From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com> To: sfrench@us.ibm.com, agruen@linbit.com, dilger.kernel@dilger.ca, sandeen@redhat.com, tytso@mit.edu, bfields@fieldses.org, jlayton@redhat.com Cc: aneesh.kumar@linux.vnet.ibm.com, linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org, Andreas Gruenbacher <agruen@suse.de> Subject: [PATCH -V5 15/24] richacl: Update the file masks in chmod() Date: Wed, 23 Feb 2011 19:22:02 +0530 [thread overview] Message-ID: <1298469131-16555-16-git-send-email-aneesh.kumar@linux.vnet.ibm.com> (raw) In-Reply-To: <1298469131-16555-1-git-send-email-aneesh.kumar@linux.vnet.ibm.com> From: Andreas Gruenbacher <agruen@suse.de> Doing a chmod() sets the file mode, which includes the file permission bits. When a file has a richacl, the permissions that the richacl grants need to be limited to what the new file permission bits allow. This is done by setting the file masks in the richacl to what the file permission bits map to. The richacl access check algorithm takes the file masks into account, which ensures that the richacl cannot grant too many permissions. It is possible to explicitly add permissions to the file masks which go beyond what the file permission bits can grant (like the ACE4_WRITE_ACL permission). The POSIX.1 standard calls this an alternate file access control mechanism. A subsequent chmod() would ensure that those permissions are disabled again. Signed-off-by: Andreas Gruenbacher <agruen@suse.de> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com> --- fs/richacl_base.c | 40 ++++++++++++++++++++++++++++++++++++++++ include/linux/richacl.h | 1 + 2 files changed, 41 insertions(+), 0 deletions(-) diff --git a/fs/richacl_base.c b/fs/richacl_base.c index 69ddb00..b59c75c 100644 --- a/fs/richacl_base.c +++ b/fs/richacl_base.c @@ -353,3 +353,43 @@ restart: acl->a_flags &= ~ACL4_MASKED; } EXPORT_SYMBOL_GPL(richacl_compute_max_masks); + +/** + * richacl_chmod - update the file masks to reflect the new mode + * @mode: new file permission bits + * + * Return a copy of @acl where the file masks have been replaced by the file + * masks corresponding to the file permission bits in @mode, or returns @acl + * itself if the file masks are already up to date. Takes over a reference + * to @acl. + */ +struct richacl * +richacl_chmod(struct richacl *acl, mode_t mode) +{ + unsigned int owner_mask, group_mask, other_mask; + struct richacl *clone; + + owner_mask = richacl_mode_to_mask(mode >> 6) | + ACE4_POSIX_OWNER_ALLOWED; + group_mask = richacl_mode_to_mask(mode >> 3); + other_mask = richacl_mode_to_mask(mode); + + if (acl->a_owner_mask == owner_mask && + acl->a_group_mask == group_mask && + acl->a_other_mask == other_mask && + (acl->a_flags & ACL4_MASKED)) + return acl; + + clone = richacl_clone(acl); + richacl_put(acl); + if (!clone) + return ERR_PTR(-ENOMEM); + + clone->a_flags |= ACL4_MASKED; + clone->a_owner_mask = owner_mask; + clone->a_group_mask = group_mask; + clone->a_other_mask = other_mask; + + return clone; +} +EXPORT_SYMBOL_GPL(richacl_chmod); diff --git a/include/linux/richacl.h b/include/linux/richacl.h index f491e59..3aa165b 100644 --- a/include/linux/richacl.h +++ b/include/linux/richacl.h @@ -288,5 +288,6 @@ extern int richacl_masks_to_mode(const struct richacl *); extern unsigned int richacl_mode_to_mask(mode_t); extern unsigned int richacl_want_to_mask(int); extern void richacl_compute_max_masks(struct richacl *); +extern struct richacl *richacl_chmod(struct richacl *, mode_t); #endif /* __RICHACL_H */ -- 1.7.1
WARNING: multiple messages have this Message-ID (diff)
From: "Aneesh Kumar K.V" <aneesh.kumar-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org> To: sfrench-r/Jw6+rmf7HQT0dZR+AlfA@public.gmane.org, agruen-63ez5xqkn6DQT0dZR+AlfA@public.gmane.org, dilger.kernel-m1MBpc4rdrD3fQ9qLvQP4Q@public.gmane.org, sandeen-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org, tytso-3s7WtUTddSA@public.gmane.org, bfields-uC3wQj2KruNg9hUCZPvPmw@public.gmane.org, jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org Cc: aneesh.kumar-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org, linux-fsdevel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-nfs-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-ext4-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-kernel-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Andreas Gruenbacher <agruen-l3A5Bk7waGM@public.gmane.org> Subject: [PATCH -V5 15/24] richacl: Update the file masks in chmod() Date: Wed, 23 Feb 2011 19:22:02 +0530 [thread overview] Message-ID: <1298469131-16555-16-git-send-email-aneesh.kumar@linux.vnet.ibm.com> (raw) In-Reply-To: <1298469131-16555-1-git-send-email-aneesh.kumar-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org> From: Andreas Gruenbacher <agruen-l3A5Bk7waGM@public.gmane.org> Doing a chmod() sets the file mode, which includes the file permission bits. When a file has a richacl, the permissions that the richacl grants need to be limited to what the new file permission bits allow. This is done by setting the file masks in the richacl to what the file permission bits map to. The richacl access check algorithm takes the file masks into account, which ensures that the richacl cannot grant too many permissions. It is possible to explicitly add permissions to the file masks which go beyond what the file permission bits can grant (like the ACE4_WRITE_ACL permission). The POSIX.1 standard calls this an alternate file access control mechanism. A subsequent chmod() would ensure that those permissions are disabled again. Signed-off-by: Andreas Gruenbacher <agruen-l3A5Bk7waGM@public.gmane.org> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar-23VcF4HTsmIX0ybBhKVfKdBPR1lH4CV8@public.gmane.org> --- fs/richacl_base.c | 40 ++++++++++++++++++++++++++++++++++++++++ include/linux/richacl.h | 1 + 2 files changed, 41 insertions(+), 0 deletions(-) diff --git a/fs/richacl_base.c b/fs/richacl_base.c index 69ddb00..b59c75c 100644 --- a/fs/richacl_base.c +++ b/fs/richacl_base.c @@ -353,3 +353,43 @@ restart: acl->a_flags &= ~ACL4_MASKED; } EXPORT_SYMBOL_GPL(richacl_compute_max_masks); + +/** + * richacl_chmod - update the file masks to reflect the new mode + * @mode: new file permission bits + * + * Return a copy of @acl where the file masks have been replaced by the file + * masks corresponding to the file permission bits in @mode, or returns @acl + * itself if the file masks are already up to date. Takes over a reference + * to @acl. + */ +struct richacl * +richacl_chmod(struct richacl *acl, mode_t mode) +{ + unsigned int owner_mask, group_mask, other_mask; + struct richacl *clone; + + owner_mask = richacl_mode_to_mask(mode >> 6) | + ACE4_POSIX_OWNER_ALLOWED; + group_mask = richacl_mode_to_mask(mode >> 3); + other_mask = richacl_mode_to_mask(mode); + + if (acl->a_owner_mask == owner_mask && + acl->a_group_mask == group_mask && + acl->a_other_mask == other_mask && + (acl->a_flags & ACL4_MASKED)) + return acl; + + clone = richacl_clone(acl); + richacl_put(acl); + if (!clone) + return ERR_PTR(-ENOMEM); + + clone->a_flags |= ACL4_MASKED; + clone->a_owner_mask = owner_mask; + clone->a_group_mask = group_mask; + clone->a_other_mask = other_mask; + + return clone; +} +EXPORT_SYMBOL_GPL(richacl_chmod); diff --git a/include/linux/richacl.h b/include/linux/richacl.h index f491e59..3aa165b 100644 --- a/include/linux/richacl.h +++ b/include/linux/richacl.h @@ -288,5 +288,6 @@ extern int richacl_masks_to_mode(const struct richacl *); extern unsigned int richacl_mode_to_mask(mode_t); extern unsigned int richacl_want_to_mask(int); extern void richacl_compute_max_masks(struct richacl *); +extern struct richacl *richacl_chmod(struct richacl *, mode_t); #endif /* __RICHACL_H */ -- 1.7.1 -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html
next prev parent reply other threads:[~2011-02-23 13:55 UTC|newest] Thread overview: 49+ messages / expand[flat|nested] mbox.gz Atom feed top 2011-02-23 13:51 [PATCH -V5 00/24] New ACL format for better NFSv4 acl interoperability Aneesh Kumar K.V 2011-02-23 13:51 ` [PATCH -V5 01/24] vfs: Indicate that the permission functions take all the MAY_* flags Aneesh Kumar K.V 2011-02-23 13:51 ` [PATCH -V5 02/24] vfs: Pass all mask flags down to iop->check_acl Aneesh Kumar K.V 2011-02-23 13:51 ` Aneesh Kumar K.V 2011-02-23 13:51 ` [PATCH -V5 03/24] vfs: Add a comment to inode_permission() Aneesh Kumar K.V 2011-02-23 13:51 ` Aneesh Kumar K.V 2011-02-23 13:51 ` [PATCH -V5 04/24] vfs: Add generic IS_ACL() test for acl support Aneesh Kumar K.V 2011-02-23 13:51 ` [PATCH -V5 05/24] vfs: Add IS_RICHACL() test for richacl support Aneesh Kumar K.V 2011-02-23 13:51 ` [PATCH -V5 06/24] vfs: Optimize out IS_RICHACL() if CONFIG_FS_RICHACL is not defined Aneesh Kumar K.V 2011-02-23 13:51 ` [PATCH -V5 07/24] vfs: Add new file and directory create permission flags Aneesh Kumar K.V 2011-02-23 13:51 ` [PATCH -V5 08/24] vfs: Add delete child and delete self " Aneesh Kumar K.V 2011-02-23 13:51 ` [PATCH -V5 09/24] vfs: Make the inode passed to inode_change_ok non-const Aneesh Kumar K.V 2011-02-23 13:51 ` [PATCH -V5 10/24] vfs: Add permission flags for setting file attributes Aneesh Kumar K.V 2011-02-23 13:51 ` [PATCH -V5 11/24] vfs: Make acl_permission_check() work for richacls Aneesh Kumar K.V 2011-02-23 13:51 ` [PATCH -V5 12/24] richacl: In-memory representation and helper functions Aneesh Kumar K.V 2011-02-23 13:52 ` [PATCH -V5 13/24] richacl: Permission mapping functions Aneesh Kumar K.V 2011-02-23 13:52 ` [PATCH -V5 14/24] richacl: Compute maximum file masks from an acl Aneesh Kumar K.V 2011-02-23 13:52 ` Aneesh Kumar K.V 2011-02-23 13:52 ` Aneesh Kumar K.V [this message] 2011-02-23 13:52 ` [PATCH -V5 15/24] richacl: Update the file masks in chmod() Aneesh Kumar K.V 2011-02-23 13:52 ` [PATCH -V5 16/24] richacl: Permission check algorithm Aneesh Kumar K.V 2011-02-23 13:52 ` [PATCH -V5 17/24] richacl: Create-time inheritance Aneesh Kumar K.V 2011-02-23 13:52 ` [PATCH -V5 18/24] richacl: Check if an acl is equivalent to a file mode Aneesh Kumar K.V 2011-02-23 13:52 ` [PATCH -V5 19/24] richacl: Automatic Inheritance Aneesh Kumar K.V 2011-02-23 13:52 ` [PATCH -V5 20/24] richacl: xattr mapping functions Aneesh Kumar K.V 2011-02-23 13:52 ` [PATCH -V5 21/24] ext4: Use IS_POSIXACL() to check for POSIX ACL support Aneesh Kumar K.V 2011-02-23 13:52 ` [PATCH -V5 22/24] vfs: Cache richacl in struct inode Aneesh Kumar K.V 2011-02-23 13:52 ` [PATCH -V5 23/24] ext4: Implement rich acl for ext4 Aneesh Kumar K.V 2011-02-23 13:52 ` [PATCH -V5 24/24] ext4: Add temporary richacl mount option " Aneesh Kumar K.V 2011-02-28 21:11 ` [PATCH -V5 00/24] New ACL format for better NFSv4 acl interoperability Ted Ts'o 2011-02-28 21:11 ` Ted Ts'o 2011-03-01 6:50 ` Aneesh Kumar K. V 2011-03-02 15:49 ` J. Bruce Fields 2011-03-02 17:47 ` Aneesh Kumar K. V 2011-03-02 17:47 ` Aneesh Kumar K. V 2011-03-02 18:58 ` J. Bruce Fields 2011-03-02 18:58 ` J. Bruce Fields 2011-03-04 10:38 ` Aneesh Kumar K. V 2011-03-05 0:32 ` J. Bruce Fields 2011-03-05 17:58 ` Aneesh Kumar K. V 2011-03-05 17:58 ` Aneesh Kumar K. V 2011-03-15 8:46 ` Andreas Gruenbacher 2011-05-11 22:16 ` Björn JACKE 2011-05-11 22:16 ` Björn JACKE 2011-05-11 22:16 ` Björn JACKE [not found] ` <E1QKJAl-00DGc7-EB-dqLtpHMqGvUyWpdLl23E4A@public.gmane.org> 2011-05-13 15:40 ` Aneesh Kumar K.V 2011-05-13 15:40 ` Aneesh Kumar K.V 2011-05-13 15:40 ` Aneesh Kumar K.V 2011-05-13 15:40 ` Aneesh Kumar K.V
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