diff mbox

[v13,21/51] ext4: Add richacl feature flag

Message ID 1446563847-14005-22-git-send-email-agruenba@redhat.com (mailing list archive)
State New, archived
Headers show

Commit Message

Andreas Gruenbacher Nov. 3, 2015, 3:16 p.m. UTC 
From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>

This feature flag selects richacl instead of posix acl support on the
file system. In addition, the "acl" mount option is needed for enabling
either of the two kinds of acls.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
---
 fs/ext4/ext4.h  |  6 ++++--
 fs/ext4/super.c | 49 ++++++++++++++++++++++++++++++++++++++++---------
 2 files changed, 44 insertions(+), 11 deletions(-)

Comments

Andreas Dilger Nov. 4, 2015, 2:18 a.m. UTC | #1 
> On Nov 3, 2015, at 8:16 AM, Andreas Gruenbacher <agruenba@redhat.com> wrote:
> 
> From: "Aneesh Kumar K.V" <aneesh.kumar@linux.vnet.ibm.com>
> 
> This feature flag selects richacl instead of posix acl support on the
> file system. In addition, the "acl" mount option is needed for enabling
> either of the two kinds of acls.

This patch confuses me.  I thought the whole point of INCOMPAT_RICHACL
was that the filesystem should never, ever be mounted without ACL support
because the ACLs will get confused without it.  In that case, it doesn't
make sense to have a mount option that _has_ to be specified to mount the
filesystem, and returns an error when trying to disable it.

It makes more sense to just enable "acl" by default if INCOMPAT_RICHACL
is set in the superblock and not need the mount option at all.

Having a mount option made more sense when enabling this support was optional
for the filesystem, and it could be mounted without it enabled, but you
wanted INCOMPAT_RICHACL to prevent that so it needs to be fixed.

Cheers, Andreas

> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
> Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
> ---
> fs/ext4/ext4.h  |  6 ++++--
> fs/ext4/super.c | 49 ++++++++++++++++++++++++++++++++++++++++---------
> 2 files changed, 44 insertions(+), 11 deletions(-)
> 
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index fd1f28b..b97a3b1 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -991,7 +991,7 @@ struct ext4_inode_info {
> #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
> #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
> #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
> -#define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
> +#define EXT4_MOUNT_ACL			0x08000	/* Access Control Lists */
> #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
> #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
> #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
> @@ -1582,6 +1582,7 @@ static inline int ext4_encrypted_inode(struct inode *inode)
> #define EXT4_FEATURE_INCOMPAT_LARGEDIR		0x4000 /* >2GB or 3-lvl htree */
> #define EXT4_FEATURE_INCOMPAT_INLINE_DATA	0x8000 /* data in inode */
> #define EXT4_FEATURE_INCOMPAT_ENCRYPT		0x10000
> +#define EXT4_FEATURE_INCOMPAT_RICHACL		0x20000
> 
> #define EXT2_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
> #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
> @@ -1607,7 +1608,8 @@ static inline int ext4_encrypted_inode(struct inode *inode)
> 					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
> 					 EXT4_FEATURE_INCOMPAT_MMP | \
> 					 EXT4_FEATURE_INCOMPAT_INLINE_DATA | \
> -					 EXT4_FEATURE_INCOMPAT_ENCRYPT)
> +					 EXT4_FEATURE_INCOMPAT_ENCRYPT | \
> +					 EXT4_FEATURE_INCOMPAT_RICHACL)
> #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
> 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
> 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index a63c7b0..7457ea8 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -1270,6 +1270,28 @@ static ext4_fsblk_t get_sb_block(void **data)
> 	return sb_block;
> }
> 
> +static int enable_acl(struct super_block *sb)
> +{
> +	sb->s_flags &= ~(MS_POSIXACL | MS_RICHACL);
> +	if (test_opt(sb, ACL)) {
> +		if (EXT4_HAS_INCOMPAT_FEATURE(sb,
> +					      EXT4_FEATURE_INCOMPAT_RICHACL)) {
> +#ifdef CONFIG_EXT4_FS_RICHACL
> +			sb->s_flags |= MS_RICHACL;
> +#else
> +			return -EOPNOTSUPP;
> +#endif
> +		} else {
> +#ifdef CONFIG_EXT4_FS_POSIX_ACL
> +			sb->s_flags |= MS_POSIXACL;
> +#else
> +			return -EOPNOTSUPP;
> +#endif
> +		}
> +	}
> +	return 0;
> +}
> +
> #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
> static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
> 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
> @@ -1416,9 +1438,9 @@ static const struct mount_opts {
> 	 MOPT_NO_EXT2 | MOPT_DATAJ},
> 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
> 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
> -#ifdef CONFIG_EXT4_FS_POSIX_ACL
> -	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
> -	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
> +#if defined(CONFIG_EXT4_FS_POSIX_ACL) || defined(CONFIG_EXT4_FS_RICHACL)
> +	{Opt_acl, EXT4_MOUNT_ACL, MOPT_SET},
> +	{Opt_noacl, EXT4_MOUNT_ACL, MOPT_CLEAR},
> #else
> 	{Opt_acl, 0, MOPT_NOSUPPORT},
> 	{Opt_noacl, 0, MOPT_NOSUPPORT},
> @@ -1466,6 +1488,13 @@ static int handle_mount_opt(struct super_block *sb, char *opt, int token,
> #endif
> 	switch (token) {
> 	case Opt_noacl:
> +#ifdef CONFIG_EXT4_FS_RICHACL
> +	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RICHACL)) {
> +		ext4_msg(sb, KERN_ERR, "Mount option \"%s\" incompatible "
> +			 "with richacl feature", opt);
> +		return -1;
> +	}
> +#endif
> 	case Opt_nouser_xattr:
> 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
> 		break;
> @@ -3576,8 +3605,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
> 		set_opt(sb, NO_UID32);
> 	/* xattr user namespace & acls are now defaulted on */
> 	set_opt(sb, XATTR_USER);
> -#ifdef CONFIG_EXT4_FS_POSIX_ACL
> -	set_opt(sb, POSIX_ACL);
> +#if defined(CONFIG_EXT4_FS_POSIX_ACL) || defined(CONFIG_EXT4_FS_RICHACL)
> +	set_opt(sb, ACL);
> #endif
> 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
> 	if (ext4_has_metadata_csum(sb))
> @@ -3660,8 +3689,9 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent)
> 		sb->s_iflags |= SB_I_CGROUPWB;
> 	}
> 
> -	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
> -		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
> +	err = enable_acl(sb);
> +	if (err)
> +		goto failed_mount;
> 
> 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
> 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
> @@ -4981,8 +5011,9 @@ static int ext4_remount(struct super_block *sb, int *flags, char *data)
> 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
> 		ext4_abort(sb, "Abort forced by user");
> 
> -	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
> -		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
> +	err = enable_acl(sb);
> +	if (err)
> +		goto restore_opts;
> 
> 	es = sbi->s_es;
> 
> --
> 2.5.0
> 


Cheers, Andreas
Andreas Gruenbacher Nov. 4, 2015, 2:28 a.m. UTC | #2 
Andreas,

On Wed, Nov 4, 2015 at 3:18 AM, Andreas Dilger <adilger@dilger.ca> wrote:
> This patch confuses me.  I thought the whole point of INCOMPAT_RICHACL
> was that the filesystem should never, ever be mounted without ACL support
> because the ACLs will get confused without it.  In that case, it doesn't
> make sense to have a mount option that _has_ to be specified to mount the
> filesystem, and returns an error when trying to disable it.
>
> It makes more sense to just enable "acl" by default if INCOMPAT_RICHACL
> is set in the superblock and not need the mount option at all.

It's the commit message that's misleading here, I'll fix it. On
richacl filesystems, the acl mount option is always on. It's only on
POSIX ACL filesystems that the mount option can be used to turn POSIX
ACLs off (which arguably wasn't such a good idea, but there we have
it).

Thanks,
Andreas
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Andreas Gruenbacher Nov. 4, 2015, 2:43 a.m. UTC | #3 
On Wed, Nov 4, 2015 at 3:28 AM, Andreas Gruenbacher <agruenba@redhat.com> wrote:
> It's the commit message that's misleading here, I'll fix it.

Commit message changed to:

    This feature flag selects richacl instead of POSIX ACL support on the
    filesystem.  When this feature is off, the "acl" and "noacl" mount options
    control whether POSIX ACLs are enabled.  When it is on, richacls are
    automatically enabled and using the "noacl" mount option leads to an error.

Thanks,
Andreas
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diff mbox

Patch

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index fd1f28b..b97a3b1 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -991,7 +991,7 @@  struct ext4_inode_info {
 #define EXT4_MOUNT_UPDATE_JOURNAL	0x01000	/* Update the journal format */
 #define EXT4_MOUNT_NO_UID32		0x02000  /* Disable 32-bit UIDs */
 #define EXT4_MOUNT_XATTR_USER		0x04000	/* Extended user attributes */
-#define EXT4_MOUNT_POSIX_ACL		0x08000	/* POSIX Access Control Lists */
+#define EXT4_MOUNT_ACL			0x08000	/* Access Control Lists */
 #define EXT4_MOUNT_NO_AUTO_DA_ALLOC	0x10000	/* No auto delalloc mapping */
 #define EXT4_MOUNT_BARRIER		0x20000 /* Use block barriers */
 #define EXT4_MOUNT_QUOTA		0x80000 /* Some quota option set */
@@ -1582,6 +1582,7 @@  static inline int ext4_encrypted_inode(struct inode *inode)
 #define EXT4_FEATURE_INCOMPAT_LARGEDIR		0x4000 /* >2GB or 3-lvl htree */
 #define EXT4_FEATURE_INCOMPAT_INLINE_DATA	0x8000 /* data in inode */
 #define EXT4_FEATURE_INCOMPAT_ENCRYPT		0x10000
+#define EXT4_FEATURE_INCOMPAT_RICHACL		0x20000
 
 #define EXT2_FEATURE_COMPAT_SUPP	EXT4_FEATURE_COMPAT_EXT_ATTR
 #define EXT2_FEATURE_INCOMPAT_SUPP	(EXT4_FEATURE_INCOMPAT_FILETYPE| \
@@ -1607,7 +1608,8 @@  static inline int ext4_encrypted_inode(struct inode *inode)
 					 EXT4_FEATURE_INCOMPAT_FLEX_BG| \
 					 EXT4_FEATURE_INCOMPAT_MMP | \
 					 EXT4_FEATURE_INCOMPAT_INLINE_DATA | \
-					 EXT4_FEATURE_INCOMPAT_ENCRYPT)
+					 EXT4_FEATURE_INCOMPAT_ENCRYPT | \
+					 EXT4_FEATURE_INCOMPAT_RICHACL)
 #define EXT4_FEATURE_RO_COMPAT_SUPP	(EXT4_FEATURE_RO_COMPAT_SPARSE_SUPER| \
 					 EXT4_FEATURE_RO_COMPAT_LARGE_FILE| \
 					 EXT4_FEATURE_RO_COMPAT_GDT_CSUM| \
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index a63c7b0..7457ea8 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -1270,6 +1270,28 @@  static ext4_fsblk_t get_sb_block(void **data)
 	return sb_block;
 }
 
+static int enable_acl(struct super_block *sb)
+{
+	sb->s_flags &= ~(MS_POSIXACL | MS_RICHACL);
+	if (test_opt(sb, ACL)) {
+		if (EXT4_HAS_INCOMPAT_FEATURE(sb,
+					      EXT4_FEATURE_INCOMPAT_RICHACL)) {
+#ifdef CONFIG_EXT4_FS_RICHACL
+			sb->s_flags |= MS_RICHACL;
+#else
+			return -EOPNOTSUPP;
+#endif
+		} else {
+#ifdef CONFIG_EXT4_FS_POSIX_ACL
+			sb->s_flags |= MS_POSIXACL;
+#else
+			return -EOPNOTSUPP;
+#endif
+		}
+	}
+	return 0;
+}
+
 #define DEFAULT_JOURNAL_IOPRIO (IOPRIO_PRIO_VALUE(IOPRIO_CLASS_BE, 3))
 static char deprecated_msg[] = "Mount option \"%s\" will be removed by %s\n"
 	"Contact linux-ext4@vger.kernel.org if you think we should keep it.\n";
@@ -1416,9 +1438,9 @@  static const struct mount_opts {
 	 MOPT_NO_EXT2 | MOPT_DATAJ},
 	{Opt_user_xattr, EXT4_MOUNT_XATTR_USER, MOPT_SET},
 	{Opt_nouser_xattr, EXT4_MOUNT_XATTR_USER, MOPT_CLEAR},
-#ifdef CONFIG_EXT4_FS_POSIX_ACL
-	{Opt_acl, EXT4_MOUNT_POSIX_ACL, MOPT_SET},
-	{Opt_noacl, EXT4_MOUNT_POSIX_ACL, MOPT_CLEAR},
+#if defined(CONFIG_EXT4_FS_POSIX_ACL) || defined(CONFIG_EXT4_FS_RICHACL)
+	{Opt_acl, EXT4_MOUNT_ACL, MOPT_SET},
+	{Opt_noacl, EXT4_MOUNT_ACL, MOPT_CLEAR},
 #else
 	{Opt_acl, 0, MOPT_NOSUPPORT},
 	{Opt_noacl, 0, MOPT_NOSUPPORT},
@@ -1466,6 +1488,13 @@  static int handle_mount_opt(struct super_block *sb, char *opt, int token,
 #endif
 	switch (token) {
 	case Opt_noacl:
+#ifdef CONFIG_EXT4_FS_RICHACL
+	if (EXT4_HAS_INCOMPAT_FEATURE(sb, EXT4_FEATURE_INCOMPAT_RICHACL)) {
+		ext4_msg(sb, KERN_ERR, "Mount option \"%s\" incompatible "
+			 "with richacl feature", opt);
+		return -1;
+	}
+#endif
 	case Opt_nouser_xattr:
 		ext4_msg(sb, KERN_WARNING, deprecated_msg, opt, "3.5");
 		break;
@@ -3576,8 +3605,8 @@  static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		set_opt(sb, NO_UID32);
 	/* xattr user namespace & acls are now defaulted on */
 	set_opt(sb, XATTR_USER);
-#ifdef CONFIG_EXT4_FS_POSIX_ACL
-	set_opt(sb, POSIX_ACL);
+#if defined(CONFIG_EXT4_FS_POSIX_ACL) || defined(CONFIG_EXT4_FS_RICHACL)
+	set_opt(sb, ACL);
 #endif
 	/* don't forget to enable journal_csum when metadata_csum is enabled. */
 	if (ext4_has_metadata_csum(sb))
@@ -3660,8 +3689,9 @@  static int ext4_fill_super(struct super_block *sb, void *data, int silent)
 		sb->s_iflags |= SB_I_CGROUPWB;
 	}
 
-	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
-		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
+	err = enable_acl(sb);
+	if (err)
+		goto failed_mount;
 
 	if (le32_to_cpu(es->s_rev_level) == EXT4_GOOD_OLD_REV &&
 	    (EXT4_HAS_COMPAT_FEATURE(sb, ~0U) ||
@@ -4981,8 +5011,9 @@  static int ext4_remount(struct super_block *sb, int *flags, char *data)
 	if (sbi->s_mount_flags & EXT4_MF_FS_ABORTED)
 		ext4_abort(sb, "Abort forced by user");
 
-	sb->s_flags = (sb->s_flags & ~MS_POSIXACL) |
-		(test_opt(sb, POSIX_ACL) ? MS_POSIXACL : 0);
+	err = enable_acl(sb);
+	if (err)
+		goto restore_opts;
 
 	es = sbi->s_es;