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2015-09-04watchdog: use park/unpark functions in update_watchdog_all_cpus()Ulrich Obergfell1-38/+2
Remove update_watchdog() and restart_watchdog_hrtimer() since these functions are no longer needed. Changes of parameters such as the sample period are honored at the time when the watchdog threads are being unparked. Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com> Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Don Zickus <dzickus@redhat.com> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Stephane Eranian <eranian@google.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04watchdog: introduce watchdog_suspend() and watchdog_resume()Ulrich Obergfell2-0/+67
This interface can be utilized to deactivate the hard and soft lockup detector temporarily. Callers are expected to minimize the duration of deactivation. Multiple deactivations are allowed to occur in parallel but should be rare in practice. [akpm@linux-foundation.org: remove unneeded static initialization] Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com> Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Don Zickus <dzickus@redhat.com> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Stephane Eranian <eranian@google.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04watchdog: introduce watchdog_park_threads() and watchdog_unpark_threads()Ulrich Obergfell1-0/+36
Originally watchdog_nmi_enable(cpu) and watchdog_nmi_disable(cpu) were only called in watchdog thread context. However, the following commits utilize these functions outside of watchdog thread context too. commit 9809b18fcf6b8d8ec4d3643677345907e6b50eca Author: Michal Hocko <mhocko@suse.cz> Date: Tue Sep 24 15:27:30 2013 -0700 watchdog: update watchdog_thresh properly commit b3738d29323344da3017a91010530cf3a58590fc Author: Stephane Eranian <eranian@google.com> Date: Mon Nov 17 20:07:03 2014 +0100 watchdog: Add watchdog enable/disable all functions Hence, it is now possible that these functions execute concurrently with the same 'cpu' argument. This concurrency is problematic because per-cpu 'watchdog_ev' can be accessed/modified without adequate synchronization. The patch series aims to address the above problem. However, instead of introducing locks to protect per-cpu 'watchdog_ev' a different approach is taken: Invoke these functions by parking and unparking the watchdog threads (to ensure they are always called in watchdog thread context). static struct smp_hotplug_thread watchdog_threads = { ... .park = watchdog_disable, // calls watchdog_nmi_disable() .unpark = watchdog_enable, // calls watchdog_nmi_enable() }; Both previously mentioned commits call these functions in a similar way and thus in principle contain some duplicate code. The patch series also avoids this duplication by providing a commonly usable mechanism. - Patch 1/4 introduces the watchdog_{park|unpark}_threads functions that park/unpark all watchdog threads specified in 'watchdog_cpumask'. They are intended to be called inside of kernel/watchdog.c only. - Patch 2/4 introduces the watchdog_{suspend|resume} functions which can be utilized by external callers to deactivate the hard and soft lockup detector temporarily. - Patch 3/4 utilizes watchdog_{park|unpark}_threads to replace some code that was introduced by commit 9809b18fcf6b8d8ec4d3643677345907e6b50eca. - Patch 4/4 utilizes watchdog_{suspend|resume} to replace some code that was introduced by commit b3738d29323344da3017a91010530cf3a58590fc. A few corner cases should be mentioned here for completeness. - kthread_park() of watchdog/N could hang if cpu N is already locked up. However, if watchdog is enabled the lockup will be detected anyway. - kthread_unpark() of watchdog/N could hang if cpu N got locked up after kthread_park(). The occurrence of this scenario should be _very_ rare in practice, in particular because it is not expected that temporary deactivation will happen frequently, and if it happens at all it is expected that the duration of deactivation will be short. This patch (of 4): introduce watchdog_park_threads() and watchdog_unpark_threads() These functions are intended to be used only from inside kernel/watchdog.c to park/unpark all watchdog threads that are specified in watchdog_cpumask. Signed-off-by: Ulrich Obergfell <uobergfe@redhat.com> Reviewed-by: Aaron Tomlin <atomlin@redhat.com> Cc: Guenter Roeck <linux@roeck-us.net> Cc: Don Zickus <dzickus@redhat.com> Cc: Ulrich Obergfell <uobergfe@redhat.com> Cc: Jiri Olsa <jolsa@kernel.org> Cc: Michal Hocko <mhocko@suse.cz> Cc: Stephane Eranian <eranian@google.com> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Frederic Weisbecker <fweisbec@gmail.com> Cc: Peter Zijlstra <a.p.zijlstra@chello.nl> Cc: Ingo Molnar <mingo@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04kernel/watchdog: move NMI function header declarations from watchdog.h to nmi.hGuenter Roeck4-14/+6
The kernel's NMI watchdog has nothing to do with the watchdog subsystem. Its header declarations should be in linux/nmi.h, not linux/watchdog.h. The code provided two sets of dummy functions if HARDLOCKUP_DETECTOR is not configured, one in the include file and one in kernel/watchdog.c. Remove the dummy functions from kernel/watchdog.c and use those from the include file. Signed-off-by: Guenter Roeck <linux@roeck-us.net> Cc: Stephane Eranian <eranian@google.com> Cc: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Ingo Molnar <mingo@kernel.org> Cc: Don Zickus <dzickus@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04watchdog: simplify housekeeping affinity with the appropriate maskFrederic Weisbecker1-4/+2
housekeeping_mask gathers all the CPUs that aren't part of the nohz_full set. This is exactly what we want the watchdog to be affine to without the need to use complicated cpumask operations. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04smpboot: allow passing the cpumask on per-cpu thread registrationFrederic Weisbecker3-12/+22
It makes the registration cheaper and simpler for the smpboot per-cpu kthread users that don't need to always update the cpumask after threads creation. [sfr@canb.auug.org.au: fix for allow passing the cpumask on per-cpu thread registration] Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04smpboot: make cleanup to mirror setupFrederic Weisbecker1-10/+2
The per-cpu kthread cleanup() callback is the mirror of the setup() callback. When the per-cpu kthread is started, it first calls setup() to initialize the resources which are then released by cleanup() when the kthread exits. Now since the introduction of a per-cpu kthread cpumask, the kthreads excluded by the cpumask on boot may happen to be parked immediately after their creation without taking the setup() stage, waiting to be asked to unpark to do so. Then when smpboot_unregister_percpu_thread() is later called, the kthread is stopped without having ever called setup(). But this triggers a bug as the kthread unconditionally calls cleanup() on exit but this doesn't mirror any setup(). Thus the kernel crashes because we try to free resources that haven't been initialized, as in the watchdog case: WATCHDOG disable 0 WATCHDOG disable 1 WATCHDOG disable 2 BUG: unable to handle kernel NULL pointer dereference at (null) IP: hrtimer_active+0x26/0x60 [...] Call Trace: hrtimer_try_to_cancel+0x1c/0x280 hrtimer_cancel+0x1d/0x30 watchdog_disable+0x56/0x70 watchdog_cleanup+0xe/0x10 smpboot_thread_fn+0x23c/0x2c0 kthread+0xf8/0x110 ret_from_fork+0x3f/0x70 This bug is currently masked with explicit kthread unparking before kthread_stop() on smpboot_destroy_threads(). This forces a call to setup() and then unpark(). We could fix this by unconditionally calling setup() on kthread entry. But setup() isn't always cheap. In the case of watchdog it launches hrtimer, perf events, etc... So we may as well like to skip it if there are chances the kthread will never be used, as in a reduced cpumask value. So let's simply do a state machine check before calling cleanup() that makes sure setup() has been called before mirroring it. And remove the nasty hack workaround. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04smpboot: fix memory leak on error handlingFrederic Weisbecker1-0/+1
The cpumask is allocated before threads get created. If the latter step fails, we need to free the cpumask. Signed-off-by: Frederic Weisbecker <fweisbec@gmail.com> Reviewed-by: Chris Metcalf <cmetcalf@ezchip.com> Reviewed-by: Thomas Gleixner <tglx@linutronix.de> Cc: Chris Metcalf <cmetcalf@ezchip.com> Cc: Don Zickus <dzickus@redhat.com> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Ulrich Obergfell <uobergfe@redhat.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04fs: create and use seq_show_option for escapingKees Cook15-30/+71
Many file systems that implement the show_options hook fail to correctly escape their output which could lead to unescaped characters (e.g. new lines) leaking into /proc/mounts and /proc/[pid]/mountinfo files. This could lead to confusion, spoofed entries (resulting in things like systemd issuing false d-bus "mount" notifications), and who knows what else. This looks like it would only be the root user stepping on themselves, but it's possible weird things could happen in containers or in other situations with delegated mount privileges. Here's an example using overlay with setuid fusermount trusting the contents of /proc/mounts (via the /etc/mtab symlink). Imagine the use of "sudo" is something more sneaky: $ BASE="ovl" $ MNT="$BASE/mnt" $ LOW="$BASE/lower" $ UP="$BASE/upper" $ WORK="$BASE/work/ 0 0 none /proc fuse.pwn user_id=1000" $ mkdir -p "$LOW" "$UP" "$WORK" $ sudo mount -t overlay -o "lowerdir=$LOW,upperdir=$UP,workdir=$WORK" none /mnt $ cat /proc/mounts none /root/ovl/mnt overlay rw,relatime,lowerdir=ovl/lower,upperdir=ovl/upper,workdir=ovl/work/ 0 0 none /proc fuse.pwn user_id=1000 0 0 $ fusermount -u /proc $ cat /proc/mounts cat: /proc/mounts: No such file or directory This fixes the problem by adding new seq_show_option and seq_show_option_n helpers, and updating the vulnerable show_option handlers to use them as needed. Some, like SELinux, need to be open coded due to unusual existing escape mechanisms. [akpm@linux-foundation.org: add lost chunk, per Kees] [keescook@chromium.org: seq_show_option should be using const parameters] Signed-off-by: Kees Cook <keescook@chromium.org> Acked-by: Serge Hallyn <serge.hallyn@canonical.com> Acked-by: Jan Kara <jack@suse.com> Acked-by: Paul Moore <paul@paul-moore.com> Cc: J. R. Okajima <hooanon05g@gmail.com> Signed-off-by: Kees Cook <keescook@chromium.org> Cc: <stable@vger.kernel.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: clean up redundant NULL checks before kfreeJoseph Qi2-5/+3
NULL check before kfree is redundant and so clean them up. Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: neaten do_error, ocfs2_error and ocfs2_abortJoe Perches14-202/+163
These uses sometimes do and sometimes don't have '\n' terminations. Make the uses consistently use '\n' terminations and remove the newline from the functions. Miscellanea: o Coalesce formats o Realign arguments Signed-off-by: Joe Perches <joe@perches.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: do not set fs read-only if rec[0] is empty while committing truncateXue jiufei1-6/+38
While appending an extent to a file, it will call these functions: ocfs2_insert_extent -> call ocfs2_grow_tree() if there's no free rec -> ocfs2_add_branch add a new branch to extent tree, now rec[0] in the leaf of rightmost path is empty -> ocfs2_do_insert_extent -> ocfs2_rotate_tree_right -> ocfs2_extend_rotate_transaction -> jbd2_journal_restart if jbd2_journal_extend fail -> ocfs2_insert_path -> ocfs2_extend_trans -> jbd2_journal_restart if jbd2_journal_extend fail -> ocfs2_insert_at_leaf -> ocfs2_et_update_clusters Function jbd2_journal_restart() may be called and it may happened that buffers dirtied in ocfs2_add_branch() are committed while buffers dirtied in ocfs2_insert_at_leaf() and ocfs2_et_update_clusters() are not. So an empty rec[0] is left in rightmost path which will cause read-only filesystem when call ocfs2_commit_truncate() with the error message: "Inode %lu has an empty extent record". This is not a serious problem, so remove the rightmost path when call ocfs2_commit_truncate(). Signed-off-by: joyce.xue <xuejiufei@huawei.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: call ocfs2_journal_access_di() before ocfs2_journal_dirty() in ↵yangwenfang1-5/+11
ocfs2_write_end_nolock() 1: After we call ocfs2_journal_access_di() in ocfs2_write_begin(), jbd2_journal_restart() may also be called, in this function transaction A's t_updates-- and obtains a new transaction B. If jbd2_journal_commit_transaction() is happened to commit transaction A, when t_updates==0, it will continue to complete commit and unfile buffer. So when jbd2_journal_dirty_metadata(), the handle is pointed a new transaction B, and the buffer head's journal head is already freed, jh->b_transaction == NULL, jh->b_next_transaction == NULL, it returns EINVAL, So it triggers the BUG_ON(status). thread 1 jbd2 ocfs2_write_begin jbd2_journal_commit_transaction ocfs2_write_begin_nolock ocfs2_start_trans jbd2__journal_start(t_updates+1, transaction A) ocfs2_journal_access_di ocfs2_write_cluster_by_desc ocfs2_mark_extent_written ocfs2_change_extent_flag ocfs2_split_extent ocfs2_extend_rotate_transaction jbd2_journal_restart (t_updates-1,transaction B) t_updates==0 __jbd2_journal_refile_buffer (jh->b_transaction = NULL) ocfs2_write_end ocfs2_write_end_nolock ocfs2_journal_dirty jbd2_journal_dirty_metadata(bug) ocfs2_commit_trans 2. In ext4, I found that: jbd2_journal_get_write_access() called by ext4_write_end. ext4_write_begin ext4_journal_start __ext4_journal_start_sb ext4_journal_check_start jbd2__journal_start ext4_write_end ext4_mark_inode_dirty ext4_reserve_inode_write ext4_journal_get_write_access jbd2_journal_get_write_access ext4_mark_iloc_dirty ext4_do_update_inode ext4_handle_dirty_metadata jbd2_journal_dirty_metadata 3. So I think we should put ocfs2_journal_access_di before ocfs2_journal_dirty in the ocfs2_write_end. and it works well after my modification. Signed-off-by: vicky <vicky.yangwenfang@huawei.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Zhangguanghui <zhang.guanghui@h3c.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: use 64bit variables to track heartbeat timeTina Ruchandani1-40/+9
o2hb_elapsed_msecs computes the time taken for a disk heartbeat. 'struct timeval' variables are used to store start and end times. On 32-bit systems, the 'tv_sec' component of 'struct timeval' will overflow in year 2038 and beyond. This patch solves the overflow with the following: 1. Replace o2hb_elapsed_msecs using 'ktime_t' values to measure start and end time, and built-in function 'ktime_ms_delta' to compute the elapsed time. ktime_get_real() is used since the code prints out the wallclock time. 2. Changes format string to print time as a single 64-bit nanoseconds value ("%lld") instead of seconds and microseconds. This simplifies the code since converting ktime_t to that format would need expensive computation. However, the debug log string is less readable than the previous format. Signed-off-by: Tina Ruchandani <ruchandani.tina@gmail.com> Suggested by: Arnd Bergmann <arnd@arndb.de> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: fix race between crashed dio and rmJoseph Qi2-1/+12
There is a race case between crashed dio and rm, which will lead to OCFS2_VALID_FL not set read-only. N1 N2 ------------------------------------------------------------------------ dd with direct flag rm file crashed with an dio entry left in orphan dir clear OCFS2_VALID_FL in ocfs2_remove_inode recover N1 and read the corrupted inode, and set filesystem read-only So we skip the inode deletion this time and wait for dio entry recovered first. Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: avoid access invalid address when read o2dlm debug messagesYiwen Jiang2-11/+21
The following case will lead to a lockres is freed but is still in use. cat /sys/kernel/debug/o2dlm/locking_state dlm_thread lockres_seq_start -> lock dlm->track_lock -> get resA resA->refs decrease to 0, call dlm_lockres_release, and wait for "cat" unlock. Although resA->refs is already set to 0, increase resA->refs, and then unlock lock dlm->track_lock -> list_del_init() -> unlock -> free resA In such a race case, invalid address access may occurs. So we should delete list res->tracking before resA->refs decrease to 0. Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com> Reviewed-by: Joseph Qi <joseph.qi@huawei.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: take inode lock in ocfs2_iop_set/get_acl()Tariq Saeed1-6/+20
This bug in mainline code is pointed out by Mark Fasheh. When ocfs2_iop_set_acl() and ocfs2_iop_get_acl() are entered from VFS layer, inode lock is not held. This seems to be regression from older kernels. The patch is to fix that. Orabug: 20189959 Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: fix BUG_ON() in ocfs2_ci_checkpointed()Tariq Saeed1-1/+8
PID: 614 TASK: ffff882a739da580 CPU: 3 COMMAND: "ocfs2dc" #0 [ffff882ecc3759b0] machine_kexec at ffffffff8103b35d #1 [ffff882ecc375a20] crash_kexec at ffffffff810b95b5 #2 [ffff882ecc375af0] oops_end at ffffffff815091d8 #3 [ffff882ecc375b20] die at ffffffff8101868b #4 [ffff882ecc375b50] do_trap at ffffffff81508bb0 #5 [ffff882ecc375ba0] do_invalid_op at ffffffff810165e5 #6 [ffff882ecc375c40] invalid_op at ffffffff815116fb [exception RIP: ocfs2_ci_checkpointed+208] RIP: ffffffffa0a7e940 RSP: ffff882ecc375cf0 RFLAGS: 00010002 RAX: 0000000000000001 RBX: 000000000000654b RCX: ffff8812dc83f1f8 RDX: 00000000000017d9 RSI: ffff8812dc83f1f8 RDI: ffffffffa0b2c318 RBP: ffff882ecc375d20 R8: ffff882ef6ecfa60 R9: ffff88301f272200 R10: 0000000000000000 R11: 0000000000000000 R12: ffffffffffffffff R13: ffff8812dc83f4f0 R14: 0000000000000000 R15: ffff8812dc83f1f8 ORIG_RAX: ffffffffffffffff CS: 0010 SS: 0018 #7 [ffff882ecc375d28] ocfs2_check_meta_downconvert at ffffffffa0a7edbd [ocfs2] #8 [ffff882ecc375d38] ocfs2_unblock_lock at ffffffffa0a84af8 [ocfs2] #9 [ffff882ecc375dc8] ocfs2_process_blocked_lock at ffffffffa0a85285 [ocfs2] #10 [ffff882ecc375e18] ocfs2_downconvert_thread_do_work at ffffffffa0a85445 [ocfs2] #11 [ffff882ecc375e68] ocfs2_downconvert_thread at ffffffffa0a854de [ocfs2] #12 [ffff882ecc375ee8] kthread at ffffffff81090da7 #13 [ffff882ecc375f48] kernel_thread_helper at ffffffff81511884 assert is tripped because the tran is not checkpointed and the lock level is PR. Some time ago, chmod command had been executed. As result, the following call chain left the inode cluster lock in PR state, latter on causing the assert. system_call_fastpath -> my_chmod -> sys_chmod -> sys_fchmodat -> notify_change -> ocfs2_setattr -> posix_acl_chmod -> ocfs2_iop_set_acl -> ocfs2_set_acl -> ocfs2_acl_set_mode Here is how. 1119 int ocfs2_setattr(struct dentry *dentry, struct iattr *attr) 1120 { 1247 ocfs2_inode_unlock(inode, 1); <<< WRONG thing to do. .. 1258 if (!status && attr->ia_valid & ATTR_MODE) { 1259 status = posix_acl_chmod(inode, inode->i_mode); 519 posix_acl_chmod(struct inode *inode, umode_t mode) 520 { .. 539 ret = inode->i_op->set_acl(inode, acl, ACL_TYPE_ACCESS); 287 int ocfs2_iop_set_acl(struct inode *inode, struct posix_acl *acl, ... 288 { 289 return ocfs2_set_acl(NULL, inode, NULL, type, acl, NULL, NULL); 224 int ocfs2_set_acl(handle_t *handle, 225 struct inode *inode, ... 231 { .. 252 ret = ocfs2_acl_set_mode(inode, di_bh, 253 handle, mode); 168 static int ocfs2_acl_set_mode(struct inode *inode, struct buffer_head ... 170 { 183 if (handle == NULL) { >>> BUG: inode lock not held in ex at this point <<< 184 handle = ocfs2_start_trans(OCFS2_SB(inode->i_sb), 185 OCFS2_INODE_UPDATE_CREDITS); ocfs2_setattr.#1247 we unlock and at #1259 call posix_acl_chmod. When we reach ocfs2_acl_set_mode.#181 and do trans, the inode cluster lock is not held in EX mode (it should be). How this could have happended? We are the lock master, were holding lock EX and have released it in ocfs2_setattr.#1247. Note that there are no holders of this lock at this point. Another node needs the lock in PR, and we downconvert from EX to PR. So the inode lock is PR when do the trans in ocfs2_acl_set_mode.#184. The trans stays in core (not flushed to disc). Now another node want the lock in EX, downconvert thread gets kicked (the one that tripped assert abovt), finds an unflushed trans but the lock is not EX (it is PR). If the lock was at EX, it would have flushed the trans ocfs2_ci_checkpointed -> ocfs2_start_checkpoint before downconverting (to NULL) for the request. ocfs2_setattr must not drop inode lock ex in this code path. If it does, takes it again before the trans, say in ocfs2_set_acl, another cluster node can get in between, execute another setattr, overwriting the one in progress on this node, resulting in a mode acl size combo that is a mix of the two. Orabug: 20189959 Signed-off-by: Tariq Saeed <tariq.x.saeed@oracle.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: optimize error handling in dlm_request_joinNorton.Zhu1-32/+39
Currently error handling in dlm_request_join is a little obscure, so optimize it to promote readability. If packet.code is invalid, reset it to JOIN_DISALLOW to keep it meaningful. It only influences the log printing. Signed-off-by: Norton.Zhu <norton.zhu@huawei.com> Cc: Srinivas Eeda <srinivas.eeda@oracle.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: fix a tiny case that inode can not removedYiwen Jiang1-0/+5
When running dirop_fileop_racer we found a case that inode can not removed. Two nodes, say Node A and Node B, mount the same ocfs2 volume. Create two dirs /race/1/ and /race/2/ in the filesystem. Node A Node B rm -r /race/2/ mv /race/1/ /race/2/ call ocfs2_unlink(), get the EX mode of /race/2/ wait for B unlock /race/2/ decrease i_nlink of /race/2/ to 0, and add inode of /race/2/ into orphan dir, unlock /race/2/ got EX mode of /race/2/. because /race/1/ is dir, so inc i_nlink of /race/2/ and update into disk, unlock /race/2/ because i_nlink of /race/2/ is not zero, this inode will always remain in orphan dir This patch fixes this case by test whether i_nlink of new dir is zero. Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Xue jiufei <xuejiufei@huawei.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: add ip_alloc_sem in direct IO to protect allocation changesWeiWei Wang1-2/+16
In ocfs2, ip_alloc_sem is used to protect allocation changes on the node. In direct IO, we add ip_alloc_sem to protect date consistent between direct-io and ocfs2_truncate_file race (buffer io use ip_alloc_sem already). Although inode->i_mutex lock is used to avoid concurrency of above situation, i think ip_alloc_sem is still needed because protect allocation changes is significant. Other filesystem like ext4 also uses rw_semaphore to protect data consistent between get_block-vs-truncate race by other means, So ip_alloc_sem in ocfs2 direct io is needed. Signed-off-by: Weiwei Wang <wangww631@huawei.com> Signed-off-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: clear the rest of the buffers on errorGoldwyn Rodrigues1-0/+6
In case a validation fails, clear the rest of the buffers and return the error to the calling function. This also facilitates bubbling up the error originating from ocfs2_error to calling functions. Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: acknowledge return value of ocfs2_error()Goldwyn Rodrigues7-83/+51
Caveat: This may return -EROFS for a read case, which seems wrong. This is happening even without this patch series though. Should we convert EROFS to EIO? Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: add errors=continueGoldwyn Rodrigues3-20/+47
OCFS2 is often used in high-availaibility systems. However, ocfs2 converts the filesystem to read-only at the drop of the hat. This may not be necessary, since turning the filesystem read-only would affect other running processes as well, decreasing availability. This attempt is to add errors=continue, which would return the EIO to the calling process and terminate furhter processing so that the filesystem is not corrupted further. However, the filesystem is not converted to read-only. As a future plan, I intend to create a small utility or extend fsck.ocfs2 to fix small errors such as in the inode. The input to the utility such as the inode can come from the kernel logs so we don't have to schedule a downtime for fixing small-enough errors. The patch changes the ocfs2_error to return an error. The error returned depends on the mount option set. If none is set, the default is to turn the filesystem read-only. Perhaps errors=continue is not the best option name. Historically it is used for making an attempt to progress in the current process itself. Should we call it errors=eio? or errors=killproc? Suggestions/Comments welcome. Sources are available at: https://github.com/goldwynr/linux/tree/error-cont Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com> Signed-off-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: flush inode data to disk and free inode when i_count becomes zeroXue jiufei1-6/+8
Disk inode deletion may be heavily delayed when one node unlink a file after the same dentry is freed on another node(say N1) because of memory shrink but inode is left in memory. This inode can only be freed while N1 doing the orphan scan work. However, N1 may skip orphan scan for several times because other nodes may do the work earlier. In our tests, it may take 1 hour on 4 nodes cluster and it hurts the user experience. So we think the inode should be freed after the data flushed to disk when i_count becomes zero to avoid such circumstances. Signed-off-by: Joyce.xue <xuejiufei@huawei.com> Cc: Joel Becker <jlbec@evilplan.org> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: trusted xattr missing CAP_SYS_ADMIN checkSanidhya Kashyap1-0/+3
The trusted extended attributes are only visible to the process which hvae CAP_SYS_ADMIN capability but the check is missing in ocfs2 xattr_handler trusted list. The check is important because this will be used for implementing mechanisms in the userspace for which other ordinary processes should not have access to. Signed-off-by: Sanidhya Kashyap <sanidhya.gatech@gmail.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Cc: Taesoo kim <taesoo@gatech.edu> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: set filesytem read-only when ocfs2_delete_entry failed.jiangyiwen1-1/+14
In ocfs2_rename, it will lead to an inode with two entried(old and new) if ocfs2_delete_entry(old) failed. Thus, filesystem will be inconsistent. The case is described below: ocfs2_rename -> ocfs2_start_trans -> ocfs2_add_entry(new) -> ocfs2_delete_entry(old) -> __ocfs2_journal_access *failed* because of -ENOMEM -> ocfs2_commit_trans So filesystem should be set to read-only at the moment. Signed-off-by: Yiwen Jiang <jiangyiwen@huawei.com> Cc: Joseph Qi <joseph.qi@huawei.com> Cc: Joel Becker <jlbec@evilplan.org> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2/dlm: use list_for_each_entry instead of list_for_eachJoseph Qi1-4/+2
Use list_for_each_entry instead of list_for_each to simplify code. Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: remove unneeded code in dlm_register_domain_handlersJoseph Qi1-2/+0
The last goto statement is unneeded, so remove it. Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: fix BUG when o2hb_register_callback failsJoseph Qi1-2/+3
In dlm_register_domain_handlers, if o2hb_register_callback fails, it will call dlm_unregister_domain_handlers to unregister. This will trigger the BUG_ON in o2hb_unregister_callback because hc_magic is 0. So we should call o2hb_setup_callback to initialize hc first. Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: remove unneeded code in ocfs2_dlm_initJoseph Qi1-2/+0
status is already initialized and it will only be 0 or negatives in the code flow. So remove the unneeded assignment after the lable 'local'. Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: adjust code to match locking/unlocking orderJoseph Qi1-17/+17
Unlocking order in ocfs2_unlink and ocfs2_rename mismatches the corresponding locking order, although it won't cause issues, adjust the code so that it looks more reasonable. Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: clean up unused local variables in ocfs2_file_write_iterJoseph Qi1-9/+0
Since commit 86b9c6f3f891 ("ocfs2: remove filesize checks for sync I/O journal commit") removes filesize checks for sync I/O journal commit, variables old_size and old_clusters are not actually used any more. So clean them up. Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: do not log twice error messagesChristophe JAILLET1-15/+5
'o2hb_map_slot_data' and 'o2hb_populate_slot_data' are called from only one place, in 'o2hb_region_dev_write'. Return value is checked and 'mlog_errno' is called to log a message if it is not 0. So there is no need to call 'mlog_errno' directly within these functions. This would result on logging the message twice. Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: do not BUG if buffer not uptodate in __ocfs2_journal_accessJoseph Qi1-1/+17
When storage network is unstable, it may trigger the BUG in __ocfs2_journal_access because of buffer not uptodate. We can retry the write in this case or return error instead of BUG. Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Reported-by: Zhangguanghui <zhang.guanghui@h3c.com> Tested-by: Zhangguanghui <zhang.guanghui@h3c.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: fix several issues of append dioJoseph Qi2-2/+10
1) Take rw EX lock in case of append dio. 2) Explicitly treat the error code -EIOCBQUEUED as normal. 3) Set di_bh to NULL after brelse if it may be used again later. Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Cc: Yiwen Jiang <jiangyiwen@huawei.com> Cc: Weiwei Wang <wangww631@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ocfs2: fix race between dio and recover orphanJoseph Qi6-41/+24
During direct io the inode will be added to orphan first and then deleted from orphan. There is a race window that the orphan entry will be deleted twice and thus trigger the BUG when validating OCFS2_DIO_ORPHANED_FL in ocfs2_del_inode_from_orphan. ocfs2_direct_IO_write ... ocfs2_add_inode_to_orphan >>>>>>>> race window. 1) another node may rm the file and then down, this node take care of orphan recovery and clear flag OCFS2_DIO_ORPHANED_FL. 2) since rw lock is unlocked, it may race with another orphan recovery and append dio. ocfs2_del_inode_from_orphan So take inode mutex lock when recovering orphans and make rw unlock at the end of aio write in case of append dio. Signed-off-by: Joseph Qi <joseph.qi@huawei.com> Reported-by: Yiwen Jiang <jiangyiwen@huawei.com> Cc: Weiwei Wang <wangww631@huawei.com> Cc: Mark Fasheh <mfasheh@suse.com> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04sh: use PFN_DOWN macroAlexander Kuleshov2-4/+4
Replace ((x) >> PAGE_SHIFT) with the predefined PFN_DOWN macro. Signed-off-by: Alexander Kuleshov <kuleshovmail@gmail.com> Acked-by: Geert Uytterhoeven <geert+renesas@glider.be> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04ntfs: delete unnecessary checks before calling iput()SF Markus Elfring1-14/+7
iput() tests whether its argument is NULL and then returns immediately. Thus the test around the call is not needed. This issue was detected by using the Coccinelle software. Signed-off-by: Markus Elfring <elfring@users.sourceforge.net> Cc: Julia Lawall <julia.lawall@lip6.fr> Reviewed-by: Anton Altaparmakov <anton@tuxera.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04scripts/spelling.txt: add some typo-wordsZhao Lei1-0/+24
I wrote a small script to show word-pair from all linux spelling-typo commits, and get following result by sort | uniq -c: 181 occured -> occurred 78 transfered -> transferred 67 recieved -> received 65 dependant -> dependent 58 wether -> whether 56 accomodate -> accommodate 54 occured -> occurred 51 recieve -> receive 47 cant -> can't 40 sucessfully -> successfully ... Some of them are not in spelling.txt, this patch adds the most common word-pairs into spelling.txt. Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04scripts: decode_stacktrace: fix ARM architecture decodingRobert Jarzmik1-1/+4
Fix the stack decoder for the ARM architecture. An ARM stack is designed as : [ 81.547704] [<c023eb04>] (bucket_find_contain) from [<c023ec88>] (check_sync+0x40/0x4f8) [ 81.559668] [<c023ec88>] (check_sync) from [<c023f8c4>] (debug_dma_sync_sg_for_cpu+0x128/0x194) [ 81.571583] [<c023f8c4>] (debug_dma_sync_sg_for_cpu) from [<c0327dec>] (__videobuf_s The current script doesn't expect the symbols to be bound by parenthesis, and triggers the following errors : awk: cmd. line:1: error: Unmatched ( or \(: / (check_sync$/ [ 81.547704] (bucket_find_contain) from (check_sync+0x40/0x4f8) Fix it by chopping starting and ending parenthesis from the each symbol name. As a side note, this probably comes from the function dump_backtrace_entry(), which is implemented differently for each architecture. That makes a single decoding script a bit a challenge. Signed-off-by: Robert Jarzmik <robert.jarzmik@free.fr> Cc: Sasha Levin <sasha.levin@oracle.com> Cc: Russell King <rmk+kernel@arm.linux.org.uk> Cc: Michal Marek <mmarek@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04scripts/Lindent: handle missing indent gracefullyJean Delvare1-0/+3
If indent is not found, bail out immediately instead of spitting random shell script error messages. Signed-off-by: Jean Delvare <jdelvare@suse.de> Cc: Joe Perches <joe@perches.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04kerneldoc: Convert error messages to GNU error message formatBart Van Assche1-19/+19
Editors like emacs and vi recognize a number of error message formats. The format used by the kerneldoc tool is not recognized by emacs. Change the kerneldoc error message format to the GNU style such that the emacs prev-error and next-error commands can be used to navigate through kerneldoc error messages. For more information about the GNU error message format, see also https://www.gnu.org/prep/standards/html_node/Errors.html. This patch has been generated via the following sed command: sed -i.orig 's/Error(\${file}:\$.):/\${file}:\$.: error:/g;s/Warning(\${file}:\$.):/\${file}:\$.: warning:/g;s/Warning(\${file}):/\${file}:1: warning:/g;s/Info(\${file}:\$.):/\${file}:\$.: info:/g' scripts/kernel-doc Signed-off-by: Bart Van Assche <bart.vanassche@sandisk.com> Cc: Johannes Berg <johannes.berg@intel.com> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04scripts/spelling.txt: spelling of uninitializedSudip Mukherjee1-0/+1
I just did a spelling mistake of uninitialized and wrote that as unintialized. Fortunately I noticed it in my final review. Signed-off-by: Sudip Mukherjee <sudip@vectorindia.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04scripts/spelling.txt: add misspelled words for checkManinder Singh1-0/+4
misspelled words for check:- chcek chck cehck I myself did these spell mistakes in changelog for patches, Thus suggesting to add in spelling.txt, so that checkpatch.pl warns it earlier. References:- ./arch/powerpc/kernel/exceptions-64e.S:456: . . . make sure you chcek https://lkml.org/lkml/2015/6/25/289 ./arch/x86/mm/pageattr.c:1368: * No need to cehck in that case [akpm@linux-foundation.org: add whcih->which, whcih I always get wrong] Signed-off-by: Maninder Singh <maninder1.s@samsung.com> Acked-by: Kees Cook <keescook@chromium.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04fsnotify: get rid of fsnotify_destroy_mark_locked()Jan Kara4-41/+61
fsnotify_destroy_mark_locked() is subtle to use because it temporarily releases group->mark_mutex. To avoid future problems with this function, split it into two. fsnotify_detach_mark() is the part that needs group->mark_mutex and fsnotify_free_mark() is the part that must be called outside of group->mark_mutex. This way it's much clearer what's going on and we also avoid some pointless acquisitions of group->mark_mutex. Signed-off-by: Jan Kara <jack@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04fsnotify: remove mark->free_listJan Kara6-63/+40
Free list is used when all marks on given inode / mount should be destroyed when inode / mount is going away. However we can free all of the marks without using a special list with some care. Signed-off-by: Jan Kara <jack@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04fsnotify: document mark lockingJan Kara1-20/+30
Signed-off-by: Jan Kara <jack@suse.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2015-09-04fsnotify: fix check in inotify fdinfo printingJan Kara1-1/+2
A check in inotify_fdinfo() checking whether mark is valid was always true due to a bug. Luckily we can never get to invalidated marks since we hold mark_mutex and invalidated marks get removed from the group list when they are invalidated under that mutex. Anyway fix the check to make code more future proof. 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>
2015-09-04fs/notify: optimize inotify/fsnotify code for unwatched filesDave Hansen1-0/+10
I have a _tiny_ microbenchmark that sits in a loop and writes single bytes to a file. Writing one byte to a tmpfs file is around 2x slower than reading one byte from a file, which is a _bit_ more than I expecte. This is a dumb benchmark, but I think it's hard to deny that write() is a hot path and we should avoid unnecessary overhead there. I did a 'perf record' of 30-second samples of read and write. The top item in a diffprofile is srcu_read_lock() from fsnotify(). There are active inotify fd's from systemd, but nothing is actually listening to the file or its part of the filesystem. I *think* we can avoid taking the srcu_read_lock() for the common case where there are no actual marks on the file. This means that there will both be nothing to notify for *and* implies that there is no need for clearing the ignore mask. This patch gave a 13.1% speedup in writes/second on my test, which is an improvement from the 10.8% that I saw with the last version. Signed-off-by: Dave Hansen <dave.hansen@linux.intel.com> Reviewed-by: Jan Kara <jack@suse.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Eric Paris <eparis@redhat.com> Cc: John McCutchan <john@johnmccutchan.com> Cc: Robert Love <rlove@rlove.org> Cc: Andi Kleen <ak@linux.intel.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>