aboutsummaryrefslogtreecommitdiffstats
path: root/Documentation/filesystems/Locking
diff options
context:
space:
mode:
Diffstat (limited to 'Documentation/filesystems/Locking')
-rw-r--r--Documentation/filesystems/Locking7
1 files changed, 4 insertions, 3 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking
index af1608070cd5..96d4293607ec 100644
--- a/Documentation/filesystems/Locking
+++ b/Documentation/filesystems/Locking
@@ -380,7 +380,7 @@ prototypes:
380 int (*open) (struct inode *, struct file *); 380 int (*open) (struct inode *, struct file *);
381 int (*flush) (struct file *); 381 int (*flush) (struct file *);
382 int (*release) (struct inode *, struct file *); 382 int (*release) (struct inode *, struct file *);
383 int (*fsync) (struct file *, struct dentry *, int datasync); 383 int (*fsync) (struct file *, int datasync);
384 int (*aio_fsync) (struct kiocb *, int datasync); 384 int (*aio_fsync) (struct kiocb *, int datasync);
385 int (*fasync) (int, struct file *, int); 385 int (*fasync) (int, struct file *, int);
386 int (*lock) (struct file *, int, struct file_lock *); 386 int (*lock) (struct file *, int, struct file_lock *);
@@ -429,8 +429,9 @@ check_flags: no
429implementations. If your fs is not using generic_file_llseek, you 429implementations. If your fs is not using generic_file_llseek, you
430need to acquire and release the appropriate locks in your ->llseek(). 430need to acquire and release the appropriate locks in your ->llseek().
431For many filesystems, it is probably safe to acquire the inode 431For many filesystems, it is probably safe to acquire the inode
432mutex. Note some filesystems (i.e. remote ones) provide no 432mutex or just to use i_size_read() instead.
433protection for i_size so you will need to use the BKL. 433Note: this does not protect the file->f_pos against concurrent modifications
434since this is something the userspace has to take care about.
434 435
435Note: ext2_release() was *the* source of contention on fs-intensive 436Note: ext2_release() was *the* source of contention on fs-intensive
436loads and dropping BKL on ->release() helps to get rid of that (we still 437loads and dropping BKL on ->release() helps to get rid of that (we still