2005-04-16 16:20:36 -06:00
|
|
|
/*
|
2007-09-20 02:31:38 -06:00
|
|
|
* fs/sysfs/symlink.c - operations for initializing and mounting sysfs
|
|
|
|
*
|
|
|
|
* Copyright (c) 2001-3 Patrick Mochel
|
|
|
|
* Copyright (c) 2007 SUSE Linux Products GmbH
|
|
|
|
* Copyright (c) 2007 Tejun Heo <teheo@suse.de>
|
|
|
|
*
|
|
|
|
* This file is released under the GPLv2.
|
|
|
|
*
|
|
|
|
* Please see Documentation/filesystems/sysfs.txt for more information.
|
2005-04-16 16:20:36 -06:00
|
|
|
*/
|
|
|
|
|
|
|
|
#define DEBUG
|
|
|
|
|
|
|
|
#include <linux/fs.h>
|
|
|
|
#include <linux/mount.h>
|
|
|
|
#include <linux/pagemap.h>
|
|
|
|
#include <linux/init.h>
|
2008-07-15 16:58:04 -06:00
|
|
|
#include <linux/module.h>
|
2009-01-14 00:45:13 -07:00
|
|
|
#include <linux/magic.h>
|
include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-24 02:04:11 -06:00
|
|
|
#include <linux/slab.h>
|
2005-04-16 16:20:36 -06:00
|
|
|
|
|
|
|
#include "sysfs.h"
|
|
|
|
|
|
|
|
|
2007-08-20 06:36:30 -06:00
|
|
|
static struct vfsmount *sysfs_mount;
|
2006-12-06 21:33:20 -07:00
|
|
|
struct kmem_cache *sysfs_dir_cachep;
|
2005-04-16 16:20:36 -06:00
|
|
|
|
2007-02-12 01:55:41 -07:00
|
|
|
static const struct super_operations sysfs_ops = {
|
2005-04-16 16:20:36 -06:00
|
|
|
.statfs = simple_statfs,
|
2007-07-31 04:15:08 -06:00
|
|
|
.drop_inode = generic_delete_inode,
|
2009-02-11 14:20:23 -07:00
|
|
|
.delete_inode = sysfs_delete_inode,
|
2005-04-16 16:20:36 -06:00
|
|
|
};
|
|
|
|
|
2007-06-13 13:27:25 -06:00
|
|
|
struct sysfs_dirent sysfs_root = {
|
2007-09-20 01:05:12 -06:00
|
|
|
.s_name = "",
|
2007-06-13 12:45:14 -06:00
|
|
|
.s_count = ATOMIC_INIT(1),
|
2007-09-20 01:05:12 -06:00
|
|
|
.s_flags = SYSFS_DIR,
|
2007-06-13 12:45:17 -06:00
|
|
|
.s_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
|
2007-06-10 23:02:45 -06:00
|
|
|
.s_ino = 1,
|
2005-04-16 16:20:36 -06:00
|
|
|
};
|
|
|
|
|
|
|
|
static int sysfs_fill_super(struct super_block *sb, void *data, int silent)
|
|
|
|
{
|
|
|
|
struct inode *inode;
|
|
|
|
struct dentry *root;
|
|
|
|
|
|
|
|
sb->s_blocksize = PAGE_CACHE_SIZE;
|
|
|
|
sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
|
|
|
|
sb->s_magic = SYSFS_MAGIC;
|
|
|
|
sb->s_op = &sysfs_ops;
|
|
|
|
sb->s_time_gran = 1;
|
|
|
|
|
2007-07-17 23:29:06 -06:00
|
|
|
/* get root inode, initialize and unlock it */
|
2009-01-21 12:55:11 -07:00
|
|
|
mutex_lock(&sysfs_mutex);
|
2010-02-12 20:22:27 -07:00
|
|
|
inode = sysfs_get_inode(sb, &sysfs_root);
|
2009-01-21 12:55:11 -07:00
|
|
|
mutex_unlock(&sysfs_mutex);
|
2007-06-13 12:45:17 -06:00
|
|
|
if (!inode) {
|
2005-04-16 16:20:36 -06:00
|
|
|
pr_debug("sysfs: could not get root inode\n");
|
|
|
|
return -ENOMEM;
|
|
|
|
}
|
|
|
|
|
2007-07-17 23:29:06 -06:00
|
|
|
/* instantiate and link root dentry */
|
2005-04-16 16:20:36 -06:00
|
|
|
root = d_alloc_root(inode);
|
|
|
|
if (!root) {
|
2008-04-30 01:55:09 -06:00
|
|
|
pr_debug("%s: could not get root dentry!\n",__func__);
|
2005-04-16 16:20:36 -06:00
|
|
|
iput(inode);
|
|
|
|
return -ENOMEM;
|
|
|
|
}
|
|
|
|
root->d_fsdata = &sysfs_root;
|
|
|
|
sb->s_root = root;
|
|
|
|
return 0;
|
|
|
|
}
|
|
|
|
|
2010-03-30 12:31:24 -06:00
|
|
|
static int sysfs_test_super(struct super_block *sb, void *data)
|
|
|
|
{
|
|
|
|
struct sysfs_super_info *sb_info = sysfs_info(sb);
|
|
|
|
struct sysfs_super_info *info = data;
|
|
|
|
int found = 1;
|
|
|
|
return found;
|
|
|
|
}
|
|
|
|
|
|
|
|
static int sysfs_set_super(struct super_block *sb, void *data)
|
|
|
|
{
|
|
|
|
int error;
|
|
|
|
error = set_anon_super(sb, data);
|
|
|
|
if (!error)
|
|
|
|
sb->s_fs_info = data;
|
|
|
|
return error;
|
|
|
|
}
|
|
|
|
|
[PATCH] VFS: Permit filesystem to override root dentry on mount
Extend the get_sb() filesystem operation to take an extra argument that
permits the VFS to pass in the target vfsmount that defines the mountpoint.
The filesystem is then required to manually set the superblock and root dentry
pointers. For most filesystems, this should be done with simple_set_mnt()
which will set the superblock pointer and then set the root dentry to the
superblock's s_root (as per the old default behaviour).
The get_sb() op now returns an integer as there's now no need to return the
superblock pointer.
This patch permits a superblock to be implicitly shared amongst several mount
points, such as can be done with NFS to avoid potential inode aliasing. In
such a case, simple_set_mnt() would not be called, and instead the mnt_root
and mnt_sb would be set directly.
The patch also makes the following changes:
(*) the get_sb_*() convenience functions in the core kernel now take a vfsmount
pointer argument and return an integer, so most filesystems have to change
very little.
(*) If one of the convenience function is not used, then get_sb() should
normally call simple_set_mnt() to instantiate the vfsmount. This will
always return 0, and so can be tail-called from get_sb().
(*) generic_shutdown_super() now calls shrink_dcache_sb() to clean up the
dcache upon superblock destruction rather than shrink_dcache_anon().
This is required because the superblock may now have multiple trees that
aren't actually bound to s_root, but that still need to be cleaned up. The
currently called functions assume that the whole tree is rooted at s_root,
and that anonymous dentries are not the roots of trees which results in
dentries being left unculled.
However, with the way NFS superblock sharing are currently set to be
implemented, these assumptions are violated: the root of the filesystem is
simply a dummy dentry and inode (the real inode for '/' may well be
inaccessible), and all the vfsmounts are rooted on anonymous[*] dentries
with child trees.
[*] Anonymous until discovered from another tree.
(*) The documentation has been adjusted, including the additional bit of
changing ext2_* into foo_* in the documentation.
[akpm@osdl.org: convert ipath_fs, do other stuff]
Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Al Viro <viro@zeniv.linux.org.uk>
Cc: Nathan Scott <nathans@sgi.com>
Cc: Roland Dreier <rolandd@cisco.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
2006-06-23 03:02:57 -06:00
|
|
|
static int sysfs_get_sb(struct file_system_type *fs_type,
|
|
|
|
int flags, const char *dev_name, void *data, struct vfsmount *mnt)
|
2005-04-16 16:20:36 -06:00
|
|
|
{
|
2010-03-30 12:31:24 -06:00
|
|
|
struct sysfs_super_info *info;
|
|
|
|
struct super_block *sb;
|
|
|
|
int error;
|
|
|
|
|
|
|
|
error = -ENOMEM;
|
|
|
|
info = kzalloc(sizeof(*info), GFP_KERNEL);
|
|
|
|
if (!info)
|
|
|
|
goto out;
|
|
|
|
sb = sget(fs_type, sysfs_test_super, sysfs_set_super, info);
|
|
|
|
if (IS_ERR(sb) || sb->s_fs_info != info)
|
|
|
|
kfree(info);
|
|
|
|
if (IS_ERR(sb)) {
|
|
|
|
error = PTR_ERR(sb);
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
if (!sb->s_root) {
|
|
|
|
sb->s_flags = flags;
|
|
|
|
error = sysfs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0);
|
|
|
|
if (error) {
|
|
|
|
deactivate_locked_super(sb);
|
|
|
|
goto out;
|
|
|
|
}
|
|
|
|
sb->s_flags |= MS_ACTIVE;
|
|
|
|
}
|
|
|
|
|
|
|
|
simple_set_mnt(mnt, sb);
|
|
|
|
error = 0;
|
|
|
|
out:
|
|
|
|
return error;
|
|
|
|
}
|
|
|
|
|
|
|
|
static void sysfs_kill_sb(struct super_block *sb)
|
|
|
|
{
|
|
|
|
struct sysfs_super_info *info = sysfs_info(sb);
|
|
|
|
|
|
|
|
kill_anon_super(sb);
|
|
|
|
kfree(info);
|
2005-04-16 16:20:36 -06:00
|
|
|
}
|
|
|
|
|
|
|
|
static struct file_system_type sysfs_fs_type = {
|
|
|
|
.name = "sysfs",
|
|
|
|
.get_sb = sysfs_get_sb,
|
2010-03-30 12:31:24 -06:00
|
|
|
.kill_sb = sysfs_kill_sb,
|
2005-04-16 16:20:36 -06:00
|
|
|
};
|
|
|
|
|
|
|
|
int __init sysfs_init(void)
|
|
|
|
{
|
|
|
|
int err = -ENOMEM;
|
|
|
|
|
|
|
|
sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache",
|
|
|
|
sizeof(struct sysfs_dirent),
|
2007-07-19 19:11:58 -06:00
|
|
|
0, 0, NULL);
|
2005-04-16 16:20:36 -06:00
|
|
|
if (!sysfs_dir_cachep)
|
|
|
|
goto out;
|
|
|
|
|
2007-10-17 00:25:46 -06:00
|
|
|
err = sysfs_inode_init();
|
|
|
|
if (err)
|
|
|
|
goto out_err;
|
|
|
|
|
2005-04-16 16:20:36 -06:00
|
|
|
err = register_filesystem(&sysfs_fs_type);
|
|
|
|
if (!err) {
|
|
|
|
sysfs_mount = kern_mount(&sysfs_fs_type);
|
|
|
|
if (IS_ERR(sysfs_mount)) {
|
|
|
|
printk(KERN_ERR "sysfs: could not mount!\n");
|
|
|
|
err = PTR_ERR(sysfs_mount);
|
|
|
|
sysfs_mount = NULL;
|
|
|
|
unregister_filesystem(&sysfs_fs_type);
|
|
|
|
goto out_err;
|
|
|
|
}
|
|
|
|
} else
|
|
|
|
goto out_err;
|
|
|
|
out:
|
|
|
|
return err;
|
|
|
|
out_err:
|
|
|
|
kmem_cache_destroy(sysfs_dir_cachep);
|
|
|
|
sysfs_dir_cachep = NULL;
|
|
|
|
goto out;
|
|
|
|
}
|
2008-07-15 16:58:04 -06:00
|
|
|
|
|
|
|
#undef sysfs_get
|
|
|
|
struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd)
|
|
|
|
{
|
|
|
|
return __sysfs_get(sd);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(sysfs_get);
|
|
|
|
|
|
|
|
#undef sysfs_put
|
|
|
|
void sysfs_put(struct sysfs_dirent *sd)
|
|
|
|
{
|
|
|
|
__sysfs_put(sd);
|
|
|
|
}
|
|
|
|
EXPORT_SYMBOL_GPL(sysfs_put);
|