X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=fs%2Fnamei.c;h=868d0cb9d473a92ccdcbe640ac44f4daf24cce62;hb=75de46b98dda624397ccb17c106e51f478a79c15;hp=941c8e8228c041d90652313f13e72f2b6e975716;hpb=6ac08c39a16f72c2d3e845cb6849a1392fa03e80;p=safe%2Fjmp%2Flinux-2.6 diff --git a/fs/namei.c b/fs/namei.c index 941c8e8..868d0cb 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -19,21 +19,22 @@ #include #include #include -#include #include #include #include #include +#include #include #include #include #include #include #include -#include +#include +#include #include -#define ACC_MODE(x) ("\000\004\002\006"[(x)&O_ACCMODE]) +#include "internal.h" /* [Feb-1997 T. Schoebel-Theuer] * Fundamental changes in the pathname lookup mechanisms (namei) @@ -106,8 +107,6 @@ * any extra contention... */ -static int link_path_walk(const char *name, struct nameidata *nd); - /* In order to reduce some races, while at the same time doing additional * checking and hopefully speeding things up, we copy filenames to the * kernel data space before using them.. @@ -167,31 +166,22 @@ void putname(const char *name) EXPORT_SYMBOL(putname); #endif - -/** - * generic_permission - check for access rights on a Posix-like filesystem - * @inode: inode to check access rights for - * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) - * @check_acl: optional callback to check for Posix ACLs - * - * Used to check for read/write/execute permissions on a file. - * We use "fsuid" for this, letting us set arbitrary permissions - * for filesystem access without changing the "normal" uids which - * are used for other things.. +/* + * This does basic POSIX ACL permission checking */ -int generic_permission(struct inode *inode, int mask, +static int acl_permission_check(struct inode *inode, int mask, int (*check_acl)(struct inode *inode, int mask)) { umode_t mode = inode->i_mode; - if (current->fsuid == inode->i_uid) + mask &= MAY_READ | MAY_WRITE | MAY_EXEC; + + if (current_fsuid() == inode->i_uid) mode >>= 6; else { if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) { int error = check_acl(inode, mask); - if (error == -EACCES) - goto check_capabilities; - else if (error != -EAGAIN) + if (error != -EAGAIN) return error; } @@ -202,22 +192,46 @@ int generic_permission(struct inode *inode, int mask, /* * If the DACs are ok we don't need any capability check. */ - if (((mode & mask & (MAY_READ|MAY_WRITE|MAY_EXEC)) == mask)) + if ((mask & ~mode) == 0) return 0; + return -EACCES; +} + +/** + * generic_permission - check for access rights on a Posix-like filesystem + * @inode: inode to check access rights for + * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) + * @check_acl: optional callback to check for Posix ACLs + * + * Used to check for read/write/execute permissions on a file. + * We use "fsuid" for this, letting us set arbitrary permissions + * for filesystem access without changing the "normal" uids which + * are used for other things.. + */ +int generic_permission(struct inode *inode, int mask, + int (*check_acl)(struct inode *inode, int mask)) +{ + int ret; + + /* + * Do the basic POSIX ACL permission checks. + */ + ret = acl_permission_check(inode, mask, check_acl); + if (ret != -EACCES) + return ret; - check_capabilities: /* * Read/write DACs are always overridable. * Executable DACs are overridable if at least one exec bit is set. */ - if (!(mask & MAY_EXEC) || - (inode->i_mode & S_IXUGO) || S_ISDIR(inode->i_mode)) + if (!(mask & MAY_EXEC) || execute_ok(inode)) if (capable(CAP_DAC_OVERRIDE)) return 0; /* * Searching includes executable on directories, else just read. */ + mask &= MAY_READ | MAY_WRITE | MAY_EXEC; if (mask == MAY_READ || (S_ISDIR(inode->i_mode) && !(mask & MAY_WRITE))) if (capable(CAP_DAC_READ_SEARCH)) return 0; @@ -225,13 +239,19 @@ int generic_permission(struct inode *inode, int mask, return -EACCES; } -int permission(struct inode *inode, int mask, struct nameidata *nd) +/** + * inode_permission - check for access rights to a given inode + * @inode: inode to check permission on + * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) + * + * Used to check for read/write/execute permissions on an inode. + * We use "fsuid" for this, letting us set arbitrary permissions + * for filesystem access without changing the "normal" uids which + * are used for other things. + */ +int inode_permission(struct inode *inode, int mask) { - int retval, submask; - struct vfsmount *mnt = NULL; - - if (nd) - mnt = nd->path.mnt; + int retval; if (mask & MAY_WRITE) { umode_t mode = inode->i_mode; @@ -250,53 +270,20 @@ int permission(struct inode *inode, int mask, struct nameidata *nd) return -EACCES; } - if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) { - /* - * MAY_EXEC on regular files is denied if the fs is mounted - * with the "noexec" flag. - */ - if (mnt && (mnt->mnt_flags & MNT_NOEXEC)) - return -EACCES; - } + if (inode->i_op->permission) + retval = inode->i_op->permission(inode, mask); + else + retval = generic_permission(inode, mask, inode->i_op->check_acl); - /* Ordinary permission routines do not understand MAY_APPEND. */ - submask = mask & ~MAY_APPEND; - if (inode->i_op && inode->i_op->permission) { - retval = inode->i_op->permission(inode, submask, nd); - if (!retval) { - /* - * Exec permission on a regular file is denied if none - * of the execute bits are set. - * - * This check should be done by the ->permission() - * method. - */ - if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode) && - !(inode->i_mode & S_IXUGO)) - return -EACCES; - } - } else { - retval = generic_permission(inode, submask, NULL); - } if (retval) return retval; - return security_inode_permission(inode, mask, nd); -} + retval = devcgroup_inode_permission(inode, mask); + if (retval) + return retval; -/** - * vfs_permission - check for access rights to a given path - * @nd: lookup result that describes the path - * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) - * - * Used to check for read/write/execute permissions on a path. - * We use "fsuid" for this, letting us set arbitrary permissions - * for filesystem access without changing the "normal" uids which - * are used for other things. - */ -int vfs_permission(struct nameidata *nd, int mask) -{ - return permission(nd->path.dentry->d_inode, mask, nd); + return security_inode_permission(inode, + mask & (MAY_READ|MAY_WRITE|MAY_EXEC|MAY_APPEND)); } /** @@ -309,11 +296,11 @@ int vfs_permission(struct nameidata *nd, int mask) * * Note: * Do not use this function in new code. All access checks should - * be done using vfs_permission(). + * be done using inode_permission(). */ int file_permission(struct file *file, int mask) { - return permission(file->f_path.dentry->d_inode, mask, NULL); + return inode_permission(file->f_path.dentry->d_inode, mask); } /* @@ -425,174 +412,102 @@ do_revalidate(struct dentry *dentry, struct nameidata *nd) } /* - * Internal lookup() using the new generic dcache. - * SMP-safe + * force_reval_path - force revalidation of a dentry + * + * In some situations the path walking code will trust dentries without + * revalidating them. This causes problems for filesystems that depend on + * d_revalidate to handle file opens (e.g. NFSv4). When FS_REVAL_DOT is set + * (which indicates that it's possible for the dentry to go stale), force + * a d_revalidate call before proceeding. + * + * Returns 0 if the revalidation was successful. If the revalidation fails, + * either return the error returned by d_revalidate or -ESTALE if the + * revalidation it just returned 0. If d_revalidate returns 0, we attempt to + * invalidate the dentry. It's up to the caller to handle putting references + * to the path if necessary. */ -static struct dentry * cached_lookup(struct dentry * parent, struct qstr * name, struct nameidata *nd) +static int +force_reval_path(struct path *path, struct nameidata *nd) { - struct dentry * dentry = __d_lookup(parent, name); + int status; + struct dentry *dentry = path->dentry; - /* lockess __d_lookup may fail due to concurrent d_move() - * in some unrelated directory, so try with d_lookup + /* + * only check on filesystems where it's possible for the dentry to + * become stale. It's assumed that if this flag is set then the + * d_revalidate op will also be defined. */ - if (!dentry) - dentry = d_lookup(parent, name); + if (!(dentry->d_sb->s_type->fs_flags & FS_REVAL_DOT)) + return 0; - if (dentry && dentry->d_op && dentry->d_op->d_revalidate) - dentry = do_revalidate(dentry, nd); + status = dentry->d_op->d_revalidate(dentry, nd); + if (status > 0) + return 0; - return dentry; + if (!status) { + d_invalidate(dentry); + status = -ESTALE; + } + return status; } /* - * Short-cut version of permission(), for calling by - * path_walk(), when dcache lock is held. Combines parts - * of permission() and generic_permission(), and tests ONLY for - * MAY_EXEC permission. + * Short-cut version of permission(), for calling on directories + * during pathname resolution. Combines parts of permission() + * and generic_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 + * short-cut DAC fails, then call ->permission() to do more * complete permission check. */ -static int exec_permission_lite(struct inode *inode, - struct nameidata *nd) +static int exec_permission(struct inode *inode) { - umode_t mode = inode->i_mode; - - if (inode->i_op && inode->i_op->permission) - return -EAGAIN; + int ret; - if (current->fsuid == inode->i_uid) - mode >>= 6; - else if (in_group_p(inode->i_gid)) - mode >>= 3; - - if (mode & MAY_EXEC) - goto ok; - - if ((inode->i_mode & S_IXUGO) && capable(CAP_DAC_OVERRIDE)) - goto ok; - - if (S_ISDIR(inode->i_mode) && capable(CAP_DAC_OVERRIDE)) + if (inode->i_op->permission) { + ret = inode->i_op->permission(inode, MAY_EXEC); + if (!ret) + goto ok; + return ret; + } + ret = acl_permission_check(inode, MAY_EXEC, inode->i_op->check_acl); + if (!ret) goto ok; - if (S_ISDIR(inode->i_mode) && capable(CAP_DAC_READ_SEARCH)) + if (capable(CAP_DAC_OVERRIDE) || capable(CAP_DAC_READ_SEARCH)) goto ok; - return -EACCES; + return ret; ok: - return security_inode_permission(inode, MAY_EXEC, nd); + return security_inode_permission(inode, MAY_EXEC); } -/* - * 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.. - * - * We get the directory semaphore, and after getting that we also - * make sure that nobody added the entry to the dcache in the meantime.. - * SMP-safe - */ -static struct dentry * real_lookup(struct dentry * parent, struct qstr * name, struct nameidata *nd) +static __always_inline void set_root(struct nameidata *nd) { - struct dentry * result; - struct inode *dir = parent->d_inode; - - mutex_lock(&dir->i_mutex); - /* - * First re-do the cached lookup just in case it was created - * while we waited for the directory semaphore.. - * - * FIXME! This could use version numbering or similar to - * avoid unnecessary cache lookups. - * - * The "dcache_lock" is purely to protect the RCU list walker - * from concurrent renames at this point (we mustn't get false - * negatives from the RCU list walk here, unlike the optimistic - * fast walk). - * - * so doing d_lookup() (with seqlock), instead of lockfree __d_lookup - */ - result = d_lookup(parent, name); - if (!result) { - struct dentry * dentry = d_alloc(parent, name); - result = ERR_PTR(-ENOMEM); - if (dentry) { - result = dir->i_op->lookup(dir, dentry, nd); - if (result) - dput(dentry); - else - result = dentry; - } - mutex_unlock(&dir->i_mutex); - return result; - } - - /* - * Uhhuh! Nasty case: the cache was re-populated while - * we waited on the semaphore. Need to revalidate. - */ - mutex_unlock(&dir->i_mutex); - if (result->d_op && result->d_op->d_revalidate) { - result = do_revalidate(result, nd); - if (!result) - result = ERR_PTR(-ENOENT); - } - return result; -} - -static int __emul_lookup_dentry(const char *, struct nameidata *); - -/* SMP-safe */ -static __always_inline int -walk_init_root(const char *name, struct nameidata *nd) -{ - struct fs_struct *fs = current->fs; - - read_lock(&fs->lock); - if (fs->altroot.dentry && !(nd->flags & LOOKUP_NOALT)) { - nd->path = fs->altroot; - path_get(&fs->altroot); - read_unlock(&fs->lock); - if (__emul_lookup_dentry(name,nd)) - return 0; + if (!nd->root.mnt) { + struct fs_struct *fs = current->fs; read_lock(&fs->lock); + nd->root = fs->root; + path_get(&nd->root); + read_unlock(&fs->lock); } - nd->path = fs->root; - path_get(&fs->root); - read_unlock(&fs->lock); - return 1; } +static int link_path_walk(const char *, struct nameidata *); + static __always_inline int __vfs_follow_link(struct nameidata *nd, const char *link) { - int res = 0; - char *name; if (IS_ERR(link)) goto fail; if (*link == '/') { + set_root(nd); path_put(&nd->path); - if (!walk_init_root(link, nd)) - /* weird __emul_prefix() stuff did it */ - goto out; - } - res = link_path_walk(link, nd); -out: - if (nd->depth || res || nd->last_type!=LAST_NORM) - return res; - /* - * If it is an iterative symlinks resolution in open_namei() we - * have to copy the last component. And all that crap because of - * bloody create() on broken symlinks. Furrfu... - */ - name = __getname(); - if (unlikely(!name)) { - path_put(&nd->path); - return -ENOMEM; + nd->path = nd->root; + path_get(&nd->root); } - strcpy(name, nd->last.name); - nd->last.name = name; - return 0; + + return link_path_walk(link, nd); fail: path_put(&nd->path); return PTR_ERR(link); @@ -608,16 +523,17 @@ static void path_put_conditional(struct path *path, struct nameidata *nd) static inline void path_to_nameidata(struct path *path, struct nameidata *nd) { dput(nd->path.dentry); - if (nd->path.mnt != path->mnt) + if (nd->path.mnt != path->mnt) { mntput(nd->path.mnt); - nd->path.mnt = path->mnt; + nd->path.mnt = path->mnt; + } nd->path.dentry = path->dentry; } -static __always_inline int __do_follow_link(struct path *path, struct nameidata *nd) +static __always_inline int +__do_follow_link(struct path *path, struct nameidata *nd, void **p) { int error; - void *cookie; struct dentry *dentry = path->dentry; touch_atime(path->mnt, dentry); @@ -628,18 +544,20 @@ static __always_inline int __do_follow_link(struct path *path, struct nameidata dget(dentry); } mntget(path->mnt); - cookie = dentry->d_inode->i_op->follow_link(dentry, nd); - error = PTR_ERR(cookie); - if (!IS_ERR(cookie)) { + nd->last_type = LAST_BIND; + *p = dentry->d_inode->i_op->follow_link(dentry, nd); + error = PTR_ERR(*p); + if (!IS_ERR(*p)) { char *s = nd_get_link(nd); error = 0; if (s) error = __vfs_follow_link(nd, s); - if (dentry->d_inode->i_op->put_link) - dentry->d_inode->i_op->put_link(dentry, nd, cookie); + else if (nd->last_type == LAST_BIND) { + error = force_reval_path(&nd->path, nd); + if (error) + path_put(&nd->path); + } } - path_put(path); - return error; } @@ -652,6 +570,7 @@ static __always_inline int __do_follow_link(struct path *path, struct nameidata */ static inline int do_follow_link(struct path *path, struct nameidata *nd) { + void *cookie; int err = -ELOOP; if (current->link_count >= MAX_NESTED_LINKS) goto loop; @@ -665,7 +584,10 @@ static inline int do_follow_link(struct path *path, struct nameidata *nd) current->link_count++; current->total_link_count++; nd->depth++; - err = __do_follow_link(path, nd); + err = __do_follow_link(path, nd, &cookie); + if (!IS_ERR(cookie) && path->dentry->d_inode->i_op->put_link) + path->dentry->d_inode->i_op->put_link(path->dentry, nd, cookie); + path_put(path); current->link_count--; nd->depth--; return err; @@ -675,23 +597,23 @@ loop: return err; } -int follow_up(struct vfsmount **mnt, struct dentry **dentry) +int follow_up(struct path *path) { struct vfsmount *parent; struct dentry *mountpoint; spin_lock(&vfsmount_lock); - parent=(*mnt)->mnt_parent; - if (parent == *mnt) { + parent = path->mnt->mnt_parent; + if (parent == path->mnt) { spin_unlock(&vfsmount_lock); return 0; } mntget(parent); - mountpoint=dget((*mnt)->mnt_mountpoint); + mountpoint = dget(path->mnt->mnt_mountpoint); spin_unlock(&vfsmount_lock); - dput(*dentry); - *dentry = mountpoint; - mntput(*mnt); - *mnt = parent; + dput(path->dentry); + path->dentry = mountpoint; + mntput(path->mnt); + path->mnt = parent; return 1; } @@ -702,7 +624,7 @@ static int __follow_mount(struct path *path) { int res = 0; while (d_mountpoint(path->dentry)) { - struct vfsmount *mounted = lookup_mnt(path->mnt, path->dentry); + struct vfsmount *mounted = lookup_mnt(path); if (!mounted) break; dput(path->dentry); @@ -715,32 +637,32 @@ static int __follow_mount(struct path *path) return res; } -static void follow_mount(struct vfsmount **mnt, struct dentry **dentry) +static void follow_mount(struct path *path) { - while (d_mountpoint(*dentry)) { - struct vfsmount *mounted = lookup_mnt(*mnt, *dentry); + while (d_mountpoint(path->dentry)) { + struct vfsmount *mounted = lookup_mnt(path); if (!mounted) break; - dput(*dentry); - mntput(*mnt); - *mnt = mounted; - *dentry = dget(mounted->mnt_root); + dput(path->dentry); + mntput(path->mnt); + path->mnt = mounted; + path->dentry = dget(mounted->mnt_root); } } /* no need for dcache_lock, as serialization is taken care in * namespace.c */ -int follow_down(struct vfsmount **mnt, struct dentry **dentry) +int follow_down(struct path *path) { struct vfsmount *mounted; - mounted = lookup_mnt(*mnt, *dentry); + mounted = lookup_mnt(path); if (mounted) { - dput(*dentry); - mntput(*mnt); - *mnt = mounted; - *dentry = dget(mounted->mnt_root); + dput(path->dentry); + mntput(path->mnt); + path->mnt = mounted; + path->dentry = dget(mounted->mnt_root); return 1; } return 0; @@ -748,41 +670,25 @@ int follow_down(struct vfsmount **mnt, struct dentry **dentry) static __always_inline void follow_dotdot(struct nameidata *nd) { - struct fs_struct *fs = current->fs; + set_root(nd); while(1) { - struct vfsmount *parent; struct dentry *old = nd->path.dentry; - read_lock(&fs->lock); - if (nd->path.dentry == fs->root.dentry && - nd->path.mnt == fs->root.mnt) { - read_unlock(&fs->lock); + if (nd->path.dentry == nd->root.dentry && + nd->path.mnt == nd->root.mnt) { break; } - read_unlock(&fs->lock); - spin_lock(&dcache_lock); if (nd->path.dentry != nd->path.mnt->mnt_root) { - nd->path.dentry = dget(nd->path.dentry->d_parent); - spin_unlock(&dcache_lock); + /* rare case of legitimate dget_parent()... */ + nd->path.dentry = dget_parent(nd->path.dentry); dput(old); break; } - spin_unlock(&dcache_lock); - spin_lock(&vfsmount_lock); - parent = nd->path.mnt->mnt_parent; - if (parent == nd->path.mnt) { - spin_unlock(&vfsmount_lock); + if (!follow_up(&nd->path)) break; - } - mntget(parent); - nd->path.dentry = dget(nd->path.mnt->mnt_mountpoint); - spin_unlock(&vfsmount_lock); - dput(old); - mntput(nd->path.mnt); - nd->path.mnt = parent; } - follow_mount(&nd->path.mnt, &nd->path.dentry); + follow_mount(&nd->path); } /* @@ -794,8 +700,19 @@ static int do_lookup(struct nameidata *nd, struct qstr *name, struct path *path) { struct vfsmount *mnt = nd->path.mnt; - struct dentry *dentry = __d_lookup(nd->path.dentry, name); + struct dentry *dentry, *parent; + struct inode *dir; + /* + * See if the low-level filesystem might want + * to use its own hash.. + */ + if (nd->path.dentry->d_op && nd->path.dentry->d_op->d_hash) { + int err = nd->path.dentry->d_op->d_hash(nd->path.dentry, name); + if (err < 0) + return err; + } + dentry = __d_lookup(nd->path.dentry, name); if (!dentry) goto need_lookup; if (dentry->d_op && dentry->d_op->d_revalidate) @@ -807,7 +724,59 @@ done: return 0; need_lookup: - dentry = real_lookup(nd->path.dentry, name, nd); + parent = nd->path.dentry; + dir = parent->d_inode; + + mutex_lock(&dir->i_mutex); + /* + * First re-do the cached lookup just in case it was created + * while we waited for the directory semaphore.. + * + * FIXME! This could use version numbering or similar to + * avoid unnecessary cache lookups. + * + * The "dcache_lock" is purely to protect the RCU list walker + * from concurrent renames at this point (we mustn't get false + * negatives from the RCU list walk here, unlike the optimistic + * fast walk). + * + * so doing d_lookup() (with seqlock), instead of lockfree __d_lookup + */ + dentry = d_lookup(parent, name); + if (!dentry) { + struct dentry *new; + + /* Don't create child dentry for a dead directory. */ + dentry = ERR_PTR(-ENOENT); + if (IS_DEADDIR(dir)) + goto out_unlock; + + new = d_alloc(parent, name); + dentry = ERR_PTR(-ENOMEM); + if (new) { + dentry = dir->i_op->lookup(dir, new, nd); + if (dentry) + dput(new); + else + dentry = new; + } +out_unlock: + mutex_unlock(&dir->i_mutex); + if (IS_ERR(dentry)) + goto fail; + goto done; + } + + /* + * Uhhuh! Nasty case: the cache was re-populated while + * we waited on the semaphore. Need to revalidate. + */ + mutex_unlock(&dir->i_mutex); + if (dentry->d_op && dentry->d_op->d_revalidate) { + dentry = do_revalidate(dentry, nd); + if (!dentry) + dentry = ERR_PTR(-ENOENT); + } if (IS_ERR(dentry)) goto fail; goto done; @@ -825,6 +794,17 @@ fail: } /* + * This is a temporary kludge to deal with "automount" symlinks; proper + * solution is to trigger them on follow_mount(), so that do_lookup() + * would DTRT. To be killed before 2.6.34-final. + */ +static inline int follow_on_final(struct inode *inode, unsigned lookup_flags) +{ + return inode && unlikely(inode->i_op->follow_link) && + ((lookup_flags & LOOKUP_FOLLOW) || S_ISDIR(inode->i_mode)); +} + +/* * Name resolution. * This is the basic name resolution function, turning a pathname into * the final dentry. We expect 'base' to be positive and a directory. @@ -832,7 +812,7 @@ fail: * Returns 0 and nd will have valid dentry and mnt on success. * Returns error and drops reference to input namei data on failure. */ -static int __link_path_walk(const char *name, struct nameidata *nd) +static int link_path_walk(const char *name, struct nameidata *nd) { struct path next; struct inode *inode; @@ -855,9 +835,7 @@ static int __link_path_walk(const char *name, struct nameidata *nd) unsigned int c; nd->flags |= LOOKUP_CONTINUE; - err = exec_permission_lite(inode, nd); - if (err == -EAGAIN) - err = vfs_permission(nd, MAY_EXEC); + err = exec_permission(inode); if (err) break; @@ -897,16 +875,6 @@ static int __link_path_walk(const char *name, struct nameidata *nd) case 1: continue; } - /* - * See if the low-level filesystem might want - * to use its own hash.. - */ - if (nd->path.dentry->d_op && nd->path.dentry->d_op->d_hash) { - err = nd->path.dentry->d_op->d_hash(nd->path.dentry, - &this); - if (err < 0) - break; - } /* This does the actual lookups.. */ err = do_lookup(nd, &this, &next); if (err) @@ -916,9 +884,6 @@ static int __link_path_walk(const char *name, struct nameidata *nd) inode = next.dentry->d_inode; if (!inode) goto out_dput; - err = -ENOTDIR; - if (!inode->i_op) - goto out_dput; if (inode->i_op->follow_link) { err = do_follow_link(&next, nd); @@ -928,9 +893,6 @@ static int __link_path_walk(const char *name, struct nameidata *nd) inode = nd->path.dentry->d_inode; if (!inode) break; - err = -ENOTDIR; - if (!inode->i_op) - break; } else path_to_nameidata(&next, nd); err = -ENOTDIR; @@ -958,18 +920,11 @@ last_component: case 1: goto return_reval; } - if (nd->path.dentry->d_op && nd->path.dentry->d_op->d_hash) { - err = nd->path.dentry->d_op->d_hash(nd->path.dentry, - &this); - if (err < 0) - break; - } err = do_lookup(nd, &this, &next); if (err) break; inode = next.dentry->d_inode; - if ((lookup_flags & LOOKUP_FOLLOW) - && inode && inode->i_op && inode->i_op->follow_link) { + if (follow_on_final(inode, lookup_flags)) { err = do_follow_link(&next, nd); if (err) goto return_err; @@ -981,7 +936,7 @@ last_component: break; if (lookup_flags & LOOKUP_DIRECTORY) { err = -ENOTDIR; - if (!inode->i_op || !inode->i_op->lookup) + if (!inode->i_op->lookup) break; } goto return_base; @@ -1020,130 +975,48 @@ return_err: return err; } -/* - * Wrapper to retry pathname resolution whenever the underlying - * file system returns an ESTALE. - * - * Retry the whole path once, forcing real lookup requests - * instead of relying on the dcache. - */ -static int link_path_walk(const char *name, struct nameidata *nd) +static int path_walk(const char *name, struct nameidata *nd) { - struct nameidata save = *nd; + struct path save = nd->path; int result; + current->total_link_count = 0; + /* make sure the stuff we saved doesn't go away */ - dget(save.path.dentry); - mntget(save.path.mnt); + path_get(&save); - result = __link_path_walk(name, nd); + result = link_path_walk(name, nd); if (result == -ESTALE) { - *nd = save; - dget(nd->path.dentry); - mntget(nd->path.mnt); + /* nd->path had been dropped */ + current->total_link_count = 0; + nd->path = save; + path_get(&nd->path); nd->flags |= LOOKUP_REVAL; - result = __link_path_walk(name, nd); + result = link_path_walk(name, nd); } - path_put(&save.path); + path_put(&save); return result; } -static int path_walk(const char *name, struct nameidata *nd) -{ - current->total_link_count = 0; - return link_path_walk(name, nd); -} - -/* - * SMP-safe: Returns 1 and nd will have valid dentry and mnt, if - * everything is done. Returns 0 and drops input nd, if lookup failed; - */ -static int __emul_lookup_dentry(const char *name, struct nameidata *nd) -{ - if (path_walk(name, nd)) - return 0; /* something went wrong... */ - - if (!nd->path.dentry->d_inode || - S_ISDIR(nd->path.dentry->d_inode->i_mode)) { - struct path old_path = nd->path; - struct qstr last = nd->last; - int last_type = nd->last_type; - struct fs_struct *fs = current->fs; - - /* - * NAME was not found in alternate root or it's a directory. - * Try to find it in the normal root: - */ - nd->last_type = LAST_ROOT; - read_lock(&fs->lock); - nd->path = fs->root; - path_get(&fs->root); - read_unlock(&fs->lock); - if (path_walk(name, nd) == 0) { - if (nd->path.dentry->d_inode) { - path_put(&old_path); - return 1; - } - path_put(&nd->path); - } - nd->path = old_path; - nd->last = last; - nd->last_type = last_type; - } - return 1; -} - -void set_fs_altroot(void) -{ - char *emul = __emul_prefix(); - struct nameidata nd; - struct path path = {}, old_path; - int err; - struct fs_struct *fs = current->fs; - - if (!emul) - goto set_it; - err = path_lookup(emul, LOOKUP_FOLLOW|LOOKUP_DIRECTORY|LOOKUP_NOALT, &nd); - if (!err) - path = nd.path; -set_it: - write_lock(&fs->lock); - old_path = fs->altroot; - fs->altroot = path; - write_unlock(&fs->lock); - if (old_path.dentry) - path_put(&old_path); -} - -/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */ -static int do_path_lookup(int dfd, const char *name, - unsigned int flags, struct nameidata *nd) +static int path_init(int dfd, const char *name, unsigned int flags, struct nameidata *nd) { int retval = 0; int fput_needed; struct file *file; - struct fs_struct *fs = current->fs; nd->last_type = LAST_ROOT; /* if there are only slashes... */ nd->flags = flags; nd->depth = 0; + nd->root.mnt = NULL; if (*name=='/') { - read_lock(&fs->lock); - if (fs->altroot.dentry && !(nd->flags & LOOKUP_NOALT)) { - nd->path = fs->altroot; - path_get(&fs->altroot); - read_unlock(&fs->lock); - if (__emul_lookup_dentry(name,nd)) - goto out; /* found in altroot */ - read_lock(&fs->lock); - } - nd->path = fs->root; - path_get(&fs->root); - read_unlock(&fs->lock); + set_root(nd); + nd->path = nd->root; + path_get(&nd->root); } else if (dfd == AT_FDCWD) { + struct fs_struct *fs = current->fs; read_lock(&fs->lock); nd->path = fs->pwd; path_get(&fs->pwd); @@ -1171,18 +1044,29 @@ static int do_path_lookup(int dfd, const char *name, fput_light(file, fput_needed); } + return 0; - retval = path_walk(name, nd); -out: +fput_fail: + fput_light(file, fput_needed); +out_fail: + return retval; +} + +/* Returns 0 and nd will be valid on success; Retuns error, otherwise. */ +static int do_path_lookup(int dfd, const char *name, + unsigned int flags, struct nameidata *nd) +{ + int retval = path_init(dfd, name, flags, nd); + if (!retval) + retval = path_walk(name, nd); if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry && nd->path.dentry->d_inode)) audit_inode(name, nd->path.dentry); -out_fail: + if (nd->root.mnt) { + path_put(&nd->root); + nd->root.mnt = NULL; + } return retval; - -fput_fail: - fput_light(file, fput_needed); - goto out_fail; } int path_lookup(const char *name, unsigned int flags, @@ -1191,6 +1075,15 @@ int path_lookup(const char *name, unsigned int flags, return do_path_lookup(AT_FDCWD, name, flags, nd); } +int kern_path(const char *name, unsigned int flags, struct path *path) +{ + struct nameidata nd; + int res = do_path_lookup(AT_FDCWD, name, flags, &nd); + if (!res) + *path = nd.path; + return res; +} + /** * vfs_path_lookup - lookup a file path relative to a dentry-vfsmount pair * @dentry: pointer to dentry of the base directory @@ -1210,84 +1103,21 @@ int vfs_path_lookup(struct dentry *dentry, struct vfsmount *mnt, nd->flags = flags; nd->depth = 0; - nd->path.mnt = mntget(mnt); - nd->path.dentry = dget(dentry); + nd->path.dentry = dentry; + nd->path.mnt = mnt; + path_get(&nd->path); + nd->root = nd->path; + path_get(&nd->root); retval = path_walk(name, nd); if (unlikely(!retval && !audit_dummy_context() && nd->path.dentry && nd->path.dentry->d_inode)) audit_inode(name, nd->path.dentry); - return retval; - -} - -static int __path_lookup_intent_open(int dfd, const char *name, - unsigned int lookup_flags, struct nameidata *nd, - int open_flags, int create_mode) -{ - struct file *filp = get_empty_filp(); - int err; - - if (filp == NULL) - return -ENFILE; - nd->intent.open.file = filp; - nd->intent.open.flags = open_flags; - nd->intent.open.create_mode = create_mode; - err = do_path_lookup(dfd, name, lookup_flags|LOOKUP_OPEN, nd); - if (IS_ERR(nd->intent.open.file)) { - if (err == 0) { - err = PTR_ERR(nd->intent.open.file); - path_put(&nd->path); - } - } else if (err != 0) - release_open_intent(nd); - return err; -} - -/** - * path_lookup_open - lookup a file path with open intent - * @dfd: the directory to use as base, or AT_FDCWD - * @name: pointer to file name - * @lookup_flags: lookup intent flags - * @nd: pointer to nameidata - * @open_flags: open intent flags - */ -int path_lookup_open(int dfd, const char *name, unsigned int lookup_flags, - struct nameidata *nd, int open_flags) -{ - return __path_lookup_intent_open(dfd, name, lookup_flags, nd, - open_flags, 0); -} - -/** - * path_lookup_create - lookup a file path with open + create intent - * @dfd: the directory to use as base, or AT_FDCWD - * @name: pointer to file name - * @lookup_flags: lookup intent flags - * @nd: pointer to nameidata - * @open_flags: open intent flags - * @create_mode: create intent flags - */ -static int path_lookup_create(int dfd, const char *name, - unsigned int lookup_flags, struct nameidata *nd, - int open_flags, int create_mode) -{ - return __path_lookup_intent_open(dfd, name, lookup_flags|LOOKUP_CREATE, - nd, open_flags, create_mode); -} - -int __user_path_lookup_open(const char __user *name, unsigned int lookup_flags, - struct nameidata *nd, int open_flags) -{ - char *tmp = getname(name); - int err = PTR_ERR(tmp); + path_put(&nd->root); + nd->root.mnt = NULL; - if (!IS_ERR(tmp)) { - err = __path_lookup_intent_open(AT_FDCWD, tmp, lookup_flags, nd, open_flags, 0); - putname(tmp); - } - return err; + return retval; } static struct dentry *__lookup_hash(struct qstr *name, @@ -1310,9 +1140,26 @@ static struct dentry *__lookup_hash(struct qstr *name, goto out; } - dentry = cached_lookup(base, name, nd); + dentry = __d_lookup(base, name); + + /* lockess __d_lookup may fail due to concurrent d_move() + * in some unrelated directory, so try with d_lookup + */ + if (!dentry) + dentry = d_lookup(base, name); + + if (dentry && dentry->d_op && dentry->d_op->d_revalidate) + dentry = do_revalidate(dentry, nd); + if (!dentry) { - struct dentry *new = d_alloc(base, name); + struct dentry *new; + + /* Don't create child dentry for a dead directory. */ + dentry = ERR_PTR(-ENOENT); + if (IS_DEADDIR(inode)) + goto out; + + new = d_alloc(base, name); dentry = ERR_PTR(-ENOMEM); if (!new) goto out; @@ -1335,7 +1182,7 @@ static struct dentry *lookup_hash(struct nameidata *nd) { int err; - err = permission(nd->path.dentry->d_inode, MAY_EXEC, nd); + err = exec_permission(nd->path.dentry->d_inode); if (err) return ERR_PTR(err); return __lookup_hash(&nd->last, nd->path.dentry, nd); @@ -1364,13 +1211,13 @@ static int __lookup_one_len(const char *name, struct qstr *this, } /** - * lookup_one_len: filesystem helper to lookup single pathname component + * lookup_one_len - filesystem helper to lookup single pathname component * @name: pathname component to lookup * @base: base directory to lookup from * @len: maximum length @len should be interpreted to * - * Note that this routine is purely a helper for filesystem useage and should - * not be called by generic code. Also note that by using this function to + * Note that this routine is purely a helper for filesystem usage and should + * not be called by generic code. Also note that by using this function the * nameidata argument is passed to the filesystem methods and a filesystem * using this helper needs to be prepared for that. */ @@ -1379,54 +1226,52 @@ struct dentry *lookup_one_len(const char *name, struct dentry *base, int len) int err; struct qstr this; - err = __lookup_one_len(name, &this, base, len); - if (err) - return ERR_PTR(err); + WARN_ON_ONCE(!mutex_is_locked(&base->d_inode->i_mutex)); - err = permission(base->d_inode, MAY_EXEC, NULL); + err = __lookup_one_len(name, &this, base, len); if (err) return ERR_PTR(err); - return __lookup_hash(&this, base, NULL); -} - -/** - * lookup_one_noperm - bad hack for sysfs - * @name: pathname component to lookup - * @base: base directory to lookup from - * - * This is a variant of lookup_one_len that doesn't perform any permission - * checks. It's a horrible hack to work around the braindead sysfs - * architecture and should not be used anywhere else. - * - * DON'T USE THIS FUNCTION EVER, thanks. - */ -struct dentry *lookup_one_noperm(const char *name, struct dentry *base) -{ - int err; - struct qstr this; - err = __lookup_one_len(name, &this, base, strlen(name)); + err = exec_permission(base->d_inode); if (err) return ERR_PTR(err); return __lookup_hash(&this, base, NULL); } -int __user_walk_fd(int dfd, const char __user *name, unsigned flags, - struct nameidata *nd) +int user_path_at(int dfd, const char __user *name, unsigned flags, + struct path *path) { + struct nameidata nd; char *tmp = getname(name); int err = PTR_ERR(tmp); - if (!IS_ERR(tmp)) { - err = do_path_lookup(dfd, tmp, flags, nd); + + BUG_ON(flags & LOOKUP_PARENT); + + err = do_path_lookup(dfd, tmp, flags, &nd); putname(tmp); + if (!err) + *path = nd.path; } return err; } -int __user_walk(const char __user *name, unsigned flags, struct nameidata *nd) +static int user_path_parent(int dfd, const char __user *path, + struct nameidata *nd, char **name) { - return __user_walk_fd(AT_FDCWD, name, flags, nd); + char *s = getname(path); + int error; + + if (IS_ERR(s)) + return PTR_ERR(s); + + error = do_path_lookup(dfd, s, LOOKUP_PARENT, nd); + if (error) + putname(s); + else + *name = s; + + return error; } /* @@ -1435,11 +1280,13 @@ int __user_walk(const char __user *name, unsigned flags, struct nameidata *nd) */ static inline int check_sticky(struct inode *dir, struct inode *inode) { + uid_t fsuid = current_fsuid(); + if (!(dir->i_mode & S_ISVTX)) return 0; - if (inode->i_uid == current->fsuid) + if (inode->i_uid == fsuid) return 0; - if (dir->i_uid == current->fsuid) + if (dir->i_uid == fsuid) return 0; return !capable(CAP_FOWNER); } @@ -1471,15 +1318,15 @@ static int may_delete(struct inode *dir,struct dentry *victim,int isdir) return -ENOENT; BUG_ON(victim->d_parent->d_inode != dir); - audit_inode_child(victim->d_name.name, victim, dir); + audit_inode_child(victim, dir); - error = permission(dir,MAY_WRITE | MAY_EXEC, NULL); + error = inode_permission(dir, MAY_WRITE | MAY_EXEC); if (error) return error; if (IS_APPEND(dir)) return -EPERM; if (check_sticky(dir, victim->d_inode)||IS_APPEND(victim->d_inode)|| - IS_IMMUTABLE(victim->d_inode)) + IS_IMMUTABLE(victim->d_inode) || IS_SWAPFILE(victim->d_inode)) return -EPERM; if (isdir) { if (!S_ISDIR(victim->d_inode->i_mode)) @@ -1503,30 +1350,13 @@ static int may_delete(struct inode *dir,struct dentry *victim,int isdir) * 3. We should have write and exec permissions on dir * 4. We can't do it if dir is immutable (done in permission()) */ -static inline int may_create(struct inode *dir, struct dentry *child, - struct nameidata *nd) +static inline int may_create(struct inode *dir, struct dentry *child) { if (child->d_inode) return -EEXIST; if (IS_DEADDIR(dir)) return -ENOENT; - return permission(dir,MAY_WRITE | MAY_EXEC, nd); -} - -/* - * O_DIRECTORY translates into forcing a directory lookup. - */ -static inline int lookup_flags(unsigned int f) -{ - unsigned long retval = LOOKUP_FOLLOW; - - if (f & O_NOFOLLOW) - retval &= ~LOOKUP_FOLLOW; - - if (f & O_DIRECTORY) - retval |= LOOKUP_DIRECTORY; - - return retval; + return inode_permission(dir, MAY_WRITE | MAY_EXEC); } /* @@ -1543,20 +1373,18 @@ struct dentry *lock_rename(struct dentry *p1, struct dentry *p2) mutex_lock(&p1->d_inode->i_sb->s_vfs_rename_mutex); - for (p = p1; p->d_parent != p; p = p->d_parent) { - if (p->d_parent == p2) { - mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT); - mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_CHILD); - return p; - } + p = d_ancestor(p2, p1); + if (p) { + mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_CHILD); + return p; } - for (p = p2; p->d_parent != p; p = p->d_parent) { - if (p->d_parent == p1) { - mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); - mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD); - return p; - } + p = d_ancestor(p1, p2); + if (p) { + mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); + mutex_lock_nested(&p2->d_inode->i_mutex, I_MUTEX_CHILD); + return p; } mutex_lock_nested(&p1->d_inode->i_mutex, I_MUTEX_PARENT); @@ -1576,300 +1404,513 @@ void unlock_rename(struct dentry *p1, struct dentry *p2) int vfs_create(struct inode *dir, struct dentry *dentry, int mode, struct nameidata *nd) { - int error = may_create(dir, dentry, nd); + int error = may_create(dir, dentry); if (error) return error; - if (!dir->i_op || !dir->i_op->create) + if (!dir->i_op->create) return -EACCES; /* shouldn't it be ENOSYS? */ mode &= S_IALLUGO; mode |= S_IFREG; error = security_inode_create(dir, dentry, mode); if (error) return error; - DQUOT_INIT(dir); error = dir->i_op->create(dir, dentry, mode, nd); if (!error) fsnotify_create(dir, dentry); return error; } -int may_open(struct nameidata *nd, int acc_mode, int flag) +int may_open(struct path *path, int acc_mode, int flag) { - struct dentry *dentry = nd->path.dentry; + struct dentry *dentry = path->dentry; struct inode *inode = dentry->d_inode; int error; if (!inode) return -ENOENT; - if (S_ISLNK(inode->i_mode)) + switch (inode->i_mode & S_IFMT) { + case S_IFLNK: return -ELOOP; - - if (S_ISDIR(inode->i_mode) && (acc_mode & MAY_WRITE)) - return -EISDIR; - - /* - * FIFO's, sockets and device files are special: they don't - * actually live on the filesystem itself, and as such you - * can write to them even if the filesystem is read-only. - */ - if (S_ISFIFO(inode->i_mode) || S_ISSOCK(inode->i_mode)) { - flag &= ~O_TRUNC; - } else if (S_ISBLK(inode->i_mode) || S_ISCHR(inode->i_mode)) { - if (nd->path.mnt->mnt_flags & MNT_NODEV) + case S_IFDIR: + if (acc_mode & MAY_WRITE) + return -EISDIR; + break; + case S_IFBLK: + case S_IFCHR: + if (path->mnt->mnt_flags & MNT_NODEV) return -EACCES; - + /*FALLTHRU*/ + case S_IFIFO: + case S_IFSOCK: flag &= ~O_TRUNC; - } else if (IS_RDONLY(inode) && (acc_mode & MAY_WRITE)) - return -EROFS; + break; + } - error = vfs_permission(nd, acc_mode); + error = inode_permission(inode, acc_mode); if (error) return error; + /* * An append-only file must be opened in append mode for writing. */ if (IS_APPEND(inode)) { - if ((flag & FMODE_WRITE) && !(flag & O_APPEND)) + if ((flag & O_ACCMODE) != O_RDONLY && !(flag & O_APPEND)) return -EPERM; if (flag & O_TRUNC) return -EPERM; } /* O_NOATIME can only be set by the owner or superuser */ - if (flag & O_NOATIME) - if (!is_owner_or_cap(inode)) - return -EPERM; + if (flag & O_NOATIME && !is_owner_or_cap(inode)) + return -EPERM; /* * Ensure there are no outstanding leases on the file. */ - error = break_lease(inode, flag); + return break_lease(inode, flag); +} + +static int handle_truncate(struct path *path) +{ + struct inode *inode = path->dentry->d_inode; + int error = get_write_access(inode); if (error) return error; - - if (flag & O_TRUNC) { - error = get_write_access(inode); - if (error) - return error; - - /* - * Refuse to truncate files with mandatory locks held on them. - */ - error = locks_verify_locked(inode); - if (!error) { - DQUOT_INIT(inode); - - error = do_truncate(dentry, 0, - ATTR_MTIME|ATTR_CTIME|ATTR_OPEN, - NULL); - } - put_write_access(inode); - if (error) - return error; - } else - if (flag & FMODE_WRITE) - DQUOT_INIT(inode); - - return 0; + /* + * Refuse to truncate files with mandatory locks held on them. + */ + error = locks_verify_locked(inode); + if (!error) + error = security_path_truncate(path, 0, + ATTR_MTIME|ATTR_CTIME|ATTR_OPEN); + if (!error) { + error = do_truncate(path->dentry, 0, + ATTR_MTIME|ATTR_CTIME|ATTR_OPEN, + NULL); + } + put_write_access(inode); + return error; } -static int open_namei_create(struct nameidata *nd, struct path *path, - int flag, int mode) +/* + * Be careful about ever adding any more callers of this + * function. Its flags must be in the namei format, not + * what get passed to sys_open(). + */ +static int __open_namei_create(struct nameidata *nd, struct path *path, + int open_flag, int mode) { int error; struct dentry *dir = nd->path.dentry; if (!IS_POSIXACL(dir->d_inode)) - mode &= ~current->fs->umask; + mode &= ~current_umask(); + error = security_path_mknod(&nd->path, path->dentry, mode, 0); + if (error) + goto out_unlock; error = vfs_create(dir->d_inode, path->dentry, mode, nd); +out_unlock: mutex_unlock(&dir->d_inode->i_mutex); dput(nd->path.dentry); nd->path.dentry = path->dentry; if (error) return error; /* Don't check for write permission, don't truncate */ - return may_open(nd, 0, flag & ~O_TRUNC); + return may_open(&nd->path, 0, open_flag & ~O_TRUNC); +} + +/* + * Note that while the flag value (low two bits) for sys_open means: + * 00 - read-only + * 01 - write-only + * 10 - read-write + * 11 - special + * it is changed into + * 00 - no permissions needed + * 01 - read-permission + * 10 - write-permission + * 11 - read-write + * for the internal routines (ie open_namei()/follow_link() etc) + * This is more logical, and also allows the 00 "no perm needed" + * to be used for symlinks (where the permissions are checked + * later). + * +*/ +static inline int open_to_namei_flags(int flag) +{ + if ((flag+1) & O_ACCMODE) + flag++; + return flag; +} + +static int open_will_truncate(int flag, struct inode *inode) +{ + /* + * We'll never write to the fs underlying + * a device file. + */ + if (special_file(inode->i_mode)) + return 0; + return (flag & O_TRUNC); +} + +static struct file *finish_open(struct nameidata *nd, + int open_flag, int acc_mode) +{ + struct file *filp; + int will_truncate; + int error; + + will_truncate = open_will_truncate(open_flag, nd->path.dentry->d_inode); + if (will_truncate) { + error = mnt_want_write(nd->path.mnt); + if (error) + goto exit; + } + error = may_open(&nd->path, acc_mode, open_flag); + if (error) { + if (will_truncate) + mnt_drop_write(nd->path.mnt); + goto exit; + } + filp = nameidata_to_filp(nd); + if (!IS_ERR(filp)) { + error = ima_file_check(filp, acc_mode); + if (error) { + fput(filp); + filp = ERR_PTR(error); + } + } + if (!IS_ERR(filp)) { + if (will_truncate) { + error = handle_truncate(&nd->path); + if (error) { + fput(filp); + filp = ERR_PTR(error); + } + } + } + /* + * It is now safe to drop the mnt write + * because the filp has had a write taken + * on its behalf. + */ + if (will_truncate) + mnt_drop_write(nd->path.mnt); + return filp; + +exit: + if (!IS_ERR(nd->intent.open.file)) + release_open_intent(nd); + path_put(&nd->path); + return ERR_PTR(error); } -/* - * open_namei() - * - * namei for open - this is in fact almost the whole open-routine. - * - * Note that the low bits of "flag" aren't the same as in the open - * system call - they are 00 - no permissions needed - * 01 - read permission needed - * 10 - write permission needed - * 11 - read/write permissions needed - * which is a lot more logical, and also allows the "no perm" needed - * for symlinks (where the permissions are checked later). - * SMP-safe - */ -int open_namei(int dfd, const char *pathname, int flag, - int mode, struct nameidata *nd) +static struct file *do_last(struct nameidata *nd, struct path *path, + int open_flag, int acc_mode, + int mode, const char *pathname) { - int acc_mode, error; - struct path path; - struct dentry *dir; - int count = 0; - - acc_mode = ACC_MODE(flag); - - /* O_TRUNC implies we need access checks for write permissions */ - if (flag & O_TRUNC) - acc_mode |= MAY_WRITE; + struct dentry *dir = nd->path.dentry; + struct file *filp; + int error = -EISDIR; + + switch (nd->last_type) { + case LAST_DOTDOT: + follow_dotdot(nd); + dir = nd->path.dentry; + case LAST_DOT: + if (nd->path.mnt->mnt_sb->s_type->fs_flags & FS_REVAL_DOT) { + if (!dir->d_op->d_revalidate(dir, nd)) { + error = -ESTALE; + goto exit; + } + } + /* fallthrough */ + case LAST_ROOT: + if (open_flag & O_CREAT) + goto exit; + /* fallthrough */ + case LAST_BIND: + audit_inode(pathname, dir); + goto ok; + } - /* Allow the LSM permission hook to distinguish append - access from general write access. */ - if (flag & O_APPEND) - acc_mode |= MAY_APPEND; + /* trailing slashes? */ + if (nd->last.name[nd->last.len]) { + if (open_flag & O_CREAT) + goto exit; + nd->flags |= LOOKUP_DIRECTORY | LOOKUP_FOLLOW; + } - /* - * The simplest case - just a plain lookup. - */ - if (!(flag & O_CREAT)) { - error = path_lookup_open(dfd, pathname, lookup_flags(flag), - nd, flag); + /* just plain open? */ + if (!(open_flag & O_CREAT)) { + error = do_lookup(nd, &nd->last, path); if (error) - return error; + goto exit; + error = -ENOENT; + if (!path->dentry->d_inode) + goto exit_dput; + if (path->dentry->d_inode->i_op->follow_link) + return NULL; + error = -ENOTDIR; + if (nd->flags & LOOKUP_DIRECTORY) { + if (!path->dentry->d_inode->i_op->lookup) + goto exit_dput; + } + path_to_nameidata(path, nd); + audit_inode(pathname, nd->path.dentry); goto ok; } - /* - * Create - we need to know the parent. - */ - error = path_lookup_create(dfd,pathname,LOOKUP_PARENT,nd,flag,mode); - if (error) - return error; - - /* - * We have the parent and last component. First of all, check - * that we are not asked to creat(2) an obvious directory - that - * will not do. - */ - error = -EISDIR; - if (nd->last_type != LAST_NORM || nd->last.name[nd->last.len]) - goto exit; - - dir = nd->path.dentry; - nd->flags &= ~LOOKUP_PARENT; + /* OK, it's O_CREAT */ mutex_lock(&dir->d_inode->i_mutex); - path.dentry = lookup_hash(nd); - path.mnt = nd->path.mnt; -do_last: - error = PTR_ERR(path.dentry); - if (IS_ERR(path.dentry)) { + path->dentry = lookup_hash(nd); + path->mnt = nd->path.mnt; + + error = PTR_ERR(path->dentry); + if (IS_ERR(path->dentry)) { mutex_unlock(&dir->d_inode->i_mutex); goto exit; } if (IS_ERR(nd->intent.open.file)) { - mutex_unlock(&dir->d_inode->i_mutex); error = PTR_ERR(nd->intent.open.file); - goto exit_dput; + goto exit_mutex_unlock; } /* Negative dentry, just create the file */ - if (!path.dentry->d_inode) { - error = open_namei_create(nd, &path, flag, mode); + if (!path->dentry->d_inode) { + /* + * This write is needed to ensure that a + * ro->rw transition does not occur between + * the time when the file is created and when + * a permanent write count is taken through + * the 'struct file' in nameidata_to_filp(). + */ + error = mnt_want_write(nd->path.mnt); if (error) + goto exit_mutex_unlock; + error = __open_namei_create(nd, path, open_flag, mode); + if (error) { + mnt_drop_write(nd->path.mnt); goto exit; - return 0; + } + filp = nameidata_to_filp(nd); + mnt_drop_write(nd->path.mnt); + if (!IS_ERR(filp)) { + error = ima_file_check(filp, acc_mode); + if (error) { + fput(filp); + filp = ERR_PTR(error); + } + } + return filp; } /* * It already exists. */ mutex_unlock(&dir->d_inode->i_mutex); - audit_inode(pathname, path.dentry); + audit_inode(pathname, path->dentry); error = -EEXIST; - if (flag & O_EXCL) + if (open_flag & O_EXCL) goto exit_dput; - if (__follow_mount(&path)) { + if (__follow_mount(path)) { error = -ELOOP; - if (flag & O_NOFOLLOW) + if (open_flag & O_NOFOLLOW) goto exit_dput; } error = -ENOENT; - if (!path.dentry->d_inode) + if (!path->dentry->d_inode) goto exit_dput; - if (path.dentry->d_inode->i_op && path.dentry->d_inode->i_op->follow_link) - goto do_link; - path_to_nameidata(&path, nd); + if (path->dentry->d_inode->i_op->follow_link) + return NULL; + + path_to_nameidata(path, nd); error = -EISDIR; - if (path.dentry->d_inode && S_ISDIR(path.dentry->d_inode->i_mode)) + if (S_ISDIR(path->dentry->d_inode->i_mode)) goto exit; ok: - error = may_open(nd, acc_mode, flag); - if (error) - goto exit; - return 0; + filp = finish_open(nd, open_flag, acc_mode); + return filp; +exit_mutex_unlock: + mutex_unlock(&dir->d_inode->i_mutex); exit_dput: - path_put_conditional(&path, nd); + path_put_conditional(path, nd); exit: if (!IS_ERR(nd->intent.open.file)) release_open_intent(nd); path_put(&nd->path); - return error; + return ERR_PTR(error); +} + +/* + * Note that the low bits of the passed in "open_flag" + * are not the same as in the local variable "flag". See + * open_to_namei_flags() for more details. + */ +struct file *do_filp_open(int dfd, const char *pathname, + int open_flag, int mode, int acc_mode) +{ + struct file *filp; + struct nameidata nd; + int error; + struct path path; + int count = 0; + int flag = open_to_namei_flags(open_flag); + int force_reval = 0; + + if (!(open_flag & O_CREAT)) + mode = 0; -do_link: - error = -ELOOP; - if (flag & O_NOFOLLOW) - goto exit_dput; /* - * This is subtle. Instead of calling do_follow_link() we do the - * thing by hands. The reason is that this way we have zero link_count - * and path_walk() (called from ->follow_link) honoring LOOKUP_PARENT. - * After that we have the parent and last component, i.e. - * we are in the same situation as after the first path_walk(). - * Well, almost - if the last component is normal we get its copy - * stored in nd->last.name and we will have to putname() it when we - * are done. Procfs-like symlinks just set LAST_BIND. + * O_SYNC is implemented as __O_SYNC|O_DSYNC. As many places only + * check for O_DSYNC if the need any syncing at all we enforce it's + * always set instead of having to deal with possibly weird behaviour + * for malicious applications setting only __O_SYNC. */ - nd->flags |= LOOKUP_PARENT; - error = security_inode_follow_link(path.dentry, nd); + if (open_flag & __O_SYNC) + open_flag |= O_DSYNC; + + if (!acc_mode) + acc_mode = MAY_OPEN | ACC_MODE(open_flag); + + /* O_TRUNC implies we need access checks for write permissions */ + if (open_flag & O_TRUNC) + acc_mode |= MAY_WRITE; + + /* Allow the LSM permission hook to distinguish append + access from general write access. */ + if (open_flag & O_APPEND) + acc_mode |= MAY_APPEND; + + /* find the parent */ +reval: + error = path_init(dfd, pathname, LOOKUP_PARENT, &nd); if (error) - goto exit_dput; - error = __do_follow_link(&path, nd); + return ERR_PTR(error); + if (force_reval) + nd.flags |= LOOKUP_REVAL; + + current->total_link_count = 0; + error = link_path_walk(pathname, &nd); if (error) { - /* Does someone understand code flow here? Or it is only - * me so stupid? Anathema to whoever designed this non-sense - * with "intent.open". - */ - release_open_intent(nd); - return error; + filp = ERR_PTR(error); + goto out; } - nd->flags &= ~LOOKUP_PARENT; - if (nd->last_type == LAST_BIND) - goto ok; - error = -EISDIR; - if (nd->last_type != LAST_NORM) - goto exit; - if (nd->last.name[nd->last.len]) { - __putname(nd->last.name); - goto exit; + if (unlikely(!audit_dummy_context()) && (open_flag & O_CREAT)) + audit_inode(pathname, nd.path.dentry); + + /* + * We have the parent and last component. + */ + + error = -ENFILE; + filp = get_empty_filp(); + if (filp == NULL) + goto exit_parent; + nd.intent.open.file = filp; + filp->f_flags = open_flag; + nd.intent.open.flags = flag; + nd.intent.open.create_mode = mode; + nd.flags &= ~LOOKUP_PARENT; + nd.flags |= LOOKUP_OPEN; + if (open_flag & O_CREAT) { + nd.flags |= LOOKUP_CREATE; + if (open_flag & O_EXCL) + nd.flags |= LOOKUP_EXCL; } - error = -ELOOP; - if (count++==32) { - __putname(nd->last.name); - goto exit; + if (open_flag & O_DIRECTORY) + nd.flags |= LOOKUP_DIRECTORY; + if (!(open_flag & O_NOFOLLOW)) + nd.flags |= LOOKUP_FOLLOW; + filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname); + while (unlikely(!filp)) { /* trailing symlink */ + struct path holder; + struct inode *inode = path.dentry->d_inode; + void *cookie; + error = -ELOOP; + /* S_ISDIR part is a temporary automount kludge */ + if (!(nd.flags & LOOKUP_FOLLOW) && !S_ISDIR(inode->i_mode)) + goto exit_dput; + if (count++ == 32) + goto exit_dput; + /* + * This is subtle. Instead of calling do_follow_link() we do + * the thing by hands. The reason is that this way we have zero + * link_count and path_walk() (called from ->follow_link) + * honoring LOOKUP_PARENT. After that we have the parent and + * last component, i.e. we are in the same situation as after + * the first path_walk(). Well, almost - if the last component + * is normal we get its copy stored in nd->last.name and we will + * have to putname() it when we are done. Procfs-like symlinks + * just set LAST_BIND. + */ + nd.flags |= LOOKUP_PARENT; + error = security_inode_follow_link(path.dentry, &nd); + if (error) + goto exit_dput; + error = __do_follow_link(&path, &nd, &cookie); + if (unlikely(error)) { + /* nd.path had been dropped */ + if (!IS_ERR(cookie) && inode->i_op->put_link) + inode->i_op->put_link(path.dentry, &nd, cookie); + path_put(&path); + release_open_intent(&nd); + filp = ERR_PTR(error); + goto out; + } + holder = path; + nd.flags &= ~LOOKUP_PARENT; + filp = do_last(&nd, &path, open_flag, acc_mode, mode, pathname); + if (inode->i_op->put_link) + inode->i_op->put_link(holder.dentry, &nd, cookie); + path_put(&holder); } - dir = nd->path.dentry; - mutex_lock(&dir->d_inode->i_mutex); - path.dentry = lookup_hash(nd); - path.mnt = nd->path.mnt; - __putname(nd->last.name); - goto do_last; +out: + if (nd.root.mnt) + path_put(&nd.root); + if (filp == ERR_PTR(-ESTALE) && !force_reval) { + force_reval = 1; + goto reval; + } + return filp; + +exit_dput: + path_put_conditional(&path, &nd); + if (!IS_ERR(nd.intent.open.file)) + release_open_intent(&nd); +exit_parent: + path_put(&nd.path); + filp = ERR_PTR(error); + goto out; +} + +/** + * filp_open - open file and return file pointer + * + * @filename: path to open + * @flags: open flags as per the open(2) second argument + * @mode: mode for the new file if O_CREAT is set, else ignored + * + * This is the helper to open a file from kernelspace if you really + * have to. But in generally you should not do this, so please move + * along, nothing to see here.. + */ +struct file *filp_open(const char *filename, int flags, int mode) +{ + return do_filp_open(AT_FDCWD, filename, flags, mode, 0); } +EXPORT_SYMBOL(filp_open); /** * lookup_create - lookup a dentry, creating it if it doesn't exist @@ -1893,7 +1934,7 @@ struct dentry *lookup_create(struct nameidata *nd, int is_dir) if (nd->last_type != LAST_NORM) goto fail; nd->flags &= ~LOOKUP_PARENT; - nd->flags |= LOOKUP_CREATE; + nd->flags |= LOOKUP_CREATE | LOOKUP_EXCL; nd->intent.open.flags = O_EXCL; /* @@ -1903,18 +1944,22 @@ struct dentry *lookup_create(struct nameidata *nd, int is_dir) if (IS_ERR(dentry)) goto fail; + if (dentry->d_inode) + goto eexist; /* * Special case - lookup gave negative, but... we had foo/bar/ * From the vfs_mknod() POV we just have a negative dentry - * all is fine. Let's be bastards - you had / on the end, you've * been asking for (non-existent) directory. -ENOENT for you. */ - if (!is_dir && nd->last.name[nd->last.len] && !dentry->d_inode) - goto enoent; + if (unlikely(!is_dir && nd->last.name[nd->last.len])) { + dput(dentry); + dentry = ERR_PTR(-ENOENT); + } return dentry; -enoent: +eexist: dput(dentry); - dentry = ERR_PTR(-ENOENT); + dentry = ERR_PTR(-EEXIST); fail: return dentry; } @@ -1922,7 +1967,7 @@ EXPORT_SYMBOL_GPL(lookup_create); int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) { - int error = may_create(dir, dentry, NULL); + int error = may_create(dir, dentry); if (error) return error; @@ -1930,44 +1975,72 @@ int vfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev) if ((S_ISCHR(mode) || S_ISBLK(mode)) && !capable(CAP_MKNOD)) return -EPERM; - if (!dir->i_op || !dir->i_op->mknod) + if (!dir->i_op->mknod) return -EPERM; + error = devcgroup_inode_mknod(mode, dev); + if (error) + return error; + error = security_inode_mknod(dir, dentry, mode, dev); if (error) return error; - DQUOT_INIT(dir); error = dir->i_op->mknod(dir, dentry, mode, dev); if (!error) fsnotify_create(dir, dentry); return error; } -asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode, - unsigned dev) +static int may_mknod(mode_t mode) { - int error = 0; - char * tmp; - struct dentry * dentry; + switch (mode & S_IFMT) { + case S_IFREG: + case S_IFCHR: + case S_IFBLK: + case S_IFIFO: + case S_IFSOCK: + case 0: /* zero mode translates to S_IFREG */ + return 0; + case S_IFDIR: + return -EPERM; + default: + return -EINVAL; + } +} + +SYSCALL_DEFINE4(mknodat, int, dfd, const char __user *, filename, int, mode, + unsigned, dev) +{ + int error; + char *tmp; + struct dentry *dentry; struct nameidata nd; if (S_ISDIR(mode)) return -EPERM; - tmp = getname(filename); - if (IS_ERR(tmp)) - return PTR_ERR(tmp); - error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd); + error = user_path_parent(dfd, filename, &nd, &tmp); if (error) - goto out; - dentry = lookup_create(&nd, 0); - error = PTR_ERR(dentry); + return error; + dentry = lookup_create(&nd, 0); + if (IS_ERR(dentry)) { + error = PTR_ERR(dentry); + goto out_unlock; + } if (!IS_POSIXACL(nd.path.dentry->d_inode)) - mode &= ~current->fs->umask; - if (!IS_ERR(dentry)) { - switch (mode & S_IFMT) { + mode &= ~current_umask(); + error = may_mknod(mode); + if (error) + goto out_dput; + error = mnt_want_write(nd.path.mnt); + if (error) + goto out_dput; + error = security_path_mknod(&nd.path, dentry, mode, dev); + if (error) + goto out_drop_write; + switch (mode & S_IFMT) { case 0: case S_IFREG: error = vfs_create(nd.path.dentry->d_inode,dentry,mode,&nd); break; @@ -1978,35 +2051,32 @@ asmlinkage long sys_mknodat(int dfd, const char __user *filename, int mode, case S_IFIFO: case S_IFSOCK: error = vfs_mknod(nd.path.dentry->d_inode,dentry,mode,0); break; - case S_IFDIR: - error = -EPERM; - break; - default: - error = -EINVAL; - } - dput(dentry); } +out_drop_write: + mnt_drop_write(nd.path.mnt); +out_dput: + dput(dentry); +out_unlock: mutex_unlock(&nd.path.dentry->d_inode->i_mutex); path_put(&nd.path); -out: putname(tmp); return error; } -asmlinkage long sys_mknod(const char __user *filename, int mode, unsigned dev) +SYSCALL_DEFINE3(mknod, const char __user *, filename, int, mode, unsigned, dev) { return sys_mknodat(AT_FDCWD, filename, mode, dev); } int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) { - int error = may_create(dir, dentry, NULL); + int error = may_create(dir, dentry); if (error) return error; - if (!dir->i_op || !dir->i_op->mkdir) + if (!dir->i_op->mkdir) return -EPERM; mode &= (S_IRWXUGO|S_ISVTX); @@ -2014,47 +2084,50 @@ int vfs_mkdir(struct inode *dir, struct dentry *dentry, int mode) if (error) return error; - DQUOT_INIT(dir); error = dir->i_op->mkdir(dir, dentry, mode); if (!error) fsnotify_mkdir(dir, dentry); return error; } -asmlinkage long sys_mkdirat(int dfd, const char __user *pathname, int mode) +SYSCALL_DEFINE3(mkdirat, int, dfd, const char __user *, pathname, int, mode) { int error = 0; char * tmp; struct dentry *dentry; struct nameidata nd; - tmp = getname(pathname); - error = PTR_ERR(tmp); - if (IS_ERR(tmp)) + error = user_path_parent(dfd, pathname, &nd, &tmp); + if (error) goto out_err; - error = do_path_lookup(dfd, tmp, LOOKUP_PARENT, &nd); - if (error) - goto out; dentry = lookup_create(&nd, 1); error = PTR_ERR(dentry); if (IS_ERR(dentry)) goto out_unlock; if (!IS_POSIXACL(nd.path.dentry->d_inode)) - mode &= ~current->fs->umask; + mode &= ~current_umask(); + error = mnt_want_write(nd.path.mnt); + if (error) + goto out_dput; + error = security_path_mkdir(&nd.path, dentry, mode); + if (error) + goto out_drop_write; error = vfs_mkdir(nd.path.dentry->d_inode, dentry, mode); +out_drop_write: + mnt_drop_write(nd.path.mnt); +out_dput: dput(dentry); out_unlock: mutex_unlock(&nd.path.dentry->d_inode->i_mutex); path_put(&nd.path); -out: putname(tmp); out_err: return error; } -asmlinkage long sys_mkdir(const char __user *pathname, int mode) +SYSCALL_DEFINE2(mkdir, const char __user *, pathname, int, mode) { return sys_mkdirat(AT_FDCWD, pathname, mode); } @@ -2093,11 +2166,9 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry) if (error) return error; - if (!dir->i_op || !dir->i_op->rmdir) + if (!dir->i_op->rmdir) return -EPERM; - DQUOT_INIT(dir); - mutex_lock(&dentry->d_inode->i_mutex); dentry_unhash(dentry); if (d_mountpoint(dentry)) @@ -2106,8 +2177,10 @@ int vfs_rmdir(struct inode *dir, struct dentry *dentry) error = security_inode_rmdir(dir, dentry); if (!error) { error = dir->i_op->rmdir(dir, dentry); - if (!error) + if (!error) { dentry->d_inode->i_flags |= S_DEAD; + dont_mount(dentry); + } } } mutex_unlock(&dentry->d_inode->i_mutex); @@ -2126,42 +2199,49 @@ static long do_rmdir(int dfd, const char __user *pathname) struct dentry *dentry; struct nameidata nd; - name = getname(pathname); - if(IS_ERR(name)) - return PTR_ERR(name); - - error = do_path_lookup(dfd, name, LOOKUP_PARENT, &nd); + error = user_path_parent(dfd, pathname, &nd, &name); if (error) - goto exit; + return error; switch(nd.last_type) { - case LAST_DOTDOT: - error = -ENOTEMPTY; - goto exit1; - case LAST_DOT: - error = -EINVAL; - goto exit1; - case LAST_ROOT: - error = -EBUSY; - goto exit1; + case LAST_DOTDOT: + error = -ENOTEMPTY; + goto exit1; + case LAST_DOT: + error = -EINVAL; + goto exit1; + case LAST_ROOT: + error = -EBUSY; + goto exit1; } + + nd.flags &= ~LOOKUP_PARENT; + mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); dentry = lookup_hash(&nd); error = PTR_ERR(dentry); if (IS_ERR(dentry)) goto exit2; + error = mnt_want_write(nd.path.mnt); + if (error) + goto exit3; + error = security_path_rmdir(&nd.path, dentry); + if (error) + goto exit4; error = vfs_rmdir(nd.path.dentry->d_inode, dentry); +exit4: + mnt_drop_write(nd.path.mnt); +exit3: dput(dentry); exit2: mutex_unlock(&nd.path.dentry->d_inode->i_mutex); exit1: path_put(&nd.path); -exit: putname(name); return error; } -asmlinkage long sys_rmdir(const char __user *pathname) +SYSCALL_DEFINE1(rmdir, const char __user *, pathname) { return do_rmdir(AT_FDCWD, pathname); } @@ -2173,18 +2253,19 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry) if (error) return error; - if (!dir->i_op || !dir->i_op->unlink) + if (!dir->i_op->unlink) return -EPERM; - DQUOT_INIT(dir); - mutex_lock(&dentry->d_inode->i_mutex); if (d_mountpoint(dentry)) error = -EBUSY; else { error = security_inode_unlink(dir, dentry); - if (!error) + if (!error) { error = dir->i_op->unlink(dir, dentry); + if (!error) + dont_mount(dentry); + } } mutex_unlock(&dentry->d_inode->i_mutex); @@ -2205,22 +2286,22 @@ int vfs_unlink(struct inode *dir, struct dentry *dentry) */ static long do_unlinkat(int dfd, const char __user *pathname) { - int error = 0; - char * name; + int error; + char *name; struct dentry *dentry; struct nameidata nd; struct inode *inode = NULL; - name = getname(pathname); - if(IS_ERR(name)) - return PTR_ERR(name); - - error = do_path_lookup(dfd, name, LOOKUP_PARENT, &nd); + error = user_path_parent(dfd, pathname, &nd, &name); if (error) - goto exit; + return error; + error = -EISDIR; if (nd.last_type != LAST_NORM) goto exit1; + + nd.flags &= ~LOOKUP_PARENT; + mutex_lock_nested(&nd.path.dentry->d_inode->i_mutex, I_MUTEX_PARENT); dentry = lookup_hash(&nd); error = PTR_ERR(dentry); @@ -2231,7 +2312,15 @@ static long do_unlinkat(int dfd, const char __user *pathname) inode = dentry->d_inode; if (inode) atomic_inc(&inode->i_count); + error = mnt_want_write(nd.path.mnt); + if (error) + goto exit2; + error = security_path_unlink(&nd.path, dentry); + if (error) + goto exit3; error = vfs_unlink(nd.path.dentry->d_inode, dentry); +exit3: + mnt_drop_write(nd.path.mnt); exit2: dput(dentry); } @@ -2240,7 +2329,6 @@ static long do_unlinkat(int dfd, const char __user *pathname) iput(inode); /* truncate the inode here */ exit1: path_put(&nd.path); -exit: putname(name); return error; @@ -2250,7 +2338,7 @@ slashes: goto exit2; } -asmlinkage long sys_unlinkat(int dfd, const char __user *pathname, int flag) +SYSCALL_DEFINE3(unlinkat, int, dfd, const char __user *, pathname, int, flag) { if ((flag & ~AT_REMOVEDIR) != 0) return -EINVAL; @@ -2261,70 +2349,74 @@ asmlinkage long sys_unlinkat(int dfd, const char __user *pathname, int flag) return do_unlinkat(dfd, pathname); } -asmlinkage long sys_unlink(const char __user *pathname) +SYSCALL_DEFINE1(unlink, const char __user *, pathname) { return do_unlinkat(AT_FDCWD, pathname); } -int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname, int mode) +int vfs_symlink(struct inode *dir, struct dentry *dentry, const char *oldname) { - int error = may_create(dir, dentry, NULL); + int error = may_create(dir, dentry); if (error) return error; - if (!dir->i_op || !dir->i_op->symlink) + if (!dir->i_op->symlink) return -EPERM; error = security_inode_symlink(dir, dentry, oldname); if (error) return error; - DQUOT_INIT(dir); error = dir->i_op->symlink(dir, dentry, oldname); if (!error) fsnotify_create(dir, dentry); return error; } -asmlinkage long sys_symlinkat(const char __user *oldname, - int newdfd, const char __user *newname) +SYSCALL_DEFINE3(symlinkat, const char __user *, oldname, + int, newdfd, const char __user *, newname) { - int error = 0; - char * from; - char * to; + int error; + char *from; + char *to; struct dentry *dentry; struct nameidata nd; from = getname(oldname); - if(IS_ERR(from)) + if (IS_ERR(from)) return PTR_ERR(from); - to = getname(newname); - error = PTR_ERR(to); - if (IS_ERR(to)) - goto out_putname; - error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd); + error = user_path_parent(newdfd, newname, &nd, &to); if (error) - goto out; + goto out_putname; + dentry = lookup_create(&nd, 0); error = PTR_ERR(dentry); if (IS_ERR(dentry)) goto out_unlock; - error = vfs_symlink(nd.path.dentry->d_inode, dentry, from, S_IALLUGO); + error = mnt_want_write(nd.path.mnt); + if (error) + goto out_dput; + error = security_path_symlink(&nd.path, dentry, from); + if (error) + goto out_drop_write; + error = vfs_symlink(nd.path.dentry->d_inode, dentry, from); +out_drop_write: + mnt_drop_write(nd.path.mnt); +out_dput: dput(dentry); out_unlock: mutex_unlock(&nd.path.dentry->d_inode->i_mutex); path_put(&nd.path); -out: putname(to); out_putname: putname(from); return error; } -asmlinkage long sys_symlink(const char __user *oldname, const char __user *newname) +SYSCALL_DEFINE2(symlink, const char __user *, oldname, const char __user *, newname) { return sys_symlinkat(oldname, AT_FDCWD, newname); } @@ -2337,7 +2429,7 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de if (!inode) return -ENOENT; - error = may_create(dir, new_dentry, NULL); + error = may_create(dir, new_dentry); if (error) return error; @@ -2349,21 +2441,20 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de */ if (IS_APPEND(inode) || IS_IMMUTABLE(inode)) return -EPERM; - if (!dir->i_op || !dir->i_op->link) + if (!dir->i_op->link) return -EPERM; - if (S_ISDIR(old_dentry->d_inode->i_mode)) + if (S_ISDIR(inode->i_mode)) return -EPERM; error = security_inode_link(old_dentry, dir, new_dentry); if (error) return error; - mutex_lock(&old_dentry->d_inode->i_mutex); - DQUOT_INIT(dir); + mutex_lock(&inode->i_mutex); error = dir->i_op->link(old_dentry, dir, new_dentry); - mutex_unlock(&old_dentry->d_inode->i_mutex); + mutex_unlock(&inode->i_mutex); if (!error) - fsnotify_link(dir, old_dentry->d_inode, new_dentry); + fsnotify_link(dir, inode, new_dentry); return error; } @@ -2376,52 +2467,57 @@ int vfs_link(struct dentry *old_dentry, struct inode *dir, struct dentry *new_de * with linux 2.0, and to avoid hard-linking to directories * and other special files. --ADM */ -asmlinkage long sys_linkat(int olddfd, const char __user *oldname, - int newdfd, const char __user *newname, - int flags) +SYSCALL_DEFINE5(linkat, int, olddfd, const char __user *, oldname, + int, newdfd, const char __user *, newname, int, flags) { struct dentry *new_dentry; - struct nameidata nd, old_nd; + struct nameidata nd; + struct path old_path; int error; - char * to; + char *to; if ((flags & ~AT_SYMLINK_FOLLOW) != 0) return -EINVAL; - to = getname(newname); - if (IS_ERR(to)) - return PTR_ERR(to); - - error = __user_walk_fd(olddfd, oldname, - flags & AT_SYMLINK_FOLLOW ? LOOKUP_FOLLOW : 0, - &old_nd); + error = user_path_at(olddfd, oldname, + flags & AT_SYMLINK_FOLLOW ? LOOKUP_FOLLOW : 0, + &old_path); if (error) - goto exit; - error = do_path_lookup(newdfd, to, LOOKUP_PARENT, &nd); + return error; + + error = user_path_parent(newdfd, newname, &nd, &to); if (error) goto out; error = -EXDEV; - if (old_nd.path.mnt != nd.path.mnt) + if (old_path.mnt != nd.path.mnt) goto out_release; new_dentry = lookup_create(&nd, 0); error = PTR_ERR(new_dentry); if (IS_ERR(new_dentry)) goto out_unlock; - error = vfs_link(old_nd.path.dentry, nd.path.dentry->d_inode, new_dentry); + error = mnt_want_write(nd.path.mnt); + if (error) + goto out_dput; + error = security_path_link(old_path.dentry, &nd.path, new_dentry); + if (error) + goto out_drop_write; + error = vfs_link(old_path.dentry, nd.path.dentry->d_inode, new_dentry); +out_drop_write: + mnt_drop_write(nd.path.mnt); +out_dput: dput(new_dentry); out_unlock: mutex_unlock(&nd.path.dentry->d_inode->i_mutex); out_release: path_put(&nd.path); -out: - path_put(&old_nd.path); -exit: putname(to); +out: + path_put(&old_path); return error; } -asmlinkage long sys_link(const char __user *oldname, const char __user *newname) +SYSCALL_DEFINE2(link, const char __user *, oldname, const char __user *, newname) { return sys_linkat(AT_FDCWD, oldname, AT_FDCWD, newname, 0); } @@ -2455,7 +2551,7 @@ asmlinkage long sys_link(const char __user *oldname, const char __user *newname) * e) conversion from fhandle to dentry may come in the wrong moment - when * we are removing the target. Solution: we will have to grab ->i_mutex * in the fhandle_to_dentry code. [FIXME - current nfsfh.c relies on - * ->i_mutex on parents, which works but leads to some truely excessive + * ->i_mutex on parents, which works but leads to some truly excessive * locking]. */ static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry, @@ -2469,7 +2565,7 @@ static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry, * we'll need to flip '..'. */ if (new_dir != old_dir) { - error = permission(old_dentry->d_inode, MAY_WRITE, NULL); + error = inode_permission(old_dentry->d_inode, MAY_WRITE); if (error) return error; } @@ -2479,17 +2575,20 @@ static int vfs_rename_dir(struct inode *old_dir, struct dentry *old_dentry, return error; target = new_dentry->d_inode; - if (target) { + if (target) mutex_lock(&target->i_mutex); - dentry_unhash(new_dentry); - } if (d_mountpoint(old_dentry)||d_mountpoint(new_dentry)) error = -EBUSY; - else + else { + if (target) + dentry_unhash(new_dentry); error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry); + } if (target) { - if (!error) + if (!error) { target->i_flags |= S_DEAD; + dont_mount(new_dentry); + } mutex_unlock(&target->i_mutex); if (d_unhashed(new_dentry)) d_rehash(new_dentry); @@ -2520,6 +2619,8 @@ static int vfs_rename_other(struct inode *old_dir, struct dentry *old_dentry, else error = old_dir->i_op->rename(old_dir, old_dentry, new_dir, new_dentry); if (!error) { + if (target) + dont_mount(new_dentry); if (!(old_dir->i_sb->s_type->fs_flags & FS_RENAME_DOES_D_MOVE)) d_move(old_dentry, new_dentry); } @@ -2544,48 +2645,45 @@ int vfs_rename(struct inode *old_dir, struct dentry *old_dentry, return error; if (!new_dentry->d_inode) - error = may_create(new_dir, new_dentry, NULL); + error = may_create(new_dir, new_dentry); else error = may_delete(new_dir, new_dentry, is_dir); if (error) return error; - if (!old_dir->i_op || !old_dir->i_op->rename) + if (!old_dir->i_op->rename) return -EPERM; - DQUOT_INIT(old_dir); - DQUOT_INIT(new_dir); - old_name = fsnotify_oldname_init(old_dentry->d_name.name); if (is_dir) error = vfs_rename_dir(old_dir,old_dentry,new_dir,new_dentry); else error = vfs_rename_other(old_dir,old_dentry,new_dir,new_dentry); - if (!error) { - const char *new_name = old_dentry->d_name.name; - fsnotify_move(old_dir, new_dir, old_name, new_name, is_dir, + if (!error) + fsnotify_move(old_dir, new_dir, old_name, is_dir, new_dentry->d_inode, old_dentry); - } fsnotify_oldname_free(old_name); return error; } -static int do_rename(int olddfd, const char *oldname, - int newdfd, const char *newname) +SYSCALL_DEFINE4(renameat, int, olddfd, const char __user *, oldname, + int, newdfd, const char __user *, newname) { - int error = 0; - struct dentry * old_dir, * new_dir; - struct dentry * old_dentry, *new_dentry; - struct dentry * trap; + struct dentry *old_dir, *new_dir; + struct dentry *old_dentry, *new_dentry; + struct dentry *trap; struct nameidata oldnd, newnd; + char *from; + char *to; + int error; - error = do_path_lookup(olddfd, oldname, LOOKUP_PARENT, &oldnd); + error = user_path_parent(olddfd, oldname, &oldnd, &from); if (error) goto exit; - error = do_path_lookup(newdfd, newname, LOOKUP_PARENT, &newnd); + error = user_path_parent(newdfd, newname, &newnd, &to); if (error) goto exit1; @@ -2602,6 +2700,10 @@ static int do_rename(int olddfd, const char *oldname, if (newnd.last_type != LAST_NORM) goto exit2; + oldnd.flags &= ~LOOKUP_PARENT; + newnd.flags &= ~LOOKUP_PARENT; + newnd.flags |= LOOKUP_RENAME_TARGET; + trap = lock_rename(new_dir, old_dir); old_dentry = lookup_hash(&oldnd); @@ -2633,8 +2735,17 @@ static int do_rename(int olddfd, const char *oldname, if (new_dentry == trap) goto exit5; + error = mnt_want_write(oldnd.path.mnt); + if (error) + goto exit5; + error = security_path_rename(&oldnd.path, old_dentry, + &newnd.path, new_dentry); + if (error) + goto exit6; error = vfs_rename(old_dir->d_inode, old_dentry, new_dir->d_inode, new_dentry); +exit6: + mnt_drop_write(oldnd.path.mnt); exit5: dput(new_dentry); exit4: @@ -2643,33 +2754,15 @@ exit3: unlock_rename(new_dir, old_dir); exit2: path_put(&newnd.path); + putname(to); exit1: path_put(&oldnd.path); -exit: - return error; -} - -asmlinkage long sys_renameat(int olddfd, const char __user *oldname, - int newdfd, const char __user *newname) -{ - int error; - char * from; - char * to; - - from = getname(oldname); - if(IS_ERR(from)) - return PTR_ERR(from); - to = getname(newname); - error = PTR_ERR(to); - if (!IS_ERR(to)) { - error = do_rename(olddfd, from, newdfd, to); - putname(to); - } putname(from); +exit: return error; } -asmlinkage long sys_rename(const char __user *oldname, const char __user *newname) +SYSCALL_DEFINE2(rename, const char __user *, oldname, const char __user *, newname) { return sys_renameat(AT_FDCWD, oldname, AT_FDCWD, newname); } @@ -2700,16 +2793,17 @@ int generic_readlink(struct dentry *dentry, char __user *buffer, int buflen) { struct nameidata nd; void *cookie; + int res; nd.depth = 0; cookie = dentry->d_inode->i_op->follow_link(dentry, &nd); - if (!IS_ERR(cookie)) { - int res = vfs_readlink(dentry, buffer, buflen, nd_get_link(&nd)); - if (dentry->d_inode->i_op->put_link) - dentry->d_inode->i_op->put_link(dentry, &nd, cookie); - cookie = ERR_PTR(res); - } - return PTR_ERR(cookie); + if (IS_ERR(cookie)) + return PTR_ERR(cookie); + + res = vfs_readlink(dentry, buffer, buflen, nd_get_link(&nd)); + if (dentry->d_inode->i_op->put_link) + dentry->d_inode->i_op->put_link(dentry, &nd, cookie); + return res; } int vfs_follow_link(struct nameidata *nd, const char *link) @@ -2720,13 +2814,16 @@ int vfs_follow_link(struct nameidata *nd, const char *link) /* get the link contents into pagecache */ static char *page_getlink(struct dentry * dentry, struct page **ppage) { - struct page * page; + char *kaddr; + struct page *page; struct address_space *mapping = dentry->d_inode->i_mapping; page = read_mapping_page(mapping, 0, NULL); if (IS_ERR(page)) return (char*)page; *ppage = page; - return kmap(page); + kaddr = kmap(page); + nd_terminate_link(kaddr, dentry->d_inode->i_size, PAGE_SIZE - 1); + return kaddr; } int page_readlink(struct dentry *dentry, char __user *buffer, int buflen) @@ -2758,18 +2855,23 @@ void page_put_link(struct dentry *dentry, struct nameidata *nd, void *cookie) } } -int __page_symlink(struct inode *inode, const char *symname, int len, - gfp_t gfp_mask) +/* + * The nofs argument instructs pagecache_write_begin to pass AOP_FLAG_NOFS + */ +int __page_symlink(struct inode *inode, const char *symname, int len, int nofs) { struct address_space *mapping = inode->i_mapping; struct page *page; void *fsdata; int err; char *kaddr; + unsigned int flags = AOP_FLAG_UNINTERRUPTIBLE; + if (nofs) + flags |= AOP_FLAG_NOFS; retry: err = pagecache_write_begin(NULL, mapping, 0, len-1, - AOP_FLAG_UNINTERRUPTIBLE, &page, &fsdata); + flags, &page, &fsdata); if (err) goto fail; @@ -2793,7 +2895,7 @@ fail: int page_symlink(struct inode *inode, const char *symname, int len) { return __page_symlink(inode, symname, len, - mapping_gfp_mask(inode->i_mapping)); + !(mapping_gfp_mask(inode->i_mapping) & __GFP_FS)); } const struct inode_operations page_symlink_inode_operations = { @@ -2802,8 +2904,7 @@ const struct inode_operations page_symlink_inode_operations = { .put_link = page_put_link, }; -EXPORT_SYMBOL(__user_walk); -EXPORT_SYMBOL(__user_walk_fd); +EXPORT_SYMBOL(user_path_at); EXPORT_SYMBOL(follow_down); EXPORT_SYMBOL(follow_up); EXPORT_SYMBOL(get_write_access); /* binfmt_aout */ @@ -2817,9 +2918,9 @@ EXPORT_SYMBOL(__page_symlink); EXPORT_SYMBOL(page_symlink); EXPORT_SYMBOL(page_symlink_inode_operations); EXPORT_SYMBOL(path_lookup); +EXPORT_SYMBOL(kern_path); EXPORT_SYMBOL(vfs_path_lookup); -EXPORT_SYMBOL(permission); -EXPORT_SYMBOL(vfs_permission); +EXPORT_SYMBOL(inode_permission); EXPORT_SYMBOL(file_permission); EXPORT_SYMBOL(unlock_rename); EXPORT_SYMBOL(vfs_create);