fs: Fix hang with BSD accounting on frozen filesystem

[~andy/linux] / include / linux / fs.h

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 2c28271ab9d40a834c50931084cb15e8860cd765..b5a24ba83b6f17c7ae98bce197559a8d7e6ef60e 100644 (file)
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -675,9 +675,11 @@ static inline loff_t i_size_read(const struct inode *inode)
 static inline void i_size_write(struct inode *inode, loff_t i_size)
 {
 #if BITS_PER_LONG==32 && defined(CONFIG_SMP)
+       preempt_disable();
        write_seqcount_begin(&inode->i_size_seqcount);
        inode->i_size = i_size;
        write_seqcount_end(&inode->i_size_seqcount);
+       preempt_enable();
 #elif BITS_PER_LONG==32 && defined(CONFIG_PREEMPT)
        preempt_disable();
        inode->i_size = i_size;
@@ -2080,7 +2082,6 @@ extern int sync_filesystem(struct super_block *);
 extern const struct file_operations def_blk_fops;
 extern const struct file_operations def_chr_fops;
 extern const struct file_operations bad_sock_fops;
-extern const struct file_operations def_fifo_fops;
 #ifdef CONFIG_BLOCK
 extern int ioctl_by_bdev(struct block_device *, unsigned, unsigned long);
 extern int blkdev_ioctl(struct block_device *, fmode_t, unsigned, unsigned long);
@@ -2152,10 +2153,6 @@ extern void init_special_inode(struct inode *, umode_t, dev_t);
 extern void make_bad_inode(struct inode *);
 extern int is_bad_inode(struct inode *);
 
-extern const struct file_operations read_pipefifo_fops;
-extern const struct file_operations write_pipefifo_fops;
-extern const struct file_operations rdwr_pipefifo_fops;
-
 #ifdef CONFIG_BLOCK
 /*
  * return READ, READA, or WRITE
@@ -2223,6 +2220,27 @@ static inline struct inode *file_inode(struct file *f)
        return f->f_inode;
 }
 
+static inline void file_start_write(struct file *file)
+{
+       if (!S_ISREG(file_inode(file)->i_mode))
+               return;
+       __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, true);
+}
+
+static inline bool file_start_write_trylock(struct file *file)
+{
+       if (!S_ISREG(file_inode(file)->i_mode))
+               return true;
+       return __sb_start_write(file_inode(file)->i_sb, SB_FREEZE_WRITE, false);
+}
+
+static inline void file_end_write(struct file *file)
+{
+       if (!S_ISREG(file_inode(file)->i_mode))
+               return;
+       __sb_end_write(file_inode(file)->i_sb, SB_FREEZE_WRITE);
+}
+
 /*
  * get_write_access() gets write permission for a file.
  * put_write_access() releases this write permission.