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filelock: convert __locks_insert_block, conflict and deadlock checks to use file_lock_core
Have both __locks_insert_block and the deadlock and conflict checking functions take a struct file_lock_core pointer instead of a struct file_lock one. Also, change posix_locks_deadlock to return bool. Signed-off-by: Jeff Layton <jlayton@kernel.org> Link: https://lore.kernel.org/r/20240131-flsplit-v3-25-c6129007ee8d@kernel.org Reviewed-by: NeilBrown <neilb@suse.de> Signed-off-by: Christian Brauner <brauner@kernel.org>
This commit is contained in:
Jeff Layton
Christian Brauner
parent
1a62c22a15
commit
b6be371400
132
fs/locks.c
132
fs/locks.c
@ -757,39 +757,41 @@ EXPORT_SYMBOL(locks_delete_block);
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* waiters, and add beneath any waiter that blocks the new waiter.
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* Thus wakeups don't happen until needed.
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*/
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static void __locks_insert_block(struct file_lock *blocker,
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struct file_lock *waiter,
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bool conflict(struct file_lock *,
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struct file_lock *))
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static void __locks_insert_block(struct file_lock *blocker_fl,
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struct file_lock *waiter_fl,
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bool conflict(struct file_lock_core *,
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struct file_lock_core *))
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{
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struct file_lock *fl;
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BUG_ON(!list_empty(&waiter->c.flc_blocked_member));
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struct file_lock_core *blocker = &blocker_fl->c;
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struct file_lock_core *waiter = &waiter_fl->c;
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struct file_lock_core *flc;
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BUG_ON(!list_empty(&waiter->flc_blocked_member));
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new_blocker:
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list_for_each_entry(fl, &blocker->c.flc_blocked_requests,
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c.flc_blocked_member)
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if (conflict(fl, waiter)) {
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blocker = fl;
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list_for_each_entry(flc, &blocker->flc_blocked_requests, flc_blocked_member)
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if (conflict(flc, waiter)) {
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blocker = flc;
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goto new_blocker;
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}
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waiter->c.flc_blocker = blocker;
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list_add_tail(&waiter->c.flc_blocked_member,
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&blocker->c.flc_blocked_requests);
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if ((blocker->c.flc_flags & (FL_POSIX|FL_OFDLCK)) == FL_POSIX)
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locks_insert_global_blocked(&waiter->c);
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waiter->flc_blocker = file_lock(blocker);
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list_add_tail(&waiter->flc_blocked_member,
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&blocker->flc_blocked_requests);
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/* The requests in waiter->fl_blocked are known to conflict with
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if ((blocker->flc_flags & (FL_POSIX|FL_OFDLCK)) == (FL_POSIX|FL_OFDLCK))
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locks_insert_global_blocked(waiter);
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/* The requests in waiter->flc_blocked are known to conflict with
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* waiter, but might not conflict with blocker, or the requests
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* and lock which block it. So they all need to be woken.
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*/
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__locks_wake_up_blocks(&waiter->c);
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__locks_wake_up_blocks(waiter);
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}
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/* Must be called with flc_lock held. */
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static void locks_insert_block(struct file_lock *blocker,
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struct file_lock *waiter,
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bool conflict(struct file_lock *,
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struct file_lock *))
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bool conflict(struct file_lock_core *,
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struct file_lock_core *))
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{
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spin_lock(&blocked_lock_lock);
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__locks_insert_block(blocker, waiter, conflict);
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@ -846,12 +848,12 @@ locks_delete_lock_ctx(struct file_lock *fl, struct list_head *dispose)
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/* Determine if lock sys_fl blocks lock caller_fl. Common functionality
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* checks for shared/exclusive status of overlapping locks.
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*/
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static bool locks_conflict(struct file_lock *caller_fl,
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struct file_lock *sys_fl)
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static bool locks_conflict(struct file_lock_core *caller_flc,
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struct file_lock_core *sys_flc)
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{
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if (lock_is_write(sys_fl))
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if (sys_flc->flc_type == F_WRLCK)
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return true;
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if (lock_is_write(caller_fl))
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if (caller_flc->flc_type == F_WRLCK)
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return true;
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return false;
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}
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@ -859,20 +861,23 @@ static bool locks_conflict(struct file_lock *caller_fl,
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/* Determine if lock sys_fl blocks lock caller_fl. POSIX specific
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* checking before calling the locks_conflict().
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*/
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static bool posix_locks_conflict(struct file_lock *caller_fl,
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struct file_lock *sys_fl)
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static bool posix_locks_conflict(struct file_lock_core *caller_flc,
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struct file_lock_core *sys_flc)
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{
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struct file_lock *caller_fl = file_lock(caller_flc);
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struct file_lock *sys_fl = file_lock(sys_flc);
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/* POSIX locks owned by the same process do not conflict with
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* each other.
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*/
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if (posix_same_owner(&caller_fl->c, &sys_fl->c))
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if (posix_same_owner(caller_flc, sys_flc))
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return false;
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/* Check whether they overlap */
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if (!locks_overlap(caller_fl, sys_fl))
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return false;
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return locks_conflict(caller_fl, sys_fl);
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return locks_conflict(caller_flc, sys_flc);
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}
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/* Determine if lock sys_fl blocks lock caller_fl. Used on xx_GETLK
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@ -881,28 +886,31 @@ static bool posix_locks_conflict(struct file_lock *caller_fl,
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static bool posix_test_locks_conflict(struct file_lock *caller_fl,
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struct file_lock *sys_fl)
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{
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struct file_lock_core *caller = &caller_fl->c;
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struct file_lock_core *sys = &sys_fl->c;
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/* F_UNLCK checks any locks on the same fd. */
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if (lock_is_unlock(caller_fl)) {
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if (!posix_same_owner(&caller_fl->c, &sys_fl->c))
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if (!posix_same_owner(caller, sys))
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return false;
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return locks_overlap(caller_fl, sys_fl);
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}
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return posix_locks_conflict(caller_fl, sys_fl);
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return posix_locks_conflict(caller, sys);
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}
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/* Determine if lock sys_fl blocks lock caller_fl. FLOCK specific
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* checking before calling the locks_conflict().
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*/
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static bool flock_locks_conflict(struct file_lock *caller_fl,
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struct file_lock *sys_fl)
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static bool flock_locks_conflict(struct file_lock_core *caller_flc,
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struct file_lock_core *sys_flc)
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{
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/* FLOCK locks referring to the same filp do not conflict with
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* each other.
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*/
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if (caller_fl->c.flc_file == sys_fl->c.flc_file)
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if (caller_flc->flc_file == sys_flc->flc_file)
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return false;
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return locks_conflict(caller_fl, sys_fl);
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return locks_conflict(caller_flc, sys_flc);
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}
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void
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@ -980,25 +988,27 @@ EXPORT_SYMBOL(posix_test_lock);
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#define MAX_DEADLK_ITERATIONS 10
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/* Find a lock that the owner of the given block_fl is blocking on. */
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static struct file_lock *what_owner_is_waiting_for(struct file_lock *block_fl)
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/* Find a lock that the owner of the given @blocker is blocking on. */
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static struct file_lock_core *what_owner_is_waiting_for(struct file_lock_core *blocker)
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{
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struct file_lock *fl;
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struct file_lock_core *flc;
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hash_for_each_possible(blocked_hash, fl, c.flc_link, posix_owner_key(&block_fl->c)) {
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if (posix_same_owner(&fl->c, &block_fl->c)) {
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while (fl->c.flc_blocker)
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fl = fl->c.flc_blocker;
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return fl;
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hash_for_each_possible(blocked_hash, flc, flc_link, posix_owner_key(blocker)) {
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if (posix_same_owner(flc, blocker)) {
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while (flc->flc_blocker)
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flc = &flc->flc_blocker->c;
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return flc;
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}
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}
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return NULL;
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}
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/* Must be called with the blocked_lock_lock held! */
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static int posix_locks_deadlock(struct file_lock *caller_fl,
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struct file_lock *block_fl)
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static bool posix_locks_deadlock(struct file_lock *caller_fl,
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struct file_lock *block_fl)
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{
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struct file_lock_core *caller = &caller_fl->c;
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struct file_lock_core *blocker = &block_fl->c;
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int i = 0;
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lockdep_assert_held(&blocked_lock_lock);
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@ -1007,16 +1017,16 @@ static int posix_locks_deadlock(struct file_lock *caller_fl,
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* This deadlock detector can't reasonably detect deadlocks with
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* FL_OFDLCK locks, since they aren't owned by a process, per-se.
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*/
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if (caller_fl->c.flc_flags & FL_OFDLCK)
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return 0;
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if (caller->flc_flags & FL_OFDLCK)
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return false;
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while ((block_fl = what_owner_is_waiting_for(block_fl))) {
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while ((blocker = what_owner_is_waiting_for(blocker))) {
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if (i++ > MAX_DEADLK_ITERATIONS)
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return 0;
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if (posix_same_owner(&caller_fl->c, &block_fl->c))
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return 1;
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return false;
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if (posix_same_owner(caller, blocker))
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return true;
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}
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return 0;
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return false;
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}
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/* Try to create a FLOCK lock on filp. We always insert new FLOCK locks
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@ -1071,7 +1081,7 @@ static int flock_lock_inode(struct inode *inode, struct file_lock *request)
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find_conflict:
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list_for_each_entry(fl, &ctx->flc_flock, c.flc_list) {
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if (!flock_locks_conflict(request, fl))
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if (!flock_locks_conflict(&request->c, &fl->c))
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continue;
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error = -EAGAIN;
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if (!(request->c.flc_flags & FL_SLEEP))
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@ -1140,7 +1150,7 @@ retry:
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*/
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if (request->c.flc_type != F_UNLCK) {
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list_for_each_entry(fl, &ctx->flc_posix, c.flc_list) {
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if (!posix_locks_conflict(request, fl))
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if (!posix_locks_conflict(&request->c, &fl->c))
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continue;
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if (fl->fl_lmops && fl->fl_lmops->lm_lock_expirable
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&& (*fl->fl_lmops->lm_lock_expirable)(fl)) {
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@ -1442,23 +1452,25 @@ static void time_out_leases(struct inode *inode, struct list_head *dispose)
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}
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}
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static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker)
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static bool leases_conflict(struct file_lock_core *lc, struct file_lock_core *bc)
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{
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bool rc;
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struct file_lock *lease = file_lock(lc);
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struct file_lock *breaker = file_lock(bc);
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if (lease->fl_lmops->lm_breaker_owns_lease
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&& lease->fl_lmops->lm_breaker_owns_lease(lease))
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return false;
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if ((breaker->c.flc_flags & FL_LAYOUT) != (lease->c.flc_flags & FL_LAYOUT)) {
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if ((bc->flc_flags & FL_LAYOUT) != (lc->flc_flags & FL_LAYOUT)) {
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rc = false;
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goto trace;
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}
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if ((breaker->c.flc_flags & FL_DELEG) && (lease->c.flc_flags & FL_LEASE)) {
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if ((bc->flc_flags & FL_DELEG) && (lc->flc_flags & FL_LEASE)) {
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rc = false;
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goto trace;
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}
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rc = locks_conflict(breaker, lease);
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rc = locks_conflict(bc, lc);
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trace:
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trace_leases_conflict(rc, lease, breaker);
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return rc;
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@ -1468,12 +1480,12 @@ static bool
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any_leases_conflict(struct inode *inode, struct file_lock *breaker)
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{
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struct file_lock_context *ctx = inode->i_flctx;
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struct file_lock *fl;
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struct file_lock_core *flc;
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lockdep_assert_held(&ctx->flc_lock);
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list_for_each_entry(fl, &ctx->flc_lease, c.flc_list) {
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if (leases_conflict(fl, breaker))
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list_for_each_entry(flc, &ctx->flc_lease, flc_list) {
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if (leases_conflict(flc, &breaker->c))
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return true;
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}
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return false;
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@ -1529,7 +1541,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type)
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}
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list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, c.flc_list) {
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if (!leases_conflict(fl, new_fl))
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if (!leases_conflict(&fl->c, &new_fl->c))
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continue;
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if (want_write) {
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if (fl->c.flc_flags & FL_UNLOCK_PENDING)
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