linux-toradex.git/fs/read_write.c, branch v2.6.22.13

use use SEEK_MAX to validate user lseek arguments

2007-05-08T18:14:59+00:00

Add SEEK_MAX and use it to validate lseek arguments from userspace.

Signed-off-by: Chris Snook 
Acked-by: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

use symbolic constants in generic lseek code

2007-05-08T18:14:59+00:00

Convert magic numbers to SEEK_* values from fs.h

Signed-off-by: Chris Snook 
Acked-by: David Howells 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] FS: speed up rw_verify_area()

2007-02-12T17:48:29+00:00

oprofile hunting showed a stall in rw_verify_area(), because of triple
indirection and potential cache misses.
(file->f_path.dentry->d_inode->i_flock)

By moving initialization of 'struct inode' pointer before the pos/count
sanity tests, we allow the compiler and processor to perform two loads by
anticipation, reducing stall, without prefetch() hints.  Even x86 arch has
enough registers to not use temporary variables and not increase text size.

I validated this patch running a bench and studied oprofile changes, and
absolute perf of the test program.

Results of my epoll_pipe_bench (source available on request) on a Pentium-M
1.6 GHz machine

Before :
# ./epoll_pipe_bench -l 30 -t 20
Avg: 436089 evts/sec read_count=8843037 write_count=8843040 21.218390 samples
per call
(best value out of 10 runs)

After :
# ./epoll_pipe_bench -l 30 -t 20
Avg: 470980 evts/sec read_count=9549871 write_count=9549894 21.216694 samples
per call
(best value out of 10 runs)

oprofile CPU_CLK_UNHALTED events gave a reduction from 5.3401 % to 2.5851 %
for the rw_verify_area() function.

Signed-off-by: Eric Dumazet 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] ifdef ->rchar, ->wchar, ->syscr, ->syscw from task_struct

2007-02-11T19:18:07+00:00

They are fat: 4x8 bytes in task_struct.
They are uncoditionally updated in every fork, read, write and sendfile.
They are used only if you have some "extended acct fields feature".

And please, please, please, read(2) knows about bytes, not characters,
why it is called "rchar"?

Signed-off-by: Alexey Dobriyan 
Cc: Jay Lan 
Cc: Balbir Singh 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] one more EXPORT_UNUSED_SYMBOL removal

2006-12-13T17:05:53+00:00

Signed-off-by: Adrian Bunk 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] VFS: change struct file to use struct path

2006-12-08T16:28:41+00:00

This patch changes struct file to use struct path instead of having
independent pointers to struct dentry and struct vfsmount, and converts all
users of f_{dentry,vfsmnt} in fs/ to use f_path.{dentry,mnt}.

Additionally, it adds two #define's to make the transition easier for users of
the f_dentry and f_vfsmnt.

Signed-off-by: Josef "Jeff" Sipek 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Add vector AIO support

2006-10-01T07:39:29+00:00

This work is initially done by Zach Brown to add support for vectored aio.
These are the core changes for AIO to support
IOCB_CMD_PREADV/IOCB_CMD_PWRITEV.

[akpm@osdl.org: huge build fix]
Signed-off-by: Zach Brown 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Badari Pulavarty 
Acked-by: Benjamin LaHaise 
Acked-by: James Morris 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Streamline generic_file_* interfaces and filemap cleanups

2006-10-01T07:39:28+00:00

This patch cleans up generic_file_*_read/write() interfaces.  Christoph
Hellwig gave me the idea for this clean ups.

In a nutshell, all filesystems should set .aio_read/.aio_write methods and use
do_sync_read/ do_sync_write() as their .read/.write methods.  This allows us
to cleanup all variants of generic_file_* routines.

Final available interfaces:

generic_file_aio_read() - read handler
generic_file_aio_write() - write handler
generic_file_aio_write_nolock() - no lock write handler

__generic_file_aio_write_nolock() - internal worker routine

Signed-off-by: Badari Pulavarty 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Remove readv/writev methods and use aio_read/aio_write instead

2006-10-01T07:39:28+00:00

This patch removes readv() and writev() methods and replaces them with
aio_read()/aio_write() methods.

Signed-off-by: Badari Pulavarty 
Signed-off-by: Christoph Hellwig 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Vectorize aio_read/aio_write fileop methods

2006-10-01T07:39:28+00:00

This patch vectorizes aio_read() and aio_write() methods to prepare for
collapsing all aio & vectored operations into one interface - which is
aio_read()/aio_write().

Signed-off-by: Badari Pulavarty 
Signed-off-by: Christoph Hellwig 
Cc: Michael Holzheu 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds