- 26 Sep, 2016 34 commits
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Anand Jain authored
btrfs_show_devname() is using the device_list_mutex, sometimes a call to blkdev_put() leads vfs calling into this func. So call blkdev_put() outside of device_list_mutex, as of now. [ 983.284212] ====================================================== [ 983.290401] [ INFO: possible circular locking dependency detected ] [ 983.296677] 4.8.0-rc5-ceph-00023-g1b39cec2 #1 Not tainted [ 983.302081] ------------------------------------------------------- [ 983.308357] umount/21720 is trying to acquire lock: [ 983.313243] (&bdev->bd_mutex){+.+.+.}, at: [<ffffffff9128ec51>] blkdev_put+0x31/0x150 [ 983.321264] [ 983.321264] but task is already holding lock: [ 983.327101] (&fs_devs->device_list_mutex){+.+...}, at: [<ffffffffc033d6f6>] __btrfs_close_devices+0x46/0x200 [btrfs] [ 983.337839] [ 983.337839] which lock already depends on the new lock. [ 983.337839] [ 983.346024] [ 983.346024] the existing dependency chain (in reverse order) is: [ 983.353512] -> #4 (&fs_devs->device_list_mutex){+.+...}: [ 983.359096] [<ffffffff910dfd0c>] lock_acquire+0x1bc/0x1f0 [ 983.365143] [<ffffffff91823125>] mutex_lock_nested+0x65/0x350 [ 983.371521] [<ffffffffc02d8116>] btrfs_show_devname+0x36/0x1f0 [btrfs] [ 983.378710] [<ffffffff9129523e>] show_vfsmnt+0x4e/0x150 [ 983.384593] [<ffffffff9126ffc7>] m_show+0x17/0x20 [ 983.389957] [<ffffffff91276405>] seq_read+0x2b5/0x3b0 [ 983.395669] [<ffffffff9124c808>] __vfs_read+0x28/0x100 [ 983.401464] [<ffffffff9124eb3b>] vfs_read+0xab/0x150 [ 983.407080] [<ffffffff9124ec32>] SyS_read+0x52/0xb0 [ 983.412609] [<ffffffff91825fc0>] entry_SYSCALL_64_fastpath+0x23/0xc1 [ 983.419617] -> #3 (namespace_sem){++++++}: [ 983.424024] [<ffffffff910dfd0c>] lock_acquire+0x1bc/0x1f0 [ 983.430074] [<ffffffff918239e9>] down_write+0x49/0x80 [ 983.435785] [<ffffffff91272457>] lock_mount+0x67/0x1c0 [ 983.441582] [<ffffffff91272ab2>] do_add_mount+0x32/0xf0 [ 983.447458] [<ffffffff9127363a>] finish_automount+0x5a/0xc0 [ 983.453682] [<ffffffff91259513>] follow_managed+0x1b3/0x2a0 [ 983.459912] [<ffffffff9125b750>] lookup_fast+0x300/0x350 [ 983.465875] [<ffffffff9125d6e7>] path_openat+0x3a7/0xaa0 [ 983.471846] [<ffffffff9125ef75>] do_filp_open+0x85/0xe0 [ 983.477731] [<ffffffff9124c41c>] do_sys_open+0x14c/0x1f0 [ 983.483702] [<ffffffff9124c4de>] SyS_open+0x1e/0x20 [ 983.489240] [<ffffffff91825fc0>] entry_SYSCALL_64_fastpath+0x23/0xc1 [ 983.496254] -> #2 (&sb->s_type->i_mutex_key#3){+.+.+.}: [ 983.501798] [<ffffffff910dfd0c>] lock_acquire+0x1bc/0x1f0 [ 983.507855] [<ffffffff918239e9>] down_write+0x49/0x80 [ 983.513558] [<ffffffff91366237>] start_creating+0x87/0x100 [ 983.519703] [<ffffffff91366647>] debugfs_create_dir+0x17/0x100 [ 983.526195] [<ffffffff911df153>] bdi_register+0x93/0x210 [ 983.532165] [<ffffffff911df313>] bdi_register_owner+0x43/0x70 [ 983.538570] [<ffffffff914080fb>] device_add_disk+0x1fb/0x450 [ 983.544888] [<ffffffff91580226>] loop_add+0x1e6/0x290 [ 983.550596] [<ffffffff91fec358>] loop_init+0x10b/0x14f [ 983.556394] [<ffffffff91002207>] do_one_initcall+0xa7/0x180 [ 983.562618] [<ffffffff91f932e0>] kernel_init_freeable+0x1cc/0x266 [ 983.569370] [<ffffffff918174be>] kernel_init+0xe/0x100 [ 983.575166] [<ffffffff9182620f>] ret_from_fork+0x1f/0x40 [ 983.581131] -> #1 (loop_index_mutex){+.+.+.}: [ 983.585801] [<ffffffff910dfd0c>] lock_acquire+0x1bc/0x1f0 [ 983.591858] [<ffffffff91823125>] mutex_lock_nested+0x65/0x350 [ 983.598256] [<ffffffff9157ed3f>] lo_open+0x1f/0x60 [ 983.603704] [<ffffffff9128eec3>] __blkdev_get+0x123/0x400 [ 983.609757] [<ffffffff9128f4ea>] blkdev_get+0x34a/0x350 [ 983.615639] [<ffffffff9128f554>] blkdev_open+0x64/0x80 [ 983.621428] [<ffffffff9124aff6>] do_dentry_open+0x1c6/0x2d0 [ 983.627651] [<ffffffff9124c029>] vfs_open+0x69/0x80 [ 983.633181] [<ffffffff9125db74>] path_openat+0x834/0xaa0 [ 983.639152] [<ffffffff9125ef75>] do_filp_open+0x85/0xe0 [ 983.645035] [<ffffffff9124c41c>] do_sys_open+0x14c/0x1f0 [ 983.650999] [<ffffffff9124c4de>] SyS_open+0x1e/0x20 [ 983.656535] [<ffffffff91825fc0>] entry_SYSCALL_64_fastpath+0x23/0xc1 [ 983.663541] -> #0 (&bdev->bd_mutex){+.+.+.}: [ 983.668107] [<ffffffff910def43>] __lock_acquire+0x1003/0x17b0 [ 983.674510] [<ffffffff910dfd0c>] lock_acquire+0x1bc/0x1f0 [ 983.680561] [<ffffffff91823125>] mutex_lock_nested+0x65/0x350 [ 983.686967] [<ffffffff9128ec51>] blkdev_put+0x31/0x150 [ 983.692761] [<ffffffffc033481f>] btrfs_close_bdev+0x4f/0x60 [btrfs] [ 983.699699] [<ffffffffc033d77b>] __btrfs_close_devices+0xcb/0x200 [btrfs] [ 983.707178] [<ffffffffc033d8db>] btrfs_close_devices+0x2b/0xa0 [btrfs] [ 983.714380] [<ffffffffc03081c5>] close_ctree+0x265/0x340 [btrfs] [ 983.721061] [<ffffffffc02d7959>] btrfs_put_super+0x19/0x20 [btrfs] [ 983.727908] [<ffffffff91250e2f>] generic_shutdown_super+0x6f/0x100 [ 983.734744] [<ffffffff91250f56>] kill_anon_super+0x16/0x30 [ 983.740888] [<ffffffffc02da97e>] btrfs_kill_super+0x1e/0x130 [btrfs] [ 983.747909] [<ffffffff91250fe9>] deactivate_locked_super+0x49/0x80 [ 983.754745] [<ffffffff912515fd>] deactivate_super+0x5d/0x70 [ 983.760977] [<ffffffff91270a1c>] cleanup_mnt+0x5c/0x80 [ 983.766773] [<ffffffff91270a92>] __cleanup_mnt+0x12/0x20 [ 983.772738] [<ffffffff910aa2fe>] task_work_run+0x7e/0xc0 [ 983.778708] [<ffffffff91081b5a>] exit_to_usermode_loop+0x7e/0xb4 [ 983.785373] [<ffffffff910039eb>] syscall_return_slowpath+0xbb/0xd0 [ 983.792212] [<ffffffff9182605c>] entry_SYSCALL_64_fastpath+0xbf/0xc1 [ 983.799225] [ 983.799225] other info that might help us debug this: [ 983.799225] [ 983.807291] Chain exists of: &bdev->bd_mutex --> namespace_sem --> &fs_devs->device_list_mutex [ 983.816521] Possible unsafe locking scenario: [ 983.816521] [ 983.822489] CPU0 CPU1 [ 983.827043] ---- ---- [ 983.831599] lock(&fs_devs->device_list_mutex); [ 983.836289] lock(namespace_sem); [ 983.842268] lock(&fs_devs->device_list_mutex); [ 983.849478] lock(&bdev->bd_mutex); [ 983.853127] [ 983.853127] *** DEADLOCK *** [ 983.853127] [ 983.859113] 3 locks held by umount/21720: [ 983.863145] #0: (&type->s_umount_key#35){++++..}, at: [<ffffffff912515f5>] deactivate_super+0x55/0x70 [ 983.872713] #1: (uuid_mutex){+.+.+.}, at: [<ffffffffc033d8d3>] btrfs_close_devices+0x23/0xa0 [btrfs] [ 983.882206] #2: (&fs_devs->device_list_mutex){+.+...}, at: [<ffffffffc033d6f6>] __btrfs_close_devices+0x46/0x200 [btrfs] [ 983.893422] [ 983.893422] stack backtrace: [ 983.897824] CPU: 6 PID: 21720 Comm: umount Not tainted 4.8.0-rc5-ceph-00023-g1b39cec2 #1 [ 983.905958] Hardware name: Supermicro SYS-5018R-WR/X10SRW-F, BIOS 1.0c 09/07/2015 [ 983.913492] 0000000000000000 ffff8c8a53c17a38 ffffffff91429521 ffffffff9260f4f0 [ 983.921018] ffffffff92642760 ffff8c8a53c17a88 ffffffff911b2b04 0000000000000050 [ 983.928542] ffffffff9237d620 ffff8c8a5294aee0 ffff8c8a5294aeb8 ffff8c8a5294aee0 [ 983.936072] Call Trace: [ 983.938545] [<ffffffff91429521>] dump_stack+0x85/0xc4 [ 983.943715] [<ffffffff911b2b04>] print_circular_bug+0x1fb/0x20c [ 983.949748] [<ffffffff910def43>] __lock_acquire+0x1003/0x17b0 [ 983.955613] [<ffffffff910dfd0c>] lock_acquire+0x1bc/0x1f0 [ 983.961123] [<ffffffff9128ec51>] ? blkdev_put+0x31/0x150 [ 983.966550] [<ffffffff91823125>] mutex_lock_nested+0x65/0x350 [ 983.972407] [<ffffffff9128ec51>] ? blkdev_put+0x31/0x150 [ 983.977832] [<ffffffff9128ec51>] blkdev_put+0x31/0x150 [ 983.983101] [<ffffffffc033481f>] btrfs_close_bdev+0x4f/0x60 [btrfs] [ 983.989500] [<ffffffffc033d77b>] __btrfs_close_devices+0xcb/0x200 [btrfs] [ 983.996415] [<ffffffffc033d8db>] btrfs_close_devices+0x2b/0xa0 [btrfs] [ 984.003068] [<ffffffffc03081c5>] close_ctree+0x265/0x340 [btrfs] [ 984.009189] [<ffffffff9126cc5e>] ? evict_inodes+0x15e/0x170 [ 984.014881] [<ffffffffc02d7959>] btrfs_put_super+0x19/0x20 [btrfs] [ 984.021176] [<ffffffff91250e2f>] generic_shutdown_super+0x6f/0x100 [ 984.027476] [<ffffffff91250f56>] kill_anon_super+0x16/0x30 [ 984.033082] [<ffffffffc02da97e>] btrfs_kill_super+0x1e/0x130 [btrfs] [ 984.039548] [<ffffffff91250fe9>] deactivate_locked_super+0x49/0x80 [ 984.045839] [<ffffffff912515fd>] deactivate_super+0x5d/0x70 [ 984.051525] [<ffffffff91270a1c>] cleanup_mnt+0x5c/0x80 [ 984.056774] [<ffffffff91270a92>] __cleanup_mnt+0x12/0x20 [ 984.062201] [<ffffffff910aa2fe>] task_work_run+0x7e/0xc0 [ 984.067625] [<ffffffff91081b5a>] exit_to_usermode_loop+0x7e/0xb4 [ 984.073747] [<ffffffff910039eb>] syscall_return_slowpath+0xbb/0xd0 [ 984.080038] [<ffffffff9182605c>] entry_SYSCALL_64_fastpath+0xbf/0xc1 Reported-by:Ilya Dryomov <idryomov@gmail.com> Signed-off-by:
Anand Jain <anand.jain@oracle.com> Reviewed-by:
David Sterba <dsterba@suse.com> Signed-off-by:
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Liu Bo authored
The extent buffer 'next' needs to be free'd conditionally. Signed-off-by:
Liu Bo <bo.li.liu@oracle.com> Reviewed-by:
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Jeff Mahoney authored
We can hit unused variable warnings when btrfs_debug and friends are just aliases for no_printk. This is due to the fs_info not getting consumed by the function call, which can happen if convenenience variables are used. This patch adds a new btrfs_no_printk static inline that consumes the convenience variable and does nothing else. It silences the unused variable warning and has no impact on the generated code: $ size fs/btrfs/extent_io.o* text data bss dec hex filename 44072 152 32 44256 ace0 fs/btrfs/extent_io.o.btrfs_no_printk 44072 152 32 44256 ace0 fs/btrfs/extent_io.o.no_printk Fixes: 27a0dd61 (Btrfs: make btrfs_debug match pr_debug handling related to DEBUG) Signed-off-by:
Jeff Mahoney <jeffm@suse.com> Signed-off-by:
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Jeff Mahoney authored
This was basically an open-coded, less flexible dynamic printk. We can just use btrfs_debug instead. Signed-off-by:
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Jeff Mahoney authored
For many printks, we want to know which file system issued the message. This patch converts most pr_* calls to use the btrfs_* versions instead. In some cases, this means adding plumbing to allow call sites access to an fs_info pointer. fs/btrfs/check-integrity.c is left alone for another day. Signed-off-by:
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Jeff Mahoney authored
This patch converts printk(KERN_* style messages to use the pr_* versions. One side effect is that anything that was KERN_DEBUG is now automatically a dynamic debug message. Signed-off-by:
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Jeff Mahoney authored
CodingStyle chapter 2: "[...] never break user-visible strings such as printk messages, because that breaks the ability to grep for them." This patch unsplits user-visible strings. Signed-off-by:
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Jeff Mahoney authored
btrfs_rm_device frees the block device but then re-opens it using the saved device name. A race exists between the close and the re-open that allows the block size to be changed. The result is getting stuck forever in the reclaim loop in __getblk_slow. This patch moves the superblock cleanup before closing the block device, which is also consistent with other callers. We also don't need a private copy of dev_name as the whole routine operates under the uuid_mutex. Signed-off-by:
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Liu Bo authored
In a corrupted btrfs image, we can come across this BUG_ON and get an unreponsive system, but if we return errors instead, its caller can handle everything gracefully by aborting the current transaction. Signed-off-by:
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Josef Bacik authored
We don't track the reloc roots in any sort of normal way, so the only way the root/commit_root nodes get free'd is if the relocation finishes successfully and the reloc root is deleted. Fix this by free'ing them in free_reloc_roots. Thanks, Signed-off-by:
Josef Bacik <jbacik@fb.com> Signed-off-by:
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Masahiro Yamada authored
Remove unneeded variables and assignments. Signed-off-by:
Masahiro Yamada <yamada.masahiro@socionext.com> Reviewed-by:
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Liu Bo authored
We need to check items in a node to make sure that we're reading a valid one, otherwise we could get various crashes while processing delayed_refs. Signed-off-by:
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Liu Bo authored
Somehow we missed btrfs_print_tree when last time we updated error handling for read_extent_block(). This keeps us from getting a NULL pointer panic when btrfs_print_tree's read_extent_block() fails. Signed-off-by:
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Liu Bo authored
Since we could get errors from the concurrent aborted transaction, the check of this BUG_ON in start_transaction is not true any more. Say, while flushing free space cache inode's dirty pages, btrfs_finish_ordered_io -> btrfs_join_transaction_nolock (the transaction has been aborted.) -> BUG_ON(type == TRANS_JOIN_NOLOCK); Signed-off-by: -
Liu Bo authored
During updating btree, we could push items between sibling nodes/leaves, for leaves data sections starts reversely from the end of the block while for nodes we only have key pairs which are stored one by one from the start of the block. So we could do try to push key pairs from one node to the next node right in the tree, and after that, we update the node's nritems to reflect the correct end while leaving the stale content in the node. One may intentionally corrupt the fs image and access the stale content by bumping the nritems and causes various crashes. This takes the in-memory @nritems as the correct one and gets to memset the unused part of a btree node. Signed-off-by:
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Liu Bo authored
When relocating tree blocks, we firstly get block information from back references in the extent tree, we then search fs tree to try to find all parents of a block. However, if fs tree is corrupted, eg. if there're some missing items, we could come across these WARN_ONs and BUG_ONs. This makes us print some error messages and return gracefully from balance. Signed-off-by:
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Josef Bacik authored
No reason to bug on in here, fs corruption could easily cause these things to happen. Signed-off-by:
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Josef Bacik authored
Nobody uses this, it makes no sense to do partial reads of extent buffers. Signed-off-by:
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Josef Bacik authored
We have a lot of random ints in btrfs_fs_info that can be put into flags. This is mostly equivalent with the exception of how we deal with quota going on or off, now instead we set a flag when we are turning it on or off and deal with that appropriately, rather than just having a pending state that the current quota_enabled gets set to. Thanks, Signed-off-by:
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Qu Wenruo authored
btrfs: extend btrfs_set_extent_delalloc and its friends to support in-band dedupe and subpage size patchset Extend btrfs_set_extent_delalloc() and extent_clear_unlock_delalloc() parameters for both in-band dedupe and subpage sector size patchset. This should reduce conflict of both patchset and the effort to rebase them. Cc: Chandan Rajendra <chandan@linux.vnet.ibm.com> Cc: David Sterba <dsterba@suse.cz> Signed-off-by:
Qu Wenruo <quwenruo@cn.fujitsu.com> Signed-off-by:
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Jeff Mahoney authored
We can re-use the dynamic debugging descriptor to make use of the dynamic debugging mechanism but still use our own printk interface. Defining the DEBUG macro works as it did before. When it's defined, all of the messages default to print. We can also enable all debug messages at boot or module-load time using the 'dyndbg' and 'btrfs.dyndbg' options. Signed-off-by:
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Luis Henriques authored
Variable 'gen' in reada_for_search() is not used since commit 58dc4ce4 ("btrfs: remove unused parameter from readahead_tree_block"). This patch simply removes this variable. Signed-off-by:
Luis Henriques <luis.henriques@canonical.com> Reviewed-by:
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Luis Henriques authored
Variable 'blocksize' in reada_walk_down() is not used since commit d3e46fea ("btrfs: sink blocksize parameter to readahead_tree_block"). This patch simply removes this variable. Signed-off-by:
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Naohiro Aota authored
Currently, btrfs_relocate_chunk() is removing relocated BG by itself. But the work can be done by btrfs_delete_unused_bgs() (and it's better since it trim the BG). Let's dedupe the code. While btrfs_delete_unused_bgs() is already hitting the relocated BG, it skip the BG since the BG has "ro" flag set (to keep balancing BG intact). On the other hand, btrfs cannot drop "ro" flag here to prevent additional writes. So this patch make use of "removed" flag. btrfs_delete_unused_bgs() now detect the flag to distinguish whether a read-only BG is relocating or not. Signed-off-by:
Naohiro Aota <naohiro.aota@hgst.com> Reviewed-by:
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Liu Bo authored
Currently we allow inconsistence about mixed flag (BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA). We'd get ENOSPC if block group has mixed flag and btrfs doesn't. If that happens, we have one space_info with mixed flag and another space_info only with BTRFS_BLOCK_GROUP_METADATA, and global_block_rsv.space_info points to the latter one, but all bytes from block_group contributes to the mixed space_info, thus all the allocation will fail with ENOSPC. This adds a check for the above case. Reported-by:
Vegard Nossum <vegard.nossum@oracle.com> Signed-off-by:
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Liu Bo authored
So we can read a btree block via readahead or intentional read, and we can end up with a memory leak when something happens as follows, 1) readahead starts to read block A but does not wait for read completion, 2) btree_readpage_end_io_hook finds that block A is corrupted, and it needs to clear all block A's pages' uptodate bit. 3) meanwhile an intentional read kicks in and checks block A's pages' uptodate to decide which page needs to be read. 4) when some pages have the uptodate bit during 3)'s check so 3) doesn't count them for eb->io_pages, but they are later cleared by 2) so we has to readpage on the page, we get the wrong eb->io_pages which results in a memory leak of this block. This fixes the problem by firstly getting all pages's locking and then checking pages' uptodate bit. t1(readahead) t2(readahead endio) t3(the following read) read_extent_buffer_pages end_bio_extent_readpage for pg in eb: for page 0,1,2 in eb: if pg is uptodate: btree_readpage_end_io_hook(pg) num_reads++ if uptodate: eb->io_pages = num_reads SetPageUptodate(pg) _______________ for pg in eb: for page 3 in eb: read_extent_buffer_pages if pg is NOT uptodate: btree_readpage_end_io_hook(pg) for pg in eb: __extent_read_full_page(pg) sanity check reports something wrong if pg is uptodate: clear_extent_buffer_uptodate(eb) num_reads++ for pg in eb: eb->io_pages = num_reads ClearPageUptodate(page) _______________ for pg in eb: if pg is NOT uptodate: __extent_read_full_page(pg) So t3's eb->io_pages is not consistent with the number of pages it's reading, and during endio(), atomic_dec_and_test(&eb->io_pages) will get a negative number so that we're not able to free the eb. Signed-off-by: -
Liu Bo authored
This BUG() has been triggered by a fuzz testing image, which contains an invalid chunk type, ie. a single stripe chunk has the raid6 type. Btrfs can handle this gracefully by returning -EIO, so besides using btrfs_warn to give us more debugging information rather than a single BUG(), we can return error properly. Signed-off-by:
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Lu Fengqi authored
Only in the case of different root_id or different object_id, check_shared identified extent as the shared. However, If a extent was referred by different offset of same file, it should also be identified as shared. In addition, check_shared's loop scale is at least n^3, so if a extent has too many references, even causes soft hang up. First, add all delayed_ref to the ref_tree and calculate the unqiue_refs, if the unique_refs is greater than one, return BACKREF_FOUND_SHARED. Then individually add the on-disk reference(inline/keyed) to the ref_tree and calculate the unique_refs of the ref_tree to check if the unique_refs is greater than one.Because once there are two references to return SHARED, so the time complexity is close to the constant. Reported-by:
Tsutomu Itoh <t-itoh@jp.fujitsu.com> Signed-off-by:
Lu Fengqi <lufq.fnst@cn.fujitsu.com> Signed-off-by:
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David Sterba authored
Reviewed-by:
Eric Sandeen <sandeen@redhat.com> Signed-off-by:
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Eric Sandeen authored
btrfs provides a helpful demonstration of how to export a global variable via debugfs; however, it is unique among other debugfs files in that it is world-writable, which causes some concern to people who are not familiar with its purpose. Fix it so that it is only user-writable. Signed-off-by:
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Liu Bo authored
While processing delayed refs, we may update block group's statistics and attach it to cur_trans->dirty_bgs, and later writing dirty block groups will process the list, which happens during btrfs_commit_transaction(). For whatever reason, the transaction is aborted and dirty_bgs is not processed in cleanup_transaction(), we end up with memory leak of these dirty block group cache. Since btrfs_start_dirty_block_groups() doesn't make it go to the commit critical section, this also adds the cleanup work inside it. Signed-off-by:
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Linus Torvalds authored
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git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-traceLinus Torvalds authored
Pull tracefs fixes from Steven Rostedt: "Al Viro has been looking at the tracefs code, and has pointed out some issues. This contains one fix by me and one by Al. I'm sure that he'll come up with more but for now I tested these patches and they don't appear to have any negative impact on tracing" * tag 'trace-v4.8-rc7' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace: fix memory leaks in tracing_buffers_splice_read() tracing: Move mutex to protect against resetting of seq data
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Dave Chinner authored
When building XFS with -Werror, it now fails with: include/linux/pagemap.h: In function 'fault_in_multipages_readable': include/linux/pagemap.h:602:16: error: variable 'c' set but not used [-Werror=unused-but-set-variable] volatile char c; ^ This is a regression caused by commit e23d4159 ("fix fault_in_multipages_...() on architectures with no-op access_ok()"). Fix it by re-adding the "(void)c" trick taht was previously used to make the compiler think the variable is used. Signed-off-by:Dave Chinner <dchinner@redhat.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Signed-off-by:
Linus Torvalds <torvalds@linux-foundation.org>
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- 25 Sep, 2016 6 commits
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Lorenzo Stoakes authored
The NUMA balancing logic uses an arch-specific PROT_NONE page table flag defined by pte_protnone() or pmd_protnone() to mark PTEs or huge page PMDs respectively as requiring balancing upon a subsequent page fault. User-defined PROT_NONE memory regions which also have this flag set will not normally invoke the NUMA balancing code as do_page_fault() will send a segfault to the process before handle_mm_fault() is even called. However if access_remote_vm() is invoked to access a PROT_NONE region of memory, handle_mm_fault() is called via faultin_page() and __get_user_pages() without any access checks being performed, meaning the NUMA balancing logic is incorrectly invoked on a non-NUMA memory region. A simple means of triggering this problem is to access PROT_NONE mmap'd memory using /proc/self/mem which reliably results in the NUMA handling functions being invoked when CONFIG_NUMA_BALANCING is set. This issue was reported in bugzilla (issue 99101) which includes some simple repro code. There are BUG_ON() checks in do_numa_page() and do_huge_pmd_numa_page() added at commit c0e7cad9 to avoid accidentally provoking strange behaviour by attempting to apply NUMA balancing to pages that are in fact PROT_NONE. The BUG_ON()'s are consistently triggered by the repro. This patch moves the PROT_NONE check into mm/memory.c rather than invoking BUG_ON() as faulting in these pages via faultin_page() is a valid reason for reaching the NUMA check with the PROT_NONE page table flag set and is therefore not always a bug. Link: https://bugzilla.kernel.org/show_bug.cgi?id=99101Reported-by:
Trevor Saunders <tbsaunde@tbsaunde.org> Signed-off-by:
Lorenzo Stoakes <lstoakes@gmail.com> Acked-by:
Rik van Riel <riel@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Mel Gorman <mgorman@techsingularity.net> Signed-off-by:
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git://git.linux-mips.org/pub/scm/ralf/upstream-linusLinus Torvalds authored
Pull MIPS fixes from Ralf Baechle: "A round of 4.8 fixes: MIPS generic code: - Add a missing ".set pop" in an early commit - Fix memory regions reaching top of physical - MAAR: Fix address alignment - vDSO: Fix Malta EVA mapping to vDSO page structs - uprobes: fix incorrect uprobe brk handling - uprobes: select HAVE_REGS_AND_STACK_ACCESS_API - Avoid a BUG warning during PR_SET_FP_MODE prctl - SMP: Fix possibility of deadlock when bringing CPUs online - R6: Remove compact branch policy Kconfig entries - Fix size calc when avoiding IPIs for small icache flushes - Fix pre-r6 emulation FPU initialisation - Fix delay slot emulation count in debugfs ATH79: - Fix test for error return of clk_register_fixed_factor. Octeon: - Fix kernel header to work for VDSO build. - Fix initialization of platform device probing. paravirt: - Fix undefined reference to smp_bootstrap" * 'upstream' of git://git.linux-mips.org/pub/scm/ralf/upstream-linus: MIPS: Fix delay slot emulation count in debugfs MIPS: SMP: Fix possibility of deadlock when bringing CPUs online MIPS: Fix pre-r6 emulation FPU initialisation MIPS: vDSO: Fix Malta EVA mapping to vDSO page structs MIPS: Select HAVE_REGS_AND_STACK_ACCESS_API MIPS: Octeon: Fix platform bus probing MIPS: Octeon: mangle-port: fix build failure with VDSO code MIPS: Avoid a BUG warning during prctl(PR_SET_FP_MODE, ...) MIPS: c-r4k: Fix size calc when avoiding IPIs for small icache flushes MIPS: Add a missing ".set pop" in an early commit MIPS: paravirt: Fix undefined reference to smp_bootstrap MIPS: Remove compact branch policy Kconfig entries MIPS: MAAR: Fix address alignment MIPS: Fix memory regions reaching top of physical MIPS: uprobes: fix incorrect uprobe brk handling MIPS: ath79: Fix test for error return of clk_register_fixed_factor().
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git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linuxLinus Torvalds authored
Pull one more powerpc fix from Michael Ellerman: "powernv/pci: Fix m64 checks for SR-IOV and window alignment from Russell Currey" * tag 'powerpc-4.8-7' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux: powerpc/powernv/pci: Fix m64 checks for SR-IOV and window alignment
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Linus Torvalds authored
The fixes to the radix tree test suite show that the multi-order case is broken. The basic reason is that the radix tree code uses tagged pointers with the "internal" bit in the low bits, and calculating the pointer indices was supposed to mask off those bits. But gcc will notice that we then use the index to re-create the pointer, and will avoid doing the arithmetic and use the tagged pointer directly. This cleans the code up, using the existing is_sibling_entry() helper to validate the sibling pointer range (instead of open-coding it), and using entry_to_node() to mask off the low tag bit from the pointer. And once you do that, you might as well just use the now cleaned-up pointer directly. [ Side note: the multi-order code isn't actually ever used in the kernel right now, and the only reason I didn't just delete all that code is that Kirill Shutemov piped up and said: "Well, my ext4-with-huge-pages patchset[1] uses multi-order entries. It also converts shmem-with-huge-pages and hugetlb to them. I'm okay with converting it to other mechanism, but I need something. (I looked into Konstantin's RFC patchset[2]. It looks okay, but I don't feel myself qualified to review it as I don't know much about radix-tree internals.)" [1] http://lkml.kernel.org/r/20160915115523.29737-1-kirill.shutemov@linux.intel.com [2] http://lkml.kernel.org/r/147230727479.9957.1087787722571077339.stgit@zurg ] Reported-by:Matthew Wilcox <mawilcox@microsoft.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Ross Zwisler <ross.zwisler@linux.intel.com> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Cc: Konstantin Khlebnikov <koct9i@gmail.com> Cc: Cedric Blancher <cedric.blancher@gmail.com> Signed-off-by:
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Matthew Wilcox authored
When we replace a multiorder entry, check that all indices reflect the new value. Also, compile the test suite with -O2, which shows other problems with the code due to some dodgy pointer operations in the radix tree code. Signed-off-by:
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Al Viro authored
Cc: stable@vger.kernel.org Signed-off-by:Al Viro <viro@zeniv.linux.org.uk>
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