Merge tag 'printk-for-6.7' of git://git.kernel.org/pub/scm/linux/kernel/git/printk...

[linux-2.6-microblaze.git] / fs / pipe.c

diff --git a/fs/pipe.c b/fs/pipe.c
index 1391901..804a7d7 100644 (file)
--- a/fs/pipe.c
+++ b/fs/pipe.c
@@ -227,6 +227,36 @@ static inline bool pipe_readable(const struct pipe_inode_info *pipe)
        return !pipe_empty(head, tail) || !writers;
 }
 
+static inline unsigned int pipe_update_tail(struct pipe_inode_info *pipe,
+                                           struct pipe_buffer *buf,
+                                           unsigned int tail)
+{
+       pipe_buf_release(pipe, buf);
+
+       /*
+        * If the pipe has a watch_queue, we need additional protection
+        * by the spinlock because notifications get posted with only
+        * this spinlock, no mutex
+        */
+       if (pipe_has_watch_queue(pipe)) {
+               spin_lock_irq(&pipe->rd_wait.lock);
+#ifdef CONFIG_WATCH_QUEUE
+               if (buf->flags & PIPE_BUF_FLAG_LOSS)
+                       pipe->note_loss = true;
+#endif
+               pipe->tail = ++tail;
+               spin_unlock_irq(&pipe->rd_wait.lock);
+               return tail;
+       }
+
+       /*
+        * Without a watch_queue, we can simply increment the tail
+        * without the spinlock - the mutex is enough.
+        */
+       pipe->tail = ++tail;
+       return tail;
+}
+
 static ssize_t
 pipe_read(struct kiocb *iocb, struct iov_iter *to)
 {
@@ -320,17 +350,8 @@ pipe_read(struct kiocb *iocb, struct iov_iter *to)
                                buf->len = 0;
                        }
 
-                       if (!buf->len) {
-                               pipe_buf_release(pipe, buf);
-                               spin_lock_irq(&pipe->rd_wait.lock);
-#ifdef CONFIG_WATCH_QUEUE
-                               if (buf->flags & PIPE_BUF_FLAG_LOSS)
-                                       pipe->note_loss = true;
-#endif
-                               tail++;
-                               pipe->tail = tail;
-                               spin_unlock_irq(&pipe->rd_wait.lock);
-                       }
+                       if (!buf->len)
+                               tail = pipe_update_tail(pipe, buf, tail);
                        total_len -= chars;
                        if (!total_len)
                                break;  /* common path: read succeeded */
@@ -437,12 +458,10 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from)
                goto out;
        }
 
-#ifdef CONFIG_WATCH_QUEUE
-       if (pipe->watch_queue) {
+       if (pipe_has_watch_queue(pipe)) {
                ret = -EXDEV;
                goto out;
        }
-#endif
 
        /*
         * If it wasn't empty we try to merge new data into
@@ -507,16 +526,7 @@ pipe_write(struct kiocb *iocb, struct iov_iter *from)
                         * it, either the reader will consume it or it'll still
                         * be there for the next write.
                         */
-                       spin_lock_irq(&pipe->rd_wait.lock);
-
-                       head = pipe->head;
-                       if (pipe_full(head, pipe->tail, pipe->max_usage)) {
-                               spin_unlock_irq(&pipe->rd_wait.lock);
-                               continue;
-                       }
-
                        pipe->head = head + 1;
-                       spin_unlock_irq(&pipe->rd_wait.lock);
 
                        /* Insert it into the buffer array */
                        buf = &pipe->bufs[head & mask];
@@ -854,7 +864,7 @@ void free_pipe_info(struct pipe_inode_info *pipe)
        kfree(pipe);
 }
 
-static struct vfsmount *pipe_mnt __read_mostly;
+static struct vfsmount *pipe_mnt __ro_after_init;
 
 /*
  * pipefs_dname() is called from d_path().
@@ -898,7 +908,7 @@ static struct inode * get_pipe_inode(void)
        inode->i_mode = S_IFIFO | S_IRUSR | S_IWUSR;
        inode->i_uid = current_fsuid();
        inode->i_gid = current_fsgid();
-       inode->i_atime = inode->i_mtime = inode_set_ctime_current(inode);
+       simple_inode_init_ts(inode);
 
        return inode;
 
@@ -1324,10 +1334,8 @@ static long pipe_set_size(struct pipe_inode_info *pipe, unsigned int arg)
        unsigned int nr_slots, size;
        long ret = 0;
 
-#ifdef CONFIG_WATCH_QUEUE
-       if (pipe->watch_queue)
+       if (pipe_has_watch_queue(pipe))
                return -EBUSY;
-#endif
 
        size = round_pipe_size(arg);
        nr_slots = size >> PAGE_SHIFT;
@@ -1379,10 +1387,8 @@ struct pipe_inode_info *get_pipe_info(struct file *file, bool for_splice)
 
        if (file->f_op != &pipefifo_fops || !pipe)
                return NULL;
-#ifdef CONFIG_WATCH_QUEUE
-       if (for_splice && pipe->watch_queue)
+       if (for_splice && pipe_has_watch_queue(pipe))
                return NULL;
-#endif
        return pipe;
 }