xfs_buf uses a semaphore for mutual exclusion, and its count value is initialized to 1, which is equivalent to a mutex. However, mutex->owner can provide more information when analyzing vmcore, making it easier for us to identify which task currently holds the lock. Signed-off-by: Jinliang Zheng <alexjlzheng@xxxxxxxxxxx> --- fs/xfs/xfs_buf.c | 9 +++++---- fs/xfs/xfs_buf.h | 4 ++-- fs/xfs/xfs_trace.h | 25 +++++-------------------- 3 files changed, 12 insertions(+), 26 deletions(-) diff --git a/fs/xfs/xfs_buf.c b/fs/xfs/xfs_buf.c index aa4dbda7b536..7c59d7905ea1 100644 --- a/fs/xfs/xfs_buf.c +++ b/fs/xfs/xfs_buf.c @@ -243,7 +243,8 @@ _xfs_buf_alloc( INIT_LIST_HEAD(&bp->b_lru); INIT_LIST_HEAD(&bp->b_list); INIT_LIST_HEAD(&bp->b_li_list); - sema_init(&bp->b_sema, 0); /* held, no waiters */ + mutex_init(&bp->b_mutex); + mutex_lock(&bp->b_mutex); /* held, no waiters */ spin_lock_init(&bp->b_lock); bp->b_target = target; bp->b_mount = target->bt_mount; @@ -1168,7 +1169,7 @@ xfs_buf_trylock( { int locked; - locked = down_trylock(&bp->b_sema) == 0; + locked = mutex_trylock(&bp->b_mutex); if (locked) trace_xfs_buf_trylock(bp, _RET_IP_); else @@ -1193,7 +1194,7 @@ xfs_buf_lock( if (atomic_read(&bp->b_pin_count) && (bp->b_flags & XBF_STALE)) xfs_log_force(bp->b_mount, 0); - down(&bp->b_sema); + mutex_lock(&bp->b_mutex); trace_xfs_buf_lock_done(bp, _RET_IP_); } @@ -1204,7 +1205,7 @@ xfs_buf_unlock( { ASSERT(xfs_buf_islocked(bp)); - up(&bp->b_sema); + mutex_unlock(&bp->b_mutex); trace_xfs_buf_unlock(bp, _RET_IP_); } diff --git a/fs/xfs/xfs_buf.h b/fs/xfs/xfs_buf.h index b1580644501f..2c48e388d451 100644 --- a/fs/xfs/xfs_buf.h +++ b/fs/xfs/xfs_buf.h @@ -171,7 +171,7 @@ struct xfs_buf { atomic_t b_hold; /* reference count */ atomic_t b_lru_ref; /* lru reclaim ref count */ xfs_buf_flags_t b_flags; /* status flags */ - struct semaphore b_sema; /* semaphore for lockables */ + struct mutex b_mutex; /* mutex for lockables */ /* * concurrent access to b_lru and b_lru_flags are protected by @@ -304,7 +304,7 @@ extern int xfs_buf_trylock(struct xfs_buf *); extern void xfs_buf_lock(struct xfs_buf *); extern void xfs_buf_unlock(struct xfs_buf *); #define xfs_buf_islocked(bp) \ - ((bp)->b_sema.count <= 0) + mutex_is_locked(&(bp)->b_mutex) static inline void xfs_buf_relse(struct xfs_buf *bp) { diff --git a/fs/xfs/xfs_trace.h b/fs/xfs/xfs_trace.h index 180ce697305a..ba6c003b82af 100644 --- a/fs/xfs/xfs_trace.h +++ b/fs/xfs/xfs_trace.h @@ -443,7 +443,6 @@ DECLARE_EVENT_CLASS(xfs_buf_class, __field(int, nblks) __field(int, hold) __field(int, pincount) - __field(unsigned, lockval) __field(unsigned, flags) __field(unsigned long, caller_ip) __field(const void *, buf_ops) @@ -454,19 +453,17 @@ DECLARE_EVENT_CLASS(xfs_buf_class, __entry->nblks = bp->b_length; __entry->hold = atomic_read(&bp->b_hold); __entry->pincount = atomic_read(&bp->b_pin_count); - __entry->lockval = bp->b_sema.count; __entry->flags = bp->b_flags; __entry->caller_ip = caller_ip; __entry->buf_ops = bp->b_ops; ), TP_printk("dev %d:%d daddr 0x%llx bbcount 0x%x hold %d pincount %d " - "lock %d flags %s bufops %pS caller %pS", + "flags %s bufops %pS caller %pS", MAJOR(__entry->dev), MINOR(__entry->dev), (unsigned long long)__entry->bno, __entry->nblks, __entry->hold, __entry->pincount, - __entry->lockval, __print_flags(__entry->flags, "|", XFS_BUF_FLAGS), __entry->buf_ops, (void *)__entry->caller_ip) @@ -514,7 +511,6 @@ DECLARE_EVENT_CLASS(xfs_buf_flags_class, __field(unsigned int, length) __field(int, hold) __field(int, pincount) - __field(unsigned, lockval) __field(unsigned, flags) __field(unsigned long, caller_ip) ), @@ -525,17 +521,15 @@ DECLARE_EVENT_CLASS(xfs_buf_flags_class, __entry->flags = flags; __entry->hold = atomic_read(&bp->b_hold); __entry->pincount = atomic_read(&bp->b_pin_count); - __entry->lockval = bp->b_sema.count; __entry->caller_ip = caller_ip; ), TP_printk("dev %d:%d daddr 0x%llx bbcount 0x%x hold %d pincount %d " - "lock %d flags %s caller %pS", + "flags %s caller %pS", MAJOR(__entry->dev), MINOR(__entry->dev), (unsigned long long)__entry->bno, __entry->length, __entry->hold, __entry->pincount, - __entry->lockval, __print_flags(__entry->flags, "|", XFS_BUF_FLAGS), (void *)__entry->caller_ip) ) @@ -558,7 +552,6 @@ TRACE_EVENT(xfs_buf_ioerror, __field(unsigned, flags) __field(int, hold) __field(int, pincount) - __field(unsigned, lockval) __field(int, error) __field(xfs_failaddr_t, caller_ip) ), @@ -568,19 +561,17 @@ TRACE_EVENT(xfs_buf_ioerror, __entry->length = bp->b_length; __entry->hold = atomic_read(&bp->b_hold); __entry->pincount = atomic_read(&bp->b_pin_count); - __entry->lockval = bp->b_sema.count; __entry->error = error; __entry->flags = bp->b_flags; __entry->caller_ip = caller_ip; ), TP_printk("dev %d:%d daddr 0x%llx bbcount 0x%x hold %d pincount %d " - "lock %d error %d flags %s caller %pS", + "error %d flags %s caller %pS", MAJOR(__entry->dev), MINOR(__entry->dev), (unsigned long long)__entry->bno, __entry->length, __entry->hold, __entry->pincount, - __entry->lockval, __entry->error, __print_flags(__entry->flags, "|", XFS_BUF_FLAGS), (void *)__entry->caller_ip) @@ -595,7 +586,6 @@ DECLARE_EVENT_CLASS(xfs_buf_item_class, __field(unsigned int, buf_len) __field(int, buf_hold) __field(int, buf_pincount) - __field(int, buf_lockval) __field(unsigned, buf_flags) __field(unsigned, bli_recur) __field(int, bli_refcount) @@ -612,18 +602,16 @@ DECLARE_EVENT_CLASS(xfs_buf_item_class, __entry->buf_flags = bip->bli_buf->b_flags; __entry->buf_hold = atomic_read(&bip->bli_buf->b_hold); __entry->buf_pincount = atomic_read(&bip->bli_buf->b_pin_count); - __entry->buf_lockval = bip->bli_buf->b_sema.count; __entry->li_flags = bip->bli_item.li_flags; ), TP_printk("dev %d:%d daddr 0x%llx bbcount 0x%x hold %d pincount %d " - "lock %d flags %s recur %d refcount %d bliflags %s " + "flags %s recur %d refcount %d bliflags %s " "liflags %s", MAJOR(__entry->dev), MINOR(__entry->dev), (unsigned long long)__entry->buf_bno, __entry->buf_len, __entry->buf_hold, __entry->buf_pincount, - __entry->buf_lockval, __print_flags(__entry->buf_flags, "|", XFS_BUF_FLAGS), __entry->bli_recur, __entry->bli_refcount, @@ -4802,7 +4790,6 @@ DECLARE_EVENT_CLASS(xfbtree_buf_class, __field(int, nblks) __field(int, hold) __field(int, pincount) - __field(unsigned int, lockval) __field(unsigned int, flags) ), TP_fast_assign( @@ -4811,16 +4798,14 @@ DECLARE_EVENT_CLASS(xfbtree_buf_class, __entry->nblks = bp->b_length; __entry->hold = atomic_read(&bp->b_hold); __entry->pincount = atomic_read(&bp->b_pin_count); - __entry->lockval = bp->b_sema.count; __entry->flags = bp->b_flags; ), - TP_printk("xfino 0x%lx daddr 0x%llx bbcount 0x%x hold %d pincount %d lock %d flags %s", + TP_printk("xfino 0x%lx daddr 0x%llx bbcount 0x%x hold %d pincount %d flags %s", __entry->xfino, (unsigned long long)__entry->bno, __entry->nblks, __entry->hold, __entry->pincount, - __entry->lockval, __print_flags(__entry->flags, "|", XFS_BUF_FLAGS)) ) -- 2.41.1