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2016-08-31binfmt_elf: switch to new creds when switching to new mmLinus Torvalds
We used to delay switching to the new credentials until after we had mapped the executable (and possible elf interpreter). That was kind of odd to begin with, since the new executable will actually then _run_ with the new creds, but whatever. The bigger problem was that we also want to make sure that we turn off prof events and tracing before we start mapping the new executable state. So while this is a cleanup, it's also a fix for a possible information leak. Reported-by: Robert Święcki <robert@swiecki.net> Tested-by: Peter Zijlstra <peterz@infradead.org> Acked-by: David Howells <dhowells@redhat.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Acked-by: Andy Lutomirski <luto@amacapital.net> Acked-by: Eric W. Biederman <ebiederm@xmission.com> Cc: Willy Tarreau <w@1wt.eu> Cc: Kees Cook <keescook@chromium.org> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-31sysfs: correctly handle read offset on PREALLOC attrsKonstantin Khlebnikov
Attributes declared with __ATTR_PREALLOC use sysfs_kf_read() which returns zero bytes for non-zero offset. This breaks script checkarray in mdadm tool in debian where /bin/sh is 'dash' because its builtin 'read' reads only one byte at a time. Script gets 'i' instead of 'idle' when reads current action from /sys/block/$dev/md/sync_action and as a result does nothing. This patch adds trivial implementation of partial read: generate whole string and move required part into buffer head. Signed-off-by: Konstantin Khlebnikov <khlebnikov@yandex-team.ru> Fixes: 4ef67a8c95f3 ("sysfs/kernfs: make read requests on pre-alloc files use the buffer.") Link: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=787950 Cc: Stable <stable@vger.kernel.org> # v3.19+ Acked-by: Tejun Heo <tj@kernel.org> Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-31kernfs: don't depend on d_find_any_alias() when generating notificationsTejun Heo
kernfs_notify_workfn() sends out file modified events for the scheduled kernfs_nodes. Because the modifications aren't from userland, it doesn't have the matching file struct at hand and can't use fsnotify_modify(). Instead, it looked up the inode and then used d_find_any_alias() to find the dentry and used fsnotify_parent() and fsnotify() directly to generate notifications. The assumption was that the relevant dentries would have been pinned if there are listeners, which isn't true as inotify doesn't pin dentries at all and watching the parent doesn't pin the child dentries even for dnotify. This led to, for example, inotify watchers not getting notifications if the system is under memory pressure and the matching dentries got reclaimed. It can also be triggered through /proc/sys/vm/drop_caches or a remount attempt which involves shrinking dcache. fsnotify_parent() only uses the dentry to access the parent inode, which kernfs can do easily. Update kernfs_notify_workfn() so that it uses fsnotify() directly for both the parent and target inodes without going through d_find_any_alias(). While at it, supply the target file name to fsnotify() from kernfs_node->name. Signed-off-by: Tejun Heo <tj@kernel.org> Reported-by: Evgeny Vereshchagin <evvers@ya.ru> Fixes: d911d9874801 ("kernfs: make kernfs_notify() trigger inotify events too") Cc: John McCutchan <john@johnmccutchan.com> Cc: Robert Love <rlove@rlove.org> Cc: Eric Paris <eparis@parisplace.org> Cc: stable@vger.kernel.org # v3.16+ Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
2016-08-30Merge tag 'nfs-for-4.8-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfsLinus Torvalds
Pull NFS client bugfixes from Trond Myklebust: "Highlights include: Stable patches: - Fix a refcount leak in nfs_callback_up_net - Fix an Oopsable condition when the flexfile pNFS driver connection to the DS fails - Fix an Oopsable condition in NFSv4.1 server callback races - Ensure pNFS clients stop doing I/O to the DS if their lease has expired, as required by the NFSv4.1 protocol Bugfixes: - Fix potential looping in the NFSv4.x migration code - Patch series to close callback races for OPEN, LAYOUTGET and LAYOUTRETURN - Silence WARN_ON when NFSv4.1 over RDMA is in use - Fix a LAYOUTCOMMIT race in the pNFS/blocks client - Fix pNFS timeout issues when the DS fails" * tag 'nfs-for-4.8-3' of git://git.linux-nfs.org/projects/trondmy/linux-nfs: NFSv4.x: Fix a refcount leak in nfs_callback_up_net NFS4: Avoid migration loops pNFS/flexfiles: Fix an Oopsable condition when connection to the DS fails NFSv4.1: Remove obsolete and incorrrect assignment in nfs4_callback_sequence NFSv4.1: Close callback races for OPEN, LAYOUTGET and LAYOUTRETURN NFSv4.1: Defer bumping the slot sequence number until we free the slot NFSv4.1: Delay callback processing when there are referring triples NFSv4.1: Fix Oopsable condition in server callback races SUNRPC: Silence WARN_ON when NFSv4.1 over RDMA is in use pnfs/blocklayout: update last_write_offset atomically with extents pNFS: The client must not do I/O to the DS if it's lease has expired pNFS: Handle NFS4ERR_OLD_STATEID correctly in LAYOUTSTAT calls pNFS/flexfiles: Set reasonable default retrans values for the data channel NFS: Allow the mount option retrans=0 pNFS/flexfiles: Fix layoutstat periodic reporting
2016-08-30NFSv4.x: Fix a refcount leak in nfs_callback_up_netTrond Myklebust
On error, the callers expect us to return without bumping nn->cb_users[]. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Cc: stable@vger.kernel.org # v3.7+
2016-08-30NFS4: Avoid migration loopsBenjamin Coddington
If a server returns itself as a location while migrating, the client may end up getting stuck attempting to migrate twice to the same server. Catch this by checking if the nfs_client found is the same as the existing client. For the other two callers to nfs4_set_client, the nfs_client will always be ERR_PTR(-EINVAL). Signed-off-by: Benjamin Coddington <bcodding@redhat.com> Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-08-30xfs: track log done items directly in the deferred pending work itemDarrick J. Wong
Christoph reports slab corruption when a deferred refcount update aborts during _defer_finish(). The cause of this was broken log item state tracking in xfs_defer_pending -- upon an abort, _defer_trans_abort() will call abort_intent on all intent items, including the ones that have already had a done item attached. This is incorrect because each intent item has 2 refcount: the first is released when the intent item is committed to the log; and the second is released when the _done_ item is committed to the log, or by the intent creator if there is no done item. In other words, once we log the done item, responsibility for releasing the intent item's second refcount is transferred to the done item and /must not/ be performed by anything else. The dfp_committed flag should have been tracking whether or not we had a done item so that _defer_trans_abort could decide if it needs to abort the intent item, but due to a thinko this was not the case. Rip it out and track the done item directly so that we do the right thing w.r.t. intent item freeing. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reported-by: Christoph Hellwig <hch@infradead.org> Reviewed-by: Dave Chinner <dchinner@redhat.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-29Merge tag 'ext4_for_linus_stable' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4 Pull ext4 fixes from Ted Ts'o: "Fix bugs that could cause kernel deadlocks or file system corruption while moving xattrs to expand the extended inode. Also add some sanity checks to the block group descriptors to make sure we don't end up overwriting the superblock" * tag 'ext4_for_linus_stable' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: ext4: avoid deadlock when expanding inode size ext4: properly align shifted xattrs when expanding inodes ext4: fix xattr shifting when expanding inodes part 2 ext4: fix xattr shifting when expanding inodes ext4: validate that metadata blocks do not overlap superblock ext4: reserve xattr index for the Hurd
2016-08-29pNFS/flexfiles: Fix an Oopsable condition when connection to the DS failsTrond Myklebust
If the attempt to connect to a DS fails inside ff_layout_pg_init_read or ff_layout_pg_init_write, then we currently end up clearing the layout segment carried by the struct nfs_pageio_descriptor, causing an Oops when we later call into ff_layout_read_pagelist/ff_layout_write_pagelist. The fix is to ensure we return the layout and then retry. Fixes: 446ca2195303 ("pNFS/flexfiles: When initing reads or writes, we...") Cc: stable@vger.kernel.org # v4.7+ Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-08-29iomap: don't set FIEMAP_EXTENT_MERGED for extent based filesystemsChristoph Hellwig
Filesystems like XFS that use extents should not set the FIEMAP_EXTENT_MERGED flag in the fiemap extent structures. To allow for both behaviors for the upcoming gfs2 usage split the iomap type field into type and flags, and only set FIEMAP_EXTENT_MERGED if the IOMAP_F_MERGED flag is set. The flags field will also come in handy for future features such as shared extents on reflink-enabled file systems. Reported-by: Andreas Gruenbacher <agruenba@redhat.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Acked-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-28NFSv4.1: Remove obsolete and incorrrect assignment in nfs4_callback_sequenceTrond Myklebust
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-08-28NFSv4.1: Close callback races for OPEN, LAYOUTGET and LAYOUTRETURNTrond Myklebust
Defer freeing the slot until after we have processed the results from OPEN and LAYOUTGET. This means that the server can rely on the mechanism in RFC5661 Section 2.10.6.3 to ensure that replies to an OPEN or LAYOUTGET/RETURN RPC call don't race with the callbacks that apply to them. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-08-28NFSv4.1: Defer bumping the slot sequence number until we free the slotTrond Myklebust
For operations like OPEN or LAYOUTGET, which return recallable state (i.e. delegations and layouts) we want to enable the mechanism for resolving recall races in RFC5661 Section 2.10.6.3. To do so, we will want to defer bumping the slot's sequence number until we have finished processing the RPC results. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-08-28NFSv4.1: Delay callback processing when there are referring triplesTrond Myklebust
If CB_SEQUENCE tells us that the processing of this request depends on the completion of one or more referring triples (see RFC 5661 Section 2.10.6.3), delay the callback processing until after the RPC requests being referred to have completed. If we end up delaying for more than 1/2 second, then fall back to returning NFS4ERR_DELAY in reply to the callback. Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
2016-08-28NFSv4.1: Fix Oopsable condition in server callback racesTrond Myklebust
The slot table hasn't been an array since v3.7. Ensure that we use nfs4_lookup_slot() to access the slot correctly. Fixes: 87dda67e7386 ("NFSv4.1: Allow SEQUENCE to resize the slot table...") Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com> Cc: stable@vger.kernel.org # v3.8+
2016-08-26Merge branch 'akpm' (patches from Andrew)Linus Torvalds
Merge fixes from Andrew Morton: "11 fixes" * emailed patches from Andrew Morton <akpm@linux-foundation.org>: mm: silently skip readahead for DAX inodes dax: fix device-dax region base fs/seq_file: fix out-of-bounds read mm: memcontrol: avoid unused function warning mm: clarify COMPACTION Kconfig text treewide: replace config_enabled() with IS_ENABLED() (2nd round) printk: fix parsing of "brl=" option soft_dirty: fix soft_dirty during THP split sysctl: handle error writing UINT_MAX to u32 fields get_maintainer: quiet noisy implicit -f vcs_file_exists checking byteswap: don't use __builtin_bswap*() with sparse
2016-08-26Merge branch 'for-linus-4.8' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs Pull btrfs fixes from Chris Mason: "We've queued up a few different fixes in here. These range from enospc corners to fsync and quota fixes, and a few targeted at error handling for corrupt metadata/fuzzing" * 'for-linus-4.8' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: Btrfs: fix lockdep warning on deadlock against an inode's log mutex Btrfs: detect corruption when non-root leaf has zero item Btrfs: check btree node's nritems btrfs: don't create or leak aliased root while cleaning up orphans Btrfs: fix em leak in find_first_block_group btrfs: do not background blkdev_put() Btrfs: clarify do_chunk_alloc()'s return value btrfs: fix fsfreeze hang caused by delayed iputs deal btrfs: update btrfs_space_info's bytes_may_use timely btrfs: divide btrfs_update_reserved_bytes() into two functions btrfs: use correct offset for reloc_inode in prealloc_file_extent_cluster() btrfs: qgroup: Fix qgroup incorrectness caused by log replay btrfs: relocation: Fix leaking qgroups numbers on data extents btrfs: qgroup: Refactor btrfs_qgroup_insert_dirty_extent() btrfs: waiting on qgroup rescan should not always be interruptible btrfs: properly track when rescan worker is running btrfs: flush_space: treat return value of do_chunk_alloc properly Btrfs: add ASSERT for block group's memory leak btrfs: backref: Fix soft lockup in __merge_refs function Btrfs: fix memory leak of reloc_root
2016-08-26Merge tag 'dlm-4.8-fixes' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm Pull dlm fix from David Teigland: "This fixes a bug introduced by recent debugfs cleanup" * tag 'dlm-4.8-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/teigland/linux-dlm: dlm: fix malfunction of dlm_tool caused by debugfs changes
2016-08-26Merge branch 'for-linus' of git://git.kernel.dk/linux-blockLinus Torvalds
Pull block fixes from Jens Axboe: "Here's a set of block fixes for the current 4.8-rc release. This contains: - a fix for a secure erase regression, from Adrian. - a fix for an mmc use-after-free bug regression, also from Adrian. - potential zero pointer deference in bdev freezing, from Andrey. - a race fix for blk_set_queue_dying() from Bart. - a set of xen blkfront fixes from Bob Liu. - three small fixes for bcache, from Eric and Kent. - a fix for a potential invalid NVMe state transition, from Gabriel. - blk-mq CPU offline fix, preventing us from issuing and completing a request on the wrong queue. From me. - revert two previous floppy changes, since they caused a user visibile regression. A better fix is in the works. - ensure that we don't send down bios that have more than 256 elements in them. Fixes a crash with bcache, for example. From Ming. - a fix for deferencing an error pointer with cgroup writeback. Fixes a regression. From Vegard" * 'for-linus' of git://git.kernel.dk/linux-block: mmc: fix use-after-free of struct request Revert "floppy: refactor open() flags handling" Revert "floppy: fix open(O_ACCMODE) for ioctl-only open" fs/block_dev: fix potential NULL ptr deref in freeze_bdev() blk-mq: improve warning for running a queue on the wrong CPU blk-mq: don't overwrite rq->mq_ctx block: make sure a big bio is split into at most 256 bvecs nvme: Fix nvme_get/set_features() with a NULL result pointer bdev: fix NULL pointer dereference xen-blkfront: free resources if xlvbd_alloc_gendisk fails xen-blkfront: introduce blkif_set_queue_limits() xen-blkfront: fix places not updated after introducing 64KB page granularity bcache: pr_err: more meaningful error message when nr_stripes is invalid bcache: RESERVE_PRIO is too small by one when prio_buckets() is a power of two. bcache: register_bcache(): call blkdev_put() when cache_alloc() fails block: Fix race triggered by blk_set_queue_dying() block: Fix secure erase nvme: Prevent controller state invalid transition
2016-08-26fs/seq_file: fix out-of-bounds readVegard Nossum
seq_read() is a nasty piece of work, not to mention buggy. It has (I think) an old bug which allows unprivileged userspace to read beyond the end of m->buf. I was getting these: BUG: KASAN: slab-out-of-bounds in seq_read+0xcd2/0x1480 at addr ffff880116889880 Read of size 2713 by task trinity-c2/1329 CPU: 2 PID: 1329 Comm: trinity-c2 Not tainted 4.8.0-rc1+ #96 Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.3-0-ge2fc41e-prebuilt.qemu-project.org 04/01/2014 Call Trace: kasan_object_err+0x1c/0x80 kasan_report_error+0x2cb/0x7e0 kasan_report+0x4e/0x80 check_memory_region+0x13e/0x1a0 kasan_check_read+0x11/0x20 seq_read+0xcd2/0x1480 proc_reg_read+0x10b/0x260 do_loop_readv_writev.part.5+0x140/0x2c0 do_readv_writev+0x589/0x860 vfs_readv+0x7b/0xd0 do_readv+0xd8/0x2c0 SyS_readv+0xb/0x10 do_syscall_64+0x1b3/0x4b0 entry_SYSCALL64_slow_path+0x25/0x25 Object at ffff880116889100, in cache kmalloc-4096 size: 4096 Allocated: PID = 1329 save_stack_trace+0x26/0x80 save_stack+0x46/0xd0 kasan_kmalloc+0xad/0xe0 __kmalloc+0x1aa/0x4a0 seq_buf_alloc+0x35/0x40 seq_read+0x7d8/0x1480 proc_reg_read+0x10b/0x260 do_loop_readv_writev.part.5+0x140/0x2c0 do_readv_writev+0x589/0x860 vfs_readv+0x7b/0xd0 do_readv+0xd8/0x2c0 SyS_readv+0xb/0x10 do_syscall_64+0x1b3/0x4b0 return_from_SYSCALL_64+0x0/0x6a Freed: PID = 0 (stack is not available) Memory state around the buggy address: ffff88011688a000: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ffff88011688a080: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 >ffff88011688a100: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ^ ffff88011688a180: fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc fc ffff88011688a200: fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb fb ================================================================== Disabling lock debugging due to kernel taint This seems to be the same thing that Dave Jones was seeing here: https://lkml.org/lkml/2016/8/12/334 There are multiple issues here: 1) If we enter the function with a non-empty buffer, there is an attempt to flush it. But it was not clearing m->from after doing so, which means that if we try to do this flush twice in a row without any call to traverse() in between, we are going to be reading from the wrong place -- the splat above, fixed by this patch. 2) If there's a short write to userspace because of page faults, the buffer may already contain multiple lines (i.e. pos has advanced by more than 1), but we don't save the progress that was made so the next call will output what we've already returned previously. Since that is a much less serious issue (and I have a headache after staring at seq_read() for the past 8 hours), I'll leave that for now. Link: http://lkml.kernel.org/r/1471447270-32093-1-git-send-email-vegard.nossum@oracle.com Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com> Reported-by: Dave Jones <davej@codemonkey.org.uk> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2016-08-26dlm: fix malfunction of dlm_tool caused by debugfs changesEric Ren
With the current kernel, `dlm_tool lockdebug` fails as below: "dlm_tool lockdebug ED0BD86DCE724393918A1AE8FDBF1EE3 can't open /sys/kernel/debug/dlm/ED0BD86DCE724393918A1AE8FDBF1EE3: Operation not permitted" This is because table_open() depends on file->f_op to tell which seq_file ops should be passed down. But, the original file ops in file->f_op is replaced by "debugfs_full_proxy_file_operations" with commit 49d200deaa68 ("debugfs: prevent access to removed files' private data"). Currently, I can think up 2 solutions: 1st, replace debugfs_create_file() with debugfs_create_file_unsafe(); 2nd, make different table_open#() accordingly. The 1st one is neat, but I don't thoroughly understand its risk. Maybe someone has a better one. Signed-off-by: Eric Ren <zren@suse.com> Signed-off-by: David Teigland <teigland@redhat.com>
2016-08-26xfs: prevent dropping ioend completions during buftarg waitBrian Foster
xfs_wait_buftarg() waits for all pending I/O, drains the ioend completion workqueue and walks the LRU until all buffers in the cache have been released. This is traditionally an unmount operation` but the mechanism is also reused during filesystem freeze. xfs_wait_buftarg() invokes drain_workqueue() as part of the quiesce, which is intended more for a shutdown sequence in that it indicates to the queue that new operations are not expected once the drain has begun. New work jobs after this point result in a WARN_ON_ONCE() and are otherwise dropped. With filesystem freeze, however, read operations are allowed and can proceed during or after the workqueue drain. If such a read occurs during the drain sequence, the workqueue infrastructure complains about the queued ioend completion work item and drops it on the floor. As a result, the buffer remains on the LRU and the freeze never completes. Despite the fact that the overall buffer cache cleanup is not necessary during freeze, fix up this operation such that it is safe to invoke during non-unmount quiesce operations. Replace the drain_workqueue() call with flush_workqueue(), which runs a similar serialization on pending workqueue jobs without causing new jobs to be dropped. This is safe for unmount as unmount independently locks out new operations by the time xfs_wait_buftarg() is invoked. cc: <stable@vger.kernel.org> Signed-off-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-26xfs: fix superblock inprogress checkDave Chinner
From inspection, the superblock sb_inprogress check is done in the verifier and triggered only for the primary superblock via a "bp->b_bn == XFS_SB_DADDR" check. Unfortunately, the primary superblock is an uncached buffer, and hence it is configured by xfs_buf_read_uncached() with: bp->b_bn = XFS_BUF_DADDR_NULL; /* always null for uncached buffers */ And so this check never triggers. Fix it. cc: <stable@vger.kernel.org> Signed-off-by: Dave Chinner <dchinner@redhat.com> Reviewed-by: Brian Foster <bfoster@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-26xfs: simple btree query range should look right if LE lookup failsDarrick J. Wong
If the initial LOOKUP_LE in the simple query range fails to find anything, we should attempt to increment the btree cursor to see if there actually /are/ records for what we're trying to find. Without this patch, a bnobt range query of (0, $agsize) returns no results because the leftmost record never has a startblock of zero. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-26xfs: fix some key handling problems in _btree_simple_query_rangeDarrick J. Wong
We only need the record's high key for the first record that we look at; for all records, we /definitely/ need the regular record key. Therefore, fix how the simple range query function gets its keys. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-26xfs: don't log the entire end of the AGFDarrick J. Wong
When we're logging the last non-spare field in the AGF, we don't need to log the spare fields, so plumb in a new AGF logging flag to help us avoid that. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-26xfs: disallow mounting of realtime + rmap filesystemsDarrick J. Wong
Since the kernel doesn't currently support the realtime rmapbt, don't allow such filesystems to be mounted. Support will appear in a future release. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-26xfs: don't perform lookups on zero-height btreesDarrick J. Wong
If the caller passes in a cursor to a zero-height btree (which is impossible), we never set block to anything but NULL, which causes the later dereference of it to crash. Instead, just return -EFSCORRUPTED. Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Dave Chinner <david@fromorbit.com>
2016-08-25fs/block_dev: fix potential NULL ptr deref in freeze_bdev()Andrey Ryabinin
Calling freeze_bdev() twice on the same block device without mounted filesystem get_super() will return NULL, which will lead to NULL-ptr dereference later in drop_super(). Check get_super() result to fix that. Note, that this is a purely theoretical issue. We have only 3 freeze_bdev() callers. 2 of them are in filesystem code and used on a device with mounted fs. The third one in lock_fs() has protection in upper-layer code against freezing block device the second time without thawing it first. Signed-off-by: Andrey Ryabinin <aryabinin@virtuozzo.com> Reviewed-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Jens Axboe <axboe@fb.com>
2016-08-25Btrfs: fix lockdep warning on deadlock against an inode's log mutexFilipe Manana
Commit 44f714dae50a ("Btrfs: improve performance on fsync against new inode after rename/unlink"), which landed in 4.8-rc2, introduced a possibility for a deadlock due to double locking of an inode's log mutex by the same task, which lockdep reports with: [23045.433975] ============================================= [23045.434748] [ INFO: possible recursive locking detected ] [23045.435426] 4.7.0-rc6-btrfs-next-34+ #1 Not tainted [23045.436044] --------------------------------------------- [23045.436044] xfs_io/3688 is trying to acquire lock: [23045.436044] (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] but task is already holding lock: [23045.436044] (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] other info that might help us debug this: [23045.436044] Possible unsafe locking scenario: [23045.436044] CPU0 [23045.436044] ---- [23045.436044] lock(&ei->log_mutex); [23045.436044] lock(&ei->log_mutex); [23045.436044] *** DEADLOCK *** [23045.436044] May be due to missing lock nesting notation [23045.436044] 3 locks held by xfs_io/3688: [23045.436044] #0: (&sb->s_type->i_mutex_key#15){+.+...}, at: [<ffffffffa035f2ae>] btrfs_sync_file+0x14e/0x425 [btrfs] [23045.436044] #1: (sb_internal#2){.+.+.+}, at: [<ffffffff8118446b>] __sb_start_write+0x5f/0xb0 [23045.436044] #2: (&ei->log_mutex){+.+...}, at: [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] stack backtrace: [23045.436044] CPU: 4 PID: 3688 Comm: xfs_io Not tainted 4.7.0-rc6-btrfs-next-34+ #1 [23045.436044] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014 [23045.436044] 0000000000000000 ffff88022f5f7860 ffffffff8127074d ffffffff82a54b70 [23045.436044] ffffffff82a54b70 ffff88022f5f7920 ffffffff81092897 ffff880228015d68 [23045.436044] 0000000000000000 ffffffff82a54b70 ffffffff829c3f00 ffff880228015d68 [23045.436044] Call Trace: [23045.436044] [<ffffffff8127074d>] dump_stack+0x67/0x90 [23045.436044] [<ffffffff81092897>] __lock_acquire+0xcbb/0xe4e [23045.436044] [<ffffffff8109155f>] ? mark_lock+0x24/0x201 [23045.436044] [<ffffffff8109179a>] ? mark_held_locks+0x5e/0x74 [23045.436044] [<ffffffff81092de0>] lock_acquire+0x12f/0x1c3 [23045.436044] [<ffffffff81092de0>] ? lock_acquire+0x12f/0x1c3 [23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffff814a51a4>] mutex_lock_nested+0x77/0x3a7 [23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffffa039705e>] ? btrfs_release_delayed_node+0xb/0xd [btrfs] [23045.436044] [<ffffffffa038552d>] btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffffa038552d>] ? btrfs_log_inode+0x13a/0xc95 [btrfs] [23045.436044] [<ffffffff810a0ed1>] ? vprintk_emit+0x453/0x465 [23045.436044] [<ffffffffa0385a61>] btrfs_log_inode+0x66e/0xc95 [btrfs] [23045.436044] [<ffffffffa03c084d>] log_new_dir_dentries+0x26c/0x359 [btrfs] [23045.436044] [<ffffffffa03865aa>] btrfs_log_inode_parent+0x4a6/0x628 [btrfs] [23045.436044] [<ffffffffa0387552>] btrfs_log_dentry_safe+0x5a/0x75 [btrfs] [23045.436044] [<ffffffffa035f464>] btrfs_sync_file+0x304/0x425 [btrfs] [23045.436044] [<ffffffff811acaf4>] vfs_fsync_range+0x8c/0x9e [23045.436044] [<ffffffff811acb22>] vfs_fsync+0x1c/0x1e [23045.436044] [<ffffffff811acc79>] do_fsync+0x31/0x4a [23045.436044] [<ffffffff811ace99>] SyS_fsync+0x10/0x14 [23045.436044] [<ffffffff814a88e5>] entry_SYSCALL_64_fastpath+0x18/0xa8 [23045.436044] [<ffffffff8108f039>] ? trace_hardirqs_off_caller+0x3f/0xaa An example reproducer for this is: $ mkfs.btrfs -f /dev/sdb $ mount /dev/sdb /mnt $ mkdir /mnt/dir $ touch /mnt/dir/foo $ sync $ mv /mnt/dir/foo /mnt/dir/bar $ touch /mnt/dir/foo $ xfs_io -c "fsync" /mnt/dir/bar This is because while logging the inode of file bar we end up logging its parent directory (since its inode has an unlink_trans field matching the current transaction id due to the rename operation), which in turn logs the inodes for all its new dentries, so that the new inode for the new file named foo gets logged which in turn triggered another logging attempt for the inode we are fsync'ing, since that inode had an old name that corresponds to the name of the new inode. So fix this by ensuring that when logging the inode for a new dentry that has a name matching an old name of some other inode, we don't log again the original inode that we are fsync'ing. Fixes: 44f714dae50a ("Btrfs: improve performance on fsync against new inode after rename/unlink") Signed-off-by: Filipe Manana <fdmanana@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25Btrfs: detect corruption when non-root leaf has zero itemLiu Bo
Right now we treat leaf which has zero item as a valid one because we could have an empty tree, that is, a root that is also a leaf without any item, however, in the same case but when the leaf is not a root, we can end up with hitting the BUG_ON(1) in btrfs_extend_item() called by setup_inline_extent_backref(). This makes us check the situation as a corruption if leaf is not its own root. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25Btrfs: check btree node's nritemsLiu Bo
When btree node (level = 1) has nritems which equals to zero, we can end up with panic due to insert_ptr()'s BUG_ON(slot > nritems); where slot is 1 and nritems is 0, as copy_for_split() calls insert_ptr(.., path->slots[1] + 1, ...); A invalid value results in the whole mess, this adds the check for btree's node nritems so that we stop reading block when when something is wrong. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25btrfs: don't create or leak aliased root while cleaning up orphansJeff Mahoney
commit 909c3a22da3 (Btrfs: fix loading of orphan roots leading to BUG_ON) avoids the BUG_ON but can add an aliased root to the dead_roots list or leak the root. Since we've already been loading roots into the radix tree, we should use it before looking the root up on disk. Cc: <stable@vger.kernel.org> # 4.5 Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25Btrfs: fix em leak in find_first_block_groupJosef Bacik
We need to call free_extent_map() on the em we look up. Signed-off-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25btrfs: do not background blkdev_put()Anand Jain
At the end of unmount/dev-delete, if the device exclusive open is not actually closed, then there might be a race with another program in the userland who is trying to open the device in exclusive mode and it may fail for eg: unmount /btrfs; fsck /dev/x btrfs dev del /dev/x /btrfs; fsck /dev/x so here background blkdev_put() is not a choice Signed-off-by: Anand Jain <Anand.Jain@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25Btrfs: clarify do_chunk_alloc()'s return valueLiu Bo
Function start_transaction() can return ERR_PTR(1) when flush is BTRFS_RESERVE_FLUSH_LIMIT, so the call graph is start_transaction (return ERR_PTR(1)) -> btrfs_block_rsv_add (return 1) -> reserve_metadata_bytes (return 1) -> flush_space (return 1) -> do_chunk_alloc (return 1) With BTRFS_RESERVE_FLUSH_LIMIT, if flush_space is already on the flush_state of ALLOC_CHUNK and it successfully allocates a new chunk, then instead of trying to reserve space again, reserve_metadata_bytes returns 1 immediately. Eventually the callers who call start_transaction() usually just do the IS_ERR() check which ERR_PTR(1) can pass, then it'll get a panic when dereferencing a pointer which is ERR_PTR(1). The following patch fixes the above problem. "btrfs: flush_space: treat return value of do_chunk_alloc properly" https://patchwork.kernel.org/patch/7778651/ This add comments to clarify do_chunk_alloc()'s return value. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25btrfs: fix fsfreeze hang caused by delayed iputs dealWang Xiaoguang
When running fstests generic/068, sometimes we got below deadlock: xfs_io D ffff8800331dbb20 0 6697 6693 0x00000080 ffff8800331dbb20 ffff88007acfc140 ffff880034d895c0 ffff8800331dc000 ffff880032d243e8 fffffffeffffffff ffff880032d24400 0000000000000001 ffff8800331dbb38 ffffffff816a9045 ffff880034d895c0 ffff8800331dbba8 Call Trace: [<ffffffff816a9045>] schedule+0x35/0x80 [<ffffffff816abab2>] rwsem_down_read_failed+0xf2/0x140 [<ffffffff8118f5e1>] ? __filemap_fdatawrite_range+0xd1/0x100 [<ffffffff8134f978>] call_rwsem_down_read_failed+0x18/0x30 [<ffffffffa06631fc>] ? btrfs_alloc_block_rsv+0x2c/0xb0 [btrfs] [<ffffffff810d32b5>] percpu_down_read+0x35/0x50 [<ffffffff81217dfc>] __sb_start_write+0x2c/0x40 [<ffffffffa067f5d5>] start_transaction+0x2a5/0x4d0 [btrfs] [<ffffffffa067f857>] btrfs_join_transaction+0x17/0x20 [btrfs] [<ffffffffa068ba34>] btrfs_evict_inode+0x3c4/0x5d0 [btrfs] [<ffffffff81230a1a>] evict+0xba/0x1a0 [<ffffffff812316b6>] iput+0x196/0x200 [<ffffffffa06851d0>] btrfs_run_delayed_iputs+0x70/0xc0 [btrfs] [<ffffffffa067f1d8>] btrfs_commit_transaction+0x928/0xa80 [btrfs] [<ffffffffa0646df0>] btrfs_freeze+0x30/0x40 [btrfs] [<ffffffff81218040>] freeze_super+0xf0/0x190 [<ffffffff81229275>] do_vfs_ioctl+0x4a5/0x5c0 [<ffffffff81003176>] ? do_audit_syscall_entry+0x66/0x70 [<ffffffff810038cf>] ? syscall_trace_enter_phase1+0x11f/0x140 [<ffffffff81229409>] SyS_ioctl+0x79/0x90 [<ffffffff81003c12>] do_syscall_64+0x62/0x110 [<ffffffff816acbe1>] entry_SYSCALL64_slow_path+0x25/0x25 >From this warning, freeze_super() already holds SB_FREEZE_FS, but btrfs_freeze() will call btrfs_commit_transaction() again, if btrfs_commit_transaction() finds that it has delayed iputs to handle, it'll start_transaction(), which will try to get SB_FREEZE_FS lock again, then deadlock occurs. The root cause is that in btrfs, sync_filesystem(sb) does not make sure all metadata is updated. There still maybe some codes adding delayed iputs, see below sample race window: CPU1 | CPU2 |-> freeze_super() | |-> sync_filesystem(sb); | | |-> cleaner_kthread() | | |-> btrfs_delete_unused_bgs() | | |-> btrfs_remove_chunk() | | |-> btrfs_remove_block_group() | | |-> btrfs_add_delayed_iput() | | |-> sb->s_writers.frozen = SB_FREEZE_FS; | |-> sb_wait_write(sb, SB_FREEZE_FS); | | acquire SB_FREEZE_FS lock. | | | |-> btrfs_freeze() | |-> btrfs_commit_transaction() | |-> btrfs_run_delayed_iputs() | | will handle delayed iputs, | | that means start_transaction() | | will be called, which will try | | to get SB_FREEZE_FS lock. | To fix this issue, introduce a "int fs_frozen" to record internally whether fs has been frozen. If fs has been frozen, we can not handle delayed iputs. Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> [ add comment to btrfs_freeze ] Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25btrfs: update btrfs_space_info's bytes_may_use timelyWang Xiaoguang
This patch can fix some false ENOSPC errors, below test script can reproduce one false ENOSPC error: #!/bin/bash dd if=/dev/zero of=fs.img bs=$((1024*1024)) count=128 dev=$(losetup --show -f fs.img) mkfs.btrfs -f -M $dev mkdir /tmp/mntpoint mount $dev /tmp/mntpoint cd /tmp/mntpoint xfs_io -f -c "falloc 0 $((64*1024*1024))" testfile Above script will fail for ENOSPC reason, but indeed fs still has free space to satisfy this request. Please see call graph: btrfs_fallocate() |-> btrfs_alloc_data_chunk_ondemand() | bytes_may_use += 64M |-> btrfs_prealloc_file_range() |-> btrfs_reserve_extent() |-> btrfs_add_reserved_bytes() | alloc_type is RESERVE_ALLOC_NO_ACCOUNT, so it does not | change bytes_may_use, and bytes_reserved += 64M. Now | bytes_may_use + bytes_reserved == 128M, which is greater | than btrfs_space_info's total_bytes, false enospc occurs. | Note, the bytes_may_use decrease operation will be done in | end of btrfs_fallocate(), which is too late. Here is another simple case for buffered write: CPU 1 | CPU 2 | |-> cow_file_range() |-> __btrfs_buffered_write() |-> btrfs_reserve_extent() | | | | | | | | | ..... | |-> btrfs_check_data_free_space() | | | | |-> extent_clear_unlock_delalloc() | In CPU 1, btrfs_reserve_extent()->find_free_extent()-> btrfs_add_reserved_bytes() do not decrease bytes_may_use, the decrease operation will be delayed to be done in extent_clear_unlock_delalloc(). Assume in this case, btrfs_reserve_extent() reserved 128MB data, CPU2's btrfs_check_data_free_space() tries to reserve 100MB data space. If 100MB > data_sinfo->total_bytes - data_sinfo->bytes_used - data_sinfo->bytes_reserved - data_sinfo->bytes_pinned - data_sinfo->bytes_readonly - data_sinfo->bytes_may_use btrfs_check_data_free_space() will try to allcate new data chunk or call btrfs_start_delalloc_roots(), or commit current transaction in order to reserve some free space, obviously a lot of work. But indeed it's not necessary as long as decreasing bytes_may_use timely, we still have free space, decreasing 128M from bytes_may_use. To fix this issue, this patch chooses to update bytes_may_use for both data and metadata in btrfs_add_reserved_bytes(). For compress path, real extent length may not be equal to file content length, so introduce a ram_bytes argument for btrfs_reserve_extent(), find_free_extent() and btrfs_add_reserved_bytes(), it's becasue bytes_may_use is increased by file content length. Then compress path can update bytes_may_use correctly. Also now we can discard RESERVE_ALLOC_NO_ACCOUNT, RESERVE_ALLOC and RESERVE_FREE. As we know, usually EXTENT_DO_ACCOUNTING is used for error path. In run_delalloc_nocow(), for inode marked as NODATACOW or extent marked as PREALLOC, we also need to update bytes_may_use, but can not pass EXTENT_DO_ACCOUNTING, because it also clears metadata reservation, so here we introduce EXTENT_CLEAR_DATA_RESV flag to indicate btrfs_clear_bit_hook() to update btrfs_space_info's bytes_may_use. Meanwhile __btrfs_prealloc_file_range() will call btrfs_free_reserved_data_space() internally for both sucessful and failed path, btrfs_prealloc_file_range()'s callers does not need to call btrfs_free_reserved_data_space() any more. Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25btrfs: divide btrfs_update_reserved_bytes() into two functionsWang Xiaoguang
This patch divides btrfs_update_reserved_bytes() into btrfs_add_reserved_bytes() and btrfs_free_reserved_bytes(), and next patch will extend btrfs_add_reserved_bytes()to fix some false ENOSPC error, please see later patch for detailed info. Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25btrfs: use correct offset for reloc_inode in prealloc_file_extent_cluster()Wang Xiaoguang
In prealloc_file_extent_cluster(), btrfs_check_data_free_space() uses wrong file offset for reloc_inode, it uses cluster->start and cluster->end, which indeed are extent's bytenr. The correct value should be cluster->[start|end] minus block group's start bytenr. start bytenr cluster->start | | extent | extent | ...| extent | |----------------------------------------------------------------| | block group reloc_inode | Signed-off-by: Wang Xiaoguang <wangxg.fnst@cn.fujitsu.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25btrfs: qgroup: Fix qgroup incorrectness caused by log replayQu Wenruo
When doing log replay at mount time(after power loss), qgroup will leak numbers of replayed data extents. The cause is almost the same of balance. So fix it by manually informing qgroup for owner changed extents. The bug can be detected by btrfs/119 test case. Cc: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-and-Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25btrfs: relocation: Fix leaking qgroups numbers on data extentsQu Wenruo
This patch fixes a REGRESSION introduced in 4.2, caused by the big quota rework. When balancing data extents, qgroup will leak all its numbers for relocated data extents. The relocation is done in the following steps for data extents: 1) Create data reloc tree and inode 2) Copy all data extents to data reloc tree And commit transaction 3) Create tree reloc tree(special snapshot) for any related subvolumes 4) Replace file extent in tree reloc tree with new extents in data reloc tree And commit transaction 5) Merge tree reloc tree with original fs, by swapping tree blocks For 1)~4), since tree reloc tree and data reloc tree doesn't count to qgroup, everything is OK. But for 5), the swapping of tree blocks will only info qgroup to track metadata extents. If metadata extents contain file extents, qgroup number for file extents will get lost, leading to corrupted qgroup accounting. The fix is, before commit transaction of step 5), manually info qgroup to track all file extents in data reloc tree. Since at commit transaction time, the tree swapping is done, and qgroup will account these data extents correctly. Cc: Mark Fasheh <mfasheh@suse.de> Reported-by: Mark Fasheh <mfasheh@suse.de> Reported-by: Filipe Manana <fdmanana@gmail.com> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25btrfs: qgroup: Refactor btrfs_qgroup_insert_dirty_extent()Qu Wenruo
Refactor btrfs_qgroup_insert_dirty_extent() function, to two functions: 1. btrfs_qgroup_insert_dirty_extent_nolock() Almost the same with original code. For delayed_ref usage, which has delayed refs locked. Change the return value type to int, since caller never needs the pointer, but only needs to know if they need to free the allocated memory. 2. btrfs_qgroup_insert_dirty_extent() The more encapsulated version. Will do the delayed_refs lock, memory allocation, quota enabled check and other things. The original design is to keep exported functions to minimal, but since more btrfs hacks exposed, like replacing path in balance, we need to record dirty extents manually, so we have to add such functions. Also, add comment for both functions, to info developers how to keep qgroup correct when doing hacks. Cc: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-and-Tested-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25btrfs: waiting on qgroup rescan should not always be interruptibleJeff Mahoney
We wait on qgroup rescan completion in three places: file system shutdown, the quota disable ioctl, and the rescan wait ioctl. If the user sends a signal while we're waiting, we continue happily along. This is expected behavior for the rescan wait ioctl. It's racy in the shutdown path but mostly works due to other unrelated synchronization points. In the quota disable path, it Oopses the kernel pretty much immediately. Cc: <stable@vger.kernel.org> # v4.4+ Signed-off-by: Jeff Mahoney <jeffm@suse.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25btrfs: properly track when rescan worker is runningJeff Mahoney
The qgroup_flags field is overloaded such that it reflects the on-disk status of qgroups and the runtime state. The BTRFS_QGROUP_STATUS_FLAG_RESCAN flag is used to indicate that a rescan operation is in progress, but if the file system is unmounted while a rescan is running, the rescan operation is paused. If the file system is then mounted read-only, the flag will still be present but the rescan operation will not have been resumed. When we go to umount, btrfs_qgroup_wait_for_completion will see the flag and interpret it to mean that the rescan worker is still running and will wait for a completion that will never come. This patch uses a separate flag to indicate when the worker is running. The locking and state surrounding the qgroup rescan worker needs a lot of attention beyond this patch but this is enough to avoid a hung umount. Cc: <stable@vger.kernel.org> # v4.4+ Signed-off-by; Jeff Mahoney <jeffm@suse.com> Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25btrfs: flush_space: treat return value of do_chunk_alloc properlyAlex Lyakas
do_chunk_alloc returns 1 when it succeeds to allocate a new chunk. But flush_space will not convert this to 0, and will also return 1. As a result, reserve_metadata_bytes will think that flush_space failed, and may potentially return this value "1" to the caller (depends how reserve_metadata_bytes was called). The caller will also treat this as an error. For example, btrfs_block_rsv_refill does: int ret = -ENOSPC; ... ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush); if (!ret) { block_rsv_add_bytes(block_rsv, num_bytes, 0); return 0; } return ret; So it will return -ENOSPC. Signed-off-by: Alex Lyakas <alex@zadarastorage.com> Reviewed-by: Josef Bacik <jbacik@fb.com> Reviewed-by: Liu Bo <bo.li.liu@oracle.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25Btrfs: add ASSERT for block group's memory leakLiu Bo
This adds several ASSERT()' s to report memory leak of block group cache. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25btrfs: backref: Fix soft lockup in __merge_refs functionQu Wenruo
When over 1000 file extents refers to one extent, find_parent_nodes() will be obviously slow, due to the O(n^2)~O(n^3) loops inside __merge_refs(). The following ftrace shows the cubic growth of execution time: 256 refs 5) + 91.768 us | __add_keyed_refs.isra.12 [btrfs](); 5) 1.447 us | __add_missing_keys.isra.13 [btrfs](); 5) ! 114.544 us | __merge_refs [btrfs](); 5) ! 136.399 us | __merge_refs [btrfs](); 512 refs 6) ! 279.859 us | __add_keyed_refs.isra.12 [btrfs](); 6) 3.164 us | __add_missing_keys.isra.13 [btrfs](); 6) ! 442.498 us | __merge_refs [btrfs](); 6) # 2091.073 us | __merge_refs [btrfs](); and 1024 refs 7) ! 368.683 us | __add_keyed_refs.isra.12 [btrfs](); 7) 4.810 us | __add_missing_keys.isra.13 [btrfs](); 7) # 2043.428 us | __merge_refs [btrfs](); 7) * 18964.23 us | __merge_refs [btrfs](); And sort them into the following char: (Unit: us) ------------------------------------------------------------------------ Trace function | 256 ref | 512 refs | 1024 refs | ------------------------------------------------------------------------ __add_keyed_refs | 91 | 249 | 368 | __add_missing_keys | 1 | 3 | 4 | __merge_refs 1st call | 114 | 442 | 2043 | __merge_refs 2nd call | 136 | 2091 | 18964 | ------------------------------------------------------------------------ We can see the that __add_keyed_refs() grows almost in linear behavior. And __add_missing_keys() in this case doesn't change much or takes much time. While for the 1st __merge_refs() it's square growth for the 2nd __merge_refs() call it's cubic growth. It's no doubt that merge_refs() will take a long long time to execute if the number of refs continues its grows. So add a cond_resced() into the loop of __merge_refs(). Although this will solve the problem of soft lockup, we need to use the new rb_tree based structure introduced by Lu Fengqi to really solve the long execution time. Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-25Btrfs: fix memory leak of reloc_rootLiu Bo
When some critical errors occur and FS would be flipped into RO, if we have an on-going balance, we can end up with a memory leak of root->reloc_root since btrfs_drop_snapshots() bails out without freeing reloc_root at the very early start. However, we're not able to free reloc_root in btrfs_drop_snapshots() because its caller, merge_reloc_roots(), still needs to access it to cleanup reloc_root's rbtree. This makes us free reloc_root when we're going to free fs/file roots. Signed-off-by: Liu Bo <bo.li.liu@oracle.com> Reviewed-by: David Sterba <dsterba@suse.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-08-24Merge tag 'upstream-4.8-rc4' of git://git.infradead.org/linux-ubifsLinus Torvalds
Pull UBIFS fixes from Richard Weinberger: "This pull requests contains fixes for two issues in UBI and UBIFS: - wrong UBIFS assertion. - a UBIFS xattr regression" * tag 'upstream-4.8-rc4' of git://git.infradead.org/linux-ubifs: ubifs: Fix xattr generic handler usage ubifs: Fix assertion in layout_in_gaps()