From 4e44b6852e03c915618ca6776b6697b436246b00 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Tue, 7 Apr 2009 11:08:56 -0400 Subject: [PATCH] Get rid of path_lookup in autofs4 Signed-off-by: Al Viro --- fs/autofs4/dev-ioctl.c | 195 +++++++++++++---------------------------- 1 file changed, 60 insertions(+), 135 deletions(-) diff --git a/fs/autofs4/dev-ioctl.c b/fs/autofs4/dev-ioctl.c index 84168c0dcc2d..f71dac9986f0 100644 --- a/fs/autofs4/dev-ioctl.c +++ b/fs/autofs4/dev-ioctl.c @@ -192,77 +192,42 @@ static int autofs_dev_ioctl_protosubver(struct file *fp, return 0; } -/* - * Walk down the mount stack looking for an autofs mount that - * has the requested device number (aka. new_encode_dev(sb->s_dev). - */ -static int autofs_dev_ioctl_find_super(struct nameidata *nd, dev_t devno) +static int find_autofs_mount(const char *pathname, + struct path *res, + int test(struct path *path, void *data), + void *data) { - struct dentry *dentry; - struct inode *inode; - struct super_block *sb; - dev_t s_dev; - unsigned int err; - + struct path path; + int err = kern_path(pathname, 0, &path); + if (err) + return err; err = -ENOENT; - - /* Lookup the dentry name at the base of our mount point */ - dentry = d_lookup(nd->path.dentry, &nd->last); - if (!dentry) - goto out; - - dput(nd->path.dentry); - nd->path.dentry = dentry; - - /* And follow the mount stack looking for our autofs mount */ - while (follow_down(&nd->path.mnt, &nd->path.dentry)) { - inode = nd->path.dentry->d_inode; - if (!inode) - break; - - sb = inode->i_sb; - s_dev = new_encode_dev(sb->s_dev); - if (devno == s_dev) { - if (sb->s_magic == AUTOFS_SUPER_MAGIC) { + while (path.dentry == path.mnt->mnt_root) { + if (path.mnt->mnt_sb->s_magic == AUTOFS_SUPER_MAGIC) { + if (test(&path, data)) { + path_get(&path); + if (!err) /* already found some */ + path_put(res); + *res = path; err = 0; - break; } } + if (!follow_up(&path.mnt, &path.dentry)) + break; } -out: + path_put(&path); return err; } -/* - * Walk down the mount stack looking for an autofs mount that - * has the requested mount type (ie. indirect, direct or offset). - */ -static int autofs_dev_ioctl_find_sbi_type(struct nameidata *nd, unsigned int type) +static int test_by_dev(struct path *path, void *p) { - struct dentry *dentry; - struct autofs_info *ino; - unsigned int err; - - err = -ENOENT; - - /* Lookup the dentry name at the base of our mount point */ - dentry = d_lookup(nd->path.dentry, &nd->last); - if (!dentry) - goto out; - - dput(nd->path.dentry); - nd->path.dentry = dentry; + return path->mnt->mnt_sb->s_dev == *(dev_t *)p; +} - /* And follow the mount stack looking for our autofs mount */ - while (follow_down(&nd->path.mnt, &nd->path.dentry)) { - ino = autofs4_dentry_ino(nd->path.dentry); - if (ino && ino->sbi->type & type) { - err = 0; - break; - } - } -out: - return err; +static int test_by_type(struct path *path, void *p) +{ + struct autofs_info *ino = autofs4_dentry_ino(path->dentry); + return ino && ino->sbi->type & *(unsigned *)p; } static void autofs_dev_ioctl_fd_install(unsigned int fd, struct file *file) @@ -283,31 +248,25 @@ static void autofs_dev_ioctl_fd_install(unsigned int fd, struct file *file) * Open a file descriptor on the autofs mount point corresponding * to the given path and device number (aka. new_encode_dev(sb->s_dev)). */ -static int autofs_dev_ioctl_open_mountpoint(const char *path, dev_t devid) +static int autofs_dev_ioctl_open_mountpoint(const char *name, dev_t devid) { - struct file *filp; - struct nameidata nd; int err, fd; fd = get_unused_fd(); if (likely(fd >= 0)) { - /* Get nameidata of the parent directory */ - err = path_lookup(path, LOOKUP_PARENT, &nd); + struct file *filp; + struct path path; + + err = find_autofs_mount(name, &path, test_by_dev, &devid); if (err) goto out; /* - * Search down, within the parent, looking for an - * autofs super block that has the device number + * Find autofs super block that has the device number * corresponding to the autofs fs we want to open. */ - err = autofs_dev_ioctl_find_super(&nd, devid); - if (err) { - path_put(&nd.path); - goto out; - } - filp = dentry_open(nd.path.dentry, nd.path.mnt, O_RDONLY, + filp = dentry_open(path.dentry, path.mnt, O_RDONLY, current_cred()); if (IS_ERR(filp)) { err = PTR_ERR(filp); @@ -340,7 +299,7 @@ static int autofs_dev_ioctl_openmount(struct file *fp, param->ioctlfd = -1; path = param->path; - devid = param->openmount.devid; + devid = new_decode_dev(param->openmount.devid); err = 0; fd = autofs_dev_ioctl_open_mountpoint(path, devid); @@ -475,8 +434,7 @@ static int autofs_dev_ioctl_requester(struct file *fp, struct autofs_dev_ioctl *param) { struct autofs_info *ino; - struct nameidata nd; - const char *path; + struct path path; dev_t devid; int err = -ENOENT; @@ -485,32 +443,24 @@ static int autofs_dev_ioctl_requester(struct file *fp, goto out; } - path = param->path; - devid = new_encode_dev(sbi->sb->s_dev); + devid = sbi->sb->s_dev; param->requester.uid = param->requester.gid = -1; - /* Get nameidata of the parent directory */ - err = path_lookup(path, LOOKUP_PARENT, &nd); + err = find_autofs_mount(param->path, &path, test_by_dev, &devid); if (err) goto out; - err = autofs_dev_ioctl_find_super(&nd, devid); - if (err) - goto out_release; - - ino = autofs4_dentry_ino(nd.path.dentry); + ino = autofs4_dentry_ino(path.dentry); if (ino) { err = 0; - autofs4_expire_wait(nd.path.dentry); + autofs4_expire_wait(path.dentry); spin_lock(&sbi->fs_lock); param->requester.uid = ino->uid; param->requester.gid = ino->gid; spin_unlock(&sbi->fs_lock); } - -out_release: - path_put(&nd.path); + path_put(&path); out: return err; } @@ -569,8 +519,8 @@ static int autofs_dev_ioctl_ismountpoint(struct file *fp, struct autofs_sb_info *sbi, struct autofs_dev_ioctl *param) { - struct nameidata nd; - const char *path; + struct path path; + const char *name; unsigned int type; unsigned int devid, magic; int err = -ENOENT; @@ -580,71 +530,46 @@ static int autofs_dev_ioctl_ismountpoint(struct file *fp, goto out; } - path = param->path; + name = param->path; type = param->ismountpoint.in.type; param->ismountpoint.out.devid = devid = 0; param->ismountpoint.out.magic = magic = 0; if (!fp || param->ioctlfd == -1) { - if (autofs_type_any(type)) { - struct super_block *sb; - - err = path_lookup(path, LOOKUP_FOLLOW, &nd); - if (err) - goto out; - - sb = nd.path.dentry->d_sb; - devid = new_encode_dev(sb->s_dev); - } else { - struct autofs_info *ino; - - err = path_lookup(path, LOOKUP_PARENT, &nd); - if (err) - goto out; - - err = autofs_dev_ioctl_find_sbi_type(&nd, type); - if (err) - goto out_release; - - ino = autofs4_dentry_ino(nd.path.dentry); - devid = autofs4_get_dev(ino->sbi); - } - + if (autofs_type_any(type)) + err = kern_path(name, LOOKUP_FOLLOW, &path); + else + err = find_autofs_mount(name, &path, test_by_type, &type); + if (err) + goto out; + devid = new_encode_dev(path.mnt->mnt_sb->s_dev); err = 0; - if (nd.path.dentry->d_inode && - nd.path.mnt->mnt_root == nd.path.dentry) { + if (path.dentry->d_inode && + path.mnt->mnt_root == path.dentry) { err = 1; - magic = nd.path.dentry->d_inode->i_sb->s_magic; + magic = path.dentry->d_inode->i_sb->s_magic; } } else { - dev_t dev = autofs4_get_dev(sbi); + dev_t dev = sbi->sb->s_dev; - err = path_lookup(path, LOOKUP_PARENT, &nd); + err = find_autofs_mount(name, &path, test_by_dev, &dev); if (err) goto out; - err = autofs_dev_ioctl_find_super(&nd, dev); - if (err) - goto out_release; - - devid = dev; + devid = new_encode_dev(dev); - err = have_submounts(nd.path.dentry); + err = have_submounts(path.dentry); - if (nd.path.mnt->mnt_mountpoint != nd.path.mnt->mnt_root) { - if (follow_down(&nd.path.mnt, &nd.path.dentry)) { - struct inode *inode = nd.path.dentry->d_inode; - magic = inode->i_sb->s_magic; - } + if (path.mnt->mnt_mountpoint != path.mnt->mnt_root) { + if (follow_down(&path.mnt, &path.dentry)) + magic = path.mnt->mnt_sb->s_magic; } } param->ismountpoint.out.devid = devid; param->ismountpoint.out.magic = magic; - -out_release: - path_put(&nd.path); + path_put(&path); out: return err; } -- 2.30.2