> On Nov 3, 2015, at 8:16 AM, Andreas Gruenbacher <agruenba@xxxxxxxxxx> wrote:
>
> From: "Aneesh Kumar K.V" <aneesh.kumar@xxxxxxxxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxxxxxxxx>
> Signed-off-by: Andreas Gruenbacher <agruenba@xxxxxxxxxx>
> ---
> 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@xxxxxxxxxxxxxxx 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
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