linux.git/fs/pipe.c, branch v2.6.23

docbook: add pipes, other fixes

2007-07-27T06:08:51+00:00

Fix some typos in pipe.c and splice.c.
Add pipes API to kernel-api.tmpl.

Signed-off-by: Randy Dunlap 
Signed-off-by: Jens Axboe

pipe: add documentation and comments

2007-07-10T06:04:16+00:00

As per Andrew Mortons request, here's a set of documentation for
the generic pipe_buf_operations hooks, the pipe, and pipe_buffer
structures.

Signed-off-by: Jens Axboe

pipe: change the ->pin() operation to ->confirm()

2007-07-10T06:04:15+00:00

The name 'pin' was badly chosen, it doesn't pin a pipe buffer
in the most commonly used sense in the kernel. So change the
name to 'confirm', after debating this issue with Hugh
Dickins a bit.

A good return from ->confirm() means that the buffer is really
there, and that the contents are good.

Signed-off-by: Jens Axboe

VFS: delay the dentry name generation on sockets and pipes

2007-05-08T18:15:03+00:00

1) Introduces a new method in 'struct dentry_operations'.  This method
   called d_dname() might be called from d_path() to build a pathname for
   special filesystems.  It is called without locks.

   Future patches (if we succeed in having one common dentry for all
   pipes/sockets) may need to change prototype of this method, but we now
   use : char *d_dname(struct dentry *dentry, char *buffer, int buflen);

2) Adds a dynamic_dname() helper function that eases d_dname() implementations

3) Defines d_dname method for sockets : No more sprintf() at socket
   creation.  This is delayed up to the moment someone does an access to
   /proc/pid/fd/...

4) Defines d_dname method for pipes : No more sprintf() at pipe
   creation.  This is delayed up to the moment someone does an access to
   /proc/pid/fd/...

A benchmark consisting of 1.000.000 calls to pipe()/close()/close() gives a
*nice* speedup on my Pentium(M) 1.6 Ghz :

3.090 s instead of 3.450 s

Signed-off-by: Eric Dumazet 
Acked-by: Christoph Hellwig 
Acked-by: Linus Torvalds 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] AUDIT_FD_PAIR

2007-02-18T02:30:15+00:00

Provide an audit record of the descriptor pair returned by pipe() and
socketpair().  Rewritten from the original posted to linux-audit by
John D. Ramsdell 

Signed-off-by: Al Viro

[PATCH] fix leaks on pipe(2) failure exits

2006-12-21T08:16:03+00:00

Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds

[PATCH] constify pipe_buf_operations

2006-12-13T17:05:47+00:00

- pipe/splice should use const pipe_buf_operations and file_operations

- struct pipe_inode_info has an unused field "start" : get rid of it.

Signed-off-by: Eric Dumazet 
Cc: Jens Axboe 
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] don't insert pipe dentries into dentry_hashtable.

2006-12-07T16:39:41+00:00

We currently insert pipe dentries into the global dentry hashtable.  This
is suboptimal because there is currently no way these entries can be used
for a lookup().  (/proc/xxx/fd/xxx uses a different mechanism).  Inserting
them in dentry hashtable slows dcache lookups.

To let __dpath() still work correctly (ie not adding a " (deleted)") after
dentry name, we do :

 - Right after d_alloc(), pretend they are hashed by clearing the
   DCACHE_UNHASHED bit.

 - Call d_instantiate() instead of d_add() : dentry is not inserted in
   hash table.

__dpath() & friends work as intended during dentry lifetime.

 - At dismantle time, once dput() must clear the dentry, setting again
   DCACHE_UNHASHED bit inside the custom d_delete() function provided by
   pipe code, so that dput() can just kill_it.

This patch, combined with (avoid RCU for never hashed dentries) reduced
time of { pipe(p); close(p[0]); close(p[1]);} on my UP machine (1.6GHz
Pentium-M) from 3.23 us to 2.86 us (But this patch does not depend on other
patches, only bench results)

Signed-off-by: Eric Dumazet 
Acked-by: David Miller 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

[PATCH] Some cleanup in the pipe code

2006-10-01T07:39:33+00:00

Split the big and hard to read do_pipe function into smaller pieces.

This creates new create_write_pipe/free_write_pipe/create_read_pipe
functions.  These functions are made global so that they can be used by
other parts of the kernel.

The resulting code is more generic and easier to read and has cleaner error
handling and less gotos.

[akpm@osdl.org: cleanup]
Signed-off-by: Andi Kleen 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds