_bytes and ->stat_ios bfq-iosched: relocate bfqg_*rwstat*() helpers block: add zone open, close and finish ioctl support block: add zone open, close and finish operations block: Simplify REQ_OP_ZONE_RESET_ALL handling block: Remove REQ_OP_ZONE_RESET plugging ...
2019-11-25Merge tag 'for-5.5/io_uring-20191121' of git://git.kernel.dk/linux-blockLinus Torvalds5-694/+2646
Pull io_uring updates from Jens Axboe: "A lot of stuff has been going on this cycle, with improving the support for networked IO (and hence unbounded request completion times) being one of the major themes. There's been a set of fixes done this week, I'll send those out as well once we're certain we're fully happy with them. This contains: - Unification of the "normal" submit path and the SQPOLL path (Pavel) - Support for sparse (and bigger) file sets, and updating of those file sets without needing to unregister/register again. - Independently sized CQ ring, instead of just making it always 2x the SQ ring size. This makes it more flexible for networked applications. - Support for overflowed CQ ring, never dropping events but providing backpressure on submits. - Add support for absolute timeouts, not just relative ones. - Support for generic cancellations. This divorces io_uring from workqueues as well, which additionally gets us one step closer to generic async system call support. - With cancellations, we can support grabbing the process file table as well, just like we do mm context. This allows support for system calls that create file descriptors, like accept4() support that's built on top of that. - Support for io_uring tracing (Dmitrii) - Support for linked timeouts. These abort an operation if it isn't completed by the time noted in the linke timeout. - Speedup tracking of poll requests - Various cleanups making the coder easier to follow (Jackie, Pavel, Bob, YueHaibing, me) - Update MAINTAINERS with new io_uring list" * tag 'for-5.5/io_uring-20191121' of git://git.kernel.dk/linux-block: (64 commits) io_uring: make POLL_ADD/POLL_REMOVE scale better io-wq: remove now redundant struct io_wq_nulls_list io_uring: Fix getting file for non-fd opcodes io_uring: introduce req_need_defer() io_uring: clean up io_uring_cancel_files() io-wq: ensure free/busy list browsing see all items io-wq: ensure we have a stable view of ->cur_work for cancellations io_wq: add get/put_work handlers to io_wq_create() io_uring: check for validity of ->rings in teardown io_uring: fix potential deadlock in io_poll_wake() io_uring: use correct "is IO worker" helper io_uring: fix -ENOENT issue with linked timer with short timeout io_uring: don't do flush cancel under inflight_lock io_uring: flag SQPOLL busy condition to userspace io_uring: make ASYNC_CANCEL work with poll and timeout io_uring: provide fallback request for OOM situations io_uring: convert accept4() -ERESTARTSYS into -EINTR io_uring: fix error clear of ->file_table in io_sqe_files_register() io_uring: separate the io_free_req and io_free_req_find_next interface io_uring: keep io_put_req only responsible for release and put req ...
2019-11-25vfs: properly and reliably lock f_pos in fdget_pos()Linus Torvalds2-6/+2
fdget_pos() is used by file operations that will read and update f_pos: things like "read()", "write()" and "lseek()" (but not, for example, "pread()/pwrite" that get their file positions elsewhere). However, it had two separate escape clauses for this, because not everybody wants or needs serialization of the file position. The first and most obvious case is the "file descriptor doesn't have a position at all", ie a stream-like file. Except we didn't actually use FMODE_STREAM, but instead used FMODE_ATOMIC_POS. The reason for that was that FMODE_STREAM didn't exist back in the days, but also that we didn't want to mark all the special cases, so we only marked the ones that _required_ position atomicity according to POSIX - regular files and directories. The case one was intentionally lazy, but now that we _do_ have FMODE_STREAM we could and should just use it. With the change to use FMODE_STREAM, there are no remaining uses for FMODE_ATOMIC_POS, and all the code to set it is deleted. Any cases where we don't want the serialization because the driver (or subsystem) doesn't use the file position should just be updated to do "stream_open()". We've done that for all the obvious and common situations, we may need a few more. Quoting Kirill Smelkov in the original FMODE_STREAM thread (see link below for full email): "And I appreciate if people could help at least somehow with "getting rid of mixed case entirely" (i.e. always lock f_pos_lock on !FMODE_STREAM), because this transition starts to diverge from my particular use-case too far. To me it makes sense to do that transition as follows: - convert nonseekable_open -> stream_open via stream_open.cocci; - audit other nonseekable_open calls and convert left users that truly don't depend on position to stream_open; - extend stream_open.cocci to analyze alloc_file_pseudo as well (this will cover pipes and sockets), or maybe convert pipes and sockets to FMODE_STREAM manually; - extend stream_open.cocci to analyze file_operations that use no_llseek or noop_llseek, but do not use nonseekable_open or alloc_file_pseudo. This might find files that have stream semantic but are opened differently; - extend stream_open.cocci to analyze file_operations whose .read/.write do not use ppos at all (independently of how file was opened); - ... - after that remove FMODE_ATOMIC_POS and always take f_pos_lock if !FMODE_STREAM; - gather bug reports for deadlocked read/write and convert missed cases to FMODE_STREAM, probably extending stream_open.cocci along the road to catch similar cases i.e. always take f_pos_lock unless a file is explicitly marked as being stream, and try to find and cover all files that are streams" We have not done the "extend stream_open.cocci to analyze alloc_file_pseudo" as well, but the previous commit did manually handle the case of pipes and sockets. The other case where we can avoid locking f_pos is the "this file descriptor only has a single user and it is us, and thus there is no need to lock it". The second test was correct, although a bit subtle and worth just re-iterating here. There are two kinds of other sources of references to the same file descriptor: file descriptors that have been explicitly shared across fork() or with dup(), and file tables having elevated reference counts due to threading (or explicit file sharing with clone()). The first case would have incremented the file count explicitly, and in the second case the previous __fdget() would have incremented it for us and set the FDPUT_FPUT flag. But in both cases the file count would be greater than one, so the "file_count(file) > 1" test catches both situations. Also note that if file_count is 1, that also means that no other thread can have access to the file table, so there also cannot be races with concurrent calls to dup()/fork()/clone() that would increment the file count any other way. Link: https://lore.kernel.org/linux-fsdevel/20190413184404.GA13490@deco.navytux.spb.ru Cc: Kirill Smelkov <kirr@nexedi.com> Cc: Eic Dumazet <edumazet@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Marco Elver <elver@google.com> Cc: Andrea Parri <parri.andrea@gmail.com> Cc: Paul McKenney <paulmck@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-11-25f2fs: stop GC when the victim becomes fully validJaegeuk Kim1-2/+8
We must stop GC, once the segment becomes fully valid. Otherwise, it can produce another dirty segments by moving valid blocks in the segment partially. Ramon hit no free segment panic sometimes and saw this case happens when validating reliable file pinning feature. Signed-off-by: Ramon Pantin <pantin@google.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2019-11-25f2fs: expose main_blkaddr in sysfsJaegeuk Kim1-0/+2
Expose in /sys/fs/f2fs/<blockdev>/main_blkaddr the block address where the main area starts. This allows user mode programs to determine: - That pinned files that are made exclusively of fully allocated 2MB segments will never be unpinned by the file system. - Where the main area starts. This is required by programs that want to verify if a file is made exclusively of 2MB f2fs segments, the alignment boundary for segments starts at this address. Testing for 2MB alignment relative to the start of the device is incorrect, because for some filesystems main_blkaddr is not at a 2MB boundary relative to the start of the device. The entry will be used when validating reliable pinning file feature proposed by "f2fs: support aligned pinned file". Signed-off-by: Ramon Pantin <pantin@google.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2019-11-25f2fs: choose hardlimit when softlimit is larger than hardlimit in f2fs_statfs_project()Chengguang Xu1-6/+14
Setting softlimit larger than hardlimit seems meaningless for disk quota but currently it is allowed. In this case, there may be a bit of comfusion for users when they run df comamnd to directory which has project quota. For example, we set 20M softlimit and 10M hardlimit of block usage limit for project quota of test_dir(project id 123). [root@hades f2fs]# repquota -P -a *** Report for project quotas on device /dev/nvme0n1p8 Block grace time: 7days; Inode grace time: 7days Block limits File limits Project used soft hard grace used soft hard grace ---------------------------------------------------------------------- 0 -- 4 0 0 1 0 0 123 +- 10248 20480 10240 2 0 0 The result of df command as below: [root@hades f2fs]# df -h /mnt/f2fs/test Filesystem Size Used Avail Use% Mounted on /dev/nvme0n1p8 20M 11M 10M 51% /mnt/f2fs Even though it looks like there is another 10M free space to use, if we write new data to diretory test(inherit project id), the write will fail with errno(-EDQUOT). After this patch, the df result looks like below. [root@hades f2fs]# df -h /mnt/f2fs/test Filesystem Size Used Avail Use% Mounted on /dev/nvme0n1p8 10M 10M 0 100% /mnt/f2fs Signed-off-by: Chengguang Xu <cgxu519@mykernel.net> Reviewed-by: Chao Yu <yuchao0@huawei.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2019-11-25vfs: mark pipes and sockets as stream-like file descriptorsLinus Torvalds1-2/+4
In commit 3975b097e577 ("convert stream-like files -> stream_open, even if they use noop_llseek") Kirill used a coccinelle script to change "nonseekable_open()" to "stream_open()", which changed the trivial cases of stream-like file descriptors to the new model with FMODE_STREAM. However, the two big cases - sockets and pipes - don't actually have that trivial pattern at all, and were thus never converted to FMODE_STREAM even though it makes lots of sense to do so. That's particularly true when looking forward to the next change: getting rid of FMODE_ATOMIC_POS entirely, and just using FMODE_STREAM to decide whether f_pos updates are needed or not. And if they are, we'll always do them atomically. This came up because KCSAN (correctly) noted that the non-locked f_pos updates are data races: they are clearly benign for the case where we don't care, but it would be good to just not have that issue exist at all. Note that the reason we used FMODE_ATOMIC_POS originally is that only doing it for the minimal required case is "safer" in that it's possible that the f_pos locking can cause unnecessary serialization across the whole write() call. And in the worst case, that kind of serialization can cause deadlock issues: think writers that need readers to empty the state using the same file descriptor. [ Note that the locking is per-file descriptor - because it protects "f_pos", which is obviously per-file descriptor - so it only affects cases where you literally use the same file descriptor to both read and write. So a regular pipe that has separate reading and writing file descriptors doesn't really have this situation even though it's the obvious case of "reader empties what a bit writer concurrently fills" But we want to make pipes as being stream-line anyway, because we don't want the unnecessary overhead of locking, and because a named pipe can be (ab-)used by reading and writing to the same file descriptor. ] There are likely a lot of other cases that might want FMODE_STREAM, and looking for ".llseek = no_llseek" users and other cases that don't have an lseek file operation at all and making them use "stream_open()" might be a good idea. But pipes and sockets are likely to be the two main cases. Cc: Kirill Smelkov <kirr@nexedi.com> Cc: Eic Dumazet <edumazet@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Alan Stern <stern@rowland.harvard.edu> Cc: Marco Elver <elver@google.com> Cc: Andrea Parri <parri.andrea@gmail.com> Cc: Paul McKenney <paulmck@kernel.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-11-25cifs: update internal module version numberSteve French1-1/+1
To 2.24 Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25cifs: Always update signing key of first channelPaulo Alcantara (SUSE)1-0/+4
Update signing key of first channel whenever generating the master sigining/encryption/decryption keys rather than only in cifs_mount(). This also fixes reconnect when re-establishing smb sessions to other servers. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25cifs: Fix retrieval of DFS referrals in cifs_mount()Paulo Alcantara (SUSE)1-10/+22
Make sure that DFS referrals are sent to newly resolved root targets as in a multi tier DFS setup. Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Link: https://lkml.kernel.org/r/05aa2995-e85e-0ff4-d003-5bb08bd17a22@canonical.com Cc: stable@vger.kernel.org Tested-by: Matthew Ruffell <matthew.ruffell@canonical.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25cifs: Fix potential softlockups while refreshing DFS cachePaulo Alcantara (SUSE)1-12/+29
We used to skip reconnects on all SMB2_IOCTL commands due to SMB3+ FSCTL_VALIDATE_NEGOTIATE_INFO - which made sense since we're still establishing a SMB session. However, when refresh_cache_worker() calls smb2_get_dfs_refer() and we're under reconnect, SMB2_ioctl() will not be able to get a proper status error (e.g. -EHOSTDOWN in case we failed to reconnect) but an -EAGAIN from cifs_send_recv() thus looping forever in refresh_cache_worker(). Fixes: e99c63e4d86d ("SMB3: Fix deadlock in validate negotiate hits reconnect") Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Suggested-by: Aurelien Aptel <aaptel@suse.com> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25cifs: Fix lookup of root ses in DFS referral cachePaulo Alcantara (SUSE)1-2/+1
We don't care about module aliasing validation in cifs_compose_mount_options(..., is_smb3) when finding the root SMB session of an DFS namespace in order to refresh DFS referral cache. The following issue has been observed when mounting with '-t smb3' and then specifying 'vers=2.0': ... Nov 08 15:27:08 tw kernel: address conversion returned 0 for FS0.WIN.LOCAL Nov 08 15:27:08 tw kernel: [kworke] ==> dns_query((null),FS0.WIN.LOCAL,13,(null)) Nov 08 15:27:08 tw kernel: [kworke] call request_key(,FS0.WIN.LOCAL,) Nov 08 15:27:08 tw kernel: [kworke] ==> dns_resolver_cmp(FS0.WIN.LOCAL,FS0.WIN.LOCAL) Nov 08 15:27:08 tw kernel: [kworke] <== dns_resolver_cmp() = 1 Nov 08 15:27:08 tw kernel: [kworke] <== dns_query() = 13 Nov 08 15:27:08 tw kernel: fs/cifs/dns_resolve.c: dns_resolve_server_name_to_ip: resolved: FS0.WIN.LOCAL to 192.168.30.26 ===> Nov 08 15:27:08 tw kernel: CIFS VFS: vers=2.0 not permitted when mounting with smb3 Nov 08 15:27:08 tw kernel: fs/cifs/dfs_cache.c: CIFS VFS: leaving refresh_tcon (xid = 26) rc = -22 ... Fixes: 5072010ccf05 ("cifs: Fix DFS cache refresher for DFS links") Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25cifs: Fix use-after-free bug in cifs_reconnect()Paulo Alcantara (SUSE)1-11/+35
Ensure we grab an active reference in cifs superblock while doing failover to prevent automounts (DFS links) of expiring and then destroying the superblock pointer. This patch fixes the following KASAN report: [ 464.301462] BUG: KASAN: use-after-free in cifs_reconnect+0x6ab/0x1350 [ 464.303052] Read of size 8 at addr ffff888155e580d0 by task cifsd/1107 [ 464.304682] CPU: 3 PID: 1107 Comm: cifsd Not tainted 5.4.0-rc4+ #13 [ 464.305552] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS rel-1.12.1-0-ga5cab58-rebuilt.opensuse.org 04/01/2014 [ 464.307146] Call Trace: [ 464.307875] dump_stack+0x5b/0x90 [ 464.308631] print_address_description.constprop.0+0x16/0x200 [ 464.309478] ? cifs_reconnect+0x6ab/0x1350 [ 464.310253] ? cifs_reconnect+0x6ab/0x1350 [ 464.311040] __kasan_report.cold+0x1a/0x41 [ 464.311811] ? cifs_reconnect+0x6ab/0x1350 [ 464.312563] kasan_report+0xe/0x20 [ 464.313300] cifs_reconnect+0x6ab/0x1350 [ 464.314062] ? extract_hostname.part.0+0x90/0x90 [ 464.314829] ? printk+0xad/0xde [ 464.315525] ? _raw_spin_lock+0x7c/0xd0 [ 464.316252] ? _raw_read_lock_irq+0x40/0x40 [ 464.316961] ? ___ratelimit+0xed/0x182 [ 464.317655] cifs_readv_from_socket+0x289/0x3b0 [ 464.318386] cifs_read_from_socket+0x98/0xd0 [ 464.319078] ? cifs_readv_from_socket+0x3b0/0x3b0 [ 464.319782] ? try_to_wake_up+0x43c/0xa90 [ 464.320463] ? cifs_small_buf_get+0x4b/0x60 [ 464.321173] ? allocate_buffers+0x98/0x1a0 [ 464.321856] cifs_demultiplex_thread+0x218/0x14a0 [ 464.322558] ? cifs_handle_standard+0x270/0x270 [ 464.323237] ? __switch_to_asm+0x40/0x70 [ 464.323893] ? __switch_to_asm+0x34/0x70 [ 464.324554] ? __switch_to_asm+0x40/0x70 [ 464.325226] ? __switch_to_asm+0x40/0x70 [ 464.325863] ? __switch_to_asm+0x34/0x70 [ 464.326505] ? __switch_to_asm+0x40/0x70 [ 464.327161] ? __switch_to_asm+0x34/0x70 [ 464.327784] ? finish_task_switch+0xa1/0x330 [ 464.328414] ? __switch_to+0x363/0x640 [ 464.329044] ? __schedule+0x575/0xaf0 [ 464.329655] ? _raw_spin_lock_irqsave+0x82/0xe0 [ 464.330301] kthread+0x1a3/0x1f0 [ 464.330884] ? cifs_handle_standard+0x270/0x270 [ 464.331624] ? kthread_create_on_node+0xd0/0xd0 [ 464.332347] ret_from_fork+0x35/0x40 [ 464.333577] Allocated by task 1110: [ 464.334381] save_stack+0x1b/0x80 [ 464.335123] __kasan_kmalloc.constprop.0+0xc2/0xd0 [ 464.335848] cifs_smb3_do_mount+0xd4/0xb00 [ 464.336619] legacy_get_tree+0x6b/0xa0 [ 464.337235] vfs_get_tree+0x41/0x110 [ 464.337975] fc_mount+0xa/0x40 [ 464.338557] vfs_kern_mount.part.0+0x6c/0x80 [ 464.339227] cifs_dfs_d_automount+0x336/0xd29 [ 464.339846] follow_managed+0x1b1/0x450 [ 464.340449] lookup_fast+0x231/0x4a0 [ 464.341039] path_openat+0x240/0x1fd0 [ 464.341634] do_filp_open+0x126/0x1c0 [ 464.342277] do_sys_open+0x1eb/0x2c0 [ 464.342957] do_syscall_64+0x5e/0x190 [ 464.343555] entry_SYSCALL_64_after_hwframe+0x44/0xa9 [ 464.344772] Freed by task 0: [ 464.345347] save_stack+0x1b/0x80 [ 464.345966] __kasan_slab_free+0x12c/0x170 [ 464.346576] kfree+0xa6/0x270 [ 464.347211] rcu_core+0x39c/0xc80 [ 464.347800] __do_softirq+0x10d/0x3da [ 464.348919] The buggy address belongs to the object at ffff888155e58000 which belongs to the cache kmalloc-256 of size 256 [ 464.350222] The buggy address is located 208 bytes inside of 256-byte region [ffff888155e58000, ffff888155e58100) [ 464.351575] The buggy address belongs to the page: [ 464.352333] page:ffffea0005579600 refcount:1 mapcount:0 mapping:ffff88815a803400 index:0x0 compound_mapcount: 0 [ 464.353583] flags: 0x200000000010200(slab|head) [ 464.354209] raw: 0200000000010200 ffffea0005576200 0000000400000004 ffff88815a803400 [ 464.355353] raw: 0000000000000000 0000000080100010 00000001ffffffff 0000000000000000 [ 464.356458] page dumped because: kasan: bad access detected [ 464.367005] Memory state around the buggy address: [ 464.367787] ffff888155e57f80: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 464.368877] ffff888155e58000: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 464.369967] >ffff888155e58080: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb [ 464.371111] ^ [ 464.371775] ffff888155e58100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 464.372893] ffff888155e58180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc [ 464.373983] ================================================================== Signed-off-by: Paulo Alcantara (SUSE) <pc@cjr.nz> Reviewed-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25cifs: dump channel info in DebugDataAurelien Aptel1-1/+34
* show server&TCP states for extra channels * mention if an interface has a channel connected to it In this version three of the patch, fixed minor printk format issue pointed out by the kbuild robot. Reported-by: kbuild test robot <lkp@intel.com> Signed-off-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25smb3: dump in_send and num_waiters stats counters by defaultSteve French2-21/+4
Number of requests in_send and the number of waiters on sendRecv are useful counters in various cases, move them from CONFIG_CIFS_STATS2 to be on by default especially with multichannel Signed-off-by: Steve French <stfrench@microsoft.com> Acked-by: Ronnie Sahlberg <lsahlber@redhat.com>
2019-11-25cifs: try harder to open new channelsAurelien Aptel1-10/+22
Previously we would only loop over the iface list once. This patch tries to loop over multiple times until all channels are opened. It will also try to reuse RSS ifaces. Signed-off-by: Aurelien Aptel <aaptel@suse.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25CIFS: Properly process SMB3 lease breaksPavel Shilovsky7-65/+57
Currenly we doesn't assume that a server may break a lease from RWH to RW which causes us setting a wrong lease state on a file and thus mistakenly flushing data and byte-range locks and purging cached data on the client. This leads to performance degradation because subsequent IOs go directly to the server. Fix this by propagating new lease state and epoch values to the oplock break handler through cifsFileInfo structure and removing the use of cifsInodeInfo flags for that. It allows to avoid some races of several lease/oplock breaks using those flags in parallel. Signed-off-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Steve French <stfrench@microsoft.com>
2019-11-25cifs: move cifsFileInfo_put logic into a work-queueRonnie Sahlberg3-27/+65
This patch moves the final part of the cifsFileInfo_put() logic where we need a write lock on lock_sem to be processed in a separate thread that holds no other locks. This is to prevent deadlocks like the one below: > there are 6 processes looping to while trying to down_write > cinode->lock_sem, 5 of them from _cifsFileInfo_put, and one from > cifs_new_fileinfo > > and there are 5 other processes which are blocked, several of them > waiting on either PG_writeback or PG_locked (which are both set), all > for the same page of the file > > 2 inode_lock() (inode->i_rwsem) for the file > 1 wait_on_page_writeback() for the page > 1 down_read(inode->i_rwsem) for the inode of the directory > 1 inode_lock()(inode->i_rwsem) for the inode of the directory > 1 __lock_page > > > so processes are blocked waiting on: > page flags PG_locked and PG_writeback for one specific page > inode->i_rwsem for the directory > inode->i_rwsem for the file > cifsInodeInflock_sem > > > > here are the more gory details (let me know if I need to provide > anything more/better): > > [0 00:48:22.765] [UN] PID: 8863 TASK: ffff8c691547c5c0 CPU: 3 > COMMAND: "reopen_file" > #0 [ffff9965007e3ba8] __schedule at ffffffff9b6e6095 > #1 [ffff9965007e3c38] schedule at ffffffff9b6e64df > #2 [ffff9965007e3c48] rwsem_down_write_slowpath at ffffffff9af283d7 > #3 [ffff9965007e3cb8] legitimize_path at ffffffff9b0f975d > #4 [ffff9965007e3d08] path_openat at ffffffff9b0fe55d > #5 [ffff9965007e3dd8] do_filp_open at ffffffff9b100a33 > #6 [ffff9965007e3ee0] do_sys_open at ffffffff9b0eb2d6 > #7 [ffff9965007e3f38] do_syscall_64 at ffffffff9ae04315 > * (I think legitimize_path is bogus) > > in path_openat > } else { > const char *s = path_init(nd, flags); > while (!(error = link_path_walk(s, nd)) && > (error = do_last(nd, file, op)) > 0) { <<<< > > do_last: > if (open_flag & O_CREAT) > inode_lock(dir->d_inode); <<<< > else > so it's trying to take inode->i_rwsem for the directory > > DENTRY INODE SUPERBLK TYPE PATH > ffff8c68bb8e79c0 ffff8c691158ef20 ffff8c6915bf9000 DIR /mnt/vm1_smb/ > inode.i_rwsem is ffff8c691158efc0 > > <struct rw_semaphore 0xffff8c691158efc0>: > owner: <struct task_struct 0xffff8c6914275d00> (UN - 8856 - > reopen_file), counter: 0x0000000000000003 > waitlist: 2 > 0xffff9965007e3c90 8863 reopen_file UN 0 1:29:22.926 > RWSEM_WAITING_FOR_WRITE > 0xffff996500393e00 9802 ls UN 0 1:17:26.700 > RWSEM_WAITING_FOR_READ > > > the owner of the inode.i_rwsem of the directory is: > > [0 00:00:00.109] [UN] PID: 8856 TASK: ffff8c6914275d00 CPU: 3 > COMMAND: "reopen_file" > #0 [ffff99650065b828] __schedule at ffffffff9b6e6095 > #1 [ffff99650065b8b8] schedule at ffffffff9b6e64df > #2 [ffff99650065b8c8] schedule_timeout at ffffffff9b6e9f89 > #3 [ffff99650065b940] msleep at ffffffff9af573a9 > #4 [ffff99650065b948] _cifsFileInfo_put.cold.63 at ffffffffc0a42dd6 [cifs] > #5 [ffff99650065ba38] cifs_writepage_locked at ffffffffc0a0b8f3 [cifs] > #6 [ffff99650065bab0] cifs_launder_page at ffffffffc0a0bb72 [cifs] > #7 [ffff99650065bb30] invalidate_inode_pages2_range at ffffffff9b04d4bd > #8 [ffff99650065bcb8] cifs_invalidate_mapping at ffffffffc0a11339 [cifs] > #9 [ffff99650065bcd0] cifs_revalidate_mapping at ffffffffc0a1139a [cifs] > #10 [ffff99650065bcf0] cifs_d_revalidate at ffffffffc0a014f6 [cifs] > #11 [ffff99650065bd08] path_openat at ffffffff9b0fe7f7 > #12 [ffff99650065bdd8] do_filp_open at ffffffff9b100a33 > #13 [ffff99650065bee0] do_sys_open at ffffffff9b0eb2d6 > #14 [ffff99650065bf38] do_syscall_64 at ffffffff9ae04315 > > cifs_launder_page is for page 0xffffd1e2c07d2480 > > crash> page.index,mapping,flags 0xffffd1e2c07d2480 > index = 0x8 > mapping = 0xffff8c68f3cd0db0 > flags = 0xfffffc0008095 > > PAGE-FLAG BIT VALUE > PG_locked 0 0000001 > PG_uptodate 2 0000004 > PG_lru 4 0000010 > PG_waiters 7 0000080 > PG_writeback 15 0008000 > > > inode is ffff8c68f3cd0c40 > inode.i_rwsem is ffff8c68f3cd0ce0 > DENTRY INODE SUPERBLK TYPE PATH > ffff8c68a1f1b480 ffff8c68f3cd0c40 ffff8c6915bf9000 REG > /mnt/vm1_smb/testfile.8853 > > > this process holds the inode->i_rwsem for the parent directory, is > laundering a page attached to the inode of the file it's opening, and in > _cifsFileInfo_put is trying to down_write the cifsInodeInflock_sem > for the file itself. > > > <struct rw_semaphore 0xffff8c68f3cd0ce0>: > owner: <struct task_struct 0xffff8c6914272e80> (UN - 8854 - > reopen_file), counter: 0x0000000000000003 > waitlist: 1 > 0xffff9965005dfd80 8855 reopen_file UN 0 1:29:22.912 > RWSEM_WAITING_FOR_WRITE > > this is the inode.i_rwsem for the file > > the owner: > > [0 00:48:22.739] [UN] PID: 8854 TASK: ffff8c6914272e80 CPU: 2 > COMMAND: "reopen_file" > #0 [ffff99650054fb38] __schedule at ffffffff9b6e6095 > #1 [ffff99650054fbc8] schedule at ffffffff9b6e64df > #2 [ffff99650054fbd8] io_schedule at ffffffff9b6e68e2 > #3 [ffff99650054fbe8] __lock_page at ffffffff9b03c56f > #4 [ffff99650054fc80] pagecache_get_page at ffffffff9b03dcdf > #5 [ffff99650054fcc0] grab_cache_page_write_begin at ffffffff9b03ef4c > #6 [ffff99650054fcd0] cifs_write_begin at ffffffffc0a064ec [cifs] > #7 [ffff99650054fd30] generic_perform_write at ffffffff9b03bba4 > #8 [ffff99650054fda8] __generic_file_write_iter at ffffffff9b04060a > #9 [ffff99650054fdf0] cifs_strict_writev.cold.70 at ffffffffc0a4469b [cifs] > #10 [ffff99650054fe48] new_sync_write at ffffffff9b0ec1dd > #11 [ffff99650054fed0] vfs_write at ffffffff9b0eed35 > #12 [ffff99650054ff00] ksys_write at ffffffff9b0eefd9 > #13 [ffff99650054ff38] do_syscall_64 at ffffffff9ae04315 > > the process holds the inode->i_rwsem for the file to which it's writing, > and is trying to __lock_page for the same page as in the other processes > > > the other tasks: > [0 00:00:00.028] [UN] PID: 8859 TASK: ffff8c6915479740 CPU: 2 > COMMAND: "reopen_file" > #0 [ffff9965007b39d8] __schedule at ffffffff9b6e6095 > #1 [ffff9965007b3a68] schedule at ffffffff9b6e64df > #2 [ffff9965007b3a78] schedule_timeout at ffffffff9b6e9f89 > #3 [ffff9965007b3af0] msleep at ffffffff9af573a9 > #4 [ffff9965007b3af8] cifs_new_fileinfo.cold.61 at ffffffffc0a42a07 [cifs] > #5 [ffff9965007b3b78] cifs_open at ffffffffc0a0709d [cifs] > #6 [ffff9965007b3cd8] do_dentry_open at ffffffff9b0e9b7a > #7 [ffff9965007b3d08] path_openat at ffffffff9b0fe34f > #8 [ffff9965007b3dd8] do_filp_open at ffffffff9b100a33 > #9 [ffff9965007b3ee0] do_sys_open at ffffffff9b0eb2d6 > #10 [ffff9965007b3f38] do_syscall_64 at ffffffff9ae04315 > > this is opening the file, and is trying to down_write cinode->lock_sem > > > [0 00:00:00.041] [UN] PID: 8860 TASK: ffff8c691547ae80 CPU: 2 > COMMAND: "reopen_file" > [0 00:00:00.057] [UN] PID: 8861 TASK: ffff8c6915478000 CPU: 3 > COMMAND: "reopen_file" > [0 00:00:00.059] [UN] PID: 8858 TASK: ffff8c6914271740 CPU: 2 > COMMAND: "reopen_file" > [0 00:00:00.109] [UN] PID: 8862 TASK: ffff8c691547dd00 CPU: 6 > COMMAND: "reopen_file" > #0 [ffff9965007c3c78] __schedule at ffffffff9b6e6095 > #1 [ffff9965007c3d08] schedule at ffffffff9b6e64df > #2 [ffff9965007c3d18] schedule_timeout at ffffffff9b6e9f89 > #3 [ffff9965007c3d90] msleep at ffffffff9af573a9 > #4 [ffff9965007c3d98] _cifsFileInfo_put.cold.63 at ffffffffc0a42dd6 [cifs] > #5 [ffff9965007c3e88] cifs_close at ffffffffc0a07aaf [cifs] > #6 [ffff9965007c3ea0] __fput at ffffffff9b0efa6e > #7 [ffff9965007c3ee8] task_work_run at ffffffff9aef1614 > #8 [ffff9965007c3f20] exit_to_usermode_loop at ffffffff9ae03d6f > #9 [ffff9965007c3f38] do_syscall_64 at ffffffff9ae0444c > > closing the file, and trying to down_write cifsi->lock_sem > > > [0 00:48:22.839] [UN] PID: 8857 TASK: ffff8c6914270000 CPU: 7 > COMMAND: "reopen_file" > #0 [ffff9965006a7cc8] __schedule at ffffffff9b6e6095 > #1 [ffff9965006a7d58] schedule at ffffffff9b6e64df > #2 [ffff9965006a7d68] io_schedule at ffffffff9b6e68e2 > #3 [ffff9965006a7d78] wait_on_page_bit at ffffffff9b03cac6 > #4 [ffff9965006a7e10] __filemap_fdatawait_range at ffffffff9b03b028 > #5 [ffff9965006a7ed8] filemap_write_and_wait at ffffffff9b040165 > #6 [ffff9965006a7ef0] cifs_flush at ffffffffc0a0c2fa [cifs] > #7 [ffff9965006a7f10] filp_close at ffffffff9b0e93f1 > #8 [ffff9965006a7f30] __x64_sys_close at ffffffff9b0e9a0e > #9 [ffff9965006a7f38] do_syscall_64 at ffffffff9ae04315 > > in __filemap_fdatawait_range > wait_on_page_writeback(page); > for the same page of the file > > > > [0 00:48:22.718] [UN] PID: 8855 TASK: ffff8c69142745c0 CPU: 7 > COMMAND: "reopen_file" > #0 [ffff9965005dfc98] __schedule at ffffffff9b6e6095 > #1 [ffff9965005dfd28] schedule at ffffffff9b6e64df > #2 [ffff9965005dfd38] rwsem_down_write_slowpath at ffffffff9af283d7 > #3 [ffff9965005dfdf0] cifs_strict_writev at ffffffffc0a0c40a [cifs] > #4 [ffff9965005dfe48] new_sync_write at ffffffff9b0ec1dd > #5 [ffff9965005dfed0] vfs_write at ffffffff9b0eed35 > #6 [ffff9965005dff00] ksys_write at ffffffff9b0eefd9 > #7 [ffff9965005dff38] do_syscall_64 at ffffffff9ae04315 > > inode_lock(inode); > > > and one 'ls' later on, to see whether the rest of the mount is available > (the test file is in the root, so we get blocked up on the directory > ->i_rwsem), so the entire mount is unavailable > > [0 00:36:26.473] [UN] PID: 9802 TASK: ffff8c691436ae80 CPU: 4 > COMMAND: "ls" > #0 [ffff996500393d28] __schedule at ffffffff9b6e6095 > #1 [ffff996500393db8] schedule at ffffffff9b6e64df > #2 [ffff996500393dc8] rwsem_down_read_slowpath at ffffffff9b6e9421 > #3 [ffff996500393e78] down_read_killable at ffffffff9b6e95e2 > #4 [ffff996500393e88] iterate_dir at ffffffff9b103c56 > #5 [ffff996500393ec8] ksys_getdents64 at ffffffff9b104b0c > #6 [ffff996500393f30] __x64_sys_getdents64 at ffffffff9b104bb6 > #7 [ffff996500393f38] do_syscall_64 at ffffffff9ae04315 > > in iterate_dir: > if (shared) > res = down_read_killable(&inode->i_rwsem); <<<< > else > res = down_write_killable(&inode->i_rwsem); > Reported-by: Frank Sorenson <sorenson@redhat.com> Reviewed-by: Pavel Shilovsky <pshilov@microsoft.com> Signed-off-by: Ronnie Sahlberg <lsahlber@redhat.com> Signed-off-by: Steve French <stfrench@microsoft.com>