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path: root/fs/btrfs/delayed-inode.h
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2016-06-25Btrfs: fix ->iterate_shared() by upgrading i_rwsem for delayed nodesOmar Sandoval
Commit fe742fd4f90f ("Revert "btrfs: switch to ->iterate_shared()"") backed out the conversion to ->iterate_shared() for Btrfs because the delayed inode handling in btrfs_real_readdir() is racy. However, we can still do readdir in parallel if there are no delayed nodes. This is a temporary fix which upgrades the shared inode lock to an exclusive lock only when we have delayed items until we come up with a more complete solution. While we're here, rename the btrfs_{get,put}_delayed_items functions to make it very clear that they're just for readdir. Tested with xfstests and by doing a parallel kernel build: while make tinyconfig && make -j4 && git clean dqfx; do : done along with a bunch of parallel finds in another shell: while true; do for ((i=0; i<4; i++)); do find . >/dev/null & done wait done Signed-off-by: Omar Sandoval <osandov@fb.com> Signed-off-by: David Sterba <dsterba@suse.com> Signed-off-by: Chris Mason <clm@fb.com>
2016-02-11btrfs: properly set the termination value of ctx->pos in readdirDavid Sterba
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>
2014-01-28Btrfs: introduce the delayed inode ref deletion for the single link inodeMiao Xie
The inode reference item is close to inode item, so we insert it simultaneously with the inode item insertion when we create a file/directory.. In fact, we also can handle the inode reference deletion by the same way. So we made this patch to introduce the delayed inode reference deletion for the single link inode(At most case, the file doesn't has hard link, so we don't take the hard link into account). This function is based on the delayed inode mechanism. After applying this patch, we can reduce the time of the file/directory deletion by ~10%. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2014-01-28Btrfs: use flags instead of the bool variants in delayed nodeMiao Xie
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <clm@fb.com>
2013-06-29[readdir] convert btrfsAl Viro
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2013-03-07Btrfs: improve the delayed inode throttlingChris Mason
The delayed inode code batches up changes to the btree in hopes of doing them in bulk. As the changes build up, processes kick off worker threads and wait for them to make progress. The current code kicks off an async work queue item for each delayed node, which creates a lot of churn. It also uses a fixed 1 HZ waiting period for the throttle, which allows us to build a lot of pending work and can slow down the commit. This changes us to watch a sequence counter as it is bumped during the operations. We kick off fewer work items and have each work item do more work. Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2013-02-20Btrfs: fix lots of orphan inodes when the space is not enoughMiao Xie
We're running into having 50-100 orphans left over with xfstests 83 because of ENOSPC when trying to start the transaction for the inode update. But in fact, it makes no sense in updating the inode for the new size while we're deleting the stupid thing. This patch fixes this problem. Reported-by: Josef Bacik <jbacik@fusionio.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-07-23Btrfs: flush delayed inodes if we're short on spaceJosef Bacik
Those crazy gentoo guys have been complaining about ENOSPC errors on their portage volumes. This is because doing things like untar tends to create lots of new files which will soak up all the reservation space in the delayed inodes. Usually this gets papered over by the fact that we will try and commit the transaction, however if this happens in the wrong spot or we choose not to commit the transaction you will be screwed. So add the ability to expclitly flush delayed inodes to free up space. Please test this out guys to make sure it works since as usual I cannot reproduce. Thanks, Signed-off-by: Josef Bacik <jbacik@fusionio.com>
2012-06-15Btrfs: destroy the items of the delayed inodes in error handling routineMiao Xie
the items of the delayed inodes were forgotten to be freed, this patch fixes it. Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@fusionio.com>
2011-07-26atomic: use <linux/atomic.h>Arun Sharma
This allows us to move duplicated code in <asm/atomic.h> (atomic_inc_not_zero() for now) to <linux/atomic.h> Signed-off-by: Arun Sharma <asharma@fb.com> Reviewed-by: Eric Dumazet <eric.dumazet@gmail.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: David Miller <davem@davemloft.net> Cc: Eric Dumazet <eric.dumazet@gmail.com> Acked-by: Mike Frysinger <vapier@gentoo.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2011-06-27btrfs: fix inconsonant inode informationMiao Xie
When iputting the inode, We may leave the delayed nodes if they have some delayed items that have not been dealt with. So when the inode is read again, we must look up the relative delayed node, and use the information in it to initialize the inode. Or we will get inconsonant inode information, it may cause that the same directory index number is allocated again, and hit the following oops: [ 5447.554187] err add delayed dir index item(name: pglog_0.965_0) into the insertion tree of the delayed node(root id: 262, inode id: 258, errno: -17) [ 5447.569766] ------------[ cut here ]------------ [ 5447.575361] kernel BUG at fs/btrfs/delayed-inode.c:1301! [SNIP] [ 5447.790721] Call Trace: [ 5447.793191] [<ffffffffa0641c4e>] btrfs_insert_dir_item+0x189/0x1bb [btrfs] [ 5447.800156] [<ffffffffa0651a45>] btrfs_add_link+0x12b/0x191 [btrfs] [ 5447.806517] [<ffffffffa0651adc>] btrfs_add_nondir+0x31/0x58 [btrfs] [ 5447.812876] [<ffffffffa0651d6a>] btrfs_create+0xf9/0x197 [btrfs] [ 5447.818961] [<ffffffff8111f840>] vfs_create+0x72/0x92 [ 5447.824090] [<ffffffff8111fa8c>] do_last+0x22c/0x40b [ 5447.829133] [<ffffffff8112076a>] path_openat+0xc0/0x2ef [ 5447.834438] [<ffffffff810c58e2>] ? __perf_event_task_sched_out+0x24/0x44 [ 5447.841216] [<ffffffff8103ecdd>] ? perf_event_task_sched_out+0x59/0x67 [ 5447.847846] [<ffffffff81121a79>] do_filp_open+0x3d/0x87 [ 5447.853156] [<ffffffff811e126c>] ? strncpy_from_user+0x43/0x4d [ 5447.859072] [<ffffffff8111f1f5>] ? getname_flags+0x2e/0x80 [ 5447.864636] [<ffffffff8111f179>] ? do_getname+0x14b/0x173 [ 5447.870112] [<ffffffff8111f1b7>] ? audit_getname+0x16/0x26 [ 5447.875682] [<ffffffff8112b1ab>] ? spin_lock+0xe/0x10 [ 5447.880882] [<ffffffff81112d39>] do_sys_open+0x69/0xae [ 5447.886153] [<ffffffff81112db1>] sys_open+0x20/0x22 [ 5447.891114] [<ffffffff813b9aab>] system_call_fastpath+0x16/0x1b Fix it by reusing the old delayed node. Reported-by: Jim Schutt <jaschut@sandia.gov> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Tested-by: Jim Schutt <jaschut@sandia.gov> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-06-17Btrfs: avoid delayed metadata items during commitsChris Mason
Snapshot creation has two phases. One is the initial snapshot setup, and the second is done during commit, while nobody is allowed to modify the root we are snapshotting. The delayed metadata insertion code can break that rule, it does a delayed inode update on the inode of the parent of the snapshot, and delayed directory item insertion. This makes sure to run the pending delayed operations before we record the snapshot root, which avoids corruptions. Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-06-17btrfs: fix wrong reservation when doing delayed inode operationsMiao Xie
We have migrated the space for the delayed inode items from trans_block_rsv to global_block_rsv, but we forgot to set trans->block_rsv to global_block_rsv when we doing delayed inode operations, and the following Oops happened: [ 9792.654889] ------------[ cut here ]------------ [ 9792.654898] WARNING: at fs/btrfs/extent-tree.c:5681 btrfs_alloc_free_block+0xca/0x27c [btrfs]() [ 9792.654899] Hardware name: To Be Filled By O.E.M. [ 9792.654900] Modules linked in: btrfs zlib_deflate libcrc32c ip6t_REJECT nf_conntrack_ipv6 nf_defrag_ipv6 ip6table_filter ip6_tables arc4 rt61pci rt2x00pci rt2x00lib snd_hda_codec_hdmi mac80211 snd_hda_codec_realtek cfg80211 snd_hda_intel edac_core snd_seq rfkill pcspkr serio_raw snd_hda_codec eeprom_93cx6 edac_mce_amd sp5100_tco i2c_piix4 k10temp snd_hwdep snd_seq_device snd_pcm floppy r8169 xhci_hcd mii snd_timer snd soundcore snd_page_alloc ipv6 firewire_ohci pata_acpi ata_generic firewire_core pata_via crc_itu_t radeon ttm drm_kms_helper drm i2c_algo_bit i2c_core [last unloaded: scsi_wait_scan] [ 9792.654919] Pid: 2762, comm: rm Tainted: G W 2.6.39+ #1 [ 9792.654920] Call Trace: [ 9792.654922] [<ffffffff81053c4a>] warn_slowpath_common+0x83/0x9b [ 9792.654925] [<ffffffff81053c7c>] warn_slowpath_null+0x1a/0x1c [ 9792.654933] [<ffffffffa038e747>] btrfs_alloc_free_block+0xca/0x27c [btrfs] [ 9792.654945] [<ffffffffa03b8562>] ? map_extent_buffer+0x6e/0xa8 [btrfs] [ 9792.654953] [<ffffffffa038189b>] __btrfs_cow_block+0xfc/0x30c [btrfs] [ 9792.654963] [<ffffffffa0396aa6>] ? btrfs_buffer_uptodate+0x47/0x58 [btrfs] [ 9792.654970] [<ffffffffa0382e48>] ? read_block_for_search+0x94/0x368 [btrfs] [ 9792.654978] [<ffffffffa0381ba9>] btrfs_cow_block+0xfe/0x146 [btrfs] [ 9792.654986] [<ffffffffa03848b0>] btrfs_search_slot+0x14d/0x4b6 [btrfs] [ 9792.654997] [<ffffffffa03b8562>] ? map_extent_buffer+0x6e/0xa8 [btrfs] [ 9792.655022] [<ffffffffa03938e8>] btrfs_lookup_inode+0x2f/0x8f [btrfs] [ 9792.655025] [<ffffffff8147afac>] ? _cond_resched+0xe/0x22 [ 9792.655027] [<ffffffff8147b892>] ? mutex_lock+0x29/0x50 [ 9792.655039] [<ffffffffa03d41b1>] btrfs_update_delayed_inode+0x72/0x137 [btrfs] [ 9792.655051] [<ffffffffa03d4ea2>] btrfs_run_delayed_items+0x90/0xdb [btrfs] [ 9792.655062] [<ffffffffa039a69b>] btrfs_commit_transaction+0x228/0x654 [btrfs] [ 9792.655064] [<ffffffff8106e8da>] ? remove_wait_queue+0x3a/0x3a [ 9792.655075] [<ffffffffa03a2fa5>] btrfs_evict_inode+0x14d/0x202 [btrfs] [ 9792.655077] [<ffffffff81132bd6>] evict+0x71/0x111 [ 9792.655079] [<ffffffff81132de0>] iput+0x12a/0x132 [ 9792.655081] [<ffffffff8112aa3a>] do_unlinkat+0x106/0x155 [ 9792.655083] [<ffffffff81127b83>] ? path_put+0x1f/0x23 [ 9792.655085] [<ffffffff8109c53c>] ? audit_syscall_entry+0x145/0x171 [ 9792.655087] [<ffffffff81128410>] ? putname+0x34/0x36 [ 9792.655090] [<ffffffff8112b441>] sys_unlinkat+0x29/0x2b [ 9792.655092] [<ffffffff81482c42>] system_call_fastpath+0x16/0x1b [ 9792.655093] ---[ end trace 02b696eb02b3f768 ]--- This patch fix it by setting the reservation of the transaction handle to the correct one. Reported-by: Josef Bacik <josef@redhat.com> Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Signed-off-by: Chris Mason <chris.mason@oracle.com>
2011-05-21btrfs: implement delayed inode items operationMiao Xie
Changelog V5 -> V6: - Fix oom when the memory load is high, by storing the delayed nodes into the root's radix tree, and letting btrfs inodes go. Changelog V4 -> V5: - Fix the race on adding the delayed node to the inode, which is spotted by Chris Mason. - Merge Chris Mason's incremental patch into this patch. - Fix deadlock between readdir() and memory fault, which is reported by Itaru Kitayama. Changelog V3 -> V4: - Fix nested lock, which is reported by Itaru Kitayama, by updating space cache inode in time. Changelog V2 -> V3: - Fix the race between the delayed worker and the task which does delayed items balance, which is reported by Tsutomu Itoh. - Modify the patch address David Sterba's comment. - Fix the bug of the cpu recursion spinlock, reported by Chris Mason Changelog V1 -> V2: - break up the global rb-tree, use a list to manage the delayed nodes, which is created for every directory and file, and used to manage the delayed directory name index items and the delayed inode item. - introduce a worker to deal with the delayed nodes. Compare with Ext3/4, the performance of file creation and deletion on btrfs is very poor. the reason is that btrfs must do a lot of b+ tree insertions, such as inode item, directory name item, directory name index and so on. If we can do some delayed b+ tree insertion or deletion, we can improve the performance, so we made this patch which implemented delayed directory name index insertion/deletion and delayed inode update. Implementation: - introduce a delayed root object into the filesystem, that use two lists to manage the delayed nodes which are created for every file/directory. One is used to manage all the delayed nodes that have delayed items. And the other is used to manage the delayed nodes which is waiting to be dealt with by the work thread. - Every delayed node has two rb-tree, one is used to manage the directory name index which is going to be inserted into b+ tree, and the other is used to manage the directory name index which is going to be deleted from b+ tree. - introduce a worker to deal with the delayed operation. This worker is used to deal with the works of the delayed directory name index items insertion and deletion and the delayed inode update. When the delayed items is beyond the lower limit, we create works for some delayed nodes and insert them into the work queue of the worker, and then go back. When the delayed items is beyond the upper bound, we create works for all the delayed nodes that haven't been dealt with, and insert them into the work queue of the worker, and then wait for that the untreated items is below some threshold value. - When we want to insert a directory name index into b+ tree, we just add the information into the delayed inserting rb-tree. And then we check the number of the delayed items and do delayed items balance. (The balance policy is above.) - When we want to delete a directory name index from the b+ tree, we search it in the inserting rb-tree at first. If we look it up, just drop it. If not, add the key of it into the delayed deleting rb-tree. Similar to the delayed inserting rb-tree, we also check the number of the delayed items and do delayed items balance. (The same to inserting manipulation) - When we want to update the metadata of some inode, we cached the data of the inode into the delayed node. the worker will flush it into the b+ tree after dealing with the delayed insertion and deletion. - We will move the delayed node to the tail of the list after we access the delayed node, By this way, we can cache more delayed items and merge more inode updates. - If we want to commit transaction, we will deal with all the delayed node. - the delayed node will be freed when we free the btrfs inode. - Before we log the inode items, we commit all the directory name index items and the delayed inode update. I did a quick test by the benchmark tool[1] and found we can improve the performance of file creation by ~15%, and file deletion by ~20%. Before applying this patch: Create files: Total files: 50000 Total time: 1.096108 Average time: 0.000022 Delete files: Total files: 50000 Total time: 1.510403 Average time: 0.000030 After applying this patch: Create files: Total files: 50000 Total time: 0.932899 Average time: 0.000019 Delete files: Total files: 50000 Total time: 1.215732 Average time: 0.000024 [1] http://marc.info/?l=linux-btrfs&m=128212635122920&q=p3 Many thanks for Kitayama-san's help! Signed-off-by: Miao Xie <miaox@cn.fujitsu.com> Reviewed-by: David Sterba <dave@jikos.cz> Tested-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com> Tested-by: Itaru Kitayama <kitayama@cl.bb4u.ne.jp> Signed-off-by: Chris Mason <chris.mason@oracle.com>