The ACL value is fetched as a part of inode initialization from the server and the permission checking function use the cached value of the ACL Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> --- fs/9p/Kconfig | 13 +++++++ fs/9p/Makefile | 1 + fs/9p/acl.c | 95 +++++++++++++++++++++++++++++++++++++++++++++++++++++ fs/9p/acl.h | 27 +++++++++++++++ fs/9p/vfs_inode.c | 11 +++++- fs/9p/vfs_super.c | 9 ++++- fs/9p/xattr.c | 48 +++++++++++++++----------- fs/9p/xattr.h | 4 ++ 8 files changed, 185 insertions(+), 23 deletions(-) create mode 100644 fs/9p/acl.c create mode 100644 fs/9p/acl.h diff --git a/fs/9p/Kconfig b/fs/9p/Kconfig index 7952337..7e05114 100644 --- a/fs/9p/Kconfig +++ b/fs/9p/Kconfig @@ -17,3 +17,16 @@ config 9P_FSCACHE Choose Y here to enable persistent, read-only local caching support for 9p clients using FS-Cache + +config 9P_FS_POSIX_ACL + bool "9P POSIX Access Control Lists" + depends on 9P_FS + select FS_POSIX_ACL + help + POSIX Access Control Lists (ACLs) support permissions for users and + groups beyond the owner/group/world scheme. + + To learn more about Access Control Lists, visit the POSIX ACLs for + Linux website <http://acl.bestbits.at/>. + + If you don't know what Access Control Lists are, say N diff --git a/fs/9p/Makefile b/fs/9p/Makefile index 91fba02..f8ba37e 100644 --- a/fs/9p/Makefile +++ b/fs/9p/Makefile @@ -13,3 +13,4 @@ obj-$(CONFIG_9P_FS) := 9p.o xattr_user.o 9p-$(CONFIG_9P_FSCACHE) += cache.o +9p-$(CONFIG_9P_FS_POSIX_ACL) += acl.o diff --git a/fs/9p/acl.c b/fs/9p/acl.c new file mode 100644 index 0000000..5de599b --- /dev/null +++ b/fs/9p/acl.c @@ -0,0 +1,95 @@ +/* + * Copyright IBM Corporation, 2010 + * Author Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2.1 of the GNU Lesser General Public License + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + * + */ + +#include <linux/module.h> +#include <linux/fs.h> +#include <net/9p/9p.h> +#include <net/9p/client.h> +#include <linux/slab.h> +#include <linux/posix_acl_xattr.h> +#include "xattr.h" + +static struct posix_acl *__v9fs_get_acl(struct p9_fid *fid, char *name) +{ + ssize_t size; + void *value = NULL; + struct posix_acl *acl = NULL;; + + size = v9fs_fid_xattr_get(fid, name, NULL, 0); + if (size > 0) { + value = kzalloc(size, GFP_NOFS); + if (!value) + return ERR_PTR(-ENOMEM); + size = v9fs_fid_xattr_get(fid, name, value, size); + if (size > 0) { + acl = posix_acl_from_xattr(value, size); + if (IS_ERR(acl)) + goto err_out; + } + } else if (size == -ENODATA || size == 0 || + size == -ENOSYS || size == -EOPNOTSUPP) { + acl = NULL; + } else + acl = ERR_PTR(-EIO); + +err_out: + kfree(value); + return acl; +} + +int v9fs_get_acl(struct inode *inode, struct p9_fid *fid) +{ + int retval = 0; + struct posix_acl *pacl, *dacl; + + /* get the default/access acl values and cache them */ + dacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_DEFAULT); + pacl = __v9fs_get_acl(fid, POSIX_ACL_XATTR_ACCESS); + + if (!IS_ERR(dacl) && !IS_ERR(pacl)) { + set_cached_acl(inode, ACL_TYPE_DEFAULT, dacl); + set_cached_acl(inode, ACL_TYPE_ACCESS, pacl); + posix_acl_release(dacl); + posix_acl_release(pacl); + } else + retval = -EIO; + + return retval; +} + +static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type) +{ + struct posix_acl *acl; + /* + * 9p Always cache the acl value when + * instantiating the inode (v9fs_inode_from_fid) + */ + acl = get_cached_acl(inode, type); + BUG_ON(acl == ACL_NOT_CACHED); + return acl; +} + +int v9fs_check_acl(struct inode *inode, int mask) +{ + struct posix_acl *acl = v9fs_get_cached_acl(inode, ACL_TYPE_ACCESS); + + if (IS_ERR(acl)) + return PTR_ERR(acl); + if (acl) { + int error = posix_acl_permission(inode, acl, mask); + posix_acl_release(acl); + return error; + } + return -EAGAIN; +} diff --git a/fs/9p/acl.h b/fs/9p/acl.h new file mode 100644 index 0000000..4c63eb1 --- /dev/null +++ b/fs/9p/acl.h @@ -0,0 +1,27 @@ +/* + * Copyright IBM Corporation, 2010 + * Author Aneesh Kumar K.V <aneesh.kumar@xxxxxxxxxxxxxxxxxx> + * + * This program is free software; you can redistribute it and/or modify it + * under the terms of version 2.1 of the GNU Lesser General Public License + * as published by the Free Software Foundation. + * + * This program is distributed in the hope that it would be useful, but + * WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. + * + */ +#ifndef FS_9P_ACL_H +#define FS_9P_ACL_H + +#ifdef CONFIG_9P_FS_POSIX_ACL +extern int v9fs_get_acl(struct inode *, struct p9_fid *); +extern int v9fs_check_acl(struct inode *inode, int mask); +#else +#define v9fs_check_acl NULL +static inline int v9fs_get_acl(struct inode *, struct p9_fid *) +{ + return 0; +} +#endif +#endif /* FS_9P_XATTR_H */ diff --git a/fs/9p/vfs_inode.c b/fs/9p/vfs_inode.c index b23b6a5..7f0aac1 100644 --- a/fs/9p/vfs_inode.c +++ b/fs/9p/vfs_inode.c @@ -36,6 +36,7 @@ #include <linux/sched.h> #include <linux/slab.h> #include <linux/xattr.h> +#include <linux/posix_acl.h> #include <net/9p/9p.h> #include <net/9p/client.h> @@ -44,6 +45,7 @@ #include "fid.h" #include "cache.h" #include "xattr.h" +#include "acl.h" static const struct inode_operations v9fs_dir_inode_operations; static const struct inode_operations v9fs_dir_inode_operations_dotu; @@ -498,6 +500,11 @@ v9fs_inode_dotl(struct v9fs_session_info *v9ses, struct p9_fid *fid, v9fs_vcookie_set_qid(ret, &st->qid); v9fs_cache_inode_get_cookie(ret); #endif + err = v9fs_get_acl(ret, fid); + if (err) { + iput(ret); + goto error; + } kfree(st); return ret; error: @@ -629,7 +636,6 @@ v9fs_create(struct v9fs_session_info *v9ses, struct inode *dir, goto error; } } - /* instantiate inode and assign the unopened fid to the dentry */ inode = v9fs_inode_from_fid(v9ses, fid, dir->i_sb); if (IS_ERR(inode)) { @@ -1964,7 +1970,7 @@ static const struct inode_operations v9fs_dir_inode_operations_dotl = { .getxattr = generic_getxattr, .removexattr = generic_removexattr, .listxattr = v9fs_listxattr, - + .check_acl = v9fs_check_acl, }; static const struct inode_operations v9fs_dir_inode_operations = { @@ -1991,6 +1997,7 @@ static const struct inode_operations v9fs_file_inode_operations_dotl = { .getxattr = generic_getxattr, .removexattr = generic_removexattr, .listxattr = v9fs_listxattr, + .check_acl = v9fs_check_acl, }; static const struct inode_operations v9fs_symlink_inode_operations = { diff --git a/fs/9p/vfs_super.c b/fs/9p/vfs_super.c index b222953..a120a48 100644 --- a/fs/9p/vfs_super.c +++ b/fs/9p/vfs_super.c @@ -46,6 +46,7 @@ #include "v9fs_vfs.h" #include "fid.h" #include "xattr.h" +#include "acl.h" static const struct super_operations v9fs_super_ops, v9fs_super_ops_dotl; @@ -88,6 +89,10 @@ v9fs_fill_super(struct super_block *sb, struct v9fs_session_info *v9ses, sb->s_flags = flags | MS_ACTIVE | MS_SYNCHRONOUS | MS_DIRSYNC | MS_NOATIME; +#ifdef CONFIG_9P_FS_POSIX_ACL + sb->s_flags |= MS_POSIXACL; +#endif + save_mount_options(sb, data); } @@ -149,7 +154,6 @@ static int v9fs_get_sb(struct file_system_type *fs_type, int flags, goto release_sb; } sb->s_root = root; - if (v9fs_proto_dotl(v9ses)) { struct p9_stat_dotl *st = NULL; st = p9_client_getattr_dotl(fid, P9_STATS_BASIC); @@ -174,6 +178,9 @@ static int v9fs_get_sb(struct file_system_type *fs_type, int flags, p9stat_free(st); kfree(st); } + retval = v9fs_get_acl(inode, fid); + if (retval) + goto release_sb; v9fs_fid_add(root, fid); diff --git a/fs/9p/xattr.c b/fs/9p/xattr.c index c434424..a3696c9 100644 --- a/fs/9p/xattr.c +++ b/fs/9p/xattr.c @@ -21,30 +21,13 @@ #include "fid.h" #include "xattr.h" -/* - * v9fs_xattr_get() - * - * Copy an extended attribute into the buffer - * provided, or compute the buffer size required. - * Buffer is NULL to compute the size of the buffer required. - * - * Returns a negative error number on failure, or the number of bytes - * used / required on success. - */ -ssize_t v9fs_xattr_get(struct dentry *dentry, const char *name, - void *buffer, size_t buffer_size) +ssize_t v9fs_fid_xattr_get(struct p9_fid *fid, const char *name, + void *buffer, size_t buffer_size) { ssize_t retval; int msize, read_count; u64 offset = 0, attr_size; - struct p9_fid *fid, *attr_fid; - - P9_DPRINTK(P9_DEBUG_VFS, "%s: name = %s value_len = %zu\n", - __func__, name, buffer_size); - - fid = v9fs_fid_lookup(dentry); - if (IS_ERR(fid)) - return PTR_ERR(fid); + struct p9_fid *attr_fid; attr_fid = p9_client_xattrwalk(fid, name, &attr_size); if (IS_ERR(attr_fid)) { @@ -88,6 +71,31 @@ error: } + +/* + * v9fs_xattr_get() + * + * Copy an extended attribute into the buffer + * provided, or compute the buffer size required. + * Buffer is NULL to compute the size of the buffer required. + * + * Returns a negative error number on failure, or the number of bytes + * used / required on success. + */ +ssize_t v9fs_xattr_get(struct dentry *dentry, const char *name, + void *buffer, size_t buffer_size) +{ + struct p9_fid *fid; + + P9_DPRINTK(P9_DEBUG_VFS, "%s: name = %s value_len = %zu\n", + __func__, name, buffer_size); + fid = v9fs_fid_lookup(dentry); + if (IS_ERR(fid)) + return PTR_ERR(fid); + + return v9fs_fid_xattr_get(fid, name, buffer, buffer_size); +} + /* * v9fs_xattr_set() * diff --git a/fs/9p/xattr.h b/fs/9p/xattr.h index 9ddf672..ec908c6 100644 --- a/fs/9p/xattr.h +++ b/fs/9p/xattr.h @@ -15,10 +15,14 @@ #define FS_9P_XATTR_H #include <linux/xattr.h> +#include <net/9p/9p.h> +#include <net/9p/client.h> extern const struct xattr_handler *v9fs_xattr_handlers[]; extern struct xattr_handler v9fs_xattr_user_handler; +extern ssize_t v9fs_fid_xattr_get(struct p9_fid *, const char *, + void *, size_t); extern ssize_t v9fs_xattr_get(struct dentry *, const char *, void *, size_t); extern int v9fs_xattr_set(struct dentry *, const char *, -- 1.7.0.4 -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
