Marcelo,
We have talked about putting the fastwalk patch into 2.4 before.
Very little has changed and it should apply cleanly to 2.4.22-pre
too ;)
This patch reduces cacheline bouncing due to numerous atomic increments
and decrements of the d_count reference counter during path walking by
holding the dcache_lock as long as the dentries are in the cache.
Linus included the original patch in 2.5.11. Al Viro made a few great
changes in 2.5.12 and Paul Menage added one fix. The following patch includes
their changes as well. The last time I had access to an 8-way this patch
showed a throughput improvement while running dbench. Here is the output:
http://west.dl.sourceforge.net/sourceforge/lse/2419fw.png
Today I tested this patch on a 2-way with dbench and found similar
throughput increase albeit on a smaller scale. I can send out the details
of that if anyone is interested.
The patch is also availabe on SourceForge here:
http://osdn.dl.sourceforge.net/sourceforge/lse/fastwalk-2.4.21-rc8.diff
Thank You.
Hanna Linder
IBM Linux Technology Center
----diff -Nrup -Xdontdiff linux-2.4.21-rc8/fs/dcache.c linux-fastwalk-rc8/fs/dcache.c --- linux-2.4.21-rc8/fs/dcache.c Tue Jun 10 16:31:20 2003 +++ linux-fastwalk-rc8/fs/dcache.c Tue Jun 10 16:34:12 2003 @@ -702,13 +702,25 @@ static inline struct list_head * d_hash( struct dentry * d_lookup(struct dentry * parent, struct qstr * name) { + struct dentry *dentry = NULL; + + spin_lock(&dcache_lock); + dentry = __d_lookup(parent,name); + if (dentry) + __dget_locked(dentry); + spin_unlock(&dcache_lock); + return dentry; +} + +struct dentry * __d_lookup(struct dentry * parent, struct qstr * name) +{ + unsigned int len = name->len; unsigned int hash = name->hash; const unsigned char *str = name->name; struct list_head *head = d_hash(parent,hash); struct list_head *tmp; - spin_lock(&dcache_lock); tmp = head->next; for (;;) { struct dentry * dentry = list_entry(tmp, struct dentry, d_hash); @@ -728,12 +740,9 @@ struct dentry * d_lookup(struct dentry * if (memcmp(dentry->d_name.name, str, len)) continue; } - __dget_locked(dentry); dentry->d_vfs_flags |= DCACHE_REFERENCED; - spin_unlock(&dcache_lock); return dentry; } - spin_unlock(&dcache_lock); return NULL; } diff -Nrup -Xdontdiff linux-2.4.21-rc8/fs/intermezzo/journal.c linux-fastwalk-rc8/fs/intermezzo/journal.c --- linux-2.4.21-rc8/fs/intermezzo/journal.c Thu Nov 28 15:53:15 2002 +++ linux-fastwalk-rc8/fs/intermezzo/journal.c Tue Jun 10 16:34:12 2003 @@ -617,8 +617,7 @@ int izo_lookup_file(struct presto_file_s CDEBUG(D_CACHE, "looking up: %s\n", path); - if (path_init(path, LOOKUP_PARENT, nd)) - error = path_walk(path, nd); + error = path_lookup(path, LOOKUP_PARENT, nd); if (error) { EXIT; return error; diff -Nrup -Xdontdiff linux-2.4.21-rc8/fs/intermezzo/presto.c linux-fastwalk-rc8/fs/intermezzo/presto.c --- linux-2.4.21-rc8/fs/intermezzo/presto.c Thu Nov 28 15:53:15 2002 +++ linux-fastwalk-rc8/fs/intermezzo/presto.c Tue Jun 10 16:34:12 2003 @@ -53,8 +53,7 @@ int presto_walk(const char *name, struct ENTRY; err = 0; - if (path_init(name, flags, nd)) - err = path_walk(name, nd); + err = path_lookup(name, flags, nd); return err; } diff -Nrup -Xdontdiff linux-2.4.21-rc8/fs/intermezzo/vfs.c linux-fastwalk-rc8/fs/intermezzo/vfs.c --- linux-2.4.21-rc8/fs/intermezzo/vfs.c Tue Jun 10 16:31:21 2003 +++ linux-fastwalk-rc8/fs/intermezzo/vfs.c Tue Jun 10 16:34:12 2003 @@ -702,8 +702,7 @@ int lento_create(const char *name, int m /* this looks up the parent */ // if (path_init(pathname, LOOKUP_FOLLOW | LOOKUP_POSITIVE, &nd)) - if (path_init(pathname, LOOKUP_PARENT, &nd)) - error = path_walk(pathname, &nd); + error = path_lookup(pathname, LOOKUP_PARENT, &nd); if (error) { EXIT; goto exit; @@ -855,12 +854,10 @@ int lento_link(const char * oldname, con struct nameidata nd, old_nd; error = 0; - if (path_init(from, LOOKUP_POSITIVE, &old_nd)) - error = path_walk(from, &old_nd); + error = path_lookup(from, LOOKUP_POSITIVE, &old_nd); if (error) goto exit; - if (path_init(to, LOOKUP_PARENT, &nd)) - error = path_walk(to, &nd); + error = path_lookup(to, LOOKUP_PARENT, &nd); if (error) goto out; error = -EXDEV; @@ -1062,8 +1059,7 @@ int lento_unlink(const char *pathname, s if(IS_ERR(name)) return PTR_ERR(name); - if (path_init(name, LOOKUP_PARENT, &nd)) - error = path_walk(name, &nd); + error = path_lookup(name, LOOKUP_PARENT, &nd); if (error) goto exit; error = -EISDIR; @@ -1223,8 +1219,7 @@ int lento_symlink(const char *oldname, c goto exit_from; } - if (path_init(to, LOOKUP_PARENT, &nd)) - error = path_walk(to, &nd); + error = path_lookup(to, LOOKUP_PARENT, &nd); if (error) { EXIT; goto exit_to; @@ -1381,8 +1376,7 @@ int lento_mkdir(const char *name, int mo return error; } - if (path_init(pathname, LOOKUP_PARENT, &nd)) - error = path_walk(pathname, &nd); + error = path_lookup(pathname, LOOKUP_PARENT, &nd); if (error) goto out_name; @@ -1527,8 +1521,7 @@ int lento_rmdir(const char *pathname, st return PTR_ERR(name); } - if (path_init(name, LOOKUP_PARENT, &nd)) - error = path_walk(name, &nd); + error = path_lookup(name, LOOKUP_PARENT, &nd); if (error) { EXIT; goto exit; @@ -1693,8 +1686,7 @@ int lento_mknod(const char *filename, in if (IS_ERR(tmp)) return PTR_ERR(tmp); - if (path_init(tmp, LOOKUP_PARENT, &nd)) - error = path_walk(tmp, &nd); + error = path_lookup(tmp, LOOKUP_PARENT, &nd); if (error) goto out; dentry = lookup_create(&nd, 0); @@ -1973,14 +1965,11 @@ int lento_do_rename(const char *oldname, ENTRY; - if (path_init(oldname, LOOKUP_PARENT, &oldnd)) - error = path_walk(oldname, &oldnd); - + error = path_lookup(oldname, LOOKUP_PARENT, &oldnd); if (error) goto exit; - if (path_init(newname, LOOKUP_PARENT, &newnd)) - error = path_walk(newname, &newnd); + error = path_lookup(newname, LOOKUP_PARENT, &newnd); if (error) goto exit1; diff -Nrup -Xdontdiff linux-2.4.21-rc8/fs/namei.c linux-fastwalk-rc8/fs/namei.c --- linux-2.4.21-rc8/fs/namei.c Tue Jun 10 16:31:25 2003 +++ linux-fastwalk-rc8/fs/namei.c Tue Jun 10 16:34:12 2003 @@ -263,7 +263,7 @@ void path_release(struct nameidata *nd) static struct dentry * cached_lookup(struct dentry * parent, struct qstr * name, int flags) { struct dentry * dentry = d_lookup(parent, name); - + if (dentry && dentry->d_op && dentry->d_op->d_revalidate) { if (!dentry->d_op->d_revalidate(dentry, flags) && !d_invalidate(dentry)) { dput(dentry); @@ -273,6 +273,61 @@ static struct dentry * cached_lookup(str return dentry; } +/*for fastwalking*/ +static inline void unlock_nd(struct nameidata *nd) +{ + struct vfsmount *mnt = nd->old_mnt; + struct dentry *dentry = nd->old_dentry; + mntget(nd->mnt); + dget_locked(nd->dentry); + nd->old_mnt = NULL; + nd->old_dentry = NULL; + spin_unlock(&dcache_lock); + dput(dentry); + mntput(mnt); +} + +static inline void lock_nd(struct nameidata *nd) +{ + spin_lock(&dcache_lock); + nd->old_mnt = nd->mnt; + nd->old_dentry = nd->dentry; +} + +/* + * Short-cut version of permission(), for calling by + * path_walk(), when dcache lock is held. Combines parts + * of permission() and vfs_permission(), and tests ONLY for + * MAY_EXEC permission. + * + * If appropriate, check DAC only. If not appropriate, or + * short-cut DAC fails, then call permission() to do more + * complete permission check. + */ +static inline int exec_permission_lite(struct inode *inode) +{ + umode_t mode = inode->i_mode; + + if ((inode->i_op && inode->i_op->permission)) + return -EAGAIN; + + if (current->fsuid == inode->i_uid) + mode >>= 6; + else if (in_group_p(inode->i_gid)) + mode >>= 3; + + if (mode & MAY_EXEC) + return 0; + + if ((inode->i_mode & S_IXUGO) && capable(CAP_DAC_OVERRIDE)) + return 0; + + if (S_ISDIR(inode->i_mode) && capable(CAP_DAC_READ_SEARCH)) + return 0; + + return -EACCES; +} + /* * This is called when everything else fails, and we actually have * to go to the low-level filesystem to find out what we should do.. @@ -354,10 +409,10 @@ loop: return -ELOOP; } -static inline int __follow_up(struct vfsmount **mnt, struct dentry **base) +int follow_up(struct vfsmount **mnt, struct dentry **dentry) { struct vfsmount *parent; - struct dentry *dentry; + struct dentry *mountpoint; spin_lock(&dcache_lock); parent=(*mnt)->mnt_parent; if (parent == *mnt) { @@ -365,18 +420,27 @@ static inline int __follow_up(struct vfs return 0; } mntget(parent); - dentry=dget((*mnt)->mnt_mountpoint); + mountpoint=dget((*mnt)->mnt_mountpoint); spin_unlock(&dcache_lock); - dput(*base); - *base = dentry; + dput(*dentry); + *dentry = mountpoint; mntput(*mnt); *mnt = parent; return 1; } -int follow_up(struct vfsmount **mnt, struct dentry **dentry) +static int follow_mount(struct vfsmount **mnt, struct dentry **dentry) { - return __follow_up(mnt, dentry); + int res = 0; + while (d_mountpoint(*dentry)) { + struct vfsmount *mounted = lookup_mnt(*mnt, *dentry); + if (!mounted) + break; + *mnt = mounted; + *dentry = mounted->mnt_root; + res = 1; + } + return res; } static inline int __follow_down(struct vfsmount **mnt, struct dentry **dentry) @@ -402,41 +466,83 @@ int follow_down(struct vfsmount **mnt, s return __follow_down(mnt,dentry); } -static inline void follow_dotdot(struct nameidata *nd) +static inline void follow_dotdot(struct vfsmount **mnt, struct dentry **dentry) { while(1) { struct vfsmount *parent; - struct dentry *dentry; - read_lock(¤t->fs->lock); - if (nd->dentry == current->fs->root && - nd->mnt == current->fs->rootmnt) { - read_unlock(¤t->fs->lock); + if (*dentry == current->fs->root && + *mnt == current->fs->rootmnt) break; - } - read_unlock(¤t->fs->lock); - spin_lock(&dcache_lock); - if (nd->dentry != nd->mnt->mnt_root) { - dentry = dget(nd->dentry->d_parent); - spin_unlock(&dcache_lock); - dput(nd->dentry); - nd->dentry = dentry; + if (*dentry != (*mnt)->mnt_root) { + *dentry = (*dentry)->d_parent; break; } - parent=nd->mnt->mnt_parent; - if (parent == nd->mnt) { - spin_unlock(&dcache_lock); + parent=(*mnt)->mnt_parent; + if (parent == *mnt) break; - } - mntget(parent); - dentry=dget(nd->mnt->mnt_mountpoint); - spin_unlock(&dcache_lock); - dput(nd->dentry); - nd->dentry = dentry; - mntput(nd->mnt); - nd->mnt = parent; + *dentry=(*mnt)->mnt_mountpoint; + *mnt = parent; } - while (d_mountpoint(nd->dentry) && __follow_down(&nd->mnt, &nd->dentry)) - ; + follow_mount(mnt, dentry); +} + +struct path { + struct vfsmount *mnt; + struct dentry *dentry; +}; + +/* + * It's more convoluted than I'd like it to be, but... it's still fairly + * small and for now I'd prefer to have fast path as straight as possible. + * It _is_ time-critical. + */ +static int do_lookup(struct nameidata *nd, struct qstr *name, + struct path *path, struct path *cached_path, + int flags) +{ + struct vfsmount *mnt = nd->mnt; + struct dentry *dentry = __d_lookup(nd->dentry, name); + + if (!dentry) + goto dcache_miss; + if (dentry->d_op && dentry->d_op->d_revalidate) + goto need_revalidate; +done: + path->mnt = mnt; + path->dentry = dentry; + return 0; + +dcache_miss: + unlock_nd(nd); + +need_lookup: + dentry = real_lookup(nd->dentry, name, LOOKUP_CONTINUE); + if (IS_ERR(dentry)) + goto fail; + mntget(mnt); +relock: + dput(cached_path->dentry); + mntput(cached_path->mnt); + cached_path->mnt = mnt; + cached_path->dentry = dentry; + lock_nd(nd); + goto done; + +need_revalidate: + mntget(mnt); + dget_locked(dentry); + unlock_nd(nd); + if (dentry->d_op->d_revalidate(dentry, flags)) + goto relock; + if (d_invalidate(dentry)) + goto relock; + dput(dentry); + mntput(mnt); + goto need_lookup; + +fail: + lock_nd(nd); + return PTR_ERR(dentry); } /* @@ -449,15 +555,15 @@ static inline void follow_dotdot(struct */ int link_path_walk(const char * name, struct nameidata *nd) { - struct dentry *dentry; + struct path next, pinned = {NULL, NULL}; struct inode *inode; int err; unsigned int lookup_flags = nd->flags; - + while (*name=='/') name++; if (!*name) - goto return_reval; + goto return_base; inode = nd->dentry->d_inode; if (current->link_count) @@ -469,8 +575,12 @@ int link_path_walk(const char * name, st struct qstr this; unsigned int c; - err = permission(inode, MAY_EXEC); - dentry = ERR_PTR(err); + err = exec_permission_lite(inode); + if (err == -EAGAIN) { + unlock_nd(nd); + err = permission(inode, MAY_EXEC); + lock_nd(nd); + } if (err) break; @@ -504,7 +614,7 @@ int link_path_walk(const char * name, st case 2: if (this.name[1] != '.') break; - follow_dotdot(nd); + follow_dotdot(&nd->mnt, &nd->dentry); inode = nd->dentry->d_inode; /* fallthrough */ case 1: @@ -520,30 +630,30 @@ int link_path_walk(const char * name, st break; } /* This does the actual lookups.. */ - dentry = cached_lookup(nd->dentry, &this, LOOKUP_CONTINUE); - if (!dentry) { - dentry = real_lookup(nd->dentry, &this, LOOKUP_CONTINUE); - err = PTR_ERR(dentry); - if (IS_ERR(dentry)) - break; - } + err = do_lookup(nd, &this, &next, &pinned, LOOKUP_CONTINUE); + if (err) + break; /* Check mountpoints.. */ - while (d_mountpoint(dentry) && __follow_down(&nd->mnt, &dentry)) - ; + follow_mount(&next.mnt, &next.dentry); err = -ENOENT; - inode = dentry->d_inode; + inode = next.dentry->d_inode; if (!inode) - goto out_dput; + break; err = -ENOTDIR; if (!inode->i_op) - goto out_dput; + break; if (inode->i_op->follow_link) { - err = do_follow_link(dentry, nd); - dput(dentry); + mntget(next.mnt); + dget_locked(next.dentry); + unlock_nd(nd); + err = do_follow_link(next.dentry, nd); + dput(next.dentry); + mntput(next.mnt); if (err) goto return_err; + lock_nd(nd); err = -ENOENT; inode = nd->dentry->d_inode; if (!inode) @@ -552,8 +662,8 @@ int link_path_walk(const char * name, st if (!inode->i_op) break; } else { - dput(nd->dentry); - nd->dentry = dentry; + nd->mnt = next.mnt; + nd->dentry = next.dentry; } err = -ENOTDIR; if (!inode->i_op->lookup) @@ -572,52 +682,47 @@ last_component: case 2: if (this.name[1] != '.') break; - follow_dotdot(nd); + follow_dotdot(&nd->mnt, &nd->dentry); inode = nd->dentry->d_inode; /* fallthrough */ case 1: - goto return_reval; + goto return_base; } if (nd->dentry->d_op && nd->dentry->d_op->d_hash) { err = nd->dentry->d_op->d_hash(nd->dentry, &this); if (err < 0) break; } - dentry = cached_lookup(nd->dentry, &this, 0); - if (!dentry) { - dentry = real_lookup(nd->dentry, &this, 0); - err = PTR_ERR(dentry); - if (IS_ERR(dentry)) - break; - } - while (d_mountpoint(dentry) && __follow_down(&nd->mnt, &dentry)) - ; - inode = dentry->d_inode; + err = do_lookup(nd, &this, &next, &pinned, 0); + if (err) + break; + follow_mount(&next.mnt, &next.dentry); + inode = next.dentry->d_inode; if ((lookup_flags & LOOKUP_FOLLOW) && inode && inode->i_op && inode->i_op->follow_link) { - err = do_follow_link(dentry, nd); - dput(dentry); + mntget(next.mnt); + dget_locked(next.dentry); + unlock_nd(nd); + err = do_follow_link(next.dentry, nd); + dput(next.dentry); + mntput(next.mnt); if (err) goto return_err; inode = nd->dentry->d_inode; + lock_nd(nd); } else { - dput(nd->dentry); - nd->dentry = dentry; + nd->mnt = next.mnt; + nd->dentry = next.dentry; } err = -ENOENT; if (!inode) - goto no_inode; + break; if (lookup_flags & LOOKUP_DIRECTORY) { err = -ENOTDIR; if (!inode->i_op || !inode->i_op->lookup) break; } goto return_base; -no_inode: - err = -ENOENT; - if (lookup_flags & (LOOKUP_POSITIVE|LOOKUP_DIRECTORY)) - break; - goto return_base; lookup_parent: nd->last = this; nd->last_type = LAST_NORM; @@ -627,33 +732,24 @@ lookup_parent: nd->last_type = LAST_DOT; else if (this.len == 2 && this.name[1] == '.') nd->last_type = LAST_DOTDOT; -return_reval: - /* - * We bypassed the ordinary revalidation routines. - * Check the cached dentry for staleness. - */ - dentry = nd->dentry; - if (dentry && dentry->d_op && dentry->d_op->d_revalidate) { - err = -ESTALE; - if (!dentry->d_op->d_revalidate(dentry, 0)) { - d_invalidate(dentry); - break; - } - } return_base: + unlock_nd(nd); + dput(pinned.dentry); + mntput(pinned.mnt); return 0; -out_dput: - dput(dentry); - break; } + unlock_nd(nd); path_release(nd); return_err: + dput(pinned.dentry); + mntput(pinned.mnt); return err; } int path_walk(const char * name, struct nameidata *nd) { current->total_link_count = 0; + lock_nd(nd); return link_path_walk(name, nd); } @@ -738,28 +834,35 @@ walk_init_root(const char *name, struct return 1; } -/* SMP-safe */ -int path_lookup(const char *path, unsigned flags, struct nameidata *nd) -{ - int error = 0; - if (path_init(path, flags, nd)) - error = path_walk(path, nd); - return error; -} - -/* SMP-safe */ -int path_init(const char *name, unsigned int flags, struct nameidata *nd) +int path_lookup(const char *name, unsigned int flags, struct nameidata *nd) { nd->last_type = LAST_ROOT; /* if there are only slashes... */ nd->flags = flags; - if (*name=='/') - return walk_init_root(name,nd); - read_lock(¤t->fs->lock); - nd->mnt = mntget(current->fs->pwdmnt); - nd->dentry = dget(current->fs->pwd); - read_unlock(¤t->fs->lock); - return 1; + if (*name=='/') { + read_lock(¤t->fs->lock); + if (current->fs->altroot && !(nd->flags & LOOKUP_NOALT)) { + nd->mnt = mntget(current->fs->altrootmnt); + nd->dentry = dget(current->fs->altroot); + read_unlock(¤t->fs->lock); + if (__emul_lookup_dentry(name,nd)) + return 0; + read_lock(¤t->fs->lock); + } + read_unlock(¤t->fs->lock); + spin_lock(&dcache_lock); + nd->mnt = current->fs->rootmnt; + nd->dentry = current->fs->root; + } + else{ + spin_lock(&dcache_lock); + nd->mnt = current->fs->pwdmnt; + nd->dentry = current->fs->pwd; + } + nd->old_mnt = NULL; + nd->old_dentry = NULL; + current->total_link_count = 0; + return link_path_walk(name, nd); } /* @@ -1964,6 +2067,7 @@ __vfs_follow_link(struct nameidata *nd, /* weird __emul_prefix() stuff did it */ goto out; } + lock_nd(nd); res = link_path_walk(link, nd); out: if (current->link_count || res || nd->last_type!=LAST_NORM) diff -Nrup -Xdontdiff linux-2.4.21-rc8/fs/namespace.c linux-fastwalk-rc8/fs/namespace.c --- linux-2.4.21-rc8/fs/namespace.c Tue Jun 10 16:31:25 2003 +++ linux-fastwalk-rc8/fs/namespace.c Tue Jun 10 16:34:12 2003 @@ -23,6 +23,7 @@ struct vfsmount *do_kern_mount(const char *type, int flags, char *name, void *data); int do_remount_sb(struct super_block *sb, int flags, void * data); +int __init init_rootfs(void); void kill_super(struct super_block *sb); extern int __init init_rootfs(void); diff -Nrup -Xdontdiff linux-2.4.21-rc8/fs/nfsd/export.c linux-fastwalk-rc8/fs/nfsd/export.c --- linux-2.4.21-rc8/fs/nfsd/export.c Thu Nov 28 15:53:15 2002 +++ linux-fastwalk-rc8/fs/nfsd/export.c Tue Jun 10 16:34:12 2003 @@ -214,8 +214,7 @@ exp_export(struct nfsctl_export *nxp) /* Look up the dentry */ err = 0; - if (path_init(nxp->ex_path, LOOKUP_POSITIVE, &nd)) - err = path_walk(nxp->ex_path, &nd); + err = path_lookup(nxp->ex_path, LOOKUP_POSITIVE, &nd); if (err) goto out_unlock; @@ -411,8 +410,7 @@ exp_rootfh(struct svc_client *clp, kdev_ err = -EPERM; if (path) { - if (path_init(path, LOOKUP_POSITIVE, &nd) && - path_walk(path, &nd)) { + if (path_lookup(path, LOOKUP_POSITIVE, &nd)) { printk("nfsd: exp_rootfh path not found %s", path); return err; } diff -Nrup -Xdontdiff linux-2.4.21-rc8/include/linux/dcache.h linux-fastwalk-rc8/include/linux/dcache.h --- linux-2.4.21-rc8/include/linux/dcache.h Thu Nov 28 15:53:15 2002 +++ linux-fastwalk-rc8/include/linux/dcache.h Tue Jun 10 16:34:12 2003 @@ -219,6 +219,7 @@ extern void d_move(struct dentry *, stru /* appendix may either be NULL or be used for transname suffixes */ extern struct dentry * d_lookup(struct dentry *, struct qstr *); +extern struct dentry * __d_lookup(struct dentry *, struct qstr *); /* validate "insecure" dentry pointer */ extern int d_validate(struct dentry *, struct dentry *); diff -Nrup -Xdontdiff linux-2.4.21-rc8/include/linux/fs.h linux-fastwalk-rc8/include/linux/fs.h --- linux-2.4.21-rc8/include/linux/fs.h Tue Jun 10 16:31:59 2003 +++ linux-fastwalk-rc8/include/linux/fs.h Tue Jun 10 16:34:12 2003 @@ -658,6 +658,8 @@ struct nameidata { struct qstr last; unsigned int flags; int last_type; + struct dentry *old_dentry; + struct vfsmount *old_mnt; }; #define DQUOT_USR_ENABLED 0x01 /* User diskquotas enabled */ @@ -1326,6 +1328,7 @@ static inline long IS_ERR(const void *pt * - require a directory * - ending slashes ok even for nonexistent files * - internal "there are more path compnents" flag + * - locked when lookup done with dcache_lock held */ #define LOOKUP_FOLLOW (1) #define LOOKUP_DIRECTORY (2) @@ -1333,6 +1336,7 @@ static inline long IS_ERR(const void *pt #define LOOKUP_POSITIVE (8) #define LOOKUP_PARENT (16) #define LOOKUP_NOALT (32) + /* * Type of the last component on LOOKUP_PARENT */ @@ -1360,7 +1364,6 @@ typedef int (*read_actor_t)(read_descrip extern loff_t default_llseek(struct file *file, loff_t offset, int origin); extern int FASTCALL(__user_walk(const char *, unsigned, struct nameidata *)); -extern int FASTCALL(path_init(const char *, unsigned, struct nameidata *)); extern int FASTCALL(path_walk(const char *, struct nameidata *)); extern int FASTCALL(path_lookup(const char *, unsigned, struct nameidata *)); extern int FASTCALL(link_path_walk(const char *, struct nameidata *)); diff -Nrup -Xdontdiff linux-2.4.21-rc8/include/linux/fs_struct.h linux-fastwalk-rc8/include/linux/fs_struct.h --- linux-2.4.21-rc8/include/linux/fs_struct.h Fri Jul 13 15:10:44 2001 +++ linux-fastwalk-rc8/include/linux/fs_struct.h Tue Jun 10 16:34:12 2003 @@ -32,10 +32,12 @@ static inline void set_fs_root(struct fs struct dentry *old_root; struct vfsmount *old_rootmnt; write_lock(&fs->lock); + spin_lock(&dcache_lock); old_root = fs->root; old_rootmnt = fs->rootmnt; fs->rootmnt = mntget(mnt); fs->root = dget(dentry); + spin_unlock(&dcache_lock); write_unlock(&fs->lock); if (old_root) { dput(old_root); @@ -55,10 +57,12 @@ static inline void set_fs_pwd(struct fs_ struct dentry *old_pwd; struct vfsmount *old_pwdmnt; write_lock(&fs->lock); + spin_lock(&dcache_lock); old_pwd = fs->pwd; old_pwdmnt = fs->pwdmnt; fs->pwdmnt = mntget(mnt); fs->pwd = dget(dentry); + spin_unlock(&dcache_lock); write_unlock(&fs->lock); if (old_pwd) { dput(old_pwd); diff -Nrup -Xdontdiff linux-2.4.21-rc8/kernel/ksyms.c linux-fastwalk-rc8/kernel/ksyms.c --- linux-2.4.21-rc8/kernel/ksyms.c Tue Jun 10 16:32:05 2003 +++ linux-fastwalk-rc8/kernel/ksyms.c Tue Jun 10 16:34:12 2003 @@ -148,8 +148,8 @@ EXPORT_SYMBOL(force_delete); EXPORT_SYMBOL(follow_up); EXPORT_SYMBOL(follow_down); EXPORT_SYMBOL(lookup_mnt); -EXPORT_SYMBOL(path_init); EXPORT_SYMBOL(path_walk); +EXPORT_SYMBOL(path_lookup); EXPORT_SYMBOL(path_release); EXPORT_SYMBOL(__user_walk); EXPORT_SYMBOL(lookup_one_len); diff -Nrup -Xdontdiff linux-2.4.21-rc8/net/unix/af_unix.c linux-fastwalk-rc8/net/unix/af_unix.c --- linux-2.4.21-rc8/net/unix/af_unix.c Thu Nov 28 15:53:16 2002 +++ linux-fastwalk-rc8/net/unix/af_unix.c Tue Jun 10 16:34:12 2003 @@ -590,9 +590,8 @@ static unix_socket *unix_find_other(stru int err = 0; if (sunname->sun_path[0]) { - if (path_init(sunname->sun_path, - LOOKUP_POSITIVE|LOOKUP_FOLLOW, &nd)) - err = path_walk(sunname->sun_path, &nd); + err = path_lookup(sunname->sun_path, + LOOKUP_POSITIVE|LOOKUP_FOLLOW, &nd); if (err) goto fail; err = permission(nd.dentry->d_inode,MAY_WRITE); @@ -685,8 +684,7 @@ static int unix_bind(struct socket *sock * Get the parent directory, calculate the hash for last * component. */ - if (path_init(sunaddr->sun_path, LOOKUP_PARENT, &nd)) - err = path_walk(sunaddr->sun_path, &nd); + err = path_lookup(sunaddr->sun_path, LOOKUP_PARENT, &nd); if (err) goto out_mknod_parent; /*
- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
This archive was generated by hypermail 2b29 : Sun Jun 15 2003 - 22:00:26 EST
