linux/fs/qnx4
jan Blunck ca572727db fs/: do not fallback to default_llseek() when readdir() uses BKL
Do not use the fallback default_llseek() if the readdir operation of the
filesystem still uses the big kernel lock.

Since llseek() modifies
file->f_pos of the directory directly it may need locking to not confuse
readdir which usually uses file->f_pos directly as well

Since the special characteristics of the BKL (unlocked on schedule) are
not necessary in this case, the inode mutex can be used for locking as
provided by generic_file_llseek().  This is only possible since all
filesystems, except reiserfs, either use a directory as a flat file or
with disk address offsets.  Reiserfs on the other hand uses a 32bit hash
off the filename as the offset so generic_file_llseek() can get used as
well since the hash is always smaller than sb->s_maxbytes (= (512 << 32) -
blocksize).

Signed-off-by: Jan Blunck <jblunck@suse.de>
Acked-by: Jan Kara <jack@suse.cz>
Acked-by: Anders Larsen <al@alarsen.net>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2010-05-27 09:12:56 -07:00
..
bitmap.c qnx4: use hweight8 2009-12-16 07:20:18 -08:00
dir.c fs/: do not fallback to default_llseek() when readdir() uses BKL 2010-05-27 09:12:56 -07:00
inode.c fs/qnx4: decrement sizeof size in strncmp 2010-02-04 11:55:46 +01:00
Kconfig qnx4: remove write support 2009-09-23 07:39:30 -07:00
Makefile qnx4: remove write support 2009-09-23 07:39:30 -07:00
namei.c qnx4fs: add missing KERN_xxx to printk() calls 2009-11-09 09:40:57 +01:00
qnx4.h qnx4: remove write support 2009-09-23 07:39:30 -07:00
README Linux-2.6.12-rc2 2005-04-16 15:20:36 -07:00

  This is a snapshot of the QNX4 filesystem for Linux.
  Please send diffs and remarks to <al@alarsen.net> .
  
Credits :

Richard "Scuba" A. Frowijn     <scuba@wxs.nl>
Frank "Jedi/Sector One" Denis  <j@pureftpd.org>
Anders Larsen                  <al@alarsen.net> (Maintainer)