diff options
| -rw-r--r-- | fs/dcache.c | 150 |
1 files changed, 70 insertions, 80 deletions
diff --git a/fs/dcache.c b/fs/dcache.c index b5f61393291..d68631f18df 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -1739,41 +1739,45 @@ shouldnt_be_hashed: * @rootmnt: vfsmnt to which the root dentry belongs * @buffer: buffer to return value in * @buflen: buffer length - * @fail_deleted: what to return for deleted files * - * Convert a dentry into an ASCII path name. If the entry has been deleted, - * then if @fail_deleted is true, ERR_PTR(-ENOENT) is returned. Otherwise, - * the the string " (deleted)" is appended. Note that this is ambiguous. + * Convert a dentry into an ASCII path name. If the entry has been deleted + * the string " (deleted)" is appended. Note that this is ambiguous. * - * Returns the buffer or an error code. + * Returns the buffer or an error code if the path was too long. + * + * "buflen" should be positive. Caller holds the dcache_lock. */ -static char *__d_path(struct dentry *dentry, struct vfsmount *vfsmnt, - struct dentry *root, struct vfsmount *rootmnt, - char *buffer, int buflen, int fail_deleted) +static char * __d_path( struct dentry *dentry, struct vfsmount *vfsmnt, + struct dentry *root, struct vfsmount *rootmnt, + char *buffer, int buflen) { - int namelen, is_slash; - - if (buflen < 2) - return ERR_PTR(-ENAMETOOLONG); - buffer += --buflen; - *buffer = '\0'; + char * end = buffer+buflen; + char * retval; + int namelen; - spin_lock(&dcache_lock); + *--end = '\0'; + buflen--; if (!IS_ROOT(dentry) && d_unhashed(dentry)) { - if (fail_deleted) { - buffer = ERR_PTR(-ENOENT); - goto out; - } - if (buflen < 10) - goto Elong; buflen -= 10; - buffer -= 10; - memcpy(buffer, " (deleted)", 10); + end -= 10; + if (buflen < 0) + goto Elong; + memcpy(end, " (deleted)", 10); } - while (dentry != root || vfsmnt != rootmnt) { + + if (buflen < 1) + goto Elong; + /* Get '/' right */ + retval = end-1; + *retval = '/'; + + for (;;) { struct dentry * parent; + if (dentry == root && vfsmnt == rootmnt) + break; if (dentry == vfsmnt->mnt_root || IS_ROOT(dentry)) { + /* Global root? */ spin_lock(&vfsmount_lock); if (vfsmnt->mnt_parent == vfsmnt) { spin_unlock(&vfsmount_lock); @@ -1787,60 +1791,33 @@ static char *__d_path(struct dentry *dentry, struct vfsmount *vfsmnt, parent = dentry->d_parent; prefetch(parent); namelen = dentry->d_name.len; - if (buflen <= namelen) - goto Elong; buflen -= namelen + 1; - buffer -= namelen; - memcpy(buffer, dentry->d_name.name, namelen); - *--buffer = '/'; + if (buflen < 0) + goto Elong; + end -= namelen; + memcpy(end, dentry->d_name.name, namelen); + *--end = '/'; + retval = end; dentry = parent; } - /* Get '/' right */ - if (*buffer != '/') - *--buffer = '/'; -out: - spin_unlock(&dcache_lock); - return buffer; + return retval; global_root: - /* - * We went past the (vfsmount, dentry) we were looking for and have - * either hit a root dentry, a lazily unmounted dentry, an - * unconnected dentry, or the file is on a pseudo filesystem. - */ namelen = dentry->d_name.len; - is_slash = (namelen == 1 && *dentry->d_name.name == '/'); - if (is_slash || (dentry->d_sb->s_flags & MS_NOUSER)) { - /* - * Make sure we won't return a pathname starting with '/'. - * - * Historically, we also glue together the root dentry and - * remaining name for pseudo filesystems like pipefs, which - * have the MS_NOUSER flag set. This results in pathnames - * like "pipe:[439336]". - */ - if (*buffer == '/') { - buffer++; - buflen++; - } - if (is_slash) - goto out; - } - if (buflen < namelen) + buflen -= namelen; + if (buflen < 0) goto Elong; - buffer -= namelen; - memcpy(buffer, dentry->d_name.name, namelen); - goto out; - + retval -= namelen-1; /* hit the slash */ + memcpy(retval, dentry->d_name.name, namelen); + return retval; Elong: - buffer = ERR_PTR(-ENAMETOOLONG); - goto out; + return ERR_PTR(-ENAMETOOLONG); } /* write full pathname into buffer and return start of pathname */ -char *d_path(struct dentry *dentry, struct vfsmount *vfsmnt, char *buf, - int buflen) +char * d_path(struct dentry *dentry, struct vfsmount *vfsmnt, + char *buf, int buflen) { char *res; struct vfsmount *rootmnt; @@ -1850,7 +1827,9 @@ char *d_path(struct dentry *dentry, struct vfsmount *vfsmnt, char *buf, rootmnt = mntget(current->fs->rootmnt); root = dget(current->fs->root); read_unlock(¤t->fs->lock); - res = __d_path(dentry, vfsmnt, root, rootmnt, buf, buflen, 0); + spin_lock(&dcache_lock); + res = __d_path(dentry, vfsmnt, root, rootmnt, buf, buflen); + spin_unlock(&dcache_lock); dput(root); mntput(rootmnt); return res; @@ -1876,10 +1855,10 @@ char *d_path(struct dentry *dentry, struct vfsmount *vfsmnt, char *buf, */ asmlinkage long sys_getcwd(char __user *buf, unsigned long size) { - int error, len; + int error; struct vfsmount *pwdmnt, *rootmnt; struct dentry *pwd, *root; - char *page = (char *) __get_free_page(GFP_USER), *cwd; + char *page = (char *) __get_free_page(GFP_USER); if (!page) return -ENOMEM; @@ -1891,18 +1870,29 @@ asmlinkage long sys_getcwd(char __user *buf, unsigned long size) root = dget(current->fs->root); read_unlock(¤t->fs->lock); - cwd = __d_path(pwd, pwdmnt, root, rootmnt, page, PAGE_SIZE, 1); - error = PTR_ERR(cwd); - if (IS_ERR(cwd)) - goto out; + error = -ENOENT; + /* Has the current directory has been unlinked? */ + spin_lock(&dcache_lock); + if (pwd->d_parent == pwd || !d_unhashed(pwd)) { + unsigned long len; + char * cwd; - error = -ERANGE; - len = PAGE_SIZE + page - cwd; - if (len <= size) { - error = len; - if (copy_to_user(buf, cwd, len)) - error = -EFAULT; - } + cwd = __d_path(pwd, pwdmnt, root, rootmnt, page, PAGE_SIZE); + spin_unlock(&dcache_lock); + + error = PTR_ERR(cwd); + if (IS_ERR(cwd)) + goto out; + + error = -ERANGE; + len = PAGE_SIZE + page - cwd; + if (len <= size) { + error = len; + if (copy_to_user(buf, cwd, len)) + error = -EFAULT; + } + } else + spin_unlock(&dcache_lock); out: dput(pwd); |