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2010-01-08Merge branch 'reiserfs/kill-bkl' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing * 'reiserfs/kill-bkl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing: reiserfs: Relax reiserfs_xattr_set_handle() while acquiring xattr locks reiserfs: Fix unreachable statement reiserfs: Don't call reiserfs_get_acl() with the reiserfs lock reiserfs: Relax lock on xattr removing reiserfs: Relax the lock before truncating pages reiserfs: Fix recursive lock on lchown reiserfs: Fix mistake in down_write() conversion
2010-01-07reiserfs: Relax reiserfs_xattr_set_handle() while acquiring xattr locksFrederic Weisbecker
Fix remaining xattr locks acquired in reiserfs_xattr_set_handle() while we are holding the reiserfs lock to avoid lock inversions. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Christian Kujau <lists@nerdbynature.de> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2010-01-07reiserfs: Fix unreachable statementJiri Slaby
Stanse found an unreachable statement in reiserfs_ioctl. There is a if followed by error assignment and `break' with no braces. Add the braces so that we don't break every time, but only in error case, so that REISERFS_IOC_SETVERSION actually works when it returns no error. Signed-off-by: Jiri Slaby <jslaby@suse.cz> Cc: Reiserfs <reiserfs-devel@vger.kernel.org> Cc: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2010-01-07reiserfs: Don't call reiserfs_get_acl() with the reiserfs lockFrederic Weisbecker
reiserfs_get_acl is usually not called under the reiserfs lock, as it doesn't need it. But it happens when it is called by reiserfs_acl_chmod(), which creates a dependency inversion against the private xattr inodes mutexes for the given inode. We need to call it without the reiserfs lock, especially since it's unnecessary. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Christian Kujau <lists@nerdbynature.de> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2010-01-05reiserfs: Relax lock on xattr removingFrederic Weisbecker
When we remove an xattr, we call lookup_and_delete_xattr() that takes some private xattr inodes mutexes. But we hold the reiserfs lock at this time, which leads to dependency inversions. We can safely call lookup_and_delete_xattr() without the reiserfs lock, where xattr inodes lookups only need the xattr inodes mutexes. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Christian Kujau <lists@nerdbynature.de> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2010-01-05reiserfs: Relax the lock before truncating pagesFrederic Weisbecker
While truncating a file, reiserfs_setattr() calls inode_setattr() that will truncate the mapping for the given inode, but for that it needs the pages locks. In order to release these, the owners need the reiserfs lock to complete their jobs. But they can't, as we don't release it before calling inode_setattr(). We need to do that to fix the following softlockups: INFO: task flush-8:0:2149 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. flush-8:0 D f51af998 0 2149 2 0x00000000 f51af9ac 00000092 00000002 f51af998 c2803304 00000000 c1894ad0 010f3000 f51af9cc c1462604 c189ef80 f51af974 c1710304 f715b450 f715b5ec c2807c40 00000000 0005bb00 c2803320 c102c55b c1710304 c2807c50 c2803304 00000246 Call Trace: [<c1462604>] ? schedule+0x434/0xb20 [<c102c55b>] ? resched_task+0x4b/0x70 [<c106fa22>] ? mark_held_locks+0x62/0x80 [<c146414d>] ? mutex_lock_nested+0x1fd/0x350 [<c14640b9>] mutex_lock_nested+0x169/0x350 [<c1178cde>] ? reiserfs_write_lock+0x2e/0x40 [<c1178cde>] reiserfs_write_lock+0x2e/0x40 [<c11719a2>] do_journal_end+0xc2/0xe70 [<c1172912>] journal_end+0xb2/0x120 [<c11686b3>] ? pathrelse+0x33/0xb0 [<c11729e4>] reiserfs_end_persistent_transaction+0x64/0x70 [<c1153caa>] reiserfs_get_block+0x12ba/0x15f0 [<c106fa22>] ? mark_held_locks+0x62/0x80 [<c1154b24>] reiserfs_writepage+0xa74/0xe80 [<c1465a27>] ? _raw_spin_unlock_irq+0x27/0x50 [<c11f3d25>] ? radix_tree_gang_lookup_tag_slot+0x95/0xc0 [<c10b5377>] ? find_get_pages_tag+0x127/0x1a0 [<c106fa22>] ? mark_held_locks+0x62/0x80 [<c106fcd4>] ? trace_hardirqs_on_caller+0x124/0x170 [<c10bc1e0>] __writepage+0x10/0x40 [<c10bc9ab>] write_cache_pages+0x16b/0x320 [<c10bc1d0>] ? __writepage+0x0/0x40 [<c10bcb88>] generic_writepages+0x28/0x40 [<c10bcbd5>] do_writepages+0x35/0x40 [<c11059f7>] writeback_single_inode+0xc7/0x330 [<c11067b2>] writeback_inodes_wb+0x2c2/0x490 [<c1106a86>] wb_writeback+0x106/0x1b0 [<c1106cf6>] wb_do_writeback+0x106/0x1e0 [<c1106c18>] ? wb_do_writeback+0x28/0x1e0 [<c1106e0a>] bdi_writeback_task+0x3a/0xb0 [<c10cbb13>] bdi_start_fn+0x63/0xc0 [<c10cbab0>] ? bdi_start_fn+0x0/0xc0 [<c105d1f4>] kthread+0x74/0x80 [<c105d180>] ? kthread+0x0/0x80 [<c100327a>] kernel_thread_helper+0x6/0x10 3 locks held by flush-8:0/2149: #0: (&type->s_umount_key#30){+++++.}, at: [<c110676f>] writeback_inodes_wb+0x27f/0x490 #1: (&journal->j_mutex){+.+...}, at: [<c117199a>] do_journal_end+0xba/0xe70 #2: (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c1178cde>] reiserfs_write_lock+0x2e/0x40 INFO: task fstest:3813 blocked for more than 120 seconds. "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. fstest D 00000002 0 3813 3812 0x00000000 f5103c94 00000082 f5103c40 00000002 f5ad5450 00000007 f5103c28 011f3000 00000006 f5ad5450 c10bb005 00000480 c1710304 f5ad5450 f5ad55ec c2907c40 00000001 f5ad5450 f5103c74 00000046 00000002 f5ad5450 00000007 f5103c6c Call Trace: [<c10bb005>] ? free_hot_cold_page+0x1d5/0x280 [<c1462d64>] io_schedule+0x74/0xc0 [<c10b5a45>] sync_page+0x35/0x60 [<c146325a>] __wait_on_bit_lock+0x4a/0x90 [<c10b5a10>] ? sync_page+0x0/0x60 [<c10b59e5>] __lock_page+0x85/0x90 [<c105d660>] ? wake_bit_function+0x0/0x60 [<c10bf654>] truncate_inode_pages_range+0x1e4/0x2d0 [<c10bf75f>] truncate_inode_pages+0x1f/0x30 [<c10bf7cf>] truncate_pagecache+0x5f/0xa0 [<c10bf86a>] vmtruncate+0x5a/0x70 [<c10fdb7d>] inode_setattr+0x5d/0x190 [<c1150117>] reiserfs_setattr+0x1f7/0x2f0 [<c1464569>] ? down_write+0x49/0x70 [<c10fde01>] notify_change+0x151/0x330 [<c10e6f3d>] do_truncate+0x6d/0xa0 [<c10f4ce2>] do_filp_open+0x9a2/0xcf0 [<c1465aec>] ? _raw_spin_unlock+0x2c/0x50 [<c10fec50>] ? alloc_fd+0xe0/0x100 [<c10e602d>] do_sys_open+0x6d/0x130 [<c1002cfb>] ? sysenter_exit+0xf/0x16 [<c10e615e>] sys_open+0x2e/0x40 [<c1002ccc>] sysenter_do_call+0x12/0x32 3 locks held by fstest/3813: #0: (&sb->s_type->i_mutex_key#4){+.+.+.}, at: [<c10e6f33>] do_truncate+0x63/0xa0 #1: (&sb->s_type->i_alloc_sem_key#3){+.+.+.}, at: [<c10fdf07>] notify_change+0x257/0x330 #2: (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c1178c8e>] reiserfs_write_lock_once+0x2e/0x50 Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Christian Kujau <lists@nerdbynature.de> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2010-01-05reiserfs: Fix recursive lock on lchownFrederic Weisbecker
On chown, reiserfs will call reiserfs_setattr() to change the owner of the given inode, but it may also recursively call reiserfs_setattr() to propagate the owner change to the private xattr files for this inode. Hence, the reiserfs lock may be acquired twice which is not wanted as reiserfs_setattr() calls journal_begin() that is going to try to relax the lock in order to safely acquire the journal mutex. Using reiserfs_write_lock_once() from reiserfs_setattr() solves the problem. This fixes the following warning, that precedes a lockdep report. WARNING: at fs/reiserfs/lock.c:95 reiserfs_lock_check_recursive+0x3f/0x50() Hardware name: MS-7418 Unwanted recursive reiserfs lock! Pid: 4189, comm: fsstress Not tainted 2.6.33-rc2-tip-atom+ #195 Call Trace: [<c1178bff>] ? reiserfs_lock_check_recursive+0x3f/0x50 [<c1178bff>] ? reiserfs_lock_check_recursive+0x3f/0x50 [<c103f7ac>] warn_slowpath_common+0x6c/0xc0 [<c1178bff>] ? reiserfs_lock_check_recursive+0x3f/0x50 [<c103f84b>] warn_slowpath_fmt+0x2b/0x30 [<c1178bff>] reiserfs_lock_check_recursive+0x3f/0x50 [<c1172ae3>] do_journal_begin_r+0x83/0x350 [<c1172f2d>] journal_begin+0x7d/0x140 [<c106509a>] ? in_group_p+0x2a/0x30 [<c10fda71>] ? inode_change_ok+0x91/0x140 [<c115007d>] reiserfs_setattr+0x15d/0x2e0 [<c10f9bf3>] ? dput+0xe3/0x140 [<c1465adc>] ? _raw_spin_unlock+0x2c/0x50 [<c117831d>] chown_one_xattr+0xd/0x10 [<c11780a3>] reiserfs_for_each_xattr+0x113/0x2c0 [<c1178310>] ? chown_one_xattr+0x0/0x10 [<c14641e9>] ? mutex_lock_nested+0x2a9/0x350 [<c117826f>] reiserfs_chown_xattrs+0x1f/0x60 [<c106509a>] ? in_group_p+0x2a/0x30 [<c10fda71>] ? inode_change_ok+0x91/0x140 [<c1150046>] reiserfs_setattr+0x126/0x2e0 [<c1177c20>] ? reiserfs_getxattr+0x0/0x90 [<c11b0d57>] ? cap_inode_need_killpriv+0x37/0x50 [<c10fde01>] notify_change+0x151/0x330 [<c10e659f>] chown_common+0x6f/0x90 [<c10e67bd>] sys_lchown+0x6d/0x80 [<c1002ccc>] sysenter_do_call+0x12/0x32 ---[ end trace 7c2b77224c1442fc ]--- Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Christian Kujau <lists@nerdbynature.de> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2010-01-03reiserfs: Fix mistake in down_write() conversionFrederic Weisbecker
Fix a mistake in commit 0719d3434747889b314a1e8add776418c4148bcf (reiserfs: Fix reiserfs lock <-> i_xattr_sem dependency inversion) that has converted a down_write() into a down_read() accidentally. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Christian Kujau <lists@nerdbynature.de> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2010-01-02Merge branch 'reiserfs/kill-bkl' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing * 'reiserfs/kill-bkl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing: reiserfs: Safely acquire i_mutex from xattr_rmdir reiserfs: Safely acquire i_mutex from reiserfs_for_each_xattr reiserfs: Fix journal mutex <-> inode mutex lock inversion reiserfs: Fix unwanted recursive reiserfs lock in reiserfs_unlink() reiserfs: Relax lock before open xattr dir in reiserfs_xattr_set_handle() reiserfs: Relax reiserfs lock while freeing the journal reiserfs: Fix reiserfs lock <-> i_mutex dependency inversion on xattr reiserfs: Warn on lock relax if taken recursively reiserfs: Fix reiserfs lock <-> i_xattr_sem dependency inversion reiserfs: Fix remaining in-reclaim-fs <-> reclaim-fs-on locking inversion reiserfs: Fix reiserfs lock <-> inode mutex dependency inversion reiserfs: Fix reiserfs lock and journal lock inversion dependency reiserfs: Fix possible recursive lock
2010-01-02reiserfs: Safely acquire i_mutex from xattr_rmdirFrederic Weisbecker
Relax the reiserfs lock before taking the inode mutex from xattr_rmdir() to avoid the usual reiserfs lock <-> inode mutex bad dependency. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Tested-by: Christian Kujau <lists@nerdbynature.de> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2010-01-02reiserfs: Safely acquire i_mutex from reiserfs_for_each_xattrFrederic Weisbecker
Relax the reiserfs lock before taking the inode mutex from reiserfs_for_each_xattr() to avoid the usual bad dependencies: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.32-atom #179 ------------------------------------------------------- rm/3242 is trying to acquire lock: (&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [<c11428ef>] reiserfs_for_each_xattr+0x23f/0x290 but task is already holding lock: (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c1143389>] reiserfs_write_lock+0x29/0x40 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&REISERFS_SB(s)->lock){+.+.+.}: [<c105ea7f>] __lock_acquire+0x11ff/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c1401aab>] mutex_lock_nested+0x5b/0x340 [<c1143339>] reiserfs_write_lock_once+0x29/0x50 [<c1117022>] reiserfs_lookup+0x62/0x140 [<c10bd85f>] __lookup_hash+0xef/0x110 [<c10bf21d>] lookup_one_len+0x8d/0xc0 [<c1141e3a>] open_xa_dir+0xea/0x1b0 [<c1142720>] reiserfs_for_each_xattr+0x70/0x290 [<c11429ba>] reiserfs_delete_xattrs+0x1a/0x60 [<c111ea2f>] reiserfs_delete_inode+0x9f/0x150 [<c10c9c32>] generic_delete_inode+0xa2/0x170 [<c10c9d4f>] generic_drop_inode+0x4f/0x70 [<c10c8b07>] iput+0x47/0x50 [<c10c0965>] do_unlinkat+0xd5/0x160 [<c10c0b13>] sys_unlinkat+0x23/0x40 [<c1002ec4>] sysenter_do_call+0x12/0x32 -> #0 (&sb->s_type->i_mutex_key#4/3){+.+.+.}: [<c105f176>] __lock_acquire+0x18f6/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c1401aab>] mutex_lock_nested+0x5b/0x340 [<c11428ef>] reiserfs_for_each_xattr+0x23f/0x290 [<c11429ba>] reiserfs_delete_xattrs+0x1a/0x60 [<c111ea2f>] reiserfs_delete_inode+0x9f/0x150 [<c10c9c32>] generic_delete_inode+0xa2/0x170 [<c10c9d4f>] generic_drop_inode+0x4f/0x70 [<c10c8b07>] iput+0x47/0x50 [<c10c0965>] do_unlinkat+0xd5/0x160 [<c10c0b13>] sys_unlinkat+0x23/0x40 [<c1002ec4>] sysenter_do_call+0x12/0x32 other info that might help us debug this: 1 lock held by rm/3242: #0: (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c1143389>] reiserfs_write_lock+0x29/0x40 stack backtrace: Pid: 3242, comm: rm Not tainted 2.6.32-atom #179 Call Trace: [<c13ffa13>] ? printk+0x18/0x1a [<c105d33a>] print_circular_bug+0xca/0xd0 [<c105f176>] __lock_acquire+0x18f6/0x19e0 [<c105c932>] ? mark_held_locks+0x62/0x80 [<c105cc3b>] ? trace_hardirqs_on+0xb/0x10 [<c1401098>] ? mutex_unlock+0x8/0x10 [<c105f2c8>] lock_acquire+0x68/0x90 [<c11428ef>] ? reiserfs_for_each_xattr+0x23f/0x290 [<c11428ef>] ? reiserfs_for_each_xattr+0x23f/0x290 [<c1401aab>] mutex_lock_nested+0x5b/0x340 [<c11428ef>] ? reiserfs_for_each_xattr+0x23f/0x290 [<c11428ef>] reiserfs_for_each_xattr+0x23f/0x290 [<c1143180>] ? delete_one_xattr+0x0/0x100 [<c11429ba>] reiserfs_delete_xattrs+0x1a/0x60 [<c1143339>] ? reiserfs_write_lock_once+0x29/0x50 [<c111ea2f>] reiserfs_delete_inode+0x9f/0x150 [<c11b0d4f>] ? _atomic_dec_and_lock+0x4f/0x70 [<c111e990>] ? reiserfs_delete_inode+0x0/0x150 [<c10c9c32>] generic_delete_inode+0xa2/0x170 [<c10c9d4f>] generic_drop_inode+0x4f/0x70 [<c10c8b07>] iput+0x47/0x50 [<c10c0965>] do_unlinkat+0xd5/0x160 [<c1401098>] ? mutex_unlock+0x8/0x10 [<c10c3e0d>] ? vfs_readdir+0x7d/0xb0 [<c10c3af0>] ? filldir64+0x0/0xf0 [<c1002ef3>] ? sysenter_exit+0xf/0x16 [<c105cbe4>] ? trace_hardirqs_on_caller+0x124/0x170 [<c10c0b13>] sys_unlinkat+0x23/0x40 [<c1002ec4>] sysenter_do_call+0x12/0x32 Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Tested-by: Christian Kujau <lists@nerdbynature.de> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2010-01-02reiserfs: Fix journal mutex <-> inode mutex lock inversionFrederic Weisbecker
We need to relax the reiserfs lock before locking the inode mutex from xattr_unlink(), otherwise we'll face the usual bad dependencies: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.32-atom #178 ------------------------------------------------------- rm/3202 is trying to acquire lock: (&journal->j_mutex){+.+...}, at: [<c113c234>] do_journal_begin_r+0x94/0x360 but task is already holding lock: (&sb->s_type->i_mutex_key#4/2){+.+...}, at: [<c1142a67>] xattr_unlink+0x57/0xb0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #2 (&sb->s_type->i_mutex_key#4/2){+.+...}: [<c105ea7f>] __lock_acquire+0x11ff/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c1401a7b>] mutex_lock_nested+0x5b/0x340 [<c1142a67>] xattr_unlink+0x57/0xb0 [<c1143179>] delete_one_xattr+0x29/0x100 [<c11427bb>] reiserfs_for_each_xattr+0x10b/0x290 [<c11429ba>] reiserfs_delete_xattrs+0x1a/0x60 [<c111ea2f>] reiserfs_delete_inode+0x9f/0x150 [<c10c9c32>] generic_delete_inode+0xa2/0x170 [<c10c9d4f>] generic_drop_inode+0x4f/0x70 [<c10c8b07>] iput+0x47/0x50 [<c10c0965>] do_unlinkat+0xd5/0x160 [<c10c0b13>] sys_unlinkat+0x23/0x40 [<c1002ec4>] sysenter_do_call+0x12/0x32 -> #1 (&REISERFS_SB(s)->lock){+.+.+.}: [<c105ea7f>] __lock_acquire+0x11ff/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c1401a7b>] mutex_lock_nested+0x5b/0x340 [<c1143359>] reiserfs_write_lock+0x29/0x40 [<c113c23c>] do_journal_begin_r+0x9c/0x360 [<c113c680>] journal_begin+0x80/0x130 [<c1127363>] reiserfs_remount+0x223/0x4e0 [<c10b6dd6>] do_remount_sb+0xa6/0x140 [<c10ce6a0>] do_mount+0x560/0x750 [<c10ce914>] sys_mount+0x84/0xb0 [<c1002ec4>] sysenter_do_call+0x12/0x32 -> #0 (&journal->j_mutex){+.+...}: [<c105f176>] __lock_acquire+0x18f6/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c1401a7b>] mutex_lock_nested+0x5b/0x340 [<c113c234>] do_journal_begin_r+0x94/0x360 [<c113c680>] journal_begin+0x80/0x130 [<c1116d63>] reiserfs_unlink+0x83/0x2e0 [<c1142a74>] xattr_unlink+0x64/0xb0 [<c1143179>] delete_one_xattr+0x29/0x100 [<c11427bb>] reiserfs_for_each_xattr+0x10b/0x290 [<c11429ba>] reiserfs_delete_xattrs+0x1a/0x60 [<c111ea2f>] reiserfs_delete_inode+0x9f/0x150 [<c10c9c32>] generic_delete_inode+0xa2/0x170 [<c10c9d4f>] generic_drop_inode+0x4f/0x70 [<c10c8b07>] iput+0x47/0x50 [<c10c0965>] do_unlinkat+0xd5/0x160 [<c10c0b13>] sys_unlinkat+0x23/0x40 [<c1002ec4>] sysenter_do_call+0x12/0x32 other info that might help us debug this: 2 locks held by rm/3202: #0: (&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [<c114274b>] reiserfs_for_each_xattr+0x9b/0x290 #1: (&sb->s_type->i_mutex_key#4/2){+.+...}, at: [<c1142a67>] xattr_unlink+0x57/0xb0 stack backtrace: Pid: 3202, comm: rm Not tainted 2.6.32-atom #178 Call Trace: [<c13ff9e3>] ? printk+0x18/0x1a [<c105d33a>] print_circular_bug+0xca/0xd0 [<c105f176>] __lock_acquire+0x18f6/0x19e0 [<c1142a67>] ? xattr_unlink+0x57/0xb0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c113c234>] ? do_journal_begin_r+0x94/0x360 [<c113c234>] ? do_journal_begin_r+0x94/0x360 [<c1401a7b>] mutex_lock_nested+0x5b/0x340 [<c113c234>] ? do_journal_begin_r+0x94/0x360 [<c113c234>] do_journal_begin_r+0x94/0x360 [<c10411b6>] ? run_timer_softirq+0x1a6/0x220 [<c103cb00>] ? __do_softirq+0x50/0x140 [<c113c680>] journal_begin+0x80/0x130 [<c103cba2>] ? __do_softirq+0xf2/0x140 [<c104f72f>] ? hrtimer_interrupt+0xdf/0x220 [<c1116d63>] reiserfs_unlink+0x83/0x2e0 [<c105c932>] ? mark_held_locks+0x62/0x80 [<c11b8d08>] ? trace_hardirqs_on_thunk+0xc/0x10 [<c1002fd8>] ? restore_all_notrace+0x0/0x18 [<c1142a67>] ? xattr_unlink+0x57/0xb0 [<c1142a74>] xattr_unlink+0x64/0xb0 [<c1143179>] delete_one_xattr+0x29/0x100 [<c11427bb>] reiserfs_for_each_xattr+0x10b/0x290 [<c1143150>] ? delete_one_xattr+0x0/0x100 [<c1401cb9>] ? mutex_lock_nested+0x299/0x340 [<c11429ba>] reiserfs_delete_xattrs+0x1a/0x60 [<c1143309>] ? reiserfs_write_lock_once+0x29/0x50 [<c111ea2f>] reiserfs_delete_inode+0x9f/0x150 [<c11b0d1f>] ? _atomic_dec_and_lock+0x4f/0x70 [<c111e990>] ? reiserfs_delete_inode+0x0/0x150 [<c10c9c32>] generic_delete_inode+0xa2/0x170 [<c10c9d4f>] generic_drop_inode+0x4f/0x70 [<c10c8b07>] iput+0x47/0x50 [<c10c0965>] do_unlinkat+0xd5/0x160 [<c1401068>] ? mutex_unlock+0x8/0x10 [<c10c3e0d>] ? vfs_readdir+0x7d/0xb0 [<c10c3af0>] ? filldir64+0x0/0xf0 [<c1002ef3>] ? sysenter_exit+0xf/0x16 [<c105cbe4>] ? trace_hardirqs_on_caller+0x124/0x170 [<c10c0b13>] sys_unlinkat+0x23/0x40 [<c1002ec4>] sysenter_do_call+0x12/0x32 Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Tested-by: Christian Kujau <lists@nerdbynature.de> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2010-01-02reiserfs: Fix unwanted recursive reiserfs lock in reiserfs_unlink()Frederic Weisbecker
reiserfs_unlink() may or may not be called under the reiserfs lock. But it also takes the reiserfs lock and can then acquire it recursively which leads to do_journal_begin_r() that fails to relax the reiserfs lock before grabbing the journal mutex, creating an unexpected lock inversion. We need to ensure reiserfs_unlink() won't get the reiserfs lock recursively using reiserfs_write_lock_once(). This fixes the following warning that precedes a lock inversion report (reiserfs lock <-> journal mutex). ------------[ cut here ]------------ WARNING: at fs/reiserfs/lock.c:95 reiserfs_lock_check_recursive+0x3a/0x50() Hardware name: MS-7418 Unwanted recursive reiserfs lock! Pid: 3208, comm: dbench Not tainted 2.6.32-atom #177 Call Trace: [<c114327a>] ? reiserfs_lock_check_recursive+0x3a/0x50 [<c114327a>] ? reiserfs_lock_check_recursive+0x3a/0x50 [<c10373a7>] warn_slowpath_common+0x67/0xc0 [<c114327a>] ? reiserfs_lock_check_recursive+0x3a/0x50 [<c1037446>] warn_slowpath_fmt+0x26/0x30 [<c114327a>] reiserfs_lock_check_recursive+0x3a/0x50 [<c113c213>] do_journal_begin_r+0x83/0x360 [<c105eb16>] ? __lock_acquire+0x1296/0x19e0 [<c1142a57>] ? xattr_unlink+0x57/0xb0 [<c113c670>] journal_begin+0x80/0x130 [<c1116d5d>] reiserfs_unlink+0x7d/0x2d0 [<c1142a57>] ? xattr_unlink+0x57/0xb0 [<c1142a57>] ? xattr_unlink+0x57/0xb0 [<c1142a57>] ? xattr_unlink+0x57/0xb0 [<c1142a64>] xattr_unlink+0x64/0xb0 [<c1143169>] delete_one_xattr+0x29/0x100 [<c11427ab>] reiserfs_for_each_xattr+0x10b/0x290 [<c1143140>] ? delete_one_xattr+0x0/0x100 [<c1401ca9>] ? mutex_lock_nested+0x299/0x340 [<c11429aa>] reiserfs_delete_xattrs+0x1a/0x60 [<c11432f9>] ? reiserfs_write_lock_once+0x29/0x50 [<c111ea1f>] reiserfs_delete_inode+0x9f/0x150 [<c11b0d0f>] ? _atomic_dec_and_lock+0x4f/0x70 [<c111e980>] ? reiserfs_delete_inode+0x0/0x150 [<c10c9c32>] generic_delete_inode+0xa2/0x170 [<c10c9d4f>] generic_drop_inode+0x4f/0x70 [<c10c8b07>] iput+0x47/0x50 [<c10c0965>] do_unlinkat+0xd5/0x160 [<c10505c6>] ? up_read+0x16/0x30 [<c1022ab7>] ? do_page_fault+0x187/0x330 [<c1002fd8>] ? restore_all_notrace+0x0/0x18 [<c1022930>] ? do_page_fault+0x0/0x330 [<c105cbe4>] ? trace_hardirqs_on_caller+0x124/0x170 [<c10c0a00>] sys_unlink+0x10/0x20 [<c1002ec4>] sysenter_do_call+0x12/0x32 ---[ end trace 2e35d71a6cc69d0c ]--- Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Tested-by: Christian Kujau <lists@nerdbynature.de> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2010-01-02reiserfs: Relax lock before open xattr dir in reiserfs_xattr_set_handle()Frederic Weisbecker
We call xattr_lookup() from reiserfs_xattr_get(). We then hold the reiserfs lock when we grab the i_mutex. But later, we may relax the reiserfs lock, creating dependency inversion between both locks. The lookups and creation jobs ar already protected by the inode mutex, so we can safely relax the reiserfs lock, dropping the unwanted reiserfs lock -> i_mutex dependency, as shown in the following lockdep report: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.32-atom #173 ------------------------------------------------------- cp/3204 is trying to acquire lock: (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c11432b9>] reiserfs_write_lock_once+0x29/0x50 but task is already holding lock: (&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [<c1141e18>] open_xa_dir+0xd8/0x1b0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sb->s_type->i_mutex_key#4/3){+.+.+.}: [<c105ea7f>] __lock_acquire+0x11ff/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c1401a2b>] mutex_lock_nested+0x5b/0x340 [<c1141d83>] open_xa_dir+0x43/0x1b0 [<c1142722>] reiserfs_for_each_xattr+0x62/0x260 [<c114299a>] reiserfs_delete_xattrs+0x1a/0x60 [<c111ea1f>] reiserfs_delete_inode+0x9f/0x150 [<c10c9c32>] generic_delete_inode+0xa2/0x170 [<c10c9d4f>] generic_drop_inode+0x4f/0x70 [<c10c8b07>] iput+0x47/0x50 [<c10c0965>] do_unlinkat+0xd5/0x160 [<c10c0a00>] sys_unlink+0x10/0x20 [<c1002ec4>] sysenter_do_call+0x12/0x32 -> #0 (&REISERFS_SB(s)->lock){+.+.+.}: [<c105f176>] __lock_acquire+0x18f6/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c1401a2b>] mutex_lock_nested+0x5b/0x340 [<c11432b9>] reiserfs_write_lock_once+0x29/0x50 [<c1117012>] reiserfs_lookup+0x62/0x140 [<c10bd85f>] __lookup_hash+0xef/0x110 [<c10bf21d>] lookup_one_len+0x8d/0xc0 [<c1141e2a>] open_xa_dir+0xea/0x1b0 [<c1141fe5>] xattr_lookup+0x15/0x160 [<c1142476>] reiserfs_xattr_get+0x56/0x2a0 [<c1144042>] reiserfs_get_acl+0xa2/0x360 [<c114461a>] reiserfs_cache_default_acl+0x3a/0x160 [<c111789c>] reiserfs_mkdir+0x6c/0x2c0 [<c10bea96>] vfs_mkdir+0xd6/0x180 [<c10c0c10>] sys_mkdirat+0xc0/0xd0 [<c10c0c40>] sys_mkdir+0x20/0x30 [<c1002ec4>] sysenter_do_call+0x12/0x32 other info that might help us debug this: 2 locks held by cp/3204: #0: (&sb->s_type->i_mutex_key#4/1){+.+.+.}, at: [<c10bd8d6>] lookup_create+0x26/0xa0 #1: (&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [<c1141e18>] open_xa_dir+0xd8/0x1b0 stack backtrace: Pid: 3204, comm: cp Not tainted 2.6.32-atom #173 Call Trace: [<c13ff993>] ? printk+0x18/0x1a [<c105d33a>] print_circular_bug+0xca/0xd0 [<c105f176>] __lock_acquire+0x18f6/0x19e0 [<c105d3aa>] ? check_usage+0x6a/0x460 [<c105f2c8>] lock_acquire+0x68/0x90 [<c11432b9>] ? reiserfs_write_lock_once+0x29/0x50 [<c11432b9>] ? reiserfs_write_lock_once+0x29/0x50 [<c1401a2b>] mutex_lock_nested+0x5b/0x340 [<c11432b9>] ? reiserfs_write_lock_once+0x29/0x50 [<c11432b9>] reiserfs_write_lock_once+0x29/0x50 [<c1117012>] reiserfs_lookup+0x62/0x140 [<c105ccca>] ? debug_check_no_locks_freed+0x8a/0x140 [<c105cbe4>] ? trace_hardirqs_on_caller+0x124/0x170 [<c10bd85f>] __lookup_hash+0xef/0x110 [<c10bf21d>] lookup_one_len+0x8d/0xc0 [<c1141e2a>] open_xa_dir+0xea/0x1b0 [<c1141fe5>] xattr_lookup+0x15/0x160 [<c1142476>] reiserfs_xattr_get+0x56/0x2a0 [<c1144042>] reiserfs_get_acl+0xa2/0x360 [<c10ca2e7>] ? new_inode+0x27/0xa0 [<c114461a>] reiserfs_cache_default_acl+0x3a/0x160 [<c1402eb7>] ? _spin_unlock+0x27/0x40 [<c111789c>] reiserfs_mkdir+0x6c/0x2c0 [<c10c7cb8>] ? __d_lookup+0x108/0x190 [<c105c932>] ? mark_held_locks+0x62/0x80 [<c1401c8d>] ? mutex_lock_nested+0x2bd/0x340 [<c10bd17a>] ? generic_permission+0x1a/0xa0 [<c11788fe>] ? security_inode_permission+0x1e/0x20 [<c10bea96>] vfs_mkdir+0xd6/0x180 [<c10c0c10>] sys_mkdirat+0xc0/0xd0 [<c10505c6>] ? up_read+0x16/0x30 [<c1002fd8>] ? restore_all_notrace+0x0/0x18 [<c10c0c40>] sys_mkdir+0x20/0x30 [<c1002ec4>] sysenter_do_call+0x12/0x32 Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Tested-by: Christian Kujau <lists@nerdbynature.de> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2010-01-02reiserfs: Relax reiserfs lock while freeing the journalFrederic Weisbecker
Keeping the reiserfs lock while freeing the journal on umount path triggers a lock inversion between bdev->bd_mutex and the reiserfs lock. We don't need the reiserfs lock at this stage. The filesystem is not usable anymore, and there are no more pending commits, everything got flushed (even this operation was done in parallel and didn't required the reiserfs lock from the current process). This fixes the following lockdep report: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.32-atom #172 ------------------------------------------------------- umount/3904 is trying to acquire lock: (&bdev->bd_mutex){+.+.+.}, at: [<c10de2c2>] __blkdev_put+0x22/0x160 but task is already holding lock: (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c1143279>] reiserfs_write_lock+0x29/0x40 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (&REISERFS_SB(s)->lock){+.+.+.}: [<c105ea7f>] __lock_acquire+0x11ff/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c140199b>] mutex_lock_nested+0x5b/0x340 [<c1143229>] reiserfs_write_lock_once+0x29/0x50 [<c111c485>] reiserfs_get_block+0x85/0x1620 [<c10e1040>] do_mpage_readpage+0x1f0/0x6d0 [<c10e1640>] mpage_readpages+0xc0/0x100 [<c1119b89>] reiserfs_readpages+0x19/0x20 [<c108f1ec>] __do_page_cache_readahead+0x1bc/0x260 [<c108f2b8>] ra_submit+0x28/0x40 [<c1087e3e>] filemap_fault+0x40e/0x420 [<c109b5fd>] __do_fault+0x3d/0x430 [<c109d47e>] handle_mm_fault+0x12e/0x790 [<c1022a65>] do_page_fault+0x135/0x330 [<c1403663>] error_code+0x6b/0x70 [<c10ef9ca>] load_elf_binary+0x82a/0x1a10 [<c10ba130>] search_binary_handler+0x90/0x1d0 [<c10bb70f>] do_execve+0x1df/0x250 [<c1001746>] sys_execve+0x46/0x70 [<c1002fa5>] syscall_call+0x7/0xb -> #2 (&mm->mmap_sem){++++++}: [<c105ea7f>] __lock_acquire+0x11ff/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c109b1ab>] might_fault+0x8b/0xb0 [<c11b8f52>] copy_to_user+0x32/0x70 [<c10c3b94>] filldir64+0xa4/0xf0 [<c1109116>] sysfs_readdir+0x116/0x210 [<c10c3e1d>] vfs_readdir+0x8d/0xb0 [<c10c3ea9>] sys_getdents64+0x69/0xb0 [<c1002ec4>] sysenter_do_call+0x12/0x32 -> #1 (sysfs_mutex){+.+.+.}: [<c105ea7f>] __lock_acquire+0x11ff/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c140199b>] mutex_lock_nested+0x5b/0x340 [<c110951c>] sysfs_addrm_start+0x2c/0xb0 [<c1109aa0>] create_dir+0x40/0x90 [<c1109b1b>] sysfs_create_dir+0x2b/0x50 [<c11b2352>] kobject_add_internal+0xc2/0x1b0 [<c11b2531>] kobject_add_varg+0x31/0x50 [<c11b25ac>] kobject_add+0x2c/0x60 [<c1258294>] device_add+0x94/0x560 [<c11036ea>] add_partition+0x18a/0x2a0 [<c110418a>] rescan_partitions+0x33a/0x450 [<c10de5bf>] __blkdev_get+0x12f/0x2d0 [<c10de76a>] blkdev_get+0xa/0x10 [<c11034b8>] register_disk+0x108/0x130 [<c11a87a9>] add_disk+0xd9/0x130 [<c12998e5>] sd_probe_async+0x105/0x1d0 [<c10528af>] async_thread+0xcf/0x230 [<c104bfd4>] kthread+0x74/0x80 [<c1003aab>] kernel_thread_helper+0x7/0x3c -> #0 (&bdev->bd_mutex){+.+.+.}: [<c105f176>] __lock_acquire+0x18f6/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c140199b>] mutex_lock_nested+0x5b/0x340 [<c10de2c2>] __blkdev_put+0x22/0x160 [<c10de40a>] blkdev_put+0xa/0x10 [<c113ce22>] free_journal_ram+0xd2/0x130 [<c113ea18>] do_journal_release+0x98/0x190 [<c113eb2a>] journal_release+0xa/0x10 [<c1128eb6>] reiserfs_put_super+0x36/0x130 [<c10b776f>] generic_shutdown_super+0x4f/0xe0 [<c10b7825>] kill_block_super+0x25/0x40 [<c11255df>] reiserfs_kill_sb+0x7f/0x90 [<c10b7f4a>] deactivate_super+0x7a/0x90 [<c10cccd8>] mntput_no_expire+0x98/0xd0 [<c10ccfcc>] sys_umount+0x4c/0x310 [<c10cd2a9>] sys_oldumount+0x19/0x20 [<c1002ec4>] sysenter_do_call+0x12/0x32 other info that might help us debug this: 2 locks held by umount/3904: #0: (&type->s_umount_key#30){+++++.}, at: [<c10b7f45>] deactivate_super+0x75/0x90 #1: (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c1143279>] reiserfs_write_lock+0x29/0x40 stack backtrace: Pid: 3904, comm: umount Not tainted 2.6.32-atom #172 Call Trace: [<c13ff903>] ? printk+0x18/0x1a [<c105d33a>] print_circular_bug+0xca/0xd0 [<c105f176>] __lock_acquire+0x18f6/0x19e0 [<c108b66f>] ? free_pcppages_bulk+0x1f/0x250 [<c105f2c8>] lock_acquire+0x68/0x90 [<c10de2c2>] ? __blkdev_put+0x22/0x160 [<c10de2c2>] ? __blkdev_put+0x22/0x160 [<c140199b>] mutex_lock_nested+0x5b/0x340 [<c10de2c2>] ? __blkdev_put+0x22/0x160 [<c105c932>] ? mark_held_locks+0x62/0x80 [<c10afe12>] ? kfree+0x92/0xd0 [<c10de2c2>] __blkdev_put+0x22/0x160 [<c105cc3b>] ? trace_hardirqs_on+0xb/0x10 [<c10de40a>] blkdev_put+0xa/0x10 [<c113ce22>] free_journal_ram+0xd2/0x130 [<c113ea18>] do_journal_release+0x98/0x190 [<c113eb2a>] journal_release+0xa/0x10 [<c1128eb6>] reiserfs_put_super+0x36/0x130 [<c1050596>] ? up_write+0x16/0x30 [<c10b776f>] generic_shutdown_super+0x4f/0xe0 [<c10b7825>] kill_block_super+0x25/0x40 [<c10f41e0>] ? vfs_quota_off+0x0/0x20 [<c11255df>] reiserfs_kill_sb+0x7f/0x90 [<c10b7f4a>] deactivate_super+0x7a/0x90 [<c10cccd8>] mntput_no_expire+0x98/0xd0 [<c10ccfcc>] sys_umount+0x4c/0x310 [<c10cd2a9>] sys_oldumount+0x19/0x20 [<c1002ec4>] sysenter_do_call+0x12/0x32 Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2010-01-02reiserfs: Fix reiserfs lock <-> i_mutex dependency inversion on xattrFrederic Weisbecker
While deleting the xattrs of an inode, we hold the reiserfs lock and grab the inode->i_mutex of the targeted inode and the root private xattr directory. Later on, we may relax the reiserfs lock for various reasons, this creates inverted dependencies. We can remove the reiserfs lock -> i_mutex dependency by relaxing the former before calling open_xa_dir(). This is fine because the lookup and creation of xattr private directories done in open_xa_dir() are covered by the targeted inode mutexes. And deeper operations in the tree are still done under the write lock. This fixes the following lockdep report: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.32-atom #173 ------------------------------------------------------- cp/3204 is trying to acquire lock: (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c11432b9>] reiserfs_write_lock_once+0x29/0x50 but task is already holding lock: (&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [<c1141e18>] open_xa_dir+0xd8/0x1b0 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sb->s_type->i_mutex_key#4/3){+.+.+.}: [<c105ea7f>] __lock_acquire+0x11ff/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c1401a2b>] mutex_lock_nested+0x5b/0x340 [<c1141d83>] open_xa_dir+0x43/0x1b0 [<c1142722>] reiserfs_for_each_xattr+0x62/0x260 [<c114299a>] reiserfs_delete_xattrs+0x1a/0x60 [<c111ea1f>] reiserfs_delete_inode+0x9f/0x150 [<c10c9c32>] generic_delete_inode+0xa2/0x170 [<c10c9d4f>] generic_drop_inode+0x4f/0x70 [<c10c8b07>] iput+0x47/0x50 [<c10c0965>] do_unlinkat+0xd5/0x160 [<c10c0a00>] sys_unlink+0x10/0x20 [<c1002ec4>] sysenter_do_call+0x12/0x32 -> #0 (&REISERFS_SB(s)->lock){+.+.+.}: [<c105f176>] __lock_acquire+0x18f6/0x19e0 [<c105f2c8>] lock_acquire+0x68/0x90 [<c1401a2b>] mutex_lock_nested+0x5b/0x340 [<c11432b9>] reiserfs_write_lock_once+0x29/0x50 [<c1117012>] reiserfs_lookup+0x62/0x140 [<c10bd85f>] __lookup_hash+0xef/0x110 [<c10bf21d>] lookup_one_len+0x8d/0xc0 [<c1141e2a>] open_xa_dir+0xea/0x1b0 [<c1141fe5>] xattr_lookup+0x15/0x160 [<c1142476>] reiserfs_xattr_get+0x56/0x2a0 [<c1144042>] reiserfs_get_acl+0xa2/0x360 [<c114461a>] reiserfs_cache_default_acl+0x3a/0x160 [<c111789c>] reiserfs_mkdir+0x6c/0x2c0 [<c10bea96>] vfs_mkdir+0xd6/0x180 [<c10c0c10>] sys_mkdirat+0xc0/0xd0 [<c10c0c40>] sys_mkdir+0x20/0x30 [<c1002ec4>] sysenter_do_call+0x12/0x32 other info that might help us debug this: 2 locks held by cp/3204: #0: (&sb->s_type->i_mutex_key#4/1){+.+.+.}, at: [<c10bd8d6>] lookup_create+0x26/0xa0 #1: (&sb->s_type->i_mutex_key#4/3){+.+.+.}, at: [<c1141e18>] open_xa_dir+0xd8/0x1b0 stack backtrace: Pid: 3204, comm: cp Not tainted 2.6.32-atom #173 Call Trace: [<c13ff993>] ? printk+0x18/0x1a [<c105d33a>] print_circular_bug+0xca/0xd0 [<c105f176>] __lock_acquire+0x18f6/0x19e0 [<c105d3aa>] ? check_usage+0x6a/0x460 [<c105f2c8>] lock_acquire+0x68/0x90 [<c11432b9>] ? reiserfs_write_lock_once+0x29/0x50 [<c11432b9>] ? reiserfs_write_lock_once+0x29/0x50 [<c1401a2b>] mutex_lock_nested+0x5b/0x340 [<c11432b9>] ? reiserfs_write_lock_once+0x29/0x50 [<c11432b9>] reiserfs_write_lock_once+0x29/0x50 [<c1117012>] reiserfs_lookup+0x62/0x140 [<c105ccca>] ? debug_check_no_locks_freed+0x8a/0x140 [<c105cbe4>] ? trace_hardirqs_on_caller+0x124/0x170 [<c10bd85f>] __lookup_hash+0xef/0x110 [<c10bf21d>] lookup_one_len+0x8d/0xc0 [<c1141e2a>] open_xa_dir+0xea/0x1b0 [<c1141fe5>] xattr_lookup+0x15/0x160 [<c1142476>] reiserfs_xattr_get+0x56/0x2a0 [<c1144042>] reiserfs_get_acl+0xa2/0x360 [<c10ca2e7>] ? new_inode+0x27/0xa0 [<c114461a>] reiserfs_cache_default_acl+0x3a/0x160 [<c1402eb7>] ? _spin_unlock+0x27/0x40 [<c111789c>] reiserfs_mkdir+0x6c/0x2c0 [<c10c7cb8>] ? __d_lookup+0x108/0x190 [<c105c932>] ? mark_held_locks+0x62/0x80 [<c1401c8d>] ? mutex_lock_nested+0x2bd/0x340 [<c10bd17a>] ? generic_permission+0x1a/0xa0 [<c11788fe>] ? security_inode_permission+0x1e/0x20 [<c10bea96>] vfs_mkdir+0xd6/0x180 [<c10c0c10>] sys_mkdirat+0xc0/0xd0 [<c10505c6>] ? up_read+0x16/0x30 [<c1002fd8>] ? restore_all_notrace+0x0/0x18 [<c10c0c40>] sys_mkdir+0x20/0x30 [<c1002ec4>] sysenter_do_call+0x12/0x32 v2: Don't drop reiserfs_mutex_lock_nested_safe() as we'll still need it later Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Tested-by: Christian Kujau <lists@nerdbynature.de> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2010-01-02reiserfs: Warn on lock relax if taken recursivelyFrederic Weisbecker
When we relax the reiserfs lock to avoid creating unwanted dependencies against others locks while grabbing these, we want to ensure it has not been taken recursively, otherwise the lock won't be really relaxed. Only its depth will be decreased. The unwanted dependency would then actually happen. To prevent from that, add a reiserfs_lock_check_recursive() call in the places that need it. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2010-01-02reiserfs: Fix reiserfs lock <-> i_xattr_sem dependency inversionFrederic Weisbecker
i_xattr_sem depends on the reiserfs lock. But after we grab i_xattr_sem, we may relax/relock the reiserfs lock while waiting on a freezed filesystem, creating a dependency inversion between the two locks. In order to avoid the i_xattr_sem -> reiserfs lock dependency, let's create a reiserfs_down_read_safe() that acts like reiserfs_mutex_lock_safe(): relax the reiserfs lock while grabbing another lock to avoid undesired dependencies induced by the heivyweight reiserfs lock. This fixes the following warning: [ 990.005931] ======================================================= [ 990.012373] [ INFO: possible circular locking dependency detected ] [ 990.013233] 2.6.33-rc1 #1 [ 990.013233] ------------------------------------------------------- [ 990.013233] dbench/1891 is trying to acquire lock: [ 990.013233] (&REISERFS_SB(s)->lock){+.+.+.}, at: [<ffffffff81159505>] reiserfs_write_lock+0x35/0x50 [ 990.013233] [ 990.013233] but task is already holding lock: [ 990.013233] (&REISERFS_I(inode)->i_xattr_sem){+.+.+.}, at: [<ffffffff8115899a>] reiserfs_xattr_set_handle+0x8a/0x470 [ 990.013233] [ 990.013233] which lock already depends on the new lock. [ 990.013233] [ 990.013233] [ 990.013233] the existing dependency chain (in reverse order) is: [ 990.013233] [ 990.013233] -> #1 (&REISERFS_I(inode)->i_xattr_sem){+.+.+.}: [ 990.013233] [<ffffffff81063afc>] __lock_acquire+0xf9c/0x1560 [ 990.013233] [<ffffffff8106414f>] lock_acquire+0x8f/0xb0 [ 990.013233] [<ffffffff814ac194>] down_write+0x44/0x80 [ 990.013233] [<ffffffff8115899a>] reiserfs_xattr_set_handle+0x8a/0x470 [ 990.013233] [<ffffffff81158e30>] reiserfs_xattr_set+0xb0/0x150 [ 990.013233] [<ffffffff8115a6aa>] user_set+0x8a/0x90 [ 990.013233] [<ffffffff8115901a>] reiserfs_setxattr+0xaa/0xb0 [ 990.013233] [<ffffffff810e2596>] __vfs_setxattr_noperm+0x36/0xa0 [ 990.013233] [<ffffffff810e26bc>] vfs_setxattr+0xbc/0xc0 [ 990.013233] [<ffffffff810e2780>] setxattr+0xc0/0x150 [ 990.013233] [<ffffffff810e289d>] sys_fsetxattr+0x8d/0xa0 [ 990.013233] [<ffffffff81002dab>] system_call_fastpath+0x16/0x1b [ 990.013233] [ 990.013233] -> #0 (&REISERFS_SB(s)->lock){+.+.+.}: [ 990.013233] [<ffffffff81063e30>] __lock_acquire+0x12d0/0x1560 [ 990.013233] [<ffffffff8106414f>] lock_acquire+0x8f/0xb0 [ 990.013233] [<ffffffff814aba77>] __mutex_lock_common+0x47/0x3b0 [ 990.013233] [<ffffffff814abebe>] mutex_lock_nested+0x3e/0x50 [ 990.013233] [<ffffffff81159505>] reiserfs_write_lock+0x35/0x50 [ 990.013233] [<ffffffff811340e5>] reiserfs_prepare_write+0x45/0x180 [ 990.013233] [<ffffffff81158bb6>] reiserfs_xattr_set_handle+0x2a6/0x470 [ 990.013233] [<ffffffff81158e30>] reiserfs_xattr_set+0xb0/0x150 [ 990.013233] [<ffffffff8115a6aa>] user_set+0x8a/0x90 [ 990.013233] [<ffffffff8115901a>] reiserfs_setxattr+0xaa/0xb0 [ 990.013233] [<ffffffff810e2596>] __vfs_setxattr_noperm+0x36/0xa0 [ 990.013233] [<ffffffff810e26bc>] vfs_setxattr+0xbc/0xc0 [ 990.013233] [<ffffffff810e2780>] setxattr+0xc0/0x150 [ 990.013233] [<ffffffff810e289d>] sys_fsetxattr+0x8d/0xa0 [ 990.013233] [<ffffffff81002dab>] system_call_fastpath+0x16/0x1b [ 990.013233] [ 990.013233] other info that might help us debug this: [ 990.013233] [ 990.013233] 2 locks held by dbench/1891: [ 990.013233] #0: (&sb->s_type->i_mutex_key#12){+.+.+.}, at: [<ffffffff810e2678>] vfs_setxattr+0x78/0xc0 [ 990.013233] #1: (&REISERFS_I(inode)->i_xattr_sem){+.+.+.}, at: [<ffffffff8115899a>] reiserfs_xattr_set_handle+0x8a/0x470 [ 990.013233] [ 990.013233] stack backtrace: [ 990.013233] Pid: 1891, comm: dbench Not tainted 2.6.33-rc1 #1 [ 990.013233] Call Trace: [ 990.013233] [<ffffffff81061639>] print_circular_bug+0xe9/0xf0 [ 990.013233] [<ffffffff81063e30>] __lock_acquire+0x12d0/0x1560 [ 990.013233] [<ffffffff8115899a>] ? reiserfs_xattr_set_handle+0x8a/0x470 [ 990.013233] [<ffffffff8106414f>] lock_acquire+0x8f/0xb0 [ 990.013233] [<ffffffff81159505>] ? reiserfs_write_lock+0x35/0x50 [ 990.013233] [<ffffffff8115899a>] ? reiserfs_xattr_set_handle+0x8a/0x470 [ 990.013233] [<ffffffff814aba77>] __mutex_lock_common+0x47/0x3b0 [ 990.013233] [<ffffffff81159505>] ? reiserfs_write_lock+0x35/0x50 [ 990.013233] [<ffffffff81159505>] ? reiserfs_write_lock+0x35/0x50 [ 990.013233] [<ffffffff81062592>] ? mark_held_locks+0x72/0xa0 [ 990.013233] [<ffffffff814ab81d>] ? __mutex_unlock_slowpath+0xbd/0x140 [ 990.013233] [<ffffffff810628ad>] ? trace_hardirqs_on_caller+0x14d/0x1a0 [ 990.013233] [<ffffffff814abebe>] mutex_lock_nested+0x3e/0x50 [ 990.013233] [<ffffffff81159505>] reiserfs_write_lock+0x35/0x50 [ 990.013233] [<ffffffff811340e5>] reiserfs_prepare_write+0x45/0x180 [ 990.013233] [<ffffffff81158bb6>] reiserfs_xattr_set_handle+0x2a6/0x470 [ 990.013233] [<ffffffff81158e30>] reiserfs_xattr_set+0xb0/0x150 [ 990.013233] [<ffffffff814abcb4>] ? __mutex_lock_common+0x284/0x3b0 [ 990.013233] [<ffffffff8115a6aa>] user_set+0x8a/0x90 [ 990.013233] [<ffffffff8115901a>] reiserfs_setxattr+0xaa/0xb0 [ 990.013233] [<ffffffff810e2596>] __vfs_setxattr_noperm+0x36/0xa0 [ 990.013233] [<ffffffff810e26bc>] vfs_setxattr+0xbc/0xc0 [ 990.013233] [<ffffffff810e2780>] setxattr+0xc0/0x150 [ 990.013233] [<ffffffff81056018>] ? sched_clock_cpu+0xb8/0x100 [ 990.013233] [<ffffffff8105eded>] ? trace_hardirqs_off+0xd/0x10 [ 990.013233] [<ffffffff810560a3>] ? cpu_clock+0x43/0x50 [ 990.013233] [<ffffffff810c6820>] ? fget+0xb0/0x110 [ 990.013233] [<ffffffff810c6770>] ? fget+0x0/0x110 [ 990.013233] [<ffffffff81002ddc>] ? sysret_check+0x27/0x62 [ 990.013233] [<ffffffff810e289d>] sys_fsetxattr+0x8d/0xa0 [ 990.013233] [<ffffffff81002dab>] system_call_fastpath+0x16/0x1b Reported-and-tested-by: Christian Kujau <lists@nerdbynature.de> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2009-12-29reiserfs: Fix remaining in-reclaim-fs <-> reclaim-fs-on locking inversionFrederic Weisbecker
Commit 500f5a0bf5f0624dae34307010e240ec090e4cde (reiserfs: Fix possible recursive lock) fixed a vmalloc under reiserfs lock that triggered a lockdep warning because of a IN-FS-RECLAIM <-> RECLAIM-FS-ON locking dependency inversion. But this patch has ommitted another vmalloc call in the same path that allocates the journal. Relax the lock for this one too. Reported-by: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu>
2009-12-17reiserfs: truncate blocks not used by a writeJan Kara
It can happen that write does not use all the blocks allocated in write_begin either because of some filesystem error (like ENOSPC) or because page with data to write has been removed from memory. We truncate these blocks so that we don't have dangling blocks beyond i_size. Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-17Revert "task_struct: make journal_info conditional"Linus Torvalds
This reverts commit e4c570c4cb7a95dbfafa3d016d2739bf3fdfe319, as requested by Alexey: "I think I gave a good enough arguments to not merge it. To iterate: * patch makes impossible to start using ext3 on EXT3_FS=n kernels without reboot. * this is done only for one pointer on task_struct" None of config options which define task_struct are tristate directly or effectively." Requested-by: Alexey Dobriyan <adobriyan@gmail.com> Acked-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16reiserfs: Fix reiserfs lock <-> inode mutex dependency inversionFrederic Weisbecker
The reiserfs lock -> inode mutex dependency gets inverted when we relax the lock while walking to the tree. To fix this, use a specialized version of reiserfs_mutex_lock_safe that takes care of mutex subclasses. Then we can grab the inode mutex with I_MUTEX_XATTR subclass without any reiserfs lock dependency. This fixes the following report: [ INFO: possible circular locking dependency detected ] 2.6.32-06793-gf405425-dirty #2 ------------------------------------------------------- mv/18566 is trying to acquire lock: (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c1110708>] reiserfs_write_lock+0x28= /0x40 but task is already holding lock: (&sb->s_type->i_mutex_key#5/3){+.+.+.}, at: [<c111033c>] reiserfs_for_each_xattr+0x10c/0x380 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&sb->s_type->i_mutex_key#5/3){+.+.+.}: [<c104f723>] validate_chain+0xa23/0xf70 [<c1050155>] __lock_acquire+0x4e5/0xa70 [<c105075a>] lock_acquire+0x7a/0xa0 [<c134c76f>] mutex_lock_nested+0x5f/0x2b0 [<c11102b4>] reiserfs_for_each_xattr+0x84/0x380 [<c1110615>] reiserfs_delete_xattrs+0x15/0x50 [<c10ef57f>] reiserfs_delete_inode+0x8f/0x140 [<c10a565c>] generic_delete_inode+0x9c/0x150 [<c10a574d>] generic_drop_inode+0x3d/0x60 [<c10a4667>] iput+0x47/0x50 [<c109cc0b>] do_unlinkat+0xdb/0x160 [<c109cca0>] sys_unlink+0x10/0x20 [<c1002c50>] sysenter_do_call+0x12/0x36 -> #0 (&REISERFS_SB(s)->lock){+.+.+.}: [<c104fc68>] validate_chain+0xf68/0xf70 [<c1050155>] __lock_acquire+0x4e5/0xa70 [<c105075a>] lock_acquire+0x7a/0xa0 [<c134c76f>] mutex_lock_nested+0x5f/0x2b0 [<c1110708>] reiserfs_write_lock+0x28/0x40 [<c1103d6b>] search_by_key+0x1f7b/0x21b0 [<c10e73ef>] search_by_entry_key+0x1f/0x3b0 [<c10e77f7>] reiserfs_find_entry+0x77/0x400 [<c10e81e5>] reiserfs_lookup+0x85/0x130 [<c109a144>] __lookup_hash+0xb4/0x110 [<c109b763>] lookup_one_len+0xb3/0x100 [<c1110350>] reiserfs_for_each_xattr+0x120/0x380 [<c1110615>] reiserfs_delete_xattrs+0x15/0x50 [<c10ef57f>] reiserfs_delete_inode+0x8f/0x140 [<c10a565c>] generic_delete_inode+0x9c/0x150 [<c10a574d>] generic_drop_inode+0x3d/0x60 [<c10a4667>] iput+0x47/0x50 [<c10a1c4f>] dentry_iput+0x6f/0xf0 [<c10a1d74>] d_kill+0x24/0x50 [<c10a396b>] dput+0x5b/0x120 [<c109ca89>] sys_renameat+0x1b9/0x230 [<c109cb28>] sys_rename+0x28/0x30 [<c1002c50>] sysenter_do_call+0x12/0x36 other info that might help us debug this: 2 locks held by mv/18566: #0: (&sb->s_type->i_mutex_key#5/1){+.+.+.}, at: [<c109b6ac>] lock_rename+0xcc/0xd0 #1: (&sb->s_type->i_mutex_key#5/3){+.+.+.}, at: [<c111033c>] reiserfs_for_each_xattr+0x10c/0x380 stack backtrace: Pid: 18566, comm: mv Tainted: G C 2.6.32-06793-gf405425-dirty #2 Call Trace: [<c134b252>] ? printk+0x18/0x1e [<c104e790>] print_circular_bug+0xc0/0xd0 [<c104fc68>] validate_chain+0xf68/0xf70 [<c104c8cb>] ? trace_hardirqs_off+0xb/0x10 [<c1050155>] __lock_acquire+0x4e5/0xa70 [<c105075a>] lock_acquire+0x7a/0xa0 [<c1110708>] ? reiserfs_write_lock+0x28/0x40 [<c134c76f>] mutex_lock_nested+0x5f/0x2b0 [<c1110708>] ? reiserfs_write_lock+0x28/0x40 [<c1110708>] ? reiserfs_write_lock+0x28/0x40 [<c134b60a>] ? schedule+0x27a/0x440 [<c1110708>] reiserfs_write_lock+0x28/0x40 [<c1103d6b>] search_by_key+0x1f7b/0x21b0 [<c1050176>] ? __lock_acquire+0x506/0xa70 [<c1051267>] ? lock_release_non_nested+0x1e7/0x340 [<c1110708>] ? reiserfs_write_lock+0x28/0x40 [<c104e354>] ? trace_hardirqs_on_caller+0x124/0x170 [<c104e3ab>] ? trace_hardirqs_on+0xb/0x10 [<c1042a55>] ? T.316+0x15/0x1a0 [<c1042d2d>] ? sched_clock_cpu+0x9d/0x100 [<c10e73ef>] search_by_entry_key+0x1f/0x3b0 [<c134bf2a>] ? __mutex_unlock_slowpath+0x9a/0x120 [<c104e354>] ? trace_hardirqs_on_caller+0x124/0x170 [<c10e77f7>] reiserfs_find_entry+0x77/0x400 [<c10e81e5>] reiserfs_lookup+0x85/0x130 [<c1042d2d>] ? sched_clock_cpu+0x9d/0x100 [<c109a144>] __lookup_hash+0xb4/0x110 [<c109b763>] lookup_one_len+0xb3/0x100 [<c1110350>] reiserfs_for_each_xattr+0x120/0x380 [<c110ffe0>] ? delete_one_xattr+0x0/0x1c0 [<c1003342>] ? math_error+0x22/0x150 [<c1110708>] ? reiserfs_write_lock+0x28/0x40 [<c1110615>] reiserfs_delete_xattrs+0x15/0x50 [<c1110708>] ? reiserfs_write_lock+0x28/0x40 [<c10ef57f>] reiserfs_delete_inode+0x8f/0x140 [<c10a561f>] ? generic_delete_inode+0x5f/0x150 [<c10ef4f0>] ? reiserfs_delete_inode+0x0/0x140 [<c10a565c>] generic_delete_inode+0x9c/0x150 [<c10a574d>] generic_drop_inode+0x3d/0x60 [<c10a4667>] iput+0x47/0x50 [<c10a1c4f>] dentry_iput+0x6f/0xf0 [<c10a1d74>] d_kill+0x24/0x50 [<c10a396b>] dput+0x5b/0x120 [<c109ca89>] sys_renameat+0x1b9/0x230 [<c1042d2d>] ? sched_clock_cpu+0x9d/0x100 [<c104c8cb>] ? trace_hardirqs_off+0xb/0x10 [<c1042dde>] ? cpu_clock+0x4e/0x60 [<c1350825>] ? do_page_fault+0x155/0x370 [<c1041816>] ? up_read+0x16/0x30 [<c1350825>] ? do_page_fault+0x155/0x370 [<c109cb28>] sys_rename+0x28/0x30 [<c1002c50>] sysenter_do_call+0x12/0x36 Reported-by: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de>
2009-12-16Merge branch 'master' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6 * 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs-2.6: (38 commits) direct I/O fallback sync simplification ocfs: stop using do_sync_mapping_range cleanup blockdev_direct_IO locking make generic_acl slightly more generic sanitize xattr handler prototypes libfs: move EXPORT_SYMBOL for d_alloc_name vfs: force reval of target when following LAST_BIND symlinks (try #7) ima: limit imbalance msg Untangling ima mess, part 3: kill dead code in ima Untangling ima mess, part 2: deal with counters Untangling ima mess, part 1: alloc_file() O_TRUNC open shouldn't fail after file truncation ima: call ima_inode_free ima_inode_free IMA: clean up the IMA counts updating code ima: only insert at inode creation time ima: valid return code from ima_inode_alloc fs: move get_empty_filp() deffinition to internal.h Sanitize exec_permission_lite() Kill cached_lookup() and real_lookup() Kill path_lookup_open() ... Trivial conflicts in fs/direct-io.c
2009-12-16sanitize xattr handler prototypesChristoph Hellwig
Add a flags argument to struct xattr_handler and pass it to all xattr handler methods. This allows using the same methods for multiple handlers, e.g. for the ACL methods which perform exactly the same action for the access and default ACLs, just using a different underlying attribute. With a little more groundwork it'll also allow sharing the methods for the regular user/trusted/secure handlers in extN, ocfs2 and jffs2 like it's already done for xfs in this patch. Also change the inode argument to the handlers to a dentry to allow using the handlers mechnism for filesystems that require it later, e.g. cifs. [with GFS2 bits updated by Steven Whitehouse <swhiteho@redhat.com>] Signed-off-by: Christoph Hellwig <hch@lst.de> Reviewed-by: James Morris <jmorris@namei.org> Acked-by: Joel Becker <joel.becker@oracle.com> Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2009-12-16reiserfs: don't compile procfs.o at all if no supportAlexey Dobriyan
* small define cleanup in header * fix #ifdeffery in procfs.c via Kconfig Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-16reiserfs: remove /proc/fs/reiserfs/versionAlexey Dobriyan
/proc/fs/reiserfs/version is on the way of removing ->read_proc interface. It's empty however, so simply remove it instead of doing dummy conversion. It's hard to see what information userspace can extract from empty file. Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-15task_struct: make journal_info conditionalHiroshi Shimamoto
journal_info in task_struct is used in journaling file system only. So introduce CONFIG_FS_JOURNAL_INFO and make it conditional. Signed-off-by: Hiroshi Shimamoto <h-shimamoto@ct.jp.nec.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: "Theodore Ts'o" <tytso@mit.edu> Cc: Steven Whitehouse <swhiteho@redhat.com> Cc: KONISHI Ryusuke <konishi.ryusuke@lab.ntt.co.jp> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-12-14reiserfs: Fix reiserfs lock and journal lock inversion dependencyFrederic Weisbecker
When we were using the bkl, we didn't care about dependencies against other locks, but the mutex conversion created new ones, which is why we have reiserfs_mutex_lock_safe(), which unlocks the reiserfs lock before acquiring another mutex. But this trick actually fails if we have acquired the reiserfs lock recursively, as we try to unlock it to acquire the new mutex without inverted dependency, but we eventually only decrease its depth. This happens in the case of a nested inode creation/deletion. Say we have no space left on the device, we create an inode and tak the lock but fail to create its entry, then we release the inode using iput(), which calls reiserfs_delete_inode() that takes the reiserfs lock recursively. The path eventually ends up in journal_begin() where we try to take the journal safely but we fail because of the reiserfs lock recursion: [ INFO: possible circular locking dependency detected ] 2.6.32-06486-g053fe57 #2 ------------------------------------------------------- vi/23454 is trying to acquire lock: (&journal->j_mutex){+.+...}, at: [<c110dac4>] do_journal_begin_r+0x64/0x2f0 but task is already holding lock: (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c11106a8>] reiserfs_write_lock+0x28/0x40 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #1 (&REISERFS_SB(s)->lock){+.+.+.}: [<c104f8f3>] validate_chain+0xa23/0xf70 [<c1050325>] __lock_acquire+0x4e5/0xa70 [<c105092a>] lock_acquire+0x7a/0xa0 [<c134c78f>] mutex_lock_nested+0x5f/0x2b0 [<c11106a8>] reiserfs_write_lock+0x28/0x40 [<c110dacb>] do_journal_begin_r+0x6b/0x2f0 [<c110ddcf>] journal_begin+0x7f/0x120 [<c10f76c2>] reiserfs_remount+0x212/0x4d0 [<c1093997>] do_remount_sb+0x67/0x140 [<c10a9ca6>] do_mount+0x436/0x6b0 [<c10a9f86>] sys_mount+0x66/0xa0 [<c1002c50>] sysenter_do_call+0x12/0x36 -> #0 (&journal->j_mutex){+.+...}: [<c104fe38>] validate_chain+0xf68/0xf70 [<c1050325>] __lock_acquire+0x4e5/0xa70 [<c105092a>] lock_acquire+0x7a/0xa0 [<c134c78f>] mutex_lock_nested+0x5f/0x2b0 [<c110dac4>] do_journal_begin_r+0x64/0x2f0 [<c110ddcf>] journal_begin+0x7f/0x120 [<c10ef52f>] reiserfs_delete_inode+0x9f/0x140 [<c10a55fc>] generic_delete_inode+0x9c/0x150 [<c10a56ed>] generic_drop_inode+0x3d/0x60 [<c10a4607>] iput+0x47/0x50 [<c10e915c>] reiserfs_create+0x16c/0x1c0 [<c109a9c1>] vfs_create+0xc1/0x130 [<c109dbec>] do_filp_open+0x81c/0x920 [<c109004f>] do_sys_open+0x4f/0x110 [<c1090179>] sys_open+0x29/0x40 [<c1002c50>] sysenter_do_call+0x12/0x36 other info that might help us debug this: 2 locks held by vi/23454: #0: (&sb->s_type->i_mutex_key#5){+.+.+.}, at: [<c109d64e>] do_filp_open+0x27e/0x920 #1: (&REISERFS_SB(s)->lock){+.+.+.}, at: [<c11106a8>] reiserfs_write_lock+0x28/0x40 stack backtrace: Pid: 23454, comm: vi Not tainted 2.6.32-06486-g053fe57 #2 Call Trace: [<c134b202>] ? printk+0x18/0x1e [<c104e960>] print_circular_bug+0xc0/0xd0 [<c104fe38>] validate_chain+0xf68/0xf70 [<c104ca9b>] ? trace_hardirqs_off+0xb/0x10 [<c1050325>] __lock_acquire+0x4e5/0xa70 [<c105092a>] lock_acquire+0x7a/0xa0 [<c110dac4>] ? do_journal_begin_r+0x64/0x2f0 [<c134c78f>] mutex_lock_nested+0x5f/0x2b0 [<c110dac4>] ? do_journal_begin_r+0x64/0x2f0 [<c110dac4>] ? do_journal_begin_r+0x64/0x2f0 [<c110ff80>] ? delete_one_xattr+0x0/0x1c0 [<c110dac4>] do_journal_begin_r+0x64/0x2f0 [<c110ddcf>] journal_begin+0x7f/0x120 [<c11105b5>] ? reiserfs_delete_xattrs+0x15/0x50 [<c10ef52f>] reiserfs_delete_inode+0x9f/0x140 [<c10a55bf>] ? generic_delete_inode+0x5f/0x150 [<c10ef490>] ? reiserfs_delete_inode+0x0/0x140 [<c10a55fc>] generic_delete_inode+0x9c/0x150 [<c10a56ed>] generic_drop_inode+0x3d/0x60 [<c10a4607>] iput+0x47/0x50 [<c10e915c>] reiserfs_create+0x16c/0x1c0 [<c1099a5d>] ? inode_permission+0x7d/0xa0 [<c109a9c1>] vfs_create+0xc1/0x130 [<c10e8ff0>] ? reiserfs_create+0x0/0x1c0 [<c109dbec>] do_filp_open+0x81c/0x920 [<c104ca9b>] ? trace_hardirqs_off+0xb/0x10 [<c134dc0d>] ? _spin_unlock+0x1d/0x20 [<c10a6eea>] ? alloc_fd+0xba/0xf0 [<c109004f>] do_sys_open+0x4f/0x110 [<c1090179>] sys_open+0x29/0x40 [<c1002c50>] sysenter_do_call+0x12/0x36 To fix this, use reiserfs_lock_once() from reiserfs_delete_inode() which prevents from adding reiserfs lock recursion. Reported-by: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de>
2009-12-14reiserfs: Fix possible recursive lockFrederic Weisbecker
While allocating the bitmap using vmalloc, we hold the reiserfs lock, which makes lockdep later reporting a possible deadlock as we may swap out pages to allocate memory and then take the reiserfs lock recursively: inconsistent {RECLAIM_FS-ON-W} -> {IN-RECLAIM_FS-W} usage. kswapd0/312 [HC0[0]:SC0[0]:HE1:SE1] takes: (&REISERFS_SB(s)->lock){+.+.?.}, at: [<c11108a8>] reiserfs_write_lock+0x28/0x40 {RECLAIM_FS-ON-W} state was registered at: [<c104e1c2>] mark_held_locks+0x62/0x90 [<c104e28a>] lockdep_trace_alloc+0x9a/0xc0 [<c108e396>] kmem_cache_alloc+0x26/0xf0 [<c10850ec>] __get_vm_area_node+0x6c/0xf0 [<c10857de>] __vmalloc_node+0x7e/0xa0 [<c108597b>] vmalloc+0x2b/0x30 [<c10e00b9>] reiserfs_init_bitmap_cache+0x39/0x70 [<c10f8178>] reiserfs_fill_super+0x2e8/0xb90 [<c1094345>] get_sb_bdev+0x145/0x180 [<c10f5a11>] get_super_block+0x21/0x30 [<c10931f0>] vfs_kern_mount+0x40/0xd0 [<c10932d9>] do_kern_mount+0x39/0xd0 [<c10a9857>] do_mount+0x2c7/0x6b0 [<c10a9ca6>] sys_mount+0x66/0xa0 [<c161589b>] mount_block_root+0xc4/0x245 [<c1615a75>] mount_root+0x59/0x5f [<c1615b8c>] prepare_namespace+0x111/0x14b [<c1615269>] kernel_init+0xcf/0xdb [<c10031fb>] kernel_thread_helper+0x7/0x1c This is actually fine for two reasons: we call vmalloc at mount time then it's not in the swapping out path. Also the reiserfs lock can be acquired recursively, but since its implementation depends on a mutex, it's hard and not necessary worth it to teach that to lockdep. The lock is useless at mount time anyway, at least until we replay the journal. But let's remove it from this path later as this needs more thinking and is a sensible change. For now we can just relax the lock around vmalloc, Reported-by: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Thomas Gleixner <tglx@linutronix.de>
2009-12-09Merge branch 'for-linus' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial * 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jikos/trivial: (42 commits) tree-wide: fix misspelling of "definition" in comments reiserfs: fix misspelling of "journaled" doc: Fix a typo in slub.txt. inotify: remove superfluous return code check hdlc: spelling fix in find_pvc() comment doc: fix regulator docs cut-and-pasteism mtd: Fix comment in Kconfig doc: Fix IRQ chip docs tree-wide: fix assorted typos all over the place drivers/ata/libata-sff.c: comment spelling fixes fix typos/grammos in Documentation/edac.txt sysctl: add missing comments fs/debugfs/inode.c: fix comment typos sgivwfb: Make use of ARRAY_SIZE. sky2: fix sky2_link_down copy/paste comment error tree-wide: fix typos "couter" -> "counter" tree-wide: fix typos "offest" -> "offset" fix kerneldoc for set_irq_msi() spidev: fix double "of of" in comment comment typo fix: sybsystem -> subsystem ...
2009-12-09Merge branch 'reiserfs/kill-bkl' of ↵Linus Torvalds
git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing * 'reiserfs/kill-bkl' of git://git.kernel.org/pub/scm/linux/kernel/git/frederic/random-tracing: (31 commits) kill-the-bkl/reiserfs: turn GFP_ATOMIC flag to GFP_NOFS in reiserfs_get_block() kill-the-bkl/reiserfs: drop the fs race watchdog from _get_block_create_0() kill-the-bkl/reiserfs: definitely drop the bkl from reiserfs_ioctl() kill-the-bkl/reiserfs: always lock the ioctl path kill-the-bkl/reiserfs: fix reiserfs lock to cpu_add_remove_lock dependency kill-the-bkl/reiserfs: Fix induced mm->mmap_sem to sysfs_mutex dependency kill-the-bkl/reiserfs: panic in case of lock imbalance kill-the-bkl/reiserfs: fix recursive reiserfs write lock in reiserfs_commit_write() kill-the-bkl/reiserfs: fix recursive reiserfs lock in reiserfs_mkdir() kill-the-bkl/reiserfs: fix "reiserfs lock" / "inode mutex" lock inversion dependency kill-the-bkl/reiserfs: move the concurrent tree accesses checks per superblock kill-the-bkl/reiserfs: acquire the inode mutex safely kill-the-bkl/reiserfs: unlock only when needed in search_by_key kill-the-bkl/reiserfs: use mutex_lock in reiserfs_mutex_lock_safe kill-the-bkl/reiserfs: factorize the locking in reiserfs_write_end() kill-the-bkl/reiserfs: reduce number of contentions in search_by_key() kill-the-bkl/reiserfs: don't hold the write recursively in reiserfs_lookup() kill-the-bkl/reiserfs: lock only once on reiserfs_get_block() kill-the-bkl/reiserfs: conditionaly release the write lock on fs_changed() kill-the-BKL/reiserfs: add reiserfs_cond_resched() ...
2009-12-07Merge commit 'v2.6.32' into reiserfs/kill-bklFrederic Weisbecker
Merge-reason: The tree was based 2.6.31. It's better to be up to date with 2.6.32. Although no conflicting changes were made in between, it gives benchmarking results closer to the lastest kernel behaviour.
2009-12-04reiserfs: fix misspelling of "journaled"Adam Buchbinder
"Journaled" is misspelled "journlaled" in an output string; this patch fixed it. No changes in functionality. Signed-off-by: Adam Buchbinder <adam.buchbinder@gmail.com> Signed-off-by: Jiri Kosina <jkosina@suse.cz>
2009-11-20kill-the-bkl/reiserfs: turn GFP_ATOMIC flag to GFP_NOFS in reiserfs_get_block()Frederic Weisbecker
GFP_ATOMIC was used in reiserfs_get_block to not lose the Bkl so that nobody can modify the tree in the middle of its work. Now that we kicked out the bkl, we can use a more friendly flag. We use GFP_NOFS here because we already hold the reiserfs lock. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Laurent Riffard <laurent.riffard@free.fr> Cc: Thomas Gleixner <tglx@linutronix.de>
2009-10-14kill-the-bkl/reiserfs: drop the fs race watchdog from _get_block_create_0()Frederic Weisbecker
We had a watchdog in _get_block_create_0() that jumped to a fixup retry path in case the bkl got relaxed while calling kmap(). This is not necessary anymore since we now have a reiserfs lock that is not implicitly relaxed while sleeping. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Laurent Riffard <laurent.riffard@free.fr> Cc: Thomas Gleixner <tglx@linutronix.de>
2009-10-14kill-the-bkl/reiserfs: definitely drop the bkl from reiserfs_ioctl()Frederic Weisbecker
The reiserfs ioctl path doesn't need the big kernel lock anymore , now that the filesystem synchronizes through its own lock. We can then turn reiserfs_ioctl() into an unlocked_ioctl callback. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Laurent Riffard <laurent.riffard@free.fr> Cc: Thomas Gleixner <tglx@linutronix.de>
2009-10-14kill-the-bkl/reiserfs: always lock the ioctl pathFrederic Weisbecker
Reiserfs uses the ioctl callback for its file operations, which means that its ioctl path is still locked by the bkl, this was synchronizing with the rest of the filsystem operations. We have changed that by locking it with the new reiserfs lock but we do that only from the compat_ioctl callback. Fix that by locking reiserfs_ioctl() everytime. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Laurent Riffard <laurent.riffard@free.fr> Cc: Thomas Gleixner <tglx@linutronix.de>
2009-10-05kill-the-bkl/reiserfs: fix reiserfs lock to cpu_add_remove_lock dependencyFrederic Weisbecker
While creating the reiserfs workqueue during the journal initialization, we are holding the reiserfs lock, but create_workqueue() also holds the cpu_add_remove_lock, creating then the following dependency: - reiserfs lock -> cpu_add_remove_lock But we also have the following existing dependencies: - mm->mmap_sem -> reiserfs lock - cpu_add_remove_lock -> cpu_hotplug.lock -> slub_lock -> sysfs_mutex The merged dependency chain then becomes: - mm->mmap_sem -> reiserfs lock -> cpu_add_remove_lock -> cpu_hotplug.lock -> slub_lock -> sysfs_mutex But when we fill a dir entry in sysfs_readir(), we are holding the sysfs_mutex and we also might fault while copying the directory entry to the user, leading to the following dependency: - sysfs_mutex -> mm->mmap_sem The end result is then a lock inversion between sysfs_mutex and mm->mmap_sem, as reported in the following lockdep warning: [ INFO: possible circular locking dependency detected ] 2.6.31-07095-g25a3912 #4 ------------------------------------------------------- udevadm/790 is trying to acquire lock: (&mm->mmap_sem){++++++}, at: [<c1098942>] might_fault+0x72/0xc0 but task is already holding lock: (sysfs_mutex){+.+.+.}, at: [<c110813c>] sysfs_readdir+0x7c/0x260 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #5 (sysfs_mutex){+.+.+.}: [...] -> #4 (slub_lock){+++++.}: [...] -> #3 (cpu_hotplug.lock){+.+.+.}: [...] -> #2 (cpu_add_remove_lock){+.+.+.}: [...] -> #1 (&REISERFS_SB(s)->lock){+.+.+.}: [...] -> #0 (&mm->mmap_sem){++++++}: [...] This can be fixed by relaxing the reiserfs lock while creating the workqueue. This is fine to relax the lock here, we just keep it around to pass through reiserfs lock checks and for paranoid reasons. Reported-by: Alexander Beregalov <a.beregalov@gmail.com> Tested-by: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Laurent Riffard <laurent.riffard@free.fr>
2009-09-22const: make struct super_block::s_qcop constAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-22const: make struct super_block::dq_op constAlexey Dobriyan
Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2009-09-17kill-the-bkl/reiserfs: Fix induced mm->mmap_sem to sysfs_mutex dependencyFrederic Weisbecker
Alexander Beregalov reported the following warning: ======================================================= [ INFO: possible circular locking dependency detected ] 2.6.31-03149-gdcc030a #1 ------------------------------------------------------- udevadm/716 is trying to acquire lock: (&mm->mmap_sem){++++++}, at: [<c107249a>] might_fault+0x4a/0xa0 but task is already holding lock: (sysfs_mutex){+.+.+.}, at: [<c10cb9aa>] sysfs_readdir+0x5a/0x200 which lock already depends on the new lock. the existing dependency chain (in reverse order) is: -> #3 (sysfs_mutex){+.+.+.}: [...] -> #2 (&bdev->bd_mutex){+.+.+.}: [...] -> #1 (&REISERFS_SB(s)->lock){+.+.+.}: [...] -> #0 (&mm->mmap_sem){++++++}: [...] On reiserfs mount path, we take the reiserfs lock and while initializing the journal, we open the device, taking the bdev->bd_mutex. Then rescan_partition() may signal the change to sysfs. We have then the following dependency: reiserfs_lock -> bd_mutex -> sysfs_mutex Later, while entering reiserfs_readpage() after a pagefault in an mmaped reiserfs file, we are holding the mm->mmap_sem, and we are going to take the reiserfs lock too. We have then the following dependency: mm->mmap_sem -> reiserfs_lock which, expanded with the previous dependency gives us: mm->mmap_sem -> reiserfs_lock -> bd_mutex -> sysfs_mutex Now while entering the sysfs readdir path, we are holding the sysfs_mutex. And when we copy a directory entry to the user buffer, we might fault and then take the mm->mmap_sem lock. Which leads to the circular locking dependency reported. We can fix that by relaxing the reiserfs lock during the call to journal_init_dev(), which is the place where we open the mounted device. This is fine to relax the lock here because we are in the begining of the reiserfs mount path and there is nothing to protect at this time, the journal is not intialized. We just keep this lock around for paranoid reasons. Reported-by: Alexander Beregalov <a.beregalov@gmail.com> Tested-by: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Laurent Riffard <laurent.riffard@free.fr>
2009-09-14kill-the-bkl/reiserfs: panic in case of lock imbalanceFrederic Weisbecker
Until now, trying to unlock the reiserfs write lock whereas the current task doesn't hold it lead to a simple warning. We should actually warn and panic in this case to avoid the user datas to reach an unstable state. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Laurent Riffard <laurent.riffard@free.fr>
2009-09-14kill-the-bkl/reiserfs: fix recursive reiserfs write lock in ↵Frederic Weisbecker
reiserfs_commit_write() reiserfs_commit_write() is always called with the write lock held. Thus the current calls to reiserfs_write_lock() in this function are acquiring the lock recursively. We can safely drop them. This also solves further assumptions for this lock to be really released while calling reiserfs_write_unlock(). Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Laurent Riffard <laurent.riffard@free.fr>
2009-09-14kill-the-bkl/reiserfs: fix recursive reiserfs lock in reiserfs_mkdir()Frederic Weisbecker
reiserfs_mkdir() acquires the reiserfs lock, assuming it has been called from the dir inodes callbacks, without the lock held. But it can also be called from other internal sites such as reiserfs_xattr_init() which already holds the lock. This recursive locking leads to further wrong assumptions. For example, later calls to reiserfs_mutex_lock_safe() won't actually unlock the reiserfs lock the time we acquire a given mutex, creating unexpected lock inversions. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Laurent Riffard <laurent.riffard@free.fr>
2009-09-14kill-the-bkl/reiserfs: fix "reiserfs lock" / "inode mutex" lock inversion ↵Frederic Weisbecker
dependency reiserfs_xattr_init is called with the reiserfs write lock held, but if the ".reiserfs_priv" entry is not created, we take the superblock root directory inode mutex until .reiserfs_priv is created. This creates a lock dependency inversion against other sites such as reiserfs_file_release() which takes an inode mutex and the reiserfs lock after. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Cc: Laurent Riffard <laurent.riffard@free.fr>
2009-09-14kill-the-bkl/reiserfs: move the concurrent tree accesses checks per superblockFrederic Weisbecker
When do_balance() balances the tree, a trick is performed to provide the ability for other tree writers/readers to check whether do_balance() is executing concurrently (requires CONFIG_REISERFS_CHECK). This is done to protect concurrent accesses to the tree. The trick is the following: When do_balance is called, a unique global variable called cur_tb takes a pointer to the current tree to be rebalanced. Once do_balance finishes its work, cur_tb takes the NULL value. Then, concurrent tree readers/writers just have to check the value of cur_tb to ensure do_balance isn't executing concurrently. If it is, then it proves that schedule() occured on do_balance(), which then relaxed the bkl that protected the tree. Now that the bkl has be turned into a mutex, this check is still fine even though do_balance() becomes preemptible: the write lock will not be automatically released on schedule(), so the tree is still protected. But this is only fine if we have a single reiserfs mountpoint. Indeed, because the bkl is a global lock, it didn't allowed concurrent executions between a tree reader/writer in a mount point and a do_balance() on another tree from another mountpoint. So assuming all these readers/writers weren't supposed to be reentrant, the current check now sometimes detect false positives with the current per-superblock mutex which allows this reentrancy. This patch keeps the concurrent tree accesses check but moves it per superblock, so that only trees from a same mount point are checked to be not accessed concurrently. [ Impact: fix spurious panic while running several reiserfs mount-points ] Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-14kill-the-bkl/reiserfs: acquire the inode mutex safelyFrederic Weisbecker
While searching a pathname, an inode mutex can be acquired in do_lookup() which calls reiserfs_lookup() which in turn acquires the write lock. On the other side reiserfs_fill_super() can acquire the write_lock and then call reiserfs_lookup_privroot() which can acquire an inode mutex (the root of the mount point). So we theoretically risk an AB - BA lock inversion that could lead to a deadlock. As for other lock dependencies found since the bkl to mutex conversion, the fix is to use reiserfs_mutex_lock_safe() which drops the lock dependency to the write lock. [ Impact: fix a possible deadlock with reiserfs ] Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-14kill-the-bkl/reiserfs: unlock only when needed in search_by_keyFrederic Weisbecker
search_by_key() is the site which most requires the lock. This is mostly because it is a very central function and also because it releases/reaqcuires the write lock at least once each time it is called. Such release/reacquire creates a lot of contention in this place and also opens more the window which let another thread changing the tree. When it happens, the current path searching over the tree must be retried from the beggining (the root) which is a wasteful and time consuming recovery. This patch factorizes two release/reacquire sequences: - reading leaf nodes blocks - reading current block The latter immediately follows the former. The whole sequence is safe as a single unlocked section because we check just after if the tree has changed during these operations. Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-14kill-the-bkl/reiserfs: use mutex_lock in reiserfs_mutex_lock_safeFrederic Weisbecker
reiserfs_mutex_lock_safe() is a hack to avoid any dependency between an internal reiserfs mutex and the write lock, it has been proposed to follow the old bkl logic. The code does the following: while (!mutex_trylock(m)) { reiserfs_write_unlock(s); schedule(); reiserfs_write_lock(s); } It then imitate the implicit behaviour of the lock when it was a Bkl and hadn't such dependency: mutex_lock(m) { if (fastpath) let's go else { wait_for_mutex() { schedule() { unlock_kernel() reacquire_lock_kernel() } } } } The problem is that by using such explicit schedule(), we don't benefit of the adaptive mutex spinning on owner. The logic in use now is: reiserfs_write_unlock(s); mutex_lock(m); // -> possible adaptive spinning reiserfs_write_lock(s); [ Impact: restore the use of adaptive spinning mutexes in reiserfs ] Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>
2009-09-14kill-the-bkl/reiserfs: factorize the locking in reiserfs_write_end()Frederic Weisbecker
reiserfs_write_end() is a hot path in reiserfs. We have two wasteful write lock lock/release inside that can be gathered without changing the code logic. This patch factorizes them out in a single protected section, reducing the number of contentions inside. [ Impact: reduce lock contention in a reiserfs hotpath ] Cc: Jeff Mahoney <jeffm@suse.com> Cc: Chris Mason <chris.mason@oracle.com> Cc: Ingo Molnar <mingo@elte.hu> Cc: Alexander Beregalov <a.beregalov@gmail.com> Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com>