![Tejun Heo](/assets/img/avatar_default.png)
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>
259 lines
6.6 KiB
C
259 lines
6.6 KiB
C
/*
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* linux/fs/nfs/namespace.c
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*
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* Copyright (C) 2005 Trond Myklebust <Trond.Myklebust@netapp.com>
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* - Modified by David Howells <dhowells@redhat.com>
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*
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* NFS namespace
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*/
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#include <linux/dcache.h>
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#include <linux/gfp.h>
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#include <linux/mount.h>
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#include <linux/namei.h>
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#include <linux/nfs_fs.h>
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#include <linux/string.h>
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#include <linux/sunrpc/clnt.h>
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#include <linux/vfs.h>
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#include "internal.h"
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#define NFSDBG_FACILITY NFSDBG_VFS
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static void nfs_expire_automounts(struct work_struct *work);
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static LIST_HEAD(nfs_automount_list);
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static DECLARE_DELAYED_WORK(nfs_automount_task, nfs_expire_automounts);
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int nfs_mountpoint_expiry_timeout = 500 * HZ;
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static struct vfsmount *nfs_do_submount(const struct vfsmount *mnt_parent,
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const struct dentry *dentry,
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struct nfs_fh *fh,
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struct nfs_fattr *fattr);
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/*
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* nfs_path - reconstruct the path given an arbitrary dentry
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* @base - arbitrary string to prepend to the path
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* @droot - pointer to root dentry for mountpoint
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* @dentry - pointer to dentry
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* @buffer - result buffer
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* @buflen - length of buffer
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*
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* Helper function for constructing the path from the
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* root dentry to an arbitrary hashed dentry.
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*
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* This is mainly for use in figuring out the path on the
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* server side when automounting on top of an existing partition.
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*/
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char *nfs_path(const char *base,
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const struct dentry *droot,
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const struct dentry *dentry,
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char *buffer, ssize_t buflen)
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{
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char *end = buffer+buflen;
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int namelen;
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*--end = '\0';
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buflen--;
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spin_lock(&dcache_lock);
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while (!IS_ROOT(dentry) && dentry != droot) {
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namelen = dentry->d_name.len;
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buflen -= namelen + 1;
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if (buflen < 0)
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goto Elong_unlock;
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end -= namelen;
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memcpy(end, dentry->d_name.name, namelen);
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*--end = '/';
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dentry = dentry->d_parent;
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}
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spin_unlock(&dcache_lock);
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if (*end != '/') {
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if (--buflen < 0)
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goto Elong;
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*--end = '/';
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}
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namelen = strlen(base);
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/* Strip off excess slashes in base string */
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while (namelen > 0 && base[namelen - 1] == '/')
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namelen--;
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buflen -= namelen;
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if (buflen < 0)
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goto Elong;
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end -= namelen;
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memcpy(end, base, namelen);
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return end;
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Elong_unlock:
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spin_unlock(&dcache_lock);
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Elong:
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return ERR_PTR(-ENAMETOOLONG);
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}
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/*
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* nfs_follow_mountpoint - handle crossing a mountpoint on the server
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* @dentry - dentry of mountpoint
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* @nd - nameidata info
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*
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* When we encounter a mountpoint on the server, we want to set up
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* a mountpoint on the client too, to prevent inode numbers from
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* colliding, and to allow "df" to work properly.
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* On NFSv4, we also want to allow for the fact that different
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* filesystems may be migrated to different servers in a failover
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* situation, and that different filesystems may want to use
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* different security flavours.
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*/
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static void * nfs_follow_mountpoint(struct dentry *dentry, struct nameidata *nd)
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{
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struct vfsmount *mnt;
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struct nfs_server *server = NFS_SERVER(dentry->d_inode);
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struct dentry *parent;
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struct nfs_fh fh;
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struct nfs_fattr fattr;
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int err;
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dprintk("--> nfs_follow_mountpoint()\n");
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err = -ESTALE;
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if (IS_ROOT(dentry))
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goto out_err;
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dprintk("%s: enter\n", __func__);
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dput(nd->path.dentry);
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nd->path.dentry = dget(dentry);
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/* Look it up again */
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parent = dget_parent(nd->path.dentry);
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err = server->nfs_client->rpc_ops->lookup(parent->d_inode,
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&nd->path.dentry->d_name,
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&fh, &fattr);
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dput(parent);
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if (err != 0)
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goto out_err;
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if (fattr.valid & NFS_ATTR_FATTR_V4_REFERRAL)
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mnt = nfs_do_refmount(nd->path.mnt, nd->path.dentry);
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else
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mnt = nfs_do_submount(nd->path.mnt, nd->path.dentry, &fh,
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&fattr);
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err = PTR_ERR(mnt);
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if (IS_ERR(mnt))
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goto out_err;
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mntget(mnt);
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err = do_add_mount(mnt, &nd->path, nd->path.mnt->mnt_flags|MNT_SHRINKABLE,
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&nfs_automount_list);
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if (err < 0) {
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mntput(mnt);
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if (err == -EBUSY)
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goto out_follow;
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goto out_err;
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}
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path_put(&nd->path);
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nd->path.mnt = mnt;
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nd->path.dentry = dget(mnt->mnt_root);
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schedule_delayed_work(&nfs_automount_task, nfs_mountpoint_expiry_timeout);
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out:
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dprintk("%s: done, returned %d\n", __func__, err);
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dprintk("<-- nfs_follow_mountpoint() = %d\n", err);
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return ERR_PTR(err);
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out_err:
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path_put(&nd->path);
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goto out;
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out_follow:
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while (d_mountpoint(nd->path.dentry) &&
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follow_down(&nd->path))
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;
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err = 0;
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goto out;
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}
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const struct inode_operations nfs_mountpoint_inode_operations = {
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.follow_link = nfs_follow_mountpoint,
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.getattr = nfs_getattr,
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};
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const struct inode_operations nfs_referral_inode_operations = {
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.follow_link = nfs_follow_mountpoint,
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};
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static void nfs_expire_automounts(struct work_struct *work)
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{
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struct list_head *list = &nfs_automount_list;
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mark_mounts_for_expiry(list);
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if (!list_empty(list))
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schedule_delayed_work(&nfs_automount_task, nfs_mountpoint_expiry_timeout);
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}
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void nfs_release_automount_timer(void)
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{
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if (list_empty(&nfs_automount_list))
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cancel_delayed_work(&nfs_automount_task);
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}
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/*
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* Clone a mountpoint of the appropriate type
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*/
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static struct vfsmount *nfs_do_clone_mount(struct nfs_server *server,
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const char *devname,
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struct nfs_clone_mount *mountdata)
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{
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#ifdef CONFIG_NFS_V4
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struct vfsmount *mnt = ERR_PTR(-EINVAL);
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switch (server->nfs_client->rpc_ops->version) {
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case 2:
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case 3:
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mnt = vfs_kern_mount(&nfs_xdev_fs_type, 0, devname, mountdata);
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break;
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case 4:
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mnt = vfs_kern_mount(&nfs4_xdev_fs_type, 0, devname, mountdata);
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}
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return mnt;
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#else
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return vfs_kern_mount(&nfs_xdev_fs_type, 0, devname, mountdata);
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#endif
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}
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/**
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* nfs_do_submount - set up mountpoint when crossing a filesystem boundary
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* @mnt_parent - mountpoint of parent directory
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* @dentry - parent directory
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* @fh - filehandle for new root dentry
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* @fattr - attributes for new root inode
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*
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*/
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static struct vfsmount *nfs_do_submount(const struct vfsmount *mnt_parent,
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const struct dentry *dentry,
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struct nfs_fh *fh,
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struct nfs_fattr *fattr)
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{
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struct nfs_clone_mount mountdata = {
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.sb = mnt_parent->mnt_sb,
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.dentry = dentry,
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.fh = fh,
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.fattr = fattr,
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};
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struct vfsmount *mnt = ERR_PTR(-ENOMEM);
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char *page = (char *) __get_free_page(GFP_USER);
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char *devname;
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dprintk("--> nfs_do_submount()\n");
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dprintk("%s: submounting on %s/%s\n", __func__,
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dentry->d_parent->d_name.name,
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dentry->d_name.name);
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if (page == NULL)
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goto out;
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devname = nfs_devname(mnt_parent, dentry, page, PAGE_SIZE);
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mnt = (struct vfsmount *)devname;
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if (IS_ERR(devname))
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goto free_page;
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mnt = nfs_do_clone_mount(NFS_SB(mnt_parent->mnt_sb), devname, &mountdata);
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free_page:
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free_page((unsigned long)page);
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out:
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dprintk("%s: done\n", __func__);
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dprintk("<-- nfs_do_submount() = %p\n", mnt);
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return mnt;
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}
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