| Message ID | 20240131-flsplit-v3-25-c6129007ee8d@kernel.org (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | filelock: split file leases out of struct file_lock | expand |
On Wed, 2024-01-31 at 18:02 -0500, Jeff Layton wrote: > 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> > --- > fs/locks.c | 132 +++++++++++++++++++++++++++++++++---------------------------- > 1 file changed, 72 insertions(+), 60 deletions(-) > > diff --git a/fs/locks.c b/fs/locks.c > index 1e8b943bd7f9..0dc1c9da858c 100644 > --- a/fs/locks.c > +++ b/fs/locks.c > @@ -757,39 +757,41 @@ EXPORT_SYMBOL(locks_delete_block); > * waiters, and add beneath any waiter that blocks the new waiter. > * Thus wakeups don't happen until needed. > */ > -static void __locks_insert_block(struct file_lock *blocker, > - struct file_lock *waiter, > - bool conflict(struct file_lock *, > - struct file_lock *)) > +static void __locks_insert_block(struct file_lock *blocker_fl, > + struct file_lock *waiter_fl, > + bool conflict(struct file_lock_core *, > + struct file_lock_core *)) > { > - struct file_lock *fl; > - BUG_ON(!list_empty(&waiter->c.flc_blocked_member)); > + struct file_lock_core *blocker = &blocker_fl->c; > + struct file_lock_core *waiter = &waiter_fl->c; > + struct file_lock_core *flc; > > + BUG_ON(!list_empty(&waiter->flc_blocked_member)); > new_blocker: > - list_for_each_entry(fl, &blocker->c.flc_blocked_requests, > - c.flc_blocked_member) > - if (conflict(fl, waiter)) { > - blocker = fl; > + list_for_each_entry(flc, &blocker->flc_blocked_requests, flc_blocked_member) > + if (conflict(flc, waiter)) { > + blocker = flc; > goto new_blocker; > } > - waiter->c.flc_blocker = blocker; > - list_add_tail(&waiter->c.flc_blocked_member, > - &blocker->c.flc_blocked_requests); > - if ((blocker->c.flc_flags & (FL_POSIX|FL_OFDLCK)) == FL_POSIX) > - locks_insert_global_blocked(&waiter->c); > + waiter->flc_blocker = file_lock(blocker); > + list_add_tail(&waiter->flc_blocked_member, > + &blocker->flc_blocked_requests); > > - /* The requests in waiter->fl_blocked are known to conflict with > + if ((blocker->flc_flags & (FL_POSIX|FL_OFDLCK)) == (FL_POSIX|FL_OFDLCK)) Christian, There is a bug in the above delta. That should read: if ((blocker->flc_flags & (FL_POSIX|FL_OFDLCK)) == FL_POSIX) I suspect that is the cause of the performance regression noted by the KTR. I believe the bug is fairly harmless -- it's just putting OFD locks into the global hash when it doesn't need to, which probably slows down deadlock checking. I'm going to spin up a patch and test it today, but I wanted to give you a heads up. I'll send the patch later today or tomorrow. > + locks_insert_global_blocked(waiter); > + > + /* The requests in waiter->flc_blocked are known to conflict with > * waiter, but might not conflict with blocker, or the requests > * and lock which block it. So they all need to be woken. > */ > - __locks_wake_up_blocks(&waiter->c); > + __locks_wake_up_blocks(waiter); > } > > /* Must be called with flc_lock held. */ > static void locks_insert_block(struct file_lock *blocker, > struct file_lock *waiter, > - bool conflict(struct file_lock *, > - struct file_lock *)) > + bool conflict(struct file_lock_core *, > + struct file_lock_core *)) > { > spin_lock(&blocked_lock_lock); > __locks_insert_block(blocker, waiter, conflict); > @@ -846,12 +848,12 @@ locks_delete_lock_ctx(struct file_lock *fl, struct list_head *dispose) > /* Determine if lock sys_fl blocks lock caller_fl. Common functionality > * checks for shared/exclusive status of overlapping locks. > */ > -static bool locks_conflict(struct file_lock *caller_fl, > - struct file_lock *sys_fl) > +static bool locks_conflict(struct file_lock_core *caller_flc, > + struct file_lock_core *sys_flc) > { > - if (lock_is_write(sys_fl)) > + if (sys_flc->flc_type == F_WRLCK) > return true; > - if (lock_is_write(caller_fl)) > + if (caller_flc->flc_type == F_WRLCK) > return true; > return false; > } > @@ -859,20 +861,23 @@ static bool locks_conflict(struct file_lock *caller_fl, > /* Determine if lock sys_fl blocks lock caller_fl. POSIX specific > * checking before calling the locks_conflict(). > */ > -static bool posix_locks_conflict(struct file_lock *caller_fl, > - struct file_lock *sys_fl) > +static bool posix_locks_conflict(struct file_lock_core *caller_flc, > + struct file_lock_core *sys_flc) > { > + struct file_lock *caller_fl = file_lock(caller_flc); > + struct file_lock *sys_fl = file_lock(sys_flc); > + > /* POSIX locks owned by the same process do not conflict with > * each other. > */ > - if (posix_same_owner(&caller_fl->c, &sys_fl->c)) > + if (posix_same_owner(caller_flc, sys_flc)) > return false; > > /* Check whether they overlap */ > if (!locks_overlap(caller_fl, sys_fl)) > return false; > > - return locks_conflict(caller_fl, sys_fl); > + return locks_conflict(caller_flc, sys_flc); > } > > /* Determine if lock sys_fl blocks lock caller_fl. Used on xx_GETLK > @@ -881,28 +886,31 @@ static bool posix_locks_conflict(struct file_lock *caller_fl, > static bool posix_test_locks_conflict(struct file_lock *caller_fl, > struct file_lock *sys_fl) > { > + struct file_lock_core *caller = &caller_fl->c; > + struct file_lock_core *sys = &sys_fl->c; > + > /* F_UNLCK checks any locks on the same fd. */ > if (lock_is_unlock(caller_fl)) { > - if (!posix_same_owner(&caller_fl->c, &sys_fl->c)) > + if (!posix_same_owner(caller, sys)) > return false; > return locks_overlap(caller_fl, sys_fl); > } > - return posix_locks_conflict(caller_fl, sys_fl); > + return posix_locks_conflict(caller, sys); > } > > /* Determine if lock sys_fl blocks lock caller_fl. FLOCK specific > * checking before calling the locks_conflict(). > */ > -static bool flock_locks_conflict(struct file_lock *caller_fl, > - struct file_lock *sys_fl) > +static bool flock_locks_conflict(struct file_lock_core *caller_flc, > + struct file_lock_core *sys_flc) > { > /* FLOCK locks referring to the same filp do not conflict with > * each other. > */ > - if (caller_fl->c.flc_file == sys_fl->c.flc_file) > + if (caller_flc->flc_file == sys_flc->flc_file) > return false; > > - return locks_conflict(caller_fl, sys_fl); > + return locks_conflict(caller_flc, sys_flc); > } > > void > @@ -980,25 +988,27 @@ EXPORT_SYMBOL(posix_test_lock); > > #define MAX_DEADLK_ITERATIONS 10 > > -/* Find a lock that the owner of the given block_fl is blocking on. */ > -static struct file_lock *what_owner_is_waiting_for(struct file_lock *block_fl) > +/* Find a lock that the owner of the given @blocker is blocking on. */ > +static struct file_lock_core *what_owner_is_waiting_for(struct file_lock_core *blocker) > { > - struct file_lock *fl; > + struct file_lock_core *flc; > > - hash_for_each_possible(blocked_hash, fl, c.flc_link, posix_owner_key(&block_fl->c)) { > - if (posix_same_owner(&fl->c, &block_fl->c)) { > - while (fl->c.flc_blocker) > - fl = fl->c.flc_blocker; > - return fl; > + hash_for_each_possible(blocked_hash, flc, flc_link, posix_owner_key(blocker)) { > + if (posix_same_owner(flc, blocker)) { > + while (flc->flc_blocker) > + flc = &flc->flc_blocker->c; > + return flc; > } > } > return NULL; > } > > /* Must be called with the blocked_lock_lock held! */ > -static int posix_locks_deadlock(struct file_lock *caller_fl, > - struct file_lock *block_fl) > +static bool posix_locks_deadlock(struct file_lock *caller_fl, > + struct file_lock *block_fl) > { > + struct file_lock_core *caller = &caller_fl->c; > + struct file_lock_core *blocker = &block_fl->c; > int i = 0; > > lockdep_assert_held(&blocked_lock_lock); > @@ -1007,16 +1017,16 @@ static int posix_locks_deadlock(struct file_lock *caller_fl, > * This deadlock detector can't reasonably detect deadlocks with > * FL_OFDLCK locks, since they aren't owned by a process, per-se. > */ > - if (caller_fl->c.flc_flags & FL_OFDLCK) > - return 0; > + if (caller->flc_flags & FL_OFDLCK) > + return false; > > - while ((block_fl = what_owner_is_waiting_for(block_fl))) { > + while ((blocker = what_owner_is_waiting_for(blocker))) { > if (i++ > MAX_DEADLK_ITERATIONS) > - return 0; > - if (posix_same_owner(&caller_fl->c, &block_fl->c)) > - return 1; > + return false; > + if (posix_same_owner(caller, blocker)) > + return true; > } > - return 0; > + return false; > } > > /* Try to create a FLOCK lock on filp. We always insert new FLOCK locks > @@ -1071,7 +1081,7 @@ static int flock_lock_inode(struct inode *inode, struct file_lock *request) > > find_conflict: > list_for_each_entry(fl, &ctx->flc_flock, c.flc_list) { > - if (!flock_locks_conflict(request, fl)) > + if (!flock_locks_conflict(&request->c, &fl->c)) > continue; > error = -EAGAIN; > if (!(request->c.flc_flags & FL_SLEEP)) > @@ -1140,7 +1150,7 @@ static int posix_lock_inode(struct inode *inode, struct file_lock *request, > */ > if (request->c.flc_type != F_UNLCK) { > list_for_each_entry(fl, &ctx->flc_posix, c.flc_list) { > - if (!posix_locks_conflict(request, fl)) > + if (!posix_locks_conflict(&request->c, &fl->c)) > continue; > if (fl->fl_lmops && fl->fl_lmops->lm_lock_expirable > && (*fl->fl_lmops->lm_lock_expirable)(fl)) { > @@ -1442,23 +1452,25 @@ static void time_out_leases(struct inode *inode, struct list_head *dispose) > } > } > > -static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker) > +static bool leases_conflict(struct file_lock_core *lc, struct file_lock_core *bc) > { > bool rc; > + struct file_lock *lease = file_lock(lc); > + struct file_lock *breaker = file_lock(bc); > > if (lease->fl_lmops->lm_breaker_owns_lease > && lease->fl_lmops->lm_breaker_owns_lease(lease)) > return false; > - if ((breaker->c.flc_flags & FL_LAYOUT) != (lease->c.flc_flags & FL_LAYOUT)) { > + if ((bc->flc_flags & FL_LAYOUT) != (lc->flc_flags & FL_LAYOUT)) { > rc = false; > goto trace; > } > - if ((breaker->c.flc_flags & FL_DELEG) && (lease->c.flc_flags & FL_LEASE)) { > + if ((bc->flc_flags & FL_DELEG) && (lc->flc_flags & FL_LEASE)) { > rc = false; > goto trace; > } > > - rc = locks_conflict(breaker, lease); > + rc = locks_conflict(bc, lc); > trace: > trace_leases_conflict(rc, lease, breaker); > return rc; > @@ -1468,12 +1480,12 @@ static bool > any_leases_conflict(struct inode *inode, struct file_lock *breaker) > { > struct file_lock_context *ctx = inode->i_flctx; > - struct file_lock *fl; > + struct file_lock_core *flc; > > lockdep_assert_held(&ctx->flc_lock); > > - list_for_each_entry(fl, &ctx->flc_lease, c.flc_list) { > - if (leases_conflict(fl, breaker)) > + list_for_each_entry(flc, &ctx->flc_lease, flc_list) { > + if (leases_conflict(flc, &breaker->c)) > return true; > } > return false; > @@ -1529,7 +1541,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) > } > > list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, c.flc_list) { > - if (!leases_conflict(fl, new_fl)) > + if (!leases_conflict(&fl->c, &new_fl->c)) > continue; > if (want_write) { > if (fl->c.flc_flags & FL_UNLOCK_PENDING) >
diff --git a/fs/locks.c b/fs/locks.c index 1e8b943bd7f9..0dc1c9da858c 100644 --- a/fs/locks.c +++ b/fs/locks.c @@ -757,39 +757,41 @@ EXPORT_SYMBOL(locks_delete_block); * waiters, and add beneath any waiter that blocks the new waiter. * Thus wakeups don't happen until needed. */ -static void __locks_insert_block(struct file_lock *blocker, - struct file_lock *waiter, - bool conflict(struct file_lock *, - struct file_lock *)) +static void __locks_insert_block(struct file_lock *blocker_fl, + struct file_lock *waiter_fl, + bool conflict(struct file_lock_core *, + struct file_lock_core *)) { - struct file_lock *fl; - BUG_ON(!list_empty(&waiter->c.flc_blocked_member)); + struct file_lock_core *blocker = &blocker_fl->c; + struct file_lock_core *waiter = &waiter_fl->c; + struct file_lock_core *flc; + BUG_ON(!list_empty(&waiter->flc_blocked_member)); new_blocker: - list_for_each_entry(fl, &blocker->c.flc_blocked_requests, - c.flc_blocked_member) - if (conflict(fl, waiter)) { - blocker = fl; + list_for_each_entry(flc, &blocker->flc_blocked_requests, flc_blocked_member) + if (conflict(flc, waiter)) { + blocker = flc; goto new_blocker; } - waiter->c.flc_blocker = blocker; - list_add_tail(&waiter->c.flc_blocked_member, - &blocker->c.flc_blocked_requests); - if ((blocker->c.flc_flags & (FL_POSIX|FL_OFDLCK)) == FL_POSIX) - locks_insert_global_blocked(&waiter->c); + waiter->flc_blocker = file_lock(blocker); + list_add_tail(&waiter->flc_blocked_member, + &blocker->flc_blocked_requests); - /* The requests in waiter->fl_blocked are known to conflict with + if ((blocker->flc_flags & (FL_POSIX|FL_OFDLCK)) == (FL_POSIX|FL_OFDLCK)) + locks_insert_global_blocked(waiter); + + /* The requests in waiter->flc_blocked are known to conflict with * waiter, but might not conflict with blocker, or the requests * and lock which block it. So they all need to be woken. */ - __locks_wake_up_blocks(&waiter->c); + __locks_wake_up_blocks(waiter); } /* Must be called with flc_lock held. */ static void locks_insert_block(struct file_lock *blocker, struct file_lock *waiter, - bool conflict(struct file_lock *, - struct file_lock *)) + bool conflict(struct file_lock_core *, + struct file_lock_core *)) { spin_lock(&blocked_lock_lock); __locks_insert_block(blocker, waiter, conflict); @@ -846,12 +848,12 @@ locks_delete_lock_ctx(struct file_lock *fl, struct list_head *dispose) /* Determine if lock sys_fl blocks lock caller_fl. Common functionality * checks for shared/exclusive status of overlapping locks. */ -static bool locks_conflict(struct file_lock *caller_fl, - struct file_lock *sys_fl) +static bool locks_conflict(struct file_lock_core *caller_flc, + struct file_lock_core *sys_flc) { - if (lock_is_write(sys_fl)) + if (sys_flc->flc_type == F_WRLCK) return true; - if (lock_is_write(caller_fl)) + if (caller_flc->flc_type == F_WRLCK) return true; return false; } @@ -859,20 +861,23 @@ static bool locks_conflict(struct file_lock *caller_fl, /* Determine if lock sys_fl blocks lock caller_fl. POSIX specific * checking before calling the locks_conflict(). */ -static bool posix_locks_conflict(struct file_lock *caller_fl, - struct file_lock *sys_fl) +static bool posix_locks_conflict(struct file_lock_core *caller_flc, + struct file_lock_core *sys_flc) { + struct file_lock *caller_fl = file_lock(caller_flc); + struct file_lock *sys_fl = file_lock(sys_flc); + /* POSIX locks owned by the same process do not conflict with * each other. */ - if (posix_same_owner(&caller_fl->c, &sys_fl->c)) + if (posix_same_owner(caller_flc, sys_flc)) return false; /* Check whether they overlap */ if (!locks_overlap(caller_fl, sys_fl)) return false; - return locks_conflict(caller_fl, sys_fl); + return locks_conflict(caller_flc, sys_flc); } /* Determine if lock sys_fl blocks lock caller_fl. Used on xx_GETLK @@ -881,28 +886,31 @@ static bool posix_locks_conflict(struct file_lock *caller_fl, static bool posix_test_locks_conflict(struct file_lock *caller_fl, struct file_lock *sys_fl) { + struct file_lock_core *caller = &caller_fl->c; + struct file_lock_core *sys = &sys_fl->c; + /* F_UNLCK checks any locks on the same fd. */ if (lock_is_unlock(caller_fl)) { - if (!posix_same_owner(&caller_fl->c, &sys_fl->c)) + if (!posix_same_owner(caller, sys)) return false; return locks_overlap(caller_fl, sys_fl); } - return posix_locks_conflict(caller_fl, sys_fl); + return posix_locks_conflict(caller, sys); } /* Determine if lock sys_fl blocks lock caller_fl. FLOCK specific * checking before calling the locks_conflict(). */ -static bool flock_locks_conflict(struct file_lock *caller_fl, - struct file_lock *sys_fl) +static bool flock_locks_conflict(struct file_lock_core *caller_flc, + struct file_lock_core *sys_flc) { /* FLOCK locks referring to the same filp do not conflict with * each other. */ - if (caller_fl->c.flc_file == sys_fl->c.flc_file) + if (caller_flc->flc_file == sys_flc->flc_file) return false; - return locks_conflict(caller_fl, sys_fl); + return locks_conflict(caller_flc, sys_flc); } void @@ -980,25 +988,27 @@ EXPORT_SYMBOL(posix_test_lock); #define MAX_DEADLK_ITERATIONS 10 -/* Find a lock that the owner of the given block_fl is blocking on. */ -static struct file_lock *what_owner_is_waiting_for(struct file_lock *block_fl) +/* Find a lock that the owner of the given @blocker is blocking on. */ +static struct file_lock_core *what_owner_is_waiting_for(struct file_lock_core *blocker) { - struct file_lock *fl; + struct file_lock_core *flc; - hash_for_each_possible(blocked_hash, fl, c.flc_link, posix_owner_key(&block_fl->c)) { - if (posix_same_owner(&fl->c, &block_fl->c)) { - while (fl->c.flc_blocker) - fl = fl->c.flc_blocker; - return fl; + hash_for_each_possible(blocked_hash, flc, flc_link, posix_owner_key(blocker)) { + if (posix_same_owner(flc, blocker)) { + while (flc->flc_blocker) + flc = &flc->flc_blocker->c; + return flc; } } return NULL; } /* Must be called with the blocked_lock_lock held! */ -static int posix_locks_deadlock(struct file_lock *caller_fl, - struct file_lock *block_fl) +static bool posix_locks_deadlock(struct file_lock *caller_fl, + struct file_lock *block_fl) { + struct file_lock_core *caller = &caller_fl->c; + struct file_lock_core *blocker = &block_fl->c; int i = 0; lockdep_assert_held(&blocked_lock_lock); @@ -1007,16 +1017,16 @@ static int posix_locks_deadlock(struct file_lock *caller_fl, * This deadlock detector can't reasonably detect deadlocks with * FL_OFDLCK locks, since they aren't owned by a process, per-se. */ - if (caller_fl->c.flc_flags & FL_OFDLCK) - return 0; + if (caller->flc_flags & FL_OFDLCK) + return false; - while ((block_fl = what_owner_is_waiting_for(block_fl))) { + while ((blocker = what_owner_is_waiting_for(blocker))) { if (i++ > MAX_DEADLK_ITERATIONS) - return 0; - if (posix_same_owner(&caller_fl->c, &block_fl->c)) - return 1; + return false; + if (posix_same_owner(caller, blocker)) + return true; } - return 0; + return false; } /* Try to create a FLOCK lock on filp. We always insert new FLOCK locks @@ -1071,7 +1081,7 @@ static int flock_lock_inode(struct inode *inode, struct file_lock *request) find_conflict: list_for_each_entry(fl, &ctx->flc_flock, c.flc_list) { - if (!flock_locks_conflict(request, fl)) + if (!flock_locks_conflict(&request->c, &fl->c)) continue; error = -EAGAIN; if (!(request->c.flc_flags & FL_SLEEP)) @@ -1140,7 +1150,7 @@ static int posix_lock_inode(struct inode *inode, struct file_lock *request, */ if (request->c.flc_type != F_UNLCK) { list_for_each_entry(fl, &ctx->flc_posix, c.flc_list) { - if (!posix_locks_conflict(request, fl)) + if (!posix_locks_conflict(&request->c, &fl->c)) continue; if (fl->fl_lmops && fl->fl_lmops->lm_lock_expirable && (*fl->fl_lmops->lm_lock_expirable)(fl)) { @@ -1442,23 +1452,25 @@ static void time_out_leases(struct inode *inode, struct list_head *dispose) } } -static bool leases_conflict(struct file_lock *lease, struct file_lock *breaker) +static bool leases_conflict(struct file_lock_core *lc, struct file_lock_core *bc) { bool rc; + struct file_lock *lease = file_lock(lc); + struct file_lock *breaker = file_lock(bc); if (lease->fl_lmops->lm_breaker_owns_lease && lease->fl_lmops->lm_breaker_owns_lease(lease)) return false; - if ((breaker->c.flc_flags & FL_LAYOUT) != (lease->c.flc_flags & FL_LAYOUT)) { + if ((bc->flc_flags & FL_LAYOUT) != (lc->flc_flags & FL_LAYOUT)) { rc = false; goto trace; } - if ((breaker->c.flc_flags & FL_DELEG) && (lease->c.flc_flags & FL_LEASE)) { + if ((bc->flc_flags & FL_DELEG) && (lc->flc_flags & FL_LEASE)) { rc = false; goto trace; } - rc = locks_conflict(breaker, lease); + rc = locks_conflict(bc, lc); trace: trace_leases_conflict(rc, lease, breaker); return rc; @@ -1468,12 +1480,12 @@ static bool any_leases_conflict(struct inode *inode, struct file_lock *breaker) { struct file_lock_context *ctx = inode->i_flctx; - struct file_lock *fl; + struct file_lock_core *flc; lockdep_assert_held(&ctx->flc_lock); - list_for_each_entry(fl, &ctx->flc_lease, c.flc_list) { - if (leases_conflict(fl, breaker)) + list_for_each_entry(flc, &ctx->flc_lease, flc_list) { + if (leases_conflict(flc, &breaker->c)) return true; } return false; @@ -1529,7 +1541,7 @@ int __break_lease(struct inode *inode, unsigned int mode, unsigned int type) } list_for_each_entry_safe(fl, tmp, &ctx->flc_lease, c.flc_list) { - if (!leases_conflict(fl, new_fl)) + if (!leases_conflict(&fl->c, &new_fl->c)) continue; if (want_write) { if (fl->c.flc_flags & FL_UNLOCK_PENDING)
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> --- fs/locks.c | 132 +++++++++++++++++++++++++++++++++---------------------------- 1 file changed, 72 insertions(+), 60 deletions(-)