alistair23-linux/fs/nfs/nfs4namespace.c
Tejun Heo 5a0e3ad6af 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>
2010-03-30 22:02:32 +09:00

269 lines
6.5 KiB
C

/*
* linux/fs/nfs/nfs4namespace.c
*
* Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
* - Modified by David Howells <dhowells@redhat.com>
*
* NFSv4 namespace
*/
#include <linux/dcache.h>
#include <linux/mount.h>
#include <linux/namei.h>
#include <linux/nfs_fs.h>
#include <linux/slab.h>
#include <linux/string.h>
#include <linux/sunrpc/clnt.h>
#include <linux/vfs.h>
#include <linux/inet.h>
#include "internal.h"
#include "nfs4_fs.h"
#include "dns_resolve.h"
#define NFSDBG_FACILITY NFSDBG_VFS
/*
* Convert the NFSv4 pathname components into a standard posix path.
*
* Note that the resulting string will be placed at the end of the buffer
*/
static inline char *nfs4_pathname_string(const struct nfs4_pathname *pathname,
char *buffer, ssize_t buflen)
{
char *end = buffer + buflen;
int n;
*--end = '\0';
buflen--;
n = pathname->ncomponents;
while (--n >= 0) {
const struct nfs4_string *component = &pathname->components[n];
buflen -= component->len + 1;
if (buflen < 0)
goto Elong;
end -= component->len;
memcpy(end, component->data, component->len);
*--end = '/';
}
return end;
Elong:
return ERR_PTR(-ENAMETOOLONG);
}
/*
* Determine the mount path as a string
*/
static char *nfs4_path(const struct vfsmount *mnt_parent,
const struct dentry *dentry,
char *buffer, ssize_t buflen)
{
const char *srvpath;
srvpath = strchr(mnt_parent->mnt_devname, ':');
if (srvpath)
srvpath++;
else
srvpath = mnt_parent->mnt_devname;
return nfs_path(srvpath, mnt_parent->mnt_root, dentry, buffer, buflen);
}
/*
* Check that fs_locations::fs_root [RFC3530 6.3] is a prefix for what we
* believe to be the server path to this dentry
*/
static int nfs4_validate_fspath(const struct vfsmount *mnt_parent,
const struct dentry *dentry,
const struct nfs4_fs_locations *locations,
char *page, char *page2)
{
const char *path, *fs_path;
path = nfs4_path(mnt_parent, dentry, page, PAGE_SIZE);
if (IS_ERR(path))
return PTR_ERR(path);
fs_path = nfs4_pathname_string(&locations->fs_path, page2, PAGE_SIZE);
if (IS_ERR(fs_path))
return PTR_ERR(fs_path);
if (strncmp(path, fs_path, strlen(fs_path)) != 0) {
dprintk("%s: path %s does not begin with fsroot %s\n",
__func__, path, fs_path);
return -ENOENT;
}
return 0;
}
static size_t nfs_parse_server_name(char *string, size_t len,
struct sockaddr *sa, size_t salen)
{
ssize_t ret;
ret = rpc_pton(string, len, sa, salen);
if (ret == 0) {
ret = nfs_dns_resolve_name(string, len, sa, salen);
if (ret < 0)
ret = 0;
}
return ret;
}
static struct vfsmount *try_location(struct nfs_clone_mount *mountdata,
char *page, char *page2,
const struct nfs4_fs_location *location)
{
struct vfsmount *mnt = ERR_PTR(-ENOENT);
char *mnt_path;
unsigned int maxbuflen;
unsigned int s;
mnt_path = nfs4_pathname_string(&location->rootpath, page2, PAGE_SIZE);
if (IS_ERR(mnt_path))
return ERR_CAST(mnt_path);
mountdata->mnt_path = mnt_path;
maxbuflen = mnt_path - 1 - page2;
for (s = 0; s < location->nservers; s++) {
const struct nfs4_string *buf = &location->servers[s];
struct sockaddr_storage addr;
if (buf->len <= 0 || buf->len >= maxbuflen)
continue;
if (memchr(buf->data, IPV6_SCOPE_DELIMITER, buf->len))
continue;
mountdata->addrlen = nfs_parse_server_name(buf->data, buf->len,
(struct sockaddr *)&addr, sizeof(addr));
if (mountdata->addrlen == 0)
continue;
mountdata->addr = (struct sockaddr *)&addr;
rpc_set_port(mountdata->addr, NFS_PORT);
memcpy(page2, buf->data, buf->len);
page2[buf->len] = '\0';
mountdata->hostname = page2;
snprintf(page, PAGE_SIZE, "%s:%s",
mountdata->hostname,
mountdata->mnt_path);
mnt = vfs_kern_mount(&nfs4_referral_fs_type, 0, page, mountdata);
if (!IS_ERR(mnt))
break;
}
return mnt;
}
/**
* nfs_follow_referral - set up mountpoint when hitting a referral on moved error
* @mnt_parent - mountpoint of parent directory
* @dentry - parent directory
* @locations - array of NFSv4 server location information
*
*/
static struct vfsmount *nfs_follow_referral(const struct vfsmount *mnt_parent,
const struct dentry *dentry,
const struct nfs4_fs_locations *locations)
{
struct vfsmount *mnt = ERR_PTR(-ENOENT);
struct nfs_clone_mount mountdata = {
.sb = mnt_parent->mnt_sb,
.dentry = dentry,
.authflavor = NFS_SB(mnt_parent->mnt_sb)->client->cl_auth->au_flavor,
};
char *page = NULL, *page2 = NULL;
int loc, error;
if (locations == NULL || locations->nlocations <= 0)
goto out;
dprintk("%s: referral at %s/%s\n", __func__,
dentry->d_parent->d_name.name, dentry->d_name.name);
page = (char *) __get_free_page(GFP_USER);
if (!page)
goto out;
page2 = (char *) __get_free_page(GFP_USER);
if (!page2)
goto out;
/* Ensure fs path is a prefix of current dentry path */
error = nfs4_validate_fspath(mnt_parent, dentry, locations, page, page2);
if (error < 0) {
mnt = ERR_PTR(error);
goto out;
}
for (loc = 0; loc < locations->nlocations; loc++) {
const struct nfs4_fs_location *location = &locations->locations[loc];
if (location == NULL || location->nservers <= 0 ||
location->rootpath.ncomponents == 0)
continue;
mnt = try_location(&mountdata, page, page2, location);
if (!IS_ERR(mnt))
break;
}
out:
free_page((unsigned long) page);
free_page((unsigned long) page2);
dprintk("%s: done\n", __func__);
return mnt;
}
/*
* nfs_do_refmount - handle crossing a referral on server
* @dentry - dentry of referral
* @nd - nameidata info
*
*/
struct vfsmount *nfs_do_refmount(const struct vfsmount *mnt_parent, struct dentry *dentry)
{
struct vfsmount *mnt = ERR_PTR(-ENOMEM);
struct dentry *parent;
struct nfs4_fs_locations *fs_locations = NULL;
struct page *page;
int err;
/* BUG_ON(IS_ROOT(dentry)); */
dprintk("%s: enter\n", __func__);
page = alloc_page(GFP_KERNEL);
if (page == NULL)
goto out;
fs_locations = kmalloc(sizeof(struct nfs4_fs_locations), GFP_KERNEL);
if (fs_locations == NULL)
goto out_free;
/* Get locations */
mnt = ERR_PTR(-ENOENT);
parent = dget_parent(dentry);
dprintk("%s: getting locations for %s/%s\n",
__func__, parent->d_name.name, dentry->d_name.name);
err = nfs4_proc_fs_locations(parent->d_inode, &dentry->d_name, fs_locations, page);
dput(parent);
if (err != 0 ||
fs_locations->nlocations <= 0 ||
fs_locations->fs_path.ncomponents <= 0)
goto out_free;
mnt = nfs_follow_referral(mnt_parent, dentry, fs_locations);
out_free:
__free_page(page);
kfree(fs_locations);
out:
dprintk("%s: done\n", __func__);
return mnt;
}