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2016-02-22f2fs: avoid multiple node page writes due to inline_dataJaegeuk Kim5-0/+63
The sceanrio is: 1. create fully node blocks 2. flush node blocks 3. write inline_data for all the node blocks again 4. flush node blocks redundantly So, this patch tries to flush inline_data when flushing node blocks. Reviewed-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-02-22f2fs: do f2fs_balance_fs when block is allocatedJaegeuk Kim1-6/+6
We should consider data block allocation to trigger f2fs_balance_fs. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-02-22f2fs: fix to overcome inline_data floodsJaegeuk Kim1-0/+7
The scenario is: 1. create lots of node blocks 2. sync 3. write lots of inline_data -> got panic due to no free space In that case, we should flush node blocks when writing inline_data in #3, and trigger gc as well. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-02-22f2fs: use writepages->lock for WB_SYNC_ALLJaegeuk Kim1-1/+1
If there are many writepages calls by multiple threads in background, we don't need to serialize to merge all the bios, since it's background. In such the case, it'd better to run writepages concurrently. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-02-22f2fs: remove needless condition checkJaegeuk Kim1-5/+1
This patch removes needless condition variable. Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-02-22f2fs: correct search area in get_new_segmentChao Yu1-3/+2
get_new_segment starts from current segment position, tries to search a free segment among its right neighbors locate in same section. But previously our search area was set as [current segment, max segment], which means we have to search to more bits in free_segmap bitmap for some worse cases. So here we correct the search area to [current segment, last segment in section] to avoid unnecessary searching. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-02-22f2fs: export dirty_nats_ratio in sysfsChao Yu4-1/+5
This patch exports a new sysfs entry 'dirty_nat_ratio' to control threshold of dirty nat entries, if current ratio exceeds configured threshold, checkpoint will be triggered in f2fs_balance_fs_bg for flushing dirty nats. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-02-22f2fs: flush dirty nat entries when exceeding thresholdChao Yu2-1/+11
When testing f2fs with xfstest, generic/251 is stuck for long time, the case uses below serials to obtain fresh released space in device, in order to prepare for following fstrim test. 1. rm -rf /mnt/dir 2. mkdir /mnt/dir/ 3. cp -axT `pwd`/ /mnt/dir/ 4. goto 1 During preparing step, all nat entries will be cached in nat cache, most of them are dirty entries with invalid blkaddr, which means nodes related to these entries have been truncated, and they could be reused after the dirty entries been checkpointed. However, there was no checkpoint been triggered, so nid allocators (e.g. mkdir, creat) will run into long journey of iterating all NAT pages, looking for free nids in alloc_nid->build_free_nids. Here, in f2fs_balance_fs_bg we give another chance to do checkpoint to flush nat entries for reusing them in free nid cache when dirty entry count exceeds 10% of max count. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-02-22f2fs: relocate is_merged_pageChao Yu3-38/+39
Operations in is_merged_page is related to inner bio cache, move it to data.c. Signed-off-by: Chao Yu <chao2.yu@samsung.com> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
2016-02-20Merge branch 'x86-urgent-for-linus' of ↵Linus Torvalds4-18/+101
git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip Pull x86 fixes from Ingo Molnar: "This is unusually large, partly due to the EFI fixes that prevent accidental deletion of EFI variables through efivarfs that may brick machines. These fixes are somewhat involved to maintain compatibility with existing install methods and other usage modes, while trying to turn off the 'rm -rf' bricking vector. Other fixes are for large page ioremap()s and for non-temporal user-memcpy()s" * 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: x86/mm: Fix vmalloc_fault() to handle large pages properly hpet: Drop stale URLs x86/uaccess/64: Handle the caching of 4-byte nocache copies properly in __copy_user_nocache() x86/uaccess/64: Make the __copy_user_nocache() assembly code more readable lib/ucs2_string: Correct ucs2 -> utf8 conversion efi: Add pstore variables to the deletion whitelist efi: Make efivarfs entries immutable by default efi: Make our variable validation list include the guid efi: Do variable name validation tests in utf8 efi: Use ucs2_as_utf8 in efivarfs instead of open coding a bad version lib/ucs2_string: Add ucs2 -> utf8 helper functions
2016-02-19Merge tag 'ext4_for_linus_stable' of ↵Linus Torvalds13-39/+176
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 bugfixes from Ted Ts'o: "Miscellaneous ext4 bug fixes for v4.5" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: fix crashes in dioread_nolock mode ext4: fix bh->b_state corruption ext4: fix memleak in ext4_readdir() ext4: remove unused parameter "newblock" in convert_initialized_extent() ext4: don't read blocks from disk after extents being swapped ext4: fix potential integer overflow ext4: add a line break for proc mb_groups display ext4: ioctl: fix erroneous return value ext4: fix scheduling in atomic on group checksum failure ext4 crypto: move context consistency check to ext4_file_open() ext4 crypto: revalidate dentry after adding or removing the key
2016-02-19Merge branch 'for-linus-4.5' of ↵Linus Torvalds1-0/+2
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fix from Chris Mason: "My for-linus-4.5 branch has a btrfs DIO error passing fix. I know how much you love DIO, so I'm going to suggest against reading it. We'll follow up with a patch to drop the error arg from dio_end_io in the next merge window." * 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: fix direct IO requests not reporting IO error to user space
2016-02-19Merge branch 'akpm' (patches from Andrew)Linus Torvalds1-14/+39
Merge fixes from Andrew Morton: "10 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm: slab: free kmem_cache_node after destroy sysfs file ipc/shm: handle removed segments gracefully in shm_mmap() MAINTAINERS: update Kselftest Framework mailing list devm_memremap_release(): fix memremap'd addr handling mm/hugetlb.c: fix incorrect proc nr_hugepages value mm, x86: fix pte_page() crash in gup_pte_range() fsnotify: turn fsnotify reaper thread into a workqueue job Revert "fsnotify: destroy marks with call_srcu instead of dedicated thread" mm: fix regression in remap_file_pages() emulation thp, dax: do not try to withdraw pgtable from non-anon VMA
2016-02-19ext4: fix crashes in dioread_nolock modeJan Kara1-20/+20
Competing overwrite DIO in dioread_nolock mode will just overwrite pointer to io_end in the inode. This may result in data corruption or extent conversion happening from IO completion interrupt because we don't properly set buffer_defer_completion() when unlocked DIO races with locked DIO to unwritten extent. Since unlocked DIO doesn't need io_end for anything, just avoid allocating it and corrupting pointer from inode for locked DIO. A cleaner fix would be to avoid these games with io_end pointer from the inode but that requires more intrusive changes so we leave that for later. Cc: stable@vger.kernel.org Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-19ext4: fix bh->b_state corruptionJan Kara1-2/+30
ext4 can update bh->b_state non-atomically in _ext4_get_block() and ext4_da_get_block_prep(). Usually this is fine since bh is just a temporary storage for mapping information on stack but in some cases it can be fully living bh attached to a page. In such case non-atomic update of bh->b_state can race with an atomic update which then gets lost. Usually when we are mapping bh and thus updating bh->b_state non-atomically, nobody else touches the bh and so things work out fine but there is one case to especially worry about: ext4_finish_bio() uses BH_Uptodate_Lock on the first bh in the page to synchronize handling of PageWriteback state. So when blocksize < pagesize, we can be atomically modifying bh->b_state of a buffer that actually isn't under IO and thus can race e.g. with delalloc trying to map that buffer. The result is that we can mistakenly set / clear BH_Uptodate_Lock bit resulting in the corruption of PageWriteback state or missed unlock of BH_Uptodate_Lock. Fix the problem by always updating bh->b_state bits atomically. CC: stable@vger.kernel.org Reported-by: Nikolay Borisov <kernel@kyup.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-18fsnotify: turn fsnotify reaper thread into a workqueue jobJeff Layton1-31/+18
We don't require a dedicated thread for fsnotify cleanup. Switch it over to a workqueue job instead that runs on the system_unbound_wq. In the interest of not thrashing the queued job too often when there are a lot of marks being removed, we delay the reaper job slightly when queueing it, to allow several to gather on the list. Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Tested-by: Eryu Guan <guaneryu@gmail.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Eric Paris <eparis@parisplace.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-18Revert "fsnotify: destroy marks with call_srcu instead of dedicated thread"Jeff Layton1-14/+52
This reverts commit c510eff6beba ("fsnotify: destroy marks with call_srcu instead of dedicated thread"). Eryu reported that he was seeing some OOM kills kick in when running a testcase that adds and removes inotify marks on a file in a tight loop. The above commit changed the code to use call_srcu to clean up the marks. While that does (in principle) work, the srcu callback job is limited to cleaning up entries in small batches and only once per jiffy. It's easily possible to overwhelm that machinery with too many call_srcu callbacks, and Eryu's reproduer did just that. There's also another potential problem with using call_srcu here. While you can obviously sleep while holding the srcu_read_lock, the callbacks run under local_bh_disable, so you can't sleep there. It's possible when putting the last reference to the fsnotify_mark that we'll end up putting a chain of references including the fsnotify_group, uid, and associated keys. While I don't see any obvious ways that that could occurs, it's probably still best to avoid using call_srcu here after all. This patch reverts the above patch. A later patch will take a different approach to eliminated the dedicated thread here. Signed-off-by: Jeff Layton <jeff.layton@primarydata.com> Reported-by: Eryu Guan <guaneryu@gmail.com> Tested-by: Eryu Guan <guaneryu@gmail.com> Cc: Jan Kara <jack@suse.com> Cc: Eric Paris <eparis@parisplace.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-17Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds3-5/+18
Pull block fixes from Jens Axboe: "A collection of fixes from the past few weeks that should go into 4.5. This contains: - Overflow fix for sysfs discard show function from Alan. - A stacking limit init fix for max_dev_sectors, so we don't end up artificially capping some use cases. From Keith. - Have blk-mq proper end unstarted requests on a dying queue, instead of pushing that to the driver. From Keith. - NVMe: - Update to Kconfig description for NVME_SCSI, since it was vague and having it on is important for some SUSE distros. From Christoph. - Set of fixes from Keith, around surprise removal. Also kills the no-merge flag, so it supports merging. - Set of fixes for lightnvm from Matias, Javier, and Wenwei. - Fix null_blk oops when asked for lightnvm, but not available. From Matias. - Copy-to-user EINTR fix from Hannes, fixing a case where SG_IO fails if interrupted by a signal. - Two floppy fixes from Jiri, fixing signal handling and blocking open. - A use-after-free fix for O_DIRECT, from Mike Krinkin. - A block module ref count fix from Roman Pen. - An fs IO wait accounting fix for O_DSYNC from Stephane Gasparini. - Smaller reallo fix for xen-blkfront from Bob Liu. - Removal of an unused struct member in the deadline IO scheduler, from Tahsin. - Also from Tahsin, properly initialize inode struct members associated with cgroup writeback, if enabled. - From Tejun, ensure that we keep the superblock pinned during cgroup writeback" * 'for-linus' of git://git.kernel.dk/linux-block: (25 commits) blk: fix overflow in queue_discard_max_hw_show writeback: initialize inode members that track writeback history writeback: keep superblock pinned during cgroup writeback association switches bio: return EINTR if copying to user space got interrupted NVMe: Rate limit nvme IO warnings NVMe: Poll device while still active during remove NVMe: Requeue requests on suspended queues NVMe: Allow request merges NVMe: Fix io incapable return values blk-mq: End unstarted requests on dying queue block: Initialize max_dev_sectors to 0 null_blk: oops when initializing without lightnvm block: fix module reference leak on put_disk() call for cgroups throttle nvme: fix Kconfig description for BLK_DEV_NVME_SCSI kernel/fs: fix I/O wait not accounted for RW O_DSYNC floppy: refactor open() flags handling lightnvm: allow to force mm initialization lightnvm: check overflow and correct mlc pairs lightnvm: fix request intersection locking in rrpc lightnvm: warn if irqs are disabled in lock laddr ...
2016-02-16writeback: initialize inode members that track writeback historyTahsin Erdogan1-0/+6
inode struct members that track cgroup writeback information should be reinitialized when inode gets allocated from kmem_cache. Otherwise, their values remain and get used by the new inode. Signed-off-by: Tahsin Erdogan <tahsin@google.com> Acked-by: Tejun Heo <tj@kernel.org> Fixes: d10c80955265 ("writeback: implement foreign cgroup inode bdi_writeback switching") Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-16Merge branch 'for-next' of git://git.samba.org/sfrench/cifs-2.6Linus Torvalds3-4/+3
Pull cifs fixes from Steve French: "A small set of cifs fixes. I am still reviewing some more, recently submitted SMB3 fixes, but these three are small and safe and ready now" * 'for-next' of git://git.samba.org/sfrench/cifs-2.6: cifs: fix erroneous return value cifs: fix potential overflow in cifs_compose_mount_options cifs: remove redundant check for null string pointer
2016-02-16writeback: keep superblock pinned during cgroup writeback association switchesTejun Heo1-4/+11
If cgroup writeback is in use, an inode is associated with a cgroup for writeback. If the inode's main dirtier changes to another cgroup, the association gets updated asynchronously. Nothing was pinning the superblock while such switches are in progress and superblock could go away while async switching is pending or in progress leading to crashes like the following. kernel BUG at fs/jbd2/transaction.c:319! invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC CPU: 1 PID: 29158 Comm: kworker/1:10 Not tainted 4.5.0-rc3 #51 Hardware name: Google Google, BIOS Google 01/01/2011 Workqueue: events inode_switch_wbs_work_fn task: ffff880213dbbd40 ti: ffff880209264000 task.ti: ffff880209264000 RIP: 0010:[<ffffffff803e6922>] [<ffffffff803e6922>] start_this_handle+0x382/0x3e0 RSP: 0018:ffff880209267c30 EFLAGS: 00010202 ... Call Trace: [<ffffffff803e6be4>] jbd2__journal_start+0xf4/0x190 [<ffffffff803cfc7e>] __ext4_journal_start_sb+0x4e/0x70 [<ffffffff803b31ec>] ext4_evict_inode+0x12c/0x3d0 [<ffffffff8035338b>] evict+0xbb/0x190 [<ffffffff80354190>] iput+0x130/0x190 [<ffffffff80360223>] inode_switch_wbs_work_fn+0x343/0x4c0 [<ffffffff80279819>] process_one_work+0x129/0x300 [<ffffffff80279b16>] worker_thread+0x126/0x480 [<ffffffff8027ed14>] kthread+0xc4/0xe0 [<ffffffff809771df>] ret_from_fork+0x3f/0x70 Fix it by bumping s_active while cgroup association switching is in flight. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-and-tested-by: Tahsin Erdogan <tahsin@google.com> Link: http://lkml.kernel.org/g/CAAeU0aNCq7LGODvVGRU-oU_o-6enii5ey0p1c26D1ZzYwkDc5A@mail.gmail.com Fixes: d10c80955265 ("writeback: implement foreign cgroup inode bdi_writeback switching") Cc: stable@vger.kernel.org #v4.5+ Signed-off-by: Jens Axboe <axboe@fb.com>
2016-02-16Merge tag 'efi-urgent' of ↵Ingo Molnar4-18/+101
git://git.kernel.org/pub/scm/linux/kernel/git/mfleming/efi into x86/urgent Pull EFI fixes from Matt Fleming: * Prevent accidental deletion of EFI variables through efivarfs that may brick machines. We use a whitelist of known-safe variables to allow things like installing distributions to work out of the box, and instead restrict vendor-specific variable deletion by making non-whitelist variables immutable (Peter Jones) Signed-off-by: Ingo Molnar <mingo@kernel.org>
2016-02-16ext4: fix memleak in ext4_readdir()Kirill Tkhai1-2/+5
When ext4_bread() fails, fname_crypto_str remains allocated after return. Fix that. Signed-off-by: Kirill Tkhai <ktkhai@virtuozzo.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> CC: Dmitry Monakhov <dmonakhov@virtuozzo.com>
2016-02-16Btrfs: fix direct IO requests not reporting IO error to user spaceFilipe Manana1-0/+2
If a bio for a direct IO request fails, we were not setting the error in the parent bio (the main DIO bio), making us not return the error to user space in btrfs_direct_IO(), that is, it made __blockdev_direct_IO() return the number of bytes issued for IO and not the error a bio created and submitted by btrfs_submit_direct() got from the block layer. This essentially happens because when we call: dio_end_io(dio_bio, bio->bi_error); It does not set dio_bio->bi_error to the value of the second argument. So just add this missing assignment in endio callbacks, just as we do in the error path at btrfs_submit_direct() when we fail to clone the dio bio or allocate its private object. This follows the convention of what is done with other similar APIs such as bio_endio() where the caller is responsible for setting the bi_error field in the bio it passes as an argument to bio_endio(). This was detected by the new generic test cases in xfstests: 271, 272, 276 and 278. Which essentially setup a dm error target, then load the error table, do a direct IO write and unload the error table. They expect the write to fail with -EIO, which was not getting reported when testing against btrfs. Cc: stable@vger.kernel.org # 4.3+ Fixes: 4246a0b63bd8 ("block: add a bi_error field to struct bio") Signed-off-by: Filipe Manana <fdmanana@suse.com>
2016-02-14Merge tag 'tty-4.5-rc4' of ↵Linus Torvalds1-0/+20
git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty Pull tty/serial fixes from Greg KH: "Here are a number of small tty and serial driver fixes for 4.5-rc4 that resolve some reported issues. One of them got reverted as it wasn't correct based on testing, and all have been in linux-next for a while" * tag 'tty-4.5-rc4' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty: Revert "8250: uniphier: allow modular build with 8250 console" pty: make sure super_block is still valid in final /dev/tty close pty: fix possible use after free of tty->driver_data tty: Add support for PCIe WCH382 2S multi-IO card serial/omap: mark wait_for_xmitr as __maybe_unused serial: omap: Prevent DoS using unprivileged ioctl(TIOCSRS485) 8250: uniphier: allow modular build with 8250 console tty: Drop krefs for interrupted tty lock
2016-02-12Merge branch 'for-linus-4.5' of ↵Linus Torvalds8-71/+131
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "This has a few fixes from Filipe, along with a readdir fix from Dave that we've been testing for some time" * 'for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: btrfs: properly set the termination value of ctx->pos in readdir Btrfs: fix hang on extent buffer lock caused by the inode_paths ioctl Btrfs: remove no longer used function extent_read_full_page_nolock() Btrfs: fix page reading in extent_same ioctl leading to csum errors Btrfs: fix invalid page accesses in extent_same (dedup) ioctl
2016-02-12Merge tag 'xfs-fixes-for-linus-4.5' of ↵Linus Torvalds1-2/+2
git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs Pull xfs fix from Dve Chinner: "This contains a fix for an endian conversion issue in new CRC validation in log recovery that was discovered on a ppc64 platform" * tag 'xfs-fixes-for-linus-4.5' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs: xfs: fix endianness error when checking log block crc on big endian platforms
2016-02-12ext4: remove unused parameter "newblock" in convert_initialized_extent()Eryu Guan1-2/+2
The "newblock" parameter is not used in convert_initialized_extent(), remove it. Signed-off-by: Eryu Guan <guaneryu@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-12ext4: don't read blocks from disk after extents being swappedEryu Guan1-3/+12
I notice ext4/307 fails occasionally on ppc64 host, reporting md5 checksum mismatch after moving data from original file to donor file. The reason is that move_extent_per_page() calls __block_write_begin() and block_commit_write() to write saved data from original inode blocks to donor inode blocks, but __block_write_begin() not only maps buffer heads but also reads block content from disk if the size is not block size aligned. At this time the physical block number in mapped buffer head is pointing to the donor file not the original file, and that results in reading wrong data to page, which get written to disk in following block_commit_write call. This also can be reproduced by the following script on 1k block size ext4 on x86_64 host: mnt=/mnt/ext4 donorfile=$mnt/donor testfile=$mnt/testfile e4compact=~/xfstests/src/e4compact rm -f $donorfile $testfile # reserve space for donor file, written by 0xaa and sync to disk to # avoid EBUSY on EXT4_IOC_MOVE_EXT xfs_io -fc "pwrite -S 0xaa 0 1m" -c "fsync" $donorfile # create test file written by 0xbb xfs_io -fc "pwrite -S 0xbb 0 1023" -c "fsync" $testfile # compute initial md5sum md5sum $testfile | tee md5sum.txt # drop cache, force e4compact to read data from disk echo 3 > /proc/sys/vm/drop_caches # test defrag echo "$testfile" | $e4compact -i -v -f $donorfile # check md5sum md5sum -c md5sum.txt Fix it by creating & mapping buffer heads only but not reading blocks from disk, because all the data in page is guaranteed to be up-to-date in mext_page_mkuptodate(). Cc: stable@vger.kernel.org Signed-off-by: Eryu Guan <guaneryu@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-12ext4: fix potential integer overflowInsu Yun1-1/+1
Since sizeof(ext_new_group_data) > sizeof(ext_new_flex_group_data), integer overflow could be happened. Therefore, need to fix integer overflow sanitization. Cc: stable@vger.kernel.org Signed-off-by: Insu Yun <wuninsu@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-12ext4: add a line break for proc mb_groups displayHuaitong Han1-1/+1
This patch adds a line break for proc mb_groups display. Signed-off-by: Huaitong Han <huaitong.han@intel.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Andreas Dilger <adilger@dilger.ca>
2016-02-11ext4: ioctl: fix erroneous return valueAnton Protopopov1-1/+1
The ext4_ioctl_setflags() function which is used in the ioctls EXT4_IOC_SETFLAGS and EXT4_IOC_FSSETXATTR may return the positive value EPERM instead of -EPERM in case of error. This bug was introduced by a recent commit 9b7365fc. The following program can be used to illustrate the wrong behavior: #include <sys/types.h> #include <sys/ioctl.h> #include <sys/stat.h> #include <fcntl.h> #include <err.h> #define FS_IOC_GETFLAGS _IOR('f', 1, long) #define FS_IOC_SETFLAGS _IOW('f', 2, long) #define FS_IMMUTABLE_FL 0x00000010 int main(void) { int fd; long flags; fd = open("file", O_RDWR|O_CREAT, 0600); if (fd < 0) err(1, "open"); if (ioctl(fd, FS_IOC_GETFLAGS, &flags) < 0) err(1, "ioctl: FS_IOC_GETFLAGS"); flags |= FS_IMMUTABLE_FL; if (ioctl(fd, FS_IOC_SETFLAGS, &flags) < 0) err(1, "ioctl: FS_IOC_SETFLAGS"); warnx("ioctl returned no error"); return 0; } Running it gives the following result: $ strace -e ioctl ./test ioctl(3, FS_IOC_GETFLAGS, 0x7ffdbd8bfd38) = 0 ioctl(3, FS_IOC_SETFLAGS, 0x7ffdbd8bfd38) = 1 test: ioctl returned no error +++ exited with 0 +++ Running the program on a kernel with the bug fixed gives the proper result: $ strace -e ioctl ./test ioctl(3, FS_IOC_GETFLAGS, 0x7ffdd2768258) = 0 ioctl(3, FS_IOC_SETFLAGS, 0x7ffdd2768258) = -1 EPERM (Operation not permitted) test: ioctl: FS_IOC_SETFLAGS: Operation not permitted +++ exited with 1 +++ Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-11ext4: fix scheduling in atomic on group checksum failureJan Kara2-5/+8
When block group checksum is wrong, we call ext4_error() while holding group spinlock from ext4_init_block_bitmap() or ext4_init_inode_bitmap() which results in scheduling while in atomic. Fix the issue by calling ext4_error() later after dropping the spinlock. CC: stable@vger.kernel.org Reported-by: Dmitry Vyukov <dvyukov@google.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Theodore Ts'o <tytso@mit.edu> Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
2016-02-11btrfs: properly set the termination value of ctx->pos in readdirDavid Sterba3-3/+16
The value of ctx->pos in the last readdir call is supposed to be set to INT_MAX due to 32bit compatibility, unless 'pos' is intentially set to a larger value, then it's LLONG_MAX. There's a report from PaX SIZE_OVERFLOW plugin that "ctx->pos++" overflows (https://forums.grsecurity.net/viewtopic.php?f=1&t=4284), on a 64bit arch, where the value is 0x7fffffffffffffff ie. LLONG_MAX before the increment. We can get to that situation like that: * emit all regular readdir entries * still in the same call to readdir, bump the last pos to INT_MAX * next call to readdir will not emit any entries, but will reach the bump code again, finds pos to be INT_MAX and sets it to LLONG_MAX Normally this is not a problem, but if we call readdir again, we'll find 'pos' set to LLONG_MAX and the unconditional increment will overflow. The report from Victor at (http://thread.gmane.org/gmane.comp.file-systems.btrfs/49500) with debugging print shows that pattern: Overflow: e Overflow: 7fffffff Overflow: 7fffffffffffffff PAX: size overflow detected in function btrfs_real_readdir fs/btrfs/inode.c:5760 cicus.935_282 max, count: 9, decl: pos; num: 0; context: dir_context; CPU: 0 PID: 2630 Comm: polkitd Not tainted 4.2.3-grsec #1 Hardware name: Gigabyte Technology Co., Ltd. H81ND2H/H81ND2H, BIOS F3 08/11/2015 ffffffff81901608 0000000000000000 ffffffff819015e6 ffffc90004973d48 ffffffff81742f0f 0000000000000007 ffffffff81901608 ffffc90004973d78 ffffffff811cb706 0000000000000000 ffff8800d47359e0 ffffc90004973ed8 Call Trace: [<ffffffff81742f0f>] dump_stack+0x4c/0x7f [<ffffffff811cb706>] report_size_overflow+0x36/0x40 [<ffffffff812ef0bc>] btrfs_real_readdir+0x69c/0x6d0 [<ffffffff811dafc8>] iterate_dir+0xa8/0x150 [<ffffffff811e6d8d>] ? __fget_light+0x2d/0x70 [<ffffffff811dba3a>] SyS_getdents+0xba/0x1c0 Overflow: 1a [<ffffffff811db070>] ? iterate_dir+0x150/0x150 [<ffffffff81749b69>] entry_SYSCALL_64_fastpath+0x12/0x83 The jump from 7fffffff to 7fffffffffffffff happens when new dir entries are not yet synced and are processed from the delayed list. Then the code could go to the bump section again even though it might not emit any new dir entries from the delayed list. The fix avoids entering the "bump" section again once we've finished emitting the entries, both for synced and delayed entries. References: https://forums.grsecurity.net/viewtopic.php?f=1&t=4284 Reported-by: Victor <services@swwu.com> CC: stable@vger.kernel.org Signed-off-by: David Sterba <dsterba@suse.com> Tested-by: Holger Hoffstätte <holger.hoffstaette@googlemail.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-10cifs: fix erroneous return valueAnton Protopopov1-1/+1
The setup_ntlmv2_rsp() function may return positive value ENOMEM instead of -ENOMEM in case of kmalloc failure. Signed-off-by: Anton Protopopov <a.s.protopopov@gmail.com> CC: Stable <stable@vger.kernel.org> Signed-off-by: Steve French <smfrench@gmail.com>
2016-02-10cifs: fix potential overflow in cifs_compose_mount_optionsInsu Yun1-1/+1
In worst case, "ip=" + sb_mountdata + ipv6 can be copied into mountdata. Therefore, for safe, it is better to add more size when allocating memory. Signed-off-by: Insu Yun <wuninsu@gmail.com> Signed-off-by: Steve French <smfrench@gmail.com>
2016-02-10cifs: remove redundant check for null string pointerColin Ian King1-2/+1
server_RFC1001_name is declared as a RFC1001_NAME_LEN_WITH_NULL sized char array in struct TCP_Server_Info so the null pointer check on server_RFC1001_name is redundant and can be removed. Detected with smatch: fs/cifs/connect.c:2982 ip_rfc1001_connect() warn: this array is probably non-NULL. 'server->server_RFC1001_name' Signed-off-by: Colin Ian King <colin.king@canonical.com> Signed-off-by: Steve French <smfrench@gmail.com>
2016-02-10efi: Make efivarfs entries immutable by defaultPeter Jones4-14/+98
"rm -rf" is bricking some peoples' laptops because of variables being used to store non-reinitializable firmware driver data that's required to POST the hardware. These are 100% bugs, and they need to be fixed, but in the mean time it shouldn't be easy to *accidentally* brick machines. We have to have delete working, and picking which variables do and don't work for deletion is quite intractable, so instead make everything immutable by default (except for a whitelist), and make tools that aren't quite so broad-spectrum unset the immutable flag. Signed-off-by: Peter Jones <pjones@redhat.com> Tested-by: Lee, Chun-Yi <jlee@suse.com> Acked-by: Matthew Garrett <mjg59@coreos.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-02-10efi: Use ucs2_as_utf8 in efivarfs instead of open coding a bad versionPeter Jones1-4/+3
Translate EFI's UCS-2 variable names to UTF-8 instead of just assuming all variable names fit in ASCII. Signed-off-by: Peter Jones <pjones@redhat.com> Acked-by: Matthew Garrett <mjg59@coreos.com> Tested-by: Lee, Chun-Yi <jlee@suse.com> Signed-off-by: Matt Fleming <matt@codeblueprint.co.uk>
2016-02-08ext4 crypto: move context consistency check to ext4_file_open()Theodore Ts'o2-2/+15
In the case where the per-file key for the directory is cached, but root does not have access to the key needed to derive the per-file key for the files in the directory, we allow the lookup to succeed, so that lstat(2) and unlink(2) can suceed. However, if a program tries to open the file, it will get an ENOKEY error. Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-07ext4 crypto: revalidate dentry after adding or removing the keyTheodore Ts'o4-0/+81
Add a validation check for dentries for encrypted directory to make sure we're not caching stale data after a key has been added or removed. Also check to make sure that status of the encryption key is updated when readdir(2) is executed. Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2016-02-08xfs: fix endianness error when checking log block crc on big endian platformsDarrick J. Wong1-2/+2
Since the checksum function and the field are both __le32, don't perform endian conversion when comparing the two. This fixes mount failures on ppc64. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-02-06pty: make sure super_block is still valid in final /dev/tty closeHerton R. Krzesinski1-0/+20
Considering current pty code and multiple devpts instances, it's possible to umount a devpts file system while a program still has /dev/tty opened pointing to a previosuly closed pty pair in that instance. In the case all ptmx and pts/N files are closed, umount can be done. If the program closes /dev/tty after umount is done, devpts_kill_index will use now an invalid super_block, which was already destroyed in the umount operation after running ->kill_sb. This is another "use after free" type of issue, but now related to the allocated super_block instance. To avoid the problem (warning at ida_remove and potential crashes) for this specific case, I added two functions in devpts which grabs additional references to the super_block, which pty code now uses so it makes sure the super block structure is still valid until pty shutdown is done. I also moved the additional inode references to the same functions, which also covered similar case with inode being freed before /dev/tty final close/shutdown. Signed-off-by: Herton R. Krzesinski <herton@redhat.com> Cc: stable@vger.kernel.org # 2.6.29+ Reviewed-by: Peter Hurley <peter@hurleysoftware.com> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-02-05Merge branch 'akpm' (patches from Andrew)Linus Torvalds4-8/+43
Merge fixes from Andrew Morton: "22 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: (22 commits) epoll: restrict EPOLLEXCLUSIVE to POLLIN and POLLOUT radix-tree: fix oops after radix_tree_iter_retry MAINTAINERS: trim the file triggers for ABI/API dax: dirty inode only if required thp: make deferred_split_scan() work again mm: replace vma_lock_anon_vma with anon_vma_lock_read/write ocfs2/dlm: clear refmap bit of recovery lock while doing local recovery cleanup um: asm/page.h: remove the pte_high member from struct pte_t mm, hugetlb: don't require CMA for runtime gigantic pages mm/hugetlb: fix gigantic page initialization/allocation mm: downgrade VM_BUG in isolate_lru_page() to warning mempolicy: do not try to queue pages from !vma_migratable() mm, vmstat: fix wrong WQ sleep when memory reclaim doesn't make any progress vmstat: make vmstat_update deferrable mm, vmstat: make quiet_vmstat lighter mm/Kconfig: correct description of DEFERRED_STRUCT_PAGE_INIT memblock: don't mark memblock_phys_mem_size() as __init dump_stack: avoid potential deadlocks mm: validate_mm browse_rb SMP race condition m32r: fix build failure due to SMP and MMU ...
2016-02-05Merge branch 'for-linus' of ↵Linus Torvalds1-3/+3
git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client Pull Ceph fixes from Sage Weil: "We have a few wire protocol compatibility fixes, ports of a few recent CRUSH mapping changes, and a couple error path fixes" * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: libceph: MOSDOpReply v7 encoding libceph: advertise support for TUNABLES5 crush: decode and initialize chooseleaf_stable crush: add chooseleaf_stable tunable crush: ensure take bucket value is valid crush: ensure bucket id is valid before indexing buckets array ceph: fix snap context leak in error path ceph: checking for IS_ERR instead of NULL
2016-02-05epoll: restrict EPOLLEXCLUSIVE to POLLIN and POLLOUTJason Baron1-6/+32
In the current implementation of the EPOLLEXCLUSIVE flag (added for 4.5-rc1), if epoll waiters create different POLL* sets and register them as exclusive against the same target fd, the current implementation will stop waking any further waiters once it finds the first idle waiter. This means that waiters could miss wakeups in certain cases. For example, when we wake up a pipe for reading we do: wake_up_interruptible_sync_poll(&pipe->wait, POLLIN | POLLRDNORM); So if one epoll set or epfd is added to pipe p with POLLIN and a second set epfd2 is added to pipe p with POLLRDNORM, only epfd may receive the wakeup since the current implementation will stop after it finds any intersection of events with a waiter that is blocked in epoll_wait(). We could potentially address this by requiring all epoll waiters that are added to p be required to pass the same set of POLL* events. IE the first EPOLL_CTL_ADD that passes EPOLLEXCLUSIVE establishes the set POLL* flags to be used by any other epfds that are added as EPOLLEXCLUSIVE. However, I think it might be somewhat confusing interface as we would have to reference count the number of users for that set, and so userspace would have to keep track of that count, or we would need a more involved interface. It also adds some shared state that we'd have store somewhere. I don't think anybody will want to bloat __wait_queue_head for this. I think what we could do instead, is to simply restrict EPOLLEXCLUSIVE such that it can only be specified with EPOLLIN and/or EPOLLOUT. So that way if the wakeup includes 'POLLIN' and not 'POLLOUT', we can stop once we hit the first idle waiter that specifies the EPOLLIN bit, since any remaining waiters that only have 'POLLOUT' set wouldn't need to be woken. Likewise, we can do the same thing if 'POLLOUT' is in the wakeup bit set and not 'POLLIN'. If both 'POLLOUT' and 'POLLIN' are set in the wake bit set (there is at least one example of this I saw in fs/pipe.c), then we just wake the entire exclusive list. Having both 'POLLOUT' and 'POLLIN' both set should not be on any performance critical path, so I think that's ok (in fs/pipe.c its in pipe_release()). We also continue to include EPOLLERR and EPOLLHUP by default in any exclusive set. Thus, the user can specify EPOLLERR and/or EPOLLHUP but is not required to do so. Since epoll waiters may be interested in other events as well besides EPOLLIN, EPOLLOUT, EPOLLERR and EPOLLHUP, these can still be added by doing a 'dup' call on the target fd and adding that as one normally would with EPOLL_CTL_ADD. Since I think that the POLLIN and POLLOUT events are what we are interest in balancing, I think that the 'dup' thing could perhaps be added to only one of the waiter threads. However, I think that EPOLLIN, EPOLLOUT, EPOLLERR and EPOLLHUP should be sufficient for the majority of use-cases. Since EPOLLEXCLUSIVE is intended to be used with a target fd shared among multiple epfds, where between 1 and n of the epfds may receive an event, it does not satisfy the semantics of EPOLLONESHOT where only 1 epfd would get an event. Thus, it is not allowed to be specified in conjunction with EPOLLEXCLUSIVE. EPOLL_CTL_MOD is also not allowed if the fd was previously added as EPOLLEXCLUSIVE. It seems with the limited number of flags to not be as interesting, but this could be relaxed at some further point. Signed-off-by: Jason Baron <jbaron@akamai.com> Tested-by: Madars Vitolins <m@silodev.com> Cc: Michael Kerrisk <mtk.manpages@gmail.com> Cc: Ingo Molnar <mingo@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Al Viro <viro@ftp.linux.org.uk> Cc: Eric Wong <normalperson@yhbt.net> Cc: Jonathan Corbet <corbet@lwn.net> Cc: Andy Lutomirski <luto@amacapital.net> Cc: Hagen Paul Pfeifer <hagen@jauu.net> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05dax: dirty inode only if requiredDmitry Monakhov1-1/+2
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org> Reviewed-by: Jan Kara <jack@suse.cz> Reviewed-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Matthew Wilcox <matthew.r.wilcox@intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05ocfs2/dlm: clear refmap bit of recovery lock while doing local recovery cleanupxuejiufei1-0/+2
When recovery master down, dlm_do_local_recovery_cleanup() only remove the $RECOVERY lock owned by dead node, but do not clear the refmap bit. Which will make umount thread falling in dead loop migrating $RECOVERY to the dead node. Signed-off-by: xuejiufei <xuejiufei@huawei.com> Reviewed-by: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Junxiao Bi <junxiao.bi@oracle.com> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05block: fix pfn_mkwrite() DAX fault handlerRoss Zwisler1-1/+7
Previously the pfn_mkwrite() fault handler for raw block devices called bldev_dax_fault() -> __dax_fault() to do a full DAX page fault. Really what the pfn_mkwrite() fault handler needs to do is call dax_pfn_mkwrite() to make sure that the radix tree entry for the given PTE is marked as dirty so that a follow-up fsync or msync call will flush it durably to media. Fixes: 5a023cdba50c ("block: enable dax for raw block devices") Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Alexander Viro <viro@zeniv.linux.org.uk> Cc: Dan Williams <dan.j.williams@intel.com> Cc: Dave Chinner <david@fromorbit.com> Reviewed-by: Jan Kara <jack@suse.cz> Cc: Matthew Wilcox <willy@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-02-05Btrfs: fix hang on extent buffer lock caused by the inode_paths ioctlFilipe Manana1-4/+6
While doing some tests I ran into an hang on an extent buffer's rwlock that produced the following trace: [39389.800012] NMI watchdog: BUG: soft lockup - CPU#15 stuck for 22s! [fdm-stress:32166] [39389.800016] NMI watchdog: BUG: soft lockup - CPU#14 stuck for 22s! [fdm-stress:32165] [39389.800016] Modules linked in: btrfs dm_mod ppdev xor sha256_generic hmac raid6_pq drbg ansi_cprng aesni_intel i2c_piix4 acpi_cpufreq aes_x86_64 ablk_helper tpm_tis parport_pc i2c_core sg cryptd evdev psmouse lrw tpm parport gf128mul serio_raw pcspkr glue_helper processor button loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel scsi_mod e1000 virtio floppy [last unloaded: btrfs] [39389.800016] irq event stamp: 0 [39389.800016] hardirqs last enabled at (0): [< (null)>] (null) [39389.800016] hardirqs last disabled at (0): [<ffffffff8104e58d>] copy_process+0x638/0x1a35 [39389.800016] softirqs last enabled at (0): [<ffffffff8104e58d>] copy_process+0x638/0x1a35 [39389.800016] softirqs last disabled at (0): [< (null)>] (null) [39389.800016] CPU: 14 PID: 32165 Comm: fdm-stress Not tainted 4.4.0-rc6-btrfs-next-18+ #1 [39389.800016] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [39389.800016] task: ffff880175b1ca40 ti: ffff8800a185c000 task.ti: ffff8800a185c000 [39389.800016] RIP: 0010:[<ffffffff810902af>] [<ffffffff810902af>] queued_spin_lock_slowpath+0x57/0x158 [39389.800016] RSP: 0018:ffff8800a185fb80 EFLAGS: 00000202 [39389.800016] RAX: 0000000000000101 RBX: ffff8801710c4e9c RCX: 0000000000000101 [39389.800016] RDX: 0000000000000100 RSI: 0000000000000001 RDI: 0000000000000001 [39389.800016] RBP: ffff8800a185fb98 R08: 0000000000000001 R09: 0000000000000000 [39389.800016] R10: ffff8800a185fb68 R11: 6db6db6db6db6db7 R12: ffff8801710c4e98 [39389.800016] R13: ffff880175b1ca40 R14: ffff8800a185fc10 R15: ffff880175b1ca40 [39389.800016] FS: 00007f6d37fff700(0000) GS:ffff8802be9c0000(0000) knlGS:0000000000000000 [39389.800016] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [39389.800016] CR2: 00007f6d300019b8 CR3: 0000000037c93000 CR4: 00000000001406e0 [39389.800016] Stack: [39389.800016] ffff8801710c4e98 ffff8801710c4e98 ffff880175b1ca40 ffff8800a185fbb0 [39389.800016] ffffffff81091e11 ffff8801710c4e98 ffff8800a185fbc8 ffffffff81091895 [39389.800016] ffff8801710c4e98 ffff8800a185fbe8 ffffffff81486c5c ffffffffa067288c [39389.800016] Call Trace: [39389.800016] [<ffffffff81091e11>] queued_read_lock_slowpath+0x46/0x60 [39389.800016] [<ffffffff81091895>] do_raw_read_lock+0x3e/0x41 [39389.800016] [<ffffffff81486c5c>] _raw_read_lock+0x3d/0x44 [39389.800016] [<ffffffffa067288c>] ? btrfs_tree_read_lock+0x54/0x125 [btrfs] [39389.800016] [<ffffffffa067288c>] btrfs_tree_read_lock+0x54/0x125 [btrfs] [39389.800016] [<ffffffffa0622ced>] ? btrfs_find_item+0xa7/0xd2 [btrfs] [39389.800016] [<ffffffffa069363f>] btrfs_ref_to_path+0xd6/0x174 [btrfs] [39389.800016] [<ffffffffa0693730>] inode_to_path+0x53/0xa2 [btrfs] [39389.800016] [<ffffffffa0693e2e>] paths_from_inode+0x117/0x2ec [btrfs] [39389.800016] [<ffffffffa0670cff>] btrfs_ioctl+0xd5b/0x2793 [btrfs] [39389.800016] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [39389.800016] [<ffffffff81276727>] ? __this_cpu_preempt_check+0x13/0x15 [39389.800016] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [39389.800016] [<ffffffff8118b3d4>] ? rcu_read_unlock+0x3e/0x5d [39389.800016] [<ffffffff811822f8>] do_vfs_ioctl+0x42b/0x4ea [39389.800016] [<ffffffff8118b4f3>] ? __fget_light+0x62/0x71 [39389.800016] [<ffffffff8118240e>] SyS_ioctl+0x57/0x79 [39389.800016] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [39389.800016] Code: b9 01 01 00 00 f7 c6 00 ff ff ff 75 32 83 fe 01 89 ca 89 f0 0f 45 d7 f0 0f b1 13 39 f0 74 04 89 c6 eb e2 ff ca 0f 84 fa 00 00 00 <8b> 03 84 c0 74 04 f3 90 eb f6 66 c7 03 01 00 e9 e6 00 00 00 e8 [39389.800012] Modules linked in: btrfs dm_mod ppdev xor sha256_generic hmac raid6_pq drbg ansi_cprng aesni_intel i2c_piix4 acpi_cpufreq aes_x86_64 ablk_helper tpm_tis parport_pc i2c_core sg cryptd evdev psmouse lrw tpm parport gf128mul serio_raw pcspkr glue_helper processor button loop autofs4 ext4 crc16 mbcache jbd2 sd_mod sr_mod cdrom ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring crc32c_intel scsi_mod e1000 virtio floppy [last unloaded: btrfs] [39389.800012] irq event stamp: 0 [39389.800012] hardirqs last enabled at (0): [< (null)>] (null) [39389.800012] hardirqs last disabled at (0): [<ffffffff8104e58d>] copy_process+0x638/0x1a35 [39389.800012] softirqs last enabled at (0): [<ffffffff8104e58d>] copy_process+0x638/0x1a35 [39389.800012] softirqs last disabled at (0): [< (null)>] (null) [39389.800012] CPU: 15 PID: 32166 Comm: fdm-stress Tainted: G L 4.4.0-rc6-btrfs-next-18+ #1 [39389.800012] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS by qemu-project.org 04/01/2014 [39389.800012] task: ffff880179294380 ti: ffff880034a60000 task.ti: ffff880034a60000 [39389.800012] RIP: 0010:[<ffffffff81091e8d>] [<ffffffff81091e8d>] queued_write_lock_slowpath+0x62/0x72 [39389.800012] RSP: 0018:ffff880034a639f0 EFLAGS: 00000206 [39389.800012] RAX: 0000000000000101 RBX: ffff8801710c4e98 RCX: 0000000000000000 [39389.800012] RDX: 00000000000000ff RSI: 0000000000000000 RDI: ffff8801710c4e9c [39389.800012] RBP: ffff880034a639f8 R08: 0000000000000001 R09: 0000000000000000 [39389.800012] R10: ffff880034a639b0 R11: 0000000000001000 R12: ffff8801710c4e98 [39389.800012] R13: 0000000000000001 R14: ffff880172cbc000 R15: ffff8801710c4e00 [39389.800012] FS: 00007f6d377fe700(0000) GS:ffff8802be9e0000(0000) knlGS:0000000000000000 [39389.800012] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 [39389.800012] CR2: 00007f6d3d3c1000 CR3: 0000000037c93000 CR4: 00000000001406e0 [39389.800012] Stack: [39389.800012] ffff8801710c4e98 ffff880034a63a10 ffffffff81091963 ffff8801710c4e98 [39389.800012] ffff880034a63a30 ffffffff81486f1b ffffffffa0672cb3 ffff8801710c4e00 [39389.800012] ffff880034a63a78 ffffffffa0672cb3 ffff8801710c4e00 ffff880034a63a58 [39389.800012] Call Trace: [39389.800012] [<ffffffff81091963>] do_raw_write_lock+0x72/0x8c [39389.800012] [<ffffffff81486f1b>] _raw_write_lock+0x3a/0x41 [39389.800012] [<ffffffffa0672cb3>] ? btrfs_tree_lock+0x119/0x251 [btrfs] [39389.800012] [<ffffffffa0672cb3>] btrfs_tree_lock+0x119/0x251 [btrfs] [39389.800012] [<ffffffffa061aeba>] ? rcu_read_unlock+0x5b/0x5d [btrfs] [39389.800012] [<ffffffffa061ce13>] ? btrfs_root_node+0xda/0xe6 [btrfs] [39389.800012] [<ffffffffa061ce83>] btrfs_lock_root_node+0x22/0x42 [btrfs] [39389.800012] [<ffffffffa062046b>] btrfs_search_slot+0x1b8/0x758 [btrfs] [39389.800012] [<ffffffff810fc6b0>] ? time_hardirqs_on+0x15/0x28 [39389.800012] [<ffffffffa06365db>] btrfs_lookup_inode+0x31/0x95 [btrfs] [39389.800012] [<ffffffff8108d62f>] ? trace_hardirqs_on+0xd/0xf [39389.800012] [<ffffffff8148482b>] ? mutex_lock_nested+0x397/0x3bc [39389.800012] [<ffffffffa068821b>] __btrfs_update_delayed_inode+0x59/0x1c0 [btrfs] [39389.800012] [<ffffffffa068858e>] __btrfs_commit_inode_delayed_items+0x194/0x5aa [btrfs] [39389.800012] [<ffffffff81486ab7>] ? _raw_spin_unlock+0x31/0x44 [39389.800012] [<ffffffffa0688a48>] __btrfs_run_delayed_items+0xa4/0x15c [btrfs] [39389.800012] [<ffffffffa0688d62>] btrfs_run_delayed_items+0x11/0x13 [btrfs] [39389.800012] [<ffffffffa064048e>] btrfs_commit_transaction+0x234/0x96e [btrfs] [39389.800012] [<ffffffffa0618d10>] btrfs_sync_fs+0x145/0x1ad [btrfs] [39389.800012] [<ffffffffa0671176>] btrfs_ioctl+0x11d2/0x2793 [btrfs] [39389.800012] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [39389.800012] [<ffffffff81140261>] ? __might_fault+0x4c/0xa7 [39389.800012] [<ffffffff81140261>] ? __might_fault+0x4c/0xa7 [39389.800012] [<ffffffff8108a8b0>] ? arch_local_irq_save+0x9/0xc [39389.800012] [<ffffffff8118b3d4>] ? rcu_read_unlock+0x3e/0x5d [39389.800012] [<ffffffff811822f8>] do_vfs_ioctl+0x42b/0x4ea [39389.800012] [<ffffffff8118b4f3>] ? __fget_light+0x62/0x71 [39389.800012] [<ffffffff8118240e>] SyS_ioctl+0x57/0x79 [39389.800012] [<ffffffff814872d7>] entry_SYSCALL_64_fastpath+0x12/0x6f [39389.800012] Code: f0 0f b1 13 85 c0 75 ef eb 2a f3 90 8a 03 84 c0 75 f8 f0 0f b0 13 84 c0 75 f0 ba ff 00 00 00 eb 0a f0 0f b1 13 ff c8 74 0b f3 90 <8b> 03 83 f8 01 75 f7 eb ed c6 43 04 00 5b 5d c3 0f 1f 44 00 00 This happens because in the code path executed by the inode_paths ioctl we end up nesting two calls to read lock a leaf's rwlock when after the first call to read_lock() and before the second call to read_lock(), another task (running the delayed items as part of a transaction commit) has already called write_lock() against the leaf's rwlock. This situation is illustrated by the following diagram: Task A Task B btrfs_ref_to_path() btrfs_commit_transaction() read_lock(&eb->lock); btrfs_run_delayed_items() __btrfs_commit_inode_delayed_items() __btrfs_update_delayed_inode() btrfs_lookup_inode() write_lock(&eb->lock); --> task waits for lock read_lock(&eb->lock); --> makes this task hang forever (and task B too of course) So fix this by avoiding doing the nested read lock, which is easily avoidable. This issue does not happen if task B calls write_lock() after task A does the second call to read_lock(), however there does not seem to exist anything in the documentation that mentions what is the expected behaviour for recursive locking of rwlocks (leaving the idea that doing so is not a good usage of rwlocks). Also, as a side effect necessary for this fix, make sure we do not needlessly read lock extent buffers when the input path has skip_locking set (used when called from send). Cc: stable@vger.kernel.org Signed-off-by: Filipe Manana <fdmanana@suse.com>