diff options
| -rw-r--r-- | fs/inode.c | 36 | ||||
| -rw-r--r-- | fs/pipe.c | 42 | ||||
| -rw-r--r-- | fs/splice.c | 50 | ||||
| -rw-r--r-- | include/linux/fs.h | 3 | ||||
| -rw-r--r-- | include/linux/pipe_fs_i.h | 5 |
5 files changed, 64 insertions, 72 deletions
@@ -1470,42 +1470,6 @@ static void __wait_on_freeing_inode(struct inode *inode) spin_lock(&inode_lock); } -/* - * We rarely want to lock two inodes that do not have a parent/child - * relationship (such as directory, child inode) simultaneously. The - * vast majority of file systems should be able to get along fine - * without this. Do not use these functions except as a last resort. - */ -void inode_double_lock(struct inode *inode1, struct inode *inode2) -{ - if (inode1 == NULL || inode2 == NULL || inode1 == inode2) { - if (inode1) - mutex_lock(&inode1->i_mutex); - else if (inode2) - mutex_lock(&inode2->i_mutex); - return; - } - - if (inode1 < inode2) { - mutex_lock_nested(&inode1->i_mutex, I_MUTEX_PARENT); - mutex_lock_nested(&inode2->i_mutex, I_MUTEX_CHILD); - } else { - mutex_lock_nested(&inode2->i_mutex, I_MUTEX_PARENT); - mutex_lock_nested(&inode1->i_mutex, I_MUTEX_CHILD); - } -} -EXPORT_SYMBOL(inode_double_lock); - -void inode_double_unlock(struct inode *inode1, struct inode *inode2) -{ - if (inode1) - mutex_unlock(&inode1->i_mutex); - - if (inode2 && inode2 != inode1) - mutex_unlock(&inode2->i_mutex); -} -EXPORT_SYMBOL(inode_double_unlock); - static __initdata unsigned long ihash_entries; static int __init set_ihash_entries(char *str) { @@ -37,6 +37,42 @@ * -- Manfred Spraul <manfred@colorfullife.com> 2002-05-09 */ +static void pipe_lock_nested(struct pipe_inode_info *pipe, int subclass) +{ + if (pipe->inode) + mutex_lock_nested(&pipe->inode->i_mutex, subclass); +} + +void pipe_lock(struct pipe_inode_info *pipe) +{ + /* + * pipe_lock() nests non-pipe inode locks (for writing to a file) + */ + pipe_lock_nested(pipe, I_MUTEX_PARENT); +} +EXPORT_SYMBOL(pipe_lock); + +void pipe_unlock(struct pipe_inode_info *pipe) +{ + if (pipe->inode) + mutex_unlock(&pipe->inode->i_mutex); +} +EXPORT_SYMBOL(pipe_unlock); + +void pipe_double_lock(struct pipe_inode_info *pipe1, + struct pipe_inode_info *pipe2) +{ + BUG_ON(pipe1 == pipe2); + + if (pipe1 < pipe2) { + pipe_lock_nested(pipe1, I_MUTEX_PARENT); + pipe_lock_nested(pipe2, I_MUTEX_CHILD); + } else { + pipe_lock_nested(pipe2, I_MUTEX_CHILD); + pipe_lock_nested(pipe1, I_MUTEX_PARENT); + } +} + /* Drop the inode semaphore and wait for a pipe event, atomically */ void pipe_wait(struct pipe_inode_info *pipe) { @@ -47,12 +83,10 @@ void pipe_wait(struct pipe_inode_info *pipe) * is considered a noninteractive wait: */ prepare_to_wait(&pipe->wait, &wait, TASK_INTERRUPTIBLE); - if (pipe->inode) - mutex_unlock(&pipe->inode->i_mutex); + pipe_unlock(pipe); schedule(); finish_wait(&pipe->wait, &wait); - if (pipe->inode) - mutex_lock(&pipe->inode->i_mutex); + pipe_lock(pipe); } static int diff --git a/fs/splice.c b/fs/splice.c index 128ee36..5384a90 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -182,8 +182,7 @@ ssize_t splice_to_pipe(struct pipe_inode_info *pipe, do_wakeup = 0; page_nr = 0; - if (pipe->inode) - mutex_lock(&pipe->inode->i_mutex); + pipe_lock(pipe); for (;;) { if (!pipe->readers) { @@ -245,15 +244,13 @@ ssize_t splice_to_pipe(struct pipe_inode_info *pipe, pipe->waiting_writers--; } - if (pipe->inode) { - mutex_unlock(&pipe->inode->i_mutex); + pipe_unlock(pipe); - if (do_wakeup) { - smp_mb(); - if (waitqueue_active(&pipe->wait)) - wake_up_interruptible(&pipe->wait); - kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); - } + if (do_wakeup) { + smp_mb(); + if (waitqueue_active(&pipe->wait)) + wake_up_interruptible(&pipe->wait); + kill_fasync(&pipe->fasync_readers, SIGIO, POLL_IN); } while (page_nr < spd_pages) @@ -801,11 +798,9 @@ ssize_t splice_from_pipe(struct pipe_inode_info *pipe, struct file *out, .u.file = out, }; - if (pipe->inode) - mutex_lock(&pipe->inode->i_mutex); + pipe_lock(pipe); ret = __splice_from_pipe(pipe, &sd, actor); - if (pipe->inode) - mutex_unlock(&pipe->inode->i_mutex); + pipe_unlock(pipe); return ret; } @@ -837,8 +832,7 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out, }; ssize_t ret; - if (pipe->inode) - mutex_lock_nested(&pipe->inode->i_mutex, I_MUTEX_PARENT); + pipe_lock(pipe); splice_from_pipe_begin(&sd); do { @@ -854,8 +848,7 @@ generic_file_splice_write(struct pipe_inode_info *pipe, struct file *out, } while (ret > 0); splice_from_pipe_end(pipe, &sd); - if (pipe->inode) - mutex_unlock(&pipe->inode->i_mutex); + pipe_unlock(pipe); if (sd.num_spliced) ret = sd.num_spliced; @@ -1348,8 +1341,7 @@ static long vmsplice_to_user(struct file *file, const struct iovec __user *iov, if (!pipe) return -EBADF; - if (pipe->inode) - mutex_lock(&pipe->inode->i_mutex); + pipe_lock(pipe); error = ret = 0; while (nr_segs) { @@ -1404,8 +1396,7 @@ static long vmsplice_to_user(struct file *file, const struct iovec __user *iov, iov++; } - if (pipe->inode) - mutex_unlock(&pipe->inode->i_mutex); + pipe_unlock(pipe); if (!ret) ret = error; @@ -1533,7 +1524,7 @@ static int link_ipipe_prep(struct pipe_inode_info *pipe, unsigned int flags) return 0; ret = 0; - mutex_lock(&pipe->inode->i_mutex); + pipe_lock(pipe); while (!pipe->nrbufs) { if (signal_pending(current)) { @@ -1551,7 +1542,7 @@ static int link_ipipe_prep(struct pipe_inode_info *pipe, unsigned int flags) pipe_wait(pipe); } - mutex_unlock(&pipe->inode->i_mutex); + pipe_unlock(pipe); return ret; } @@ -1571,7 +1562,7 @@ static int link_opipe_prep(struct pipe_inode_info *pipe, unsigned int flags) return 0; ret = 0; - mutex_lock(&pipe->inode->i_mutex); + pipe_lock(pipe); while (pipe->nrbufs >= PIPE_BUFFERS) { if (!pipe->readers) { @@ -1592,7 +1583,7 @@ static int link_opipe_prep(struct pipe_inode_info *pipe, unsigned int flags) pipe->waiting_writers--; } - mutex_unlock(&pipe->inode->i_mutex); + pipe_unlock(pipe); return ret; } @@ -1608,10 +1599,10 @@ static int link_pipe(struct pipe_inode_info *ipipe, /* * Potential ABBA deadlock, work around it by ordering lock - * grabbing by inode address. Otherwise two different processes + * grabbing by pipe info address. Otherwise two different processes * could deadlock (one doing tee from A -> B, the other from B -> A). */ - inode_double_lock(ipipe->inode, opipe->inode); + pipe_double_lock(ipipe, opipe); do { if (!opipe->readers) { @@ -1662,7 +1653,8 @@ static int link_pipe(struct pipe_inode_info *ipipe, if (!ret && ipipe->waiting_writers && (flags & SPLICE_F_NONBLOCK)) ret = -EAGAIN; - inode_double_unlock(ipipe->inode, opipe->inode); + pipe_unlock(ipipe); + pipe_unlock(opipe); /* * If we put data in the output pipe, wakeup any potential readers. diff --git a/include/linux/fs.h b/include/linux/fs.h index 907d8f5..e766be0 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -797,9 +797,6 @@ enum inode_i_mutex_lock_class I_MUTEX_QUOTA }; -extern void inode_double_lock(struct inode *inode1, struct inode *inode2); -extern void inode_double_unlock(struct inode *inode1, struct inode *inode2); - /* * NOTE: in a 32bit arch with a preemptable kernel and * an UP compile the i_size_read/write must be atomic diff --git a/include/linux/pipe_fs_i.h b/include/linux/pipe_fs_i.h index 8e41202..c8f0385 100644 --- a/include/linux/pipe_fs_i.h +++ b/include/linux/pipe_fs_i.h @@ -134,6 +134,11 @@ struct pipe_buf_operations { memory allocation, whereas PIPE_BUF makes atomicity guarantees. */ #define PIPE_SIZE PAGE_SIZE +/* Pipe lock and unlock operations */ +void pipe_lock(struct pipe_inode_info *); +void pipe_unlock(struct pipe_inode_info *); +void pipe_double_lock(struct pipe_inode_info *, struct pipe_inode_info *); + /* Drop the inode semaphore and wait for a pipe event, atomically */ void pipe_wait(struct pipe_inode_info *pipe); |
