* [PATCH v2 0/3] ext4: Add support for mounted updates to the superblock via an ioctl
@ 2025-09-17 3:22 Theodore Ts'o via B4 Relay
2025-09-17 3:22 ` [PATCH v2 1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() Theodore Ts'o via B4 Relay
` (3 more replies)
0 siblings, 4 replies; 10+ messages in thread
From: Theodore Ts'o via B4 Relay @ 2025-09-17 3:22 UTC (permalink / raw)
To: tytso; +Cc: linux-ext4, linux-api, stable
This patch series enables a future version of tune2fs to be able to
modify certain parts of the ext4 superblock without to write to the
block device.
The first patch fixes a potential buffer overrun caused by a
maliciously moified superblock. The second patch adds support for
32-bit uid and gid's which can have access to the reserved blocks pool.
The last patch adds the ioctl's which will be used by tune2fs.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
Changes in v2:
- fix bugs that were detected using sparse
- remove tune (unsafe) ability to clear certain compat faatures
- add the ability to set the encoding and encoding flags for case folding
- Link to v1: https://lore.kernel.org/r/20250908-tune2fs-v1-0-e3a6929f3355@mit.edu
---
Theodore Ts'o (3):
ext4: avoid potential buffer over-read in parse_apply_sb_mount_options()
ext4: add support for 32-bit default reserved uid and gid values
ext4: implemet new ioctls to set and get superblock parameters
fs/ext4/ext4.h | 16 +++-
fs/ext4/ioctl.c | 312 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
fs/ext4/super.c | 25 +++----
include/uapi/linux/ext4.h | 53 +++++++++++++
4 files changed, 382 insertions(+), 24 deletions(-)
---
base-commit: b320789d6883cc00ac78ce83bccbfe7ed58afcf0
change-id: 20250830-tune2fs-3376beb72403
Best regards,
--
Theodore Ts'o <tytso@mit.edu>
^ permalink raw reply [flat|nested] 10+ messages in thread
* [PATCH v2 1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options()
2025-09-17 3:22 [PATCH v2 0/3] ext4: Add support for mounted updates to the superblock via an ioctl Theodore Ts'o via B4 Relay
@ 2025-09-17 3:22 ` Theodore Ts'o via B4 Relay
2025-09-17 16:05 ` Jan Kara
2025-09-17 3:22 ` [PATCH v2 2/3] ext4: add support for 32-bit default reserved uid and gid values Theodore Ts'o via B4 Relay
` (2 subsequent siblings)
3 siblings, 1 reply; 10+ messages in thread
From: Theodore Ts'o via B4 Relay @ 2025-09-17 3:22 UTC (permalink / raw)
To: tytso; +Cc: linux-ext4, linux-api, stable
From: Theodore Ts'o <tytso@mit.edu>
Unlike other strings in the ext4 superblock, we rely on tune2fs to
make sure s_mount_opts is NUL terminated. Harden
parse_apply_sb_mount_options() by treating s_mount_opts as a potential
__nonstring.
Cc: stable@vger.kernel.org
Fixes: 8b67f04ab9de ("ext4: Add mount options in superblock")
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
fs/ext4/super.c | 17 +++++------------
1 file changed, 5 insertions(+), 12 deletions(-)
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 699c15db28a82f26809bf68533454a242596f0fd..94c98446c84f9a4614971d246ca7f001de610a8a 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2460,7 +2460,7 @@ static int parse_apply_sb_mount_options(struct super_block *sb,
struct ext4_fs_context *m_ctx)
{
struct ext4_sb_info *sbi = EXT4_SB(sb);
- char *s_mount_opts = NULL;
+ char s_mount_opts[65];
struct ext4_fs_context *s_ctx = NULL;
struct fs_context *fc = NULL;
int ret = -ENOMEM;
@@ -2468,15 +2468,11 @@ static int parse_apply_sb_mount_options(struct super_block *sb,
if (!sbi->s_es->s_mount_opts[0])
return 0;
- s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
- sizeof(sbi->s_es->s_mount_opts),
- GFP_KERNEL);
- if (!s_mount_opts)
- return ret;
+ strscpy_pad(s_mount_opts, sbi->s_es->s_mount_opts);
fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
if (!fc)
- goto out_free;
+ return -ENOMEM;
s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
if (!s_ctx)
@@ -2508,11 +2504,8 @@ static int parse_apply_sb_mount_options(struct super_block *sb,
ret = 0;
out_free:
- if (fc) {
- ext4_fc_free(fc);
- kfree(fc);
- }
- kfree(s_mount_opts);
+ ext4_fc_free(fc);
+ kfree(fc);
return ret;
}
--
2.51.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v2 2/3] ext4: add support for 32-bit default reserved uid and gid values
2025-09-17 3:22 [PATCH v2 0/3] ext4: Add support for mounted updates to the superblock via an ioctl Theodore Ts'o via B4 Relay
2025-09-17 3:22 ` [PATCH v2 1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() Theodore Ts'o via B4 Relay
@ 2025-09-17 3:22 ` Theodore Ts'o via B4 Relay
2025-09-17 16:10 ` Jan Kara
2025-09-17 3:22 ` [PATCH v2 3/3] ext4: implemet new ioctls to set and get superblock parameters Theodore Ts'o via B4 Relay
2025-09-26 21:47 ` [PATCH v2 0/3] ext4: Add support for mounted updates to the superblock via an ioctl Theodore Ts'o
3 siblings, 1 reply; 10+ messages in thread
From: Theodore Ts'o via B4 Relay @ 2025-09-17 3:22 UTC (permalink / raw)
To: tytso; +Cc: linux-ext4, linux-api
From: Theodore Ts'o <tytso@mit.edu>
Support for specifying the default user id and group id that is
allowed to use the reserved block space was added way back when Linux
only supported 16-bit uid's and gid's. (Yeah, that long ago.) It's
not a commonly used feature, but let's add support for 32-bit user and
group id's.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
fs/ext4/ext4.h | 16 +++++++++++++++-
fs/ext4/super.c | 8 ++++----
2 files changed, 19 insertions(+), 5 deletions(-)
diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index 01a6e2de7fc3ef0e20b039d3200b9c9bd656f59f..4bfcd5f0c74fda30db4009ee28fbee00a2f6b76f 100644
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1442,7 +1442,9 @@ struct ext4_super_block {
__le16 s_encoding; /* Filename charset encoding */
__le16 s_encoding_flags; /* Filename charset encoding flags */
__le32 s_orphan_file_inum; /* Inode for tracking orphan inodes */
- __le32 s_reserved[94]; /* Padding to the end of the block */
+ __le16 s_def_resuid_hi;
+ __le16 s_def_resgid_hi;
+ __le32 s_reserved[93]; /* Padding to the end of the block */
__le32 s_checksum; /* crc32c(superblock) */
};
@@ -1812,6 +1814,18 @@ static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
}
+static inline int ext4_get_resuid(struct ext4_super_block *es)
+{
+ return(le16_to_cpu(es->s_def_resuid) |
+ (le16_to_cpu(es->s_def_resuid_hi) << 16));
+}
+
+static inline int ext4_get_resgid(struct ext4_super_block *es)
+{
+ return(le16_to_cpu(es->s_def_resgid) |
+ (le16_to_cpu(es->s_def_resgid_hi) << 16));
+}
+
/*
* Returns: sbi->field[index]
* Used to access an array element from the following sbi fields which require
diff --git a/fs/ext4/super.c b/fs/ext4/super.c
index 94c98446c84f9a4614971d246ca7f001de610a8a..0256c8f7c6cee2b8d9295f2fa9a7acd904382e83 100644
--- a/fs/ext4/super.c
+++ b/fs/ext4/super.c
@@ -2951,11 +2951,11 @@ static int _ext4_show_options(struct seq_file *seq, struct super_block *sb,
}
if (nodefs || !uid_eq(sbi->s_resuid, make_kuid(&init_user_ns, EXT4_DEF_RESUID)) ||
- le16_to_cpu(es->s_def_resuid) != EXT4_DEF_RESUID)
+ ext4_get_resuid(es) != EXT4_DEF_RESUID)
SEQ_OPTS_PRINT("resuid=%u",
from_kuid_munged(&init_user_ns, sbi->s_resuid));
if (nodefs || !gid_eq(sbi->s_resgid, make_kgid(&init_user_ns, EXT4_DEF_RESGID)) ||
- le16_to_cpu(es->s_def_resgid) != EXT4_DEF_RESGID)
+ ext4_get_resgid(es) != EXT4_DEF_RESGID)
SEQ_OPTS_PRINT("resgid=%u",
from_kgid_munged(&init_user_ns, sbi->s_resgid));
def_errors = nodefs ? -1 : le16_to_cpu(es->s_errors);
@@ -5270,8 +5270,8 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
ext4_set_def_opts(sb, es);
- sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
- sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
+ sbi->s_resuid = make_kuid(&init_user_ns, ext4_get_resuid(es));
+ sbi->s_resgid = make_kgid(&init_user_ns, ext4_get_resuid(es));
sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
--
2.51.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* [PATCH v2 3/3] ext4: implemet new ioctls to set and get superblock parameters
2025-09-17 3:22 [PATCH v2 0/3] ext4: Add support for mounted updates to the superblock via an ioctl Theodore Ts'o via B4 Relay
2025-09-17 3:22 ` [PATCH v2 1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() Theodore Ts'o via B4 Relay
2025-09-17 3:22 ` [PATCH v2 2/3] ext4: add support for 32-bit default reserved uid and gid values Theodore Ts'o via B4 Relay
@ 2025-09-17 3:22 ` Theodore Ts'o via B4 Relay
2025-09-17 16:22 ` Jan Kara
2025-09-18 16:57 ` Darrick J. Wong
2025-09-26 21:47 ` [PATCH v2 0/3] ext4: Add support for mounted updates to the superblock via an ioctl Theodore Ts'o
3 siblings, 2 replies; 10+ messages in thread
From: Theodore Ts'o via B4 Relay @ 2025-09-17 3:22 UTC (permalink / raw)
To: tytso; +Cc: linux-ext4, linux-api
From: Theodore Ts'o <tytso@mit.edu>
Implement the EXT4_IOC_GET_TUNE_SB_PARAM and
EXT4_IOC_SET_TUNE_SB_PARAM ioctls, which allow certains superblock
parameters to be set while the file system is mounted, without needing
write access to the block device.
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
---
fs/ext4/ioctl.c | 312 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
include/uapi/linux/ext4.h | 53 +++++++++++++
2 files changed, 358 insertions(+), 7 deletions(-)
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index 84e3c73952d72e436429489f5fc8b7ae1c01c7a1..a93a7baae990cc5580d2ddb3ffcc72fe15246978 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -27,14 +27,16 @@
#include "fsmap.h"
#include <trace/events/ext4.h>
-typedef void ext4_update_sb_callback(struct ext4_super_block *es,
- const void *arg);
+typedef void ext4_update_sb_callback(struct ext4_sb_info *sbi,
+ struct ext4_super_block *es,
+ const void *arg);
/*
* Superblock modification callback function for changing file system
* label
*/
-static void ext4_sb_setlabel(struct ext4_super_block *es, const void *arg)
+static void ext4_sb_setlabel(struct ext4_sb_info *sbi,
+ struct ext4_super_block *es, const void *arg)
{
/* Sanity check, this should never happen */
BUILD_BUG_ON(sizeof(es->s_volume_name) < EXT4_LABEL_MAX);
@@ -46,7 +48,8 @@ static void ext4_sb_setlabel(struct ext4_super_block *es, const void *arg)
* Superblock modification callback function for changing file system
* UUID.
*/
-static void ext4_sb_setuuid(struct ext4_super_block *es, const void *arg)
+static void ext4_sb_setuuid(struct ext4_sb_info *sbi,
+ struct ext4_super_block *es, const void *arg)
{
memcpy(es->s_uuid, (__u8 *)arg, UUID_SIZE);
}
@@ -71,7 +74,7 @@ int ext4_update_primary_sb(struct super_block *sb, handle_t *handle,
goto out_err;
lock_buffer(bh);
- func(es, arg);
+ func(sbi, es, arg);
ext4_superblock_csum_set(sb);
unlock_buffer(bh);
@@ -149,7 +152,7 @@ static int ext4_update_backup_sb(struct super_block *sb,
unlock_buffer(bh);
goto out_bh;
}
- func(es, arg);
+ func(EXT4_SB(sb), es, arg);
if (ext4_has_feature_metadata_csum(sb))
es->s_checksum = ext4_superblock_csum(es);
set_buffer_uptodate(bh);
@@ -1230,6 +1233,295 @@ static int ext4_ioctl_setuuid(struct file *filp,
return ret;
}
+
+#define TUNE_OPS_SUPPORTED (EXT4_TUNE_FL_ERRORS_BEHAVIOR | \
+ EXT4_TUNE_FL_MNT_COUNT | EXT4_TUNE_FL_MAX_MNT_COUNT | \
+ EXT4_TUNE_FL_CHECKINTRVAL | EXT4_TUNE_FL_LAST_CHECK_TIME | \
+ EXT4_TUNE_FL_RESERVED_BLOCKS | EXT4_TUNE_FL_RESERVED_UID | \
+ EXT4_TUNE_FL_RESERVED_GID | EXT4_TUNE_FL_DEFAULT_MNT_OPTS | \
+ EXT4_TUNE_FL_DEF_HASH_ALG | EXT4_TUNE_FL_RAID_STRIDE | \
+ EXT4_TUNE_FL_RAID_STRIPE_WIDTH | EXT4_TUNE_FL_MOUNT_OPTS | \
+ EXT4_TUNE_FL_FEATURES | EXT4_TUNE_FL_EDIT_FEATURES | \
+ EXT4_TUNE_FL_FORCE_FSCK | EXT4_TUNE_FL_ENCODING | \
+ EXT4_TUNE_FL_ENCODING_FLAGS)
+
+#define EXT4_TUNE_SET_COMPAT_SUPP \
+ (EXT4_FEATURE_COMPAT_DIR_INDEX | \
+ EXT4_FEATURE_COMPAT_STABLE_INODES)
+#define EXT4_TUNE_SET_INCOMPAT_SUPP \
+ (EXT4_FEATURE_INCOMPAT_EXTENTS | \
+ EXT4_FEATURE_INCOMPAT_EA_INODE | \
+ EXT4_FEATURE_INCOMPAT_ENCRYPT | \
+ EXT4_FEATURE_INCOMPAT_CSUM_SEED | \
+ EXT4_FEATURE_INCOMPAT_LARGEDIR | \
+ EXT4_FEATURE_INCOMPAT_CASEFOLD)
+#define EXT4_TUNE_SET_RO_COMPAT_SUPP \
+ (EXT4_FEATURE_RO_COMPAT_LARGE_FILE | \
+ EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
+ EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
+ EXT4_FEATURE_RO_COMPAT_PROJECT | \
+ EXT4_FEATURE_RO_COMPAT_VERITY)
+
+#define EXT4_TUNE_CLEAR_COMPAT_SUPP (0)
+#define EXT4_TUNE_CLEAR_INCOMPAT_SUPP (0)
+#define EXT4_TUNE_CLEAR_RO_COMPAT_SUPP (0)
+
+#define SB_ENC_SUPP_MASK (SB_ENC_STRICT_MODE_FL | \
+ SB_ENC_NO_COMPAT_FALLBACK_FL)
+
+static int ext4_ioctl_get_tune_sb(struct ext4_sb_info *sbi,
+ struct ext4_tune_sb_params __user *params)
+{
+ struct ext4_tune_sb_params ret;
+ struct ext4_super_block *es = sbi->s_es;
+
+ memset(&ret, 0, sizeof(ret));
+ ret.set_flags = TUNE_OPS_SUPPORTED;
+ ret.errors_behavior = le16_to_cpu(es->s_errors);
+ ret.mnt_count = le16_to_cpu(es->s_mnt_count);
+ ret.max_mnt_count = le16_to_cpu(es->s_max_mnt_count);
+ ret.checkinterval = le32_to_cpu(es->s_checkinterval);
+ ret.last_check_time = le32_to_cpu(es->s_lastcheck);
+ ret.reserved_blocks = ext4_r_blocks_count(es);
+ ret.blocks_count = ext4_blocks_count(es);
+ ret.reserved_uid = ext4_get_resuid(es);
+ ret.reserved_gid = ext4_get_resgid(es);
+ ret.default_mnt_opts = le32_to_cpu(es->s_default_mount_opts);
+ ret.def_hash_alg = es->s_def_hash_version;
+ ret.raid_stride = le16_to_cpu(es->s_raid_stride);
+ ret.raid_stripe_width = le32_to_cpu(es->s_raid_stripe_width);
+ ret.encoding = le16_to_cpu(es->s_encoding);
+ ret.encoding_flags = le16_to_cpu(es->s_encoding_flags);
+ strscpy_pad(ret.mount_opts, es->s_mount_opts);
+ ret.feature_compat = le32_to_cpu(es->s_feature_compat);
+ ret.feature_incompat = le32_to_cpu(es->s_feature_incompat);
+ ret.feature_ro_compat = le32_to_cpu(es->s_feature_ro_compat);
+ ret.set_feature_compat_mask = EXT4_TUNE_SET_COMPAT_SUPP;
+ ret.set_feature_incompat_mask = EXT4_TUNE_SET_INCOMPAT_SUPP;
+ ret.set_feature_ro_compat_mask = EXT4_TUNE_SET_RO_COMPAT_SUPP;
+ ret.clear_feature_compat_mask = EXT4_TUNE_CLEAR_COMPAT_SUPP;
+ ret.clear_feature_incompat_mask = EXT4_TUNE_CLEAR_INCOMPAT_SUPP;
+ ret.clear_feature_ro_compat_mask = EXT4_TUNE_CLEAR_RO_COMPAT_SUPP;
+ if (copy_to_user(params, &ret, sizeof(ret)))
+ return -EFAULT;
+ return 0;
+}
+
+static void ext4_sb_setparams(struct ext4_sb_info *sbi,
+ struct ext4_super_block *es, const void *arg)
+{
+ const struct ext4_tune_sb_params *params = arg;
+
+ if (params->set_flags & EXT4_TUNE_FL_ERRORS_BEHAVIOR)
+ es->s_errors = cpu_to_le16(params->errors_behavior);
+ if (params->set_flags & EXT4_TUNE_FL_MNT_COUNT)
+ es->s_mnt_count = cpu_to_le16(params->mnt_count);
+ if (params->set_flags & EXT4_TUNE_FL_MAX_MNT_COUNT)
+ es->s_max_mnt_count = cpu_to_le16(params->max_mnt_count);
+ if (params->set_flags & EXT4_TUNE_FL_CHECKINTRVAL)
+ es->s_checkinterval = cpu_to_le32(params->checkinterval);
+ if (params->set_flags & EXT4_TUNE_FL_LAST_CHECK_TIME)
+ es->s_lastcheck = cpu_to_le32(params->last_check_time);
+ if (params->set_flags & EXT4_TUNE_FL_RESERVED_BLOCKS) {
+ ext4_fsblk_t blk = params->reserved_blocks;
+
+ es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
+ es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
+ }
+ if (params->set_flags & EXT4_TUNE_FL_RESERVED_UID) {
+ int uid = params->reserved_uid;
+
+ es->s_def_resuid = cpu_to_le16(uid & 0xFFFF);
+ es->s_def_resuid_hi = cpu_to_le16(uid >> 16);
+ }
+ if (params->set_flags & EXT4_TUNE_FL_RESERVED_GID) {
+ int gid = params->reserved_gid;
+
+ es->s_def_resgid = cpu_to_le16(gid & 0xFFFF);
+ es->s_def_resgid_hi = cpu_to_le16(gid >> 16);
+ }
+ if (params->set_flags & EXT4_TUNE_FL_DEFAULT_MNT_OPTS)
+ es->s_default_mount_opts = cpu_to_le32(params->default_mnt_opts);
+ if (params->set_flags & EXT4_TUNE_FL_DEF_HASH_ALG)
+ es->s_def_hash_version = params->def_hash_alg;
+ if (params->set_flags & EXT4_TUNE_FL_RAID_STRIDE)
+ es->s_raid_stride = cpu_to_le16(params->raid_stride);
+ if (params->set_flags & EXT4_TUNE_FL_RAID_STRIPE_WIDTH)
+ es->s_raid_stripe_width =
+ cpu_to_le32(params->raid_stripe_width);
+ if (params->set_flags & EXT4_TUNE_FL_ENCODING)
+ es->s_encoding = cpu_to_le16(params->encoding);
+ if (params->set_flags & EXT4_TUNE_FL_ENCODING_FLAGS)
+ es->s_encoding_flags = cpu_to_le16(params->encoding_flags);
+ strscpy_pad(es->s_mount_opts, params->mount_opts);
+ if (params->set_flags & EXT4_TUNE_FL_EDIT_FEATURES) {
+ es->s_feature_compat |=
+ cpu_to_le32(params->set_feature_compat_mask);
+ es->s_feature_incompat |=
+ cpu_to_le32(params->set_feature_incompat_mask);
+ es->s_feature_ro_compat |=
+ cpu_to_le32(params->set_feature_ro_compat_mask);
+ es->s_feature_compat &=
+ ~cpu_to_le32(params->clear_feature_compat_mask);
+ es->s_feature_incompat &=
+ ~cpu_to_le32(params->clear_feature_incompat_mask);
+ es->s_feature_ro_compat &=
+ ~cpu_to_le32(params->clear_feature_ro_compat_mask);
+ if (params->set_feature_compat_mask &
+ EXT4_FEATURE_COMPAT_DIR_INDEX)
+ es->s_def_hash_version = sbi->s_def_hash_version;
+ if (params->set_feature_incompat_mask &
+ EXT4_FEATURE_INCOMPAT_CSUM_SEED)
+ es->s_checksum_seed = cpu_to_le32(sbi->s_csum_seed);
+ }
+ if (params->set_flags & EXT4_TUNE_FL_FORCE_FSCK)
+ es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
+}
+
+static int ext4_ioctl_set_tune_sb(struct file *filp,
+ struct ext4_tune_sb_params __user *in)
+{
+ struct ext4_tune_sb_params params;
+ struct super_block *sb = file_inode(filp)->i_sb;
+ struct ext4_sb_info *sbi = EXT4_SB(sb);
+ struct ext4_super_block *es = sbi->s_es;
+ int enabling_casefold = 0;
+ int ret;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ if (copy_from_user(¶ms, in, sizeof(params)))
+ return -EFAULT;
+
+ if ((params.set_flags & ~TUNE_OPS_SUPPORTED) != 0)
+ return -EOPNOTSUPP;
+
+ if ((params.set_flags & EXT4_TUNE_FL_ERRORS_BEHAVIOR) &&
+ (params.errors_behavior > EXT4_ERRORS_PANIC))
+ return -EINVAL;
+
+ if ((params.set_flags & EXT4_TUNE_FL_RESERVED_BLOCKS) &&
+ (params.reserved_blocks > ext4_blocks_count(sbi->s_es) / 2))
+ return -EINVAL;
+ if ((params.set_flags & EXT4_TUNE_FL_DEF_HASH_ALG) &&
+ ((params.def_hash_alg > DX_HASH_LAST) ||
+ (params.def_hash_alg == DX_HASH_SIPHASH)))
+ return -EINVAL;
+ if ((params.set_flags & EXT4_TUNE_FL_FEATURES) &&
+ (params.set_flags & EXT4_TUNE_FL_EDIT_FEATURES))
+ return -EINVAL;
+
+ if (params.set_flags & EXT4_TUNE_FL_FEATURES) {
+ params.set_feature_compat_mask =
+ params.feature_compat &
+ ~le32_to_cpu(es->s_feature_compat);
+ params.set_feature_incompat_mask =
+ params.feature_incompat &
+ ~le32_to_cpu(es->s_feature_incompat);
+ params.set_feature_ro_compat_mask =
+ params.feature_ro_compat &
+ ~le32_to_cpu(es->s_feature_ro_compat);
+ params.clear_feature_compat_mask =
+ ~params.feature_compat &
+ le32_to_cpu(es->s_feature_compat);
+ params.clear_feature_incompat_mask =
+ ~params.feature_incompat &
+ le32_to_cpu(es->s_feature_incompat);
+ params.clear_feature_ro_compat_mask =
+ ~params.feature_ro_compat &
+ le32_to_cpu(es->s_feature_ro_compat);
+ params.set_flags |= EXT4_TUNE_FL_EDIT_FEATURES;
+ }
+ if (params.set_flags & EXT4_TUNE_FL_EDIT_FEATURES) {
+ if ((params.set_feature_compat_mask &
+ ~EXT4_TUNE_SET_COMPAT_SUPP) ||
+ (params.set_feature_incompat_mask &
+ ~EXT4_TUNE_SET_INCOMPAT_SUPP) ||
+ (params.set_feature_ro_compat_mask &
+ ~EXT4_TUNE_SET_RO_COMPAT_SUPP) ||
+ (params.clear_feature_compat_mask &
+ ~EXT4_TUNE_CLEAR_COMPAT_SUPP) ||
+ (params.clear_feature_incompat_mask &
+ ~EXT4_TUNE_CLEAR_INCOMPAT_SUPP) ||
+ (params.clear_feature_ro_compat_mask &
+ ~EXT4_TUNE_CLEAR_RO_COMPAT_SUPP))
+ return -EOPNOTSUPP;
+
+ /*
+ * Filter out the features that are already set from
+ * the set_mask.
+ */
+ params.set_feature_compat_mask &=
+ ~le32_to_cpu(es->s_feature_compat);
+ params.set_feature_incompat_mask &=
+ ~le32_to_cpu(es->s_feature_incompat);
+ params.set_feature_ro_compat_mask &=
+ ~le32_to_cpu(es->s_feature_ro_compat);
+ if ((params.set_feature_incompat_mask &
+ EXT4_FEATURE_INCOMPAT_CASEFOLD)) {
+ enabling_casefold = 1;
+ if (!(params.set_flags & EXT4_TUNE_FL_ENCODING)) {
+ params.encoding = EXT4_ENC_UTF8_12_1;
+ params.set_flags |= EXT4_TUNE_FL_ENCODING;
+ }
+ if (!(params.set_flags & EXT4_TUNE_FL_ENCODING_FLAGS)) {
+ params.encoding_flags = 0;
+ params.set_flags |= EXT4_TUNE_FL_ENCODING_FLAGS;
+ }
+ }
+ if ((params.set_feature_compat_mask &
+ EXT4_FEATURE_COMPAT_DIR_INDEX)) {
+ uuid_t uu;
+
+ memcpy(&uu, sbi->s_hash_seed, UUID_SIZE);
+ if (uuid_is_null(&uu))
+ generate_random_uuid((char *)
+ &sbi->s_hash_seed);
+ if (params.set_flags & EXT4_TUNE_FL_DEF_HASH_ALG)
+ sbi->s_def_hash_version = params.def_hash_alg;
+ else if (sbi->s_def_hash_version == 0)
+ sbi->s_def_hash_version = DX_HASH_HALF_MD4;
+ if (!(es->s_flags &
+ cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH)) &&
+ !(es->s_flags &
+ cpu_to_le32(EXT2_FLAGS_SIGNED_HASH))) {
+#ifdef __CHAR_UNSIGNED__
+ sbi->s_hash_unsigned = 3;
+#else
+ sbi->s_hash_unsigned = 0;
+#endif
+ }
+ }
+ }
+ if (params.set_flags & EXT4_TUNE_FL_ENCODING) {
+ if (!enabling_casefold)
+ return -EINVAL;
+ if (params.encoding == 0)
+ params.encoding = EXT4_ENC_UTF8_12_1;
+ else if (params.encoding != EXT4_ENC_UTF8_12_1)
+ return -EINVAL;
+ }
+ if (params.set_flags & EXT4_TUNE_FL_ENCODING_FLAGS) {
+ if (!enabling_casefold)
+ return -EINVAL;
+ if (params.encoding_flags & ~SB_ENC_SUPP_MASK)
+ return -EINVAL;
+ }
+
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+
+ ret = ext4_update_superblocks_fn(sb, ext4_sb_setparams, ¶ms);
+ mnt_drop_write_file(filp);
+
+ if (params.set_flags & EXT4_TUNE_FL_DEF_HASH_ALG)
+ sbi->s_def_hash_version = params.def_hash_alg;
+
+ return ret;
+}
+
static long __ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
@@ -1616,6 +1908,11 @@ static long __ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
return ext4_ioctl_getuuid(EXT4_SB(sb), (void __user *)arg);
case EXT4_IOC_SETFSUUID:
return ext4_ioctl_setuuid(filp, (const void __user *)arg);
+ case EXT4_IOC_GET_TUNE_SB_PARAM:
+ return ext4_ioctl_get_tune_sb(EXT4_SB(sb),
+ (void __user *)arg);
+ case EXT4_IOC_SET_TUNE_SB_PARAM:
+ return ext4_ioctl_set_tune_sb(filp, (void __user *)arg);
default:
return -ENOTTY;
}
@@ -1703,7 +2000,8 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
}
#endif
-static void set_overhead(struct ext4_super_block *es, const void *arg)
+static void set_overhead(struct ext4_sb_info *sbi,
+ struct ext4_super_block *es, const void *arg)
{
es->s_overhead_clusters = cpu_to_le32(*((unsigned long *) arg));
}
diff --git a/include/uapi/linux/ext4.h b/include/uapi/linux/ext4.h
index 1c4c2dd29112cda9f7dc91d917492cffc33ee524..411dcc1e4a35c8c6a10f3768d17b8cc50cff4c34 100644
--- a/include/uapi/linux/ext4.h
+++ b/include/uapi/linux/ext4.h
@@ -33,6 +33,8 @@
#define EXT4_IOC_CHECKPOINT _IOW('f', 43, __u32)
#define EXT4_IOC_GETFSUUID _IOR('f', 44, struct fsuuid)
#define EXT4_IOC_SETFSUUID _IOW('f', 44, struct fsuuid)
+#define EXT4_IOC_GET_TUNE_SB_PARAM _IOR('f', 45, struct ext4_tune_sb_params)
+#define EXT4_IOC_SET_TUNE_SB_PARAM _IOW('f', 46, struct ext4_tune_sb_params)
#define EXT4_IOC_SHUTDOWN _IOR('X', 125, __u32)
@@ -108,6 +110,57 @@ struct ext4_new_group_input {
__u16 unused;
};
+struct ext4_tune_sb_params {
+ __u32 set_flags;
+ __u32 checkinterval;
+ __u16 errors_behavior;
+ __u16 mnt_count;
+ __u16 max_mnt_count;
+ __u16 raid_stride;
+ __u64 last_check_time;
+ __u64 reserved_blocks;
+ __u64 blocks_count;
+ __u32 default_mnt_opts;
+ __u32 reserved_uid;
+ __u32 reserved_gid;
+ __u32 raid_stripe_width;
+ __u16 encoding;
+ __u16 encoding_flags;
+ __u8 def_hash_alg;
+ __u8 pad_1;
+ __u16 pad_2;
+ __u32 feature_compat;
+ __u32 feature_incompat;
+ __u32 feature_ro_compat;
+ __u32 set_feature_compat_mask;
+ __u32 set_feature_incompat_mask;
+ __u32 set_feature_ro_compat_mask;
+ __u32 clear_feature_compat_mask;
+ __u32 clear_feature_incompat_mask;
+ __u32 clear_feature_ro_compat_mask;
+ __u8 mount_opts[64];
+ __u8 pad[64];
+};
+
+#define EXT4_TUNE_FL_ERRORS_BEHAVIOR 0x00000001
+#define EXT4_TUNE_FL_MNT_COUNT 0x00000002
+#define EXT4_TUNE_FL_MAX_MNT_COUNT 0x00000004
+#define EXT4_TUNE_FL_CHECKINTRVAL 0x00000008
+#define EXT4_TUNE_FL_LAST_CHECK_TIME 0x00000010
+#define EXT4_TUNE_FL_RESERVED_BLOCKS 0x00000020
+#define EXT4_TUNE_FL_RESERVED_UID 0x00000040
+#define EXT4_TUNE_FL_RESERVED_GID 0x00000080
+#define EXT4_TUNE_FL_DEFAULT_MNT_OPTS 0x00000100
+#define EXT4_TUNE_FL_DEF_HASH_ALG 0x00000200
+#define EXT4_TUNE_FL_RAID_STRIDE 0x00000400
+#define EXT4_TUNE_FL_RAID_STRIPE_WIDTH 0x00000800
+#define EXT4_TUNE_FL_MOUNT_OPTS 0x00001000
+#define EXT4_TUNE_FL_FEATURES 0x00002000
+#define EXT4_TUNE_FL_EDIT_FEATURES 0x00004000
+#define EXT4_TUNE_FL_FORCE_FSCK 0x00008000
+#define EXT4_TUNE_FL_ENCODING 0x00010000
+#define EXT4_TUNE_FL_ENCODING_FLAGS 0x00020000
+
/*
* Returned by EXT4_IOC_GET_ES_CACHE as an additional possible flag.
* It indicates that the entry in extent status cache is for a hole.
--
2.51.0
^ permalink raw reply related [flat|nested] 10+ messages in thread
* Re: [PATCH v2 1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options()
2025-09-17 3:22 ` [PATCH v2 1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() Theodore Ts'o via B4 Relay
@ 2025-09-17 16:05 ` Jan Kara
2025-09-18 16:55 ` Darrick J. Wong
0 siblings, 1 reply; 10+ messages in thread
From: Jan Kara @ 2025-09-17 16:05 UTC (permalink / raw)
To: tytso; +Cc: linux-ext4, linux-api, stable
On Tue 16-09-25 23:22:47, Theodore Ts'o via B4 Relay wrote:
> From: Theodore Ts'o <tytso@mit.edu>
>
> Unlike other strings in the ext4 superblock, we rely on tune2fs to
> make sure s_mount_opts is NUL terminated. Harden
> parse_apply_sb_mount_options() by treating s_mount_opts as a potential
> __nonstring.
>
> Cc: stable@vger.kernel.org
> Fixes: 8b67f04ab9de ("ext4: Add mount options in superblock")
> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
> ---
> fs/ext4/super.c | 17 +++++------------
> 1 file changed, 5 insertions(+), 12 deletions(-)
>
> diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> index 699c15db28a82f26809bf68533454a242596f0fd..94c98446c84f9a4614971d246ca7f001de610a8a 100644
> --- a/fs/ext4/super.c
> +++ b/fs/ext4/super.c
> @@ -2460,7 +2460,7 @@ static int parse_apply_sb_mount_options(struct super_block *sb,
> struct ext4_fs_context *m_ctx)
> {
> struct ext4_sb_info *sbi = EXT4_SB(sb);
> - char *s_mount_opts = NULL;
> + char s_mount_opts[65];
> struct ext4_fs_context *s_ctx = NULL;
> struct fs_context *fc = NULL;
> int ret = -ENOMEM;
> @@ -2468,15 +2468,11 @@ static int parse_apply_sb_mount_options(struct super_block *sb,
> if (!sbi->s_es->s_mount_opts[0])
> return 0;
>
> - s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
> - sizeof(sbi->s_es->s_mount_opts),
> - GFP_KERNEL);
> - if (!s_mount_opts)
> - return ret;
> + strscpy_pad(s_mount_opts, sbi->s_es->s_mount_opts);
>
> fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
> if (!fc)
> - goto out_free;
> + return -ENOMEM;
>
> s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
> if (!s_ctx)
> @@ -2508,11 +2504,8 @@ static int parse_apply_sb_mount_options(struct super_block *sb,
> ret = 0;
>
> out_free:
> - if (fc) {
> - ext4_fc_free(fc);
> - kfree(fc);
> - }
> - kfree(s_mount_opts);
> + ext4_fc_free(fc);
> + kfree(fc);
> return ret;
> }
>
>
> --
> 2.51.0
>
>
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2 2/3] ext4: add support for 32-bit default reserved uid and gid values
2025-09-17 3:22 ` [PATCH v2 2/3] ext4: add support for 32-bit default reserved uid and gid values Theodore Ts'o via B4 Relay
@ 2025-09-17 16:10 ` Jan Kara
0 siblings, 0 replies; 10+ messages in thread
From: Jan Kara @ 2025-09-17 16:10 UTC (permalink / raw)
To: tytso; +Cc: linux-ext4, linux-api
On Tue 16-09-25 23:22:48, Theodore Ts'o via B4 Relay wrote:
> From: Theodore Ts'o <tytso@mit.edu>
>
> Support for specifying the default user id and group id that is
> allowed to use the reserved block space was added way back when Linux
> only supported 16-bit uid's and gid's. (Yeah, that long ago.) It's
> not a commonly used feature, but let's add support for 32-bit user and
> group id's.
>
> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
> ---
> fs/ext4/ext4.h | 16 +++++++++++++++-
> fs/ext4/super.c | 8 ++++----
> 2 files changed, 19 insertions(+), 5 deletions(-)
>
> diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
> index 01a6e2de7fc3ef0e20b039d3200b9c9bd656f59f..4bfcd5f0c74fda30db4009ee28fbee00a2f6b76f 100644
> --- a/fs/ext4/ext4.h
> +++ b/fs/ext4/ext4.h
> @@ -1442,7 +1442,9 @@ struct ext4_super_block {
> __le16 s_encoding; /* Filename charset encoding */
> __le16 s_encoding_flags; /* Filename charset encoding flags */
> __le32 s_orphan_file_inum; /* Inode for tracking orphan inodes */
> - __le32 s_reserved[94]; /* Padding to the end of the block */
> + __le16 s_def_resuid_hi;
> + __le16 s_def_resgid_hi;
> + __le32 s_reserved[93]; /* Padding to the end of the block */
> __le32 s_checksum; /* crc32c(superblock) */
> };
>
> @@ -1812,6 +1814,18 @@ static inline int ext4_valid_inum(struct super_block *sb, unsigned long ino)
> ino <= le32_to_cpu(EXT4_SB(sb)->s_es->s_inodes_count));
> }
>
> +static inline int ext4_get_resuid(struct ext4_super_block *es)
> +{
> + return(le16_to_cpu(es->s_def_resuid) |
> + (le16_to_cpu(es->s_def_resuid_hi) << 16));
> +}
I'd prefer a style like:
return le16_to_cpu(es->s_def_resuid) |
(le16_to_cpu(es->s_def_resuid_hi) << 16);
but whatever...
> @@ -5270,8 +5270,8 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
>
> ext4_set_def_opts(sb, es);
>
> - sbi->s_resuid = make_kuid(&init_user_ns, le16_to_cpu(es->s_def_resuid));
> - sbi->s_resgid = make_kgid(&init_user_ns, le16_to_cpu(es->s_def_resgid));
> + sbi->s_resuid = make_kuid(&init_user_ns, ext4_get_resuid(es));
> + sbi->s_resgid = make_kgid(&init_user_ns, ext4_get_resuid(es));
^^^^ ext4_get_resgid() here.
> sbi->s_commit_interval = JBD2_DEFAULT_MAX_COMMIT_AGE * HZ;
> sbi->s_min_batch_time = EXT4_DEF_MIN_BATCH_TIME;
> sbi->s_max_batch_time = EXT4_DEF_MAX_BATCH_TIME;
Honza
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2 3/3] ext4: implemet new ioctls to set and get superblock parameters
2025-09-17 3:22 ` [PATCH v2 3/3] ext4: implemet new ioctls to set and get superblock parameters Theodore Ts'o via B4 Relay
@ 2025-09-17 16:22 ` Jan Kara
2025-09-18 16:57 ` Darrick J. Wong
1 sibling, 0 replies; 10+ messages in thread
From: Jan Kara @ 2025-09-17 16:22 UTC (permalink / raw)
To: tytso; +Cc: linux-ext4, linux-api
On Tue 16-09-25 23:22:49, Theodore Ts'o via B4 Relay wrote:
> From: Theodore Ts'o <tytso@mit.edu>
>
> Implement the EXT4_IOC_GET_TUNE_SB_PARAM and
> EXT4_IOC_SET_TUNE_SB_PARAM ioctls, which allow certains superblock
> parameters to be set while the file system is mounted, without needing
> write access to the block device.
>
> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Looks good. Feel free to add:
Reviewed-by: Jan Kara <jack@suse.cz>
Honza
> ---
> fs/ext4/ioctl.c | 312 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
> include/uapi/linux/ext4.h | 53 +++++++++++++
> 2 files changed, 358 insertions(+), 7 deletions(-)
>
> diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
> index 84e3c73952d72e436429489f5fc8b7ae1c01c7a1..a93a7baae990cc5580d2ddb3ffcc72fe15246978 100644
> --- a/fs/ext4/ioctl.c
> +++ b/fs/ext4/ioctl.c
> @@ -27,14 +27,16 @@
> #include "fsmap.h"
> #include <trace/events/ext4.h>
>
> -typedef void ext4_update_sb_callback(struct ext4_super_block *es,
> - const void *arg);
> +typedef void ext4_update_sb_callback(struct ext4_sb_info *sbi,
> + struct ext4_super_block *es,
> + const void *arg);
>
> /*
> * Superblock modification callback function for changing file system
> * label
> */
> -static void ext4_sb_setlabel(struct ext4_super_block *es, const void *arg)
> +static void ext4_sb_setlabel(struct ext4_sb_info *sbi,
> + struct ext4_super_block *es, const void *arg)
> {
> /* Sanity check, this should never happen */
> BUILD_BUG_ON(sizeof(es->s_volume_name) < EXT4_LABEL_MAX);
> @@ -46,7 +48,8 @@ static void ext4_sb_setlabel(struct ext4_super_block *es, const void *arg)
> * Superblock modification callback function for changing file system
> * UUID.
> */
> -static void ext4_sb_setuuid(struct ext4_super_block *es, const void *arg)
> +static void ext4_sb_setuuid(struct ext4_sb_info *sbi,
> + struct ext4_super_block *es, const void *arg)
> {
> memcpy(es->s_uuid, (__u8 *)arg, UUID_SIZE);
> }
> @@ -71,7 +74,7 @@ int ext4_update_primary_sb(struct super_block *sb, handle_t *handle,
> goto out_err;
>
> lock_buffer(bh);
> - func(es, arg);
> + func(sbi, es, arg);
> ext4_superblock_csum_set(sb);
> unlock_buffer(bh);
>
> @@ -149,7 +152,7 @@ static int ext4_update_backup_sb(struct super_block *sb,
> unlock_buffer(bh);
> goto out_bh;
> }
> - func(es, arg);
> + func(EXT4_SB(sb), es, arg);
> if (ext4_has_feature_metadata_csum(sb))
> es->s_checksum = ext4_superblock_csum(es);
> set_buffer_uptodate(bh);
> @@ -1230,6 +1233,295 @@ static int ext4_ioctl_setuuid(struct file *filp,
> return ret;
> }
>
> +
> +#define TUNE_OPS_SUPPORTED (EXT4_TUNE_FL_ERRORS_BEHAVIOR | \
> + EXT4_TUNE_FL_MNT_COUNT | EXT4_TUNE_FL_MAX_MNT_COUNT | \
> + EXT4_TUNE_FL_CHECKINTRVAL | EXT4_TUNE_FL_LAST_CHECK_TIME | \
> + EXT4_TUNE_FL_RESERVED_BLOCKS | EXT4_TUNE_FL_RESERVED_UID | \
> + EXT4_TUNE_FL_RESERVED_GID | EXT4_TUNE_FL_DEFAULT_MNT_OPTS | \
> + EXT4_TUNE_FL_DEF_HASH_ALG | EXT4_TUNE_FL_RAID_STRIDE | \
> + EXT4_TUNE_FL_RAID_STRIPE_WIDTH | EXT4_TUNE_FL_MOUNT_OPTS | \
> + EXT4_TUNE_FL_FEATURES | EXT4_TUNE_FL_EDIT_FEATURES | \
> + EXT4_TUNE_FL_FORCE_FSCK | EXT4_TUNE_FL_ENCODING | \
> + EXT4_TUNE_FL_ENCODING_FLAGS)
> +
> +#define EXT4_TUNE_SET_COMPAT_SUPP \
> + (EXT4_FEATURE_COMPAT_DIR_INDEX | \
> + EXT4_FEATURE_COMPAT_STABLE_INODES)
> +#define EXT4_TUNE_SET_INCOMPAT_SUPP \
> + (EXT4_FEATURE_INCOMPAT_EXTENTS | \
> + EXT4_FEATURE_INCOMPAT_EA_INODE | \
> + EXT4_FEATURE_INCOMPAT_ENCRYPT | \
> + EXT4_FEATURE_INCOMPAT_CSUM_SEED | \
> + EXT4_FEATURE_INCOMPAT_LARGEDIR | \
> + EXT4_FEATURE_INCOMPAT_CASEFOLD)
> +#define EXT4_TUNE_SET_RO_COMPAT_SUPP \
> + (EXT4_FEATURE_RO_COMPAT_LARGE_FILE | \
> + EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
> + EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
> + EXT4_FEATURE_RO_COMPAT_PROJECT | \
> + EXT4_FEATURE_RO_COMPAT_VERITY)
> +
> +#define EXT4_TUNE_CLEAR_COMPAT_SUPP (0)
> +#define EXT4_TUNE_CLEAR_INCOMPAT_SUPP (0)
> +#define EXT4_TUNE_CLEAR_RO_COMPAT_SUPP (0)
> +
> +#define SB_ENC_SUPP_MASK (SB_ENC_STRICT_MODE_FL | \
> + SB_ENC_NO_COMPAT_FALLBACK_FL)
> +
> +static int ext4_ioctl_get_tune_sb(struct ext4_sb_info *sbi,
> + struct ext4_tune_sb_params __user *params)
> +{
> + struct ext4_tune_sb_params ret;
> + struct ext4_super_block *es = sbi->s_es;
> +
> + memset(&ret, 0, sizeof(ret));
> + ret.set_flags = TUNE_OPS_SUPPORTED;
> + ret.errors_behavior = le16_to_cpu(es->s_errors);
> + ret.mnt_count = le16_to_cpu(es->s_mnt_count);
> + ret.max_mnt_count = le16_to_cpu(es->s_max_mnt_count);
> + ret.checkinterval = le32_to_cpu(es->s_checkinterval);
> + ret.last_check_time = le32_to_cpu(es->s_lastcheck);
> + ret.reserved_blocks = ext4_r_blocks_count(es);
> + ret.blocks_count = ext4_blocks_count(es);
> + ret.reserved_uid = ext4_get_resuid(es);
> + ret.reserved_gid = ext4_get_resgid(es);
> + ret.default_mnt_opts = le32_to_cpu(es->s_default_mount_opts);
> + ret.def_hash_alg = es->s_def_hash_version;
> + ret.raid_stride = le16_to_cpu(es->s_raid_stride);
> + ret.raid_stripe_width = le32_to_cpu(es->s_raid_stripe_width);
> + ret.encoding = le16_to_cpu(es->s_encoding);
> + ret.encoding_flags = le16_to_cpu(es->s_encoding_flags);
> + strscpy_pad(ret.mount_opts, es->s_mount_opts);
> + ret.feature_compat = le32_to_cpu(es->s_feature_compat);
> + ret.feature_incompat = le32_to_cpu(es->s_feature_incompat);
> + ret.feature_ro_compat = le32_to_cpu(es->s_feature_ro_compat);
> + ret.set_feature_compat_mask = EXT4_TUNE_SET_COMPAT_SUPP;
> + ret.set_feature_incompat_mask = EXT4_TUNE_SET_INCOMPAT_SUPP;
> + ret.set_feature_ro_compat_mask = EXT4_TUNE_SET_RO_COMPAT_SUPP;
> + ret.clear_feature_compat_mask = EXT4_TUNE_CLEAR_COMPAT_SUPP;
> + ret.clear_feature_incompat_mask = EXT4_TUNE_CLEAR_INCOMPAT_SUPP;
> + ret.clear_feature_ro_compat_mask = EXT4_TUNE_CLEAR_RO_COMPAT_SUPP;
> + if (copy_to_user(params, &ret, sizeof(ret)))
> + return -EFAULT;
> + return 0;
> +}
> +
> +static void ext4_sb_setparams(struct ext4_sb_info *sbi,
> + struct ext4_super_block *es, const void *arg)
> +{
> + const struct ext4_tune_sb_params *params = arg;
> +
> + if (params->set_flags & EXT4_TUNE_FL_ERRORS_BEHAVIOR)
> + es->s_errors = cpu_to_le16(params->errors_behavior);
> + if (params->set_flags & EXT4_TUNE_FL_MNT_COUNT)
> + es->s_mnt_count = cpu_to_le16(params->mnt_count);
> + if (params->set_flags & EXT4_TUNE_FL_MAX_MNT_COUNT)
> + es->s_max_mnt_count = cpu_to_le16(params->max_mnt_count);
> + if (params->set_flags & EXT4_TUNE_FL_CHECKINTRVAL)
> + es->s_checkinterval = cpu_to_le32(params->checkinterval);
> + if (params->set_flags & EXT4_TUNE_FL_LAST_CHECK_TIME)
> + es->s_lastcheck = cpu_to_le32(params->last_check_time);
> + if (params->set_flags & EXT4_TUNE_FL_RESERVED_BLOCKS) {
> + ext4_fsblk_t blk = params->reserved_blocks;
> +
> + es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
> + es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
> + }
> + if (params->set_flags & EXT4_TUNE_FL_RESERVED_UID) {
> + int uid = params->reserved_uid;
> +
> + es->s_def_resuid = cpu_to_le16(uid & 0xFFFF);
> + es->s_def_resuid_hi = cpu_to_le16(uid >> 16);
> + }
> + if (params->set_flags & EXT4_TUNE_FL_RESERVED_GID) {
> + int gid = params->reserved_gid;
> +
> + es->s_def_resgid = cpu_to_le16(gid & 0xFFFF);
> + es->s_def_resgid_hi = cpu_to_le16(gid >> 16);
> + }
> + if (params->set_flags & EXT4_TUNE_FL_DEFAULT_MNT_OPTS)
> + es->s_default_mount_opts = cpu_to_le32(params->default_mnt_opts);
> + if (params->set_flags & EXT4_TUNE_FL_DEF_HASH_ALG)
> + es->s_def_hash_version = params->def_hash_alg;
> + if (params->set_flags & EXT4_TUNE_FL_RAID_STRIDE)
> + es->s_raid_stride = cpu_to_le16(params->raid_stride);
> + if (params->set_flags & EXT4_TUNE_FL_RAID_STRIPE_WIDTH)
> + es->s_raid_stripe_width =
> + cpu_to_le32(params->raid_stripe_width);
> + if (params->set_flags & EXT4_TUNE_FL_ENCODING)
> + es->s_encoding = cpu_to_le16(params->encoding);
> + if (params->set_flags & EXT4_TUNE_FL_ENCODING_FLAGS)
> + es->s_encoding_flags = cpu_to_le16(params->encoding_flags);
> + strscpy_pad(es->s_mount_opts, params->mount_opts);
> + if (params->set_flags & EXT4_TUNE_FL_EDIT_FEATURES) {
> + es->s_feature_compat |=
> + cpu_to_le32(params->set_feature_compat_mask);
> + es->s_feature_incompat |=
> + cpu_to_le32(params->set_feature_incompat_mask);
> + es->s_feature_ro_compat |=
> + cpu_to_le32(params->set_feature_ro_compat_mask);
> + es->s_feature_compat &=
> + ~cpu_to_le32(params->clear_feature_compat_mask);
> + es->s_feature_incompat &=
> + ~cpu_to_le32(params->clear_feature_incompat_mask);
> + es->s_feature_ro_compat &=
> + ~cpu_to_le32(params->clear_feature_ro_compat_mask);
> + if (params->set_feature_compat_mask &
> + EXT4_FEATURE_COMPAT_DIR_INDEX)
> + es->s_def_hash_version = sbi->s_def_hash_version;
> + if (params->set_feature_incompat_mask &
> + EXT4_FEATURE_INCOMPAT_CSUM_SEED)
> + es->s_checksum_seed = cpu_to_le32(sbi->s_csum_seed);
> + }
> + if (params->set_flags & EXT4_TUNE_FL_FORCE_FSCK)
> + es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
> +}
> +
> +static int ext4_ioctl_set_tune_sb(struct file *filp,
> + struct ext4_tune_sb_params __user *in)
> +{
> + struct ext4_tune_sb_params params;
> + struct super_block *sb = file_inode(filp)->i_sb;
> + struct ext4_sb_info *sbi = EXT4_SB(sb);
> + struct ext4_super_block *es = sbi->s_es;
> + int enabling_casefold = 0;
> + int ret;
> +
> + if (!capable(CAP_SYS_ADMIN))
> + return -EPERM;
> +
> + if (copy_from_user(¶ms, in, sizeof(params)))
> + return -EFAULT;
> +
> + if ((params.set_flags & ~TUNE_OPS_SUPPORTED) != 0)
> + return -EOPNOTSUPP;
> +
> + if ((params.set_flags & EXT4_TUNE_FL_ERRORS_BEHAVIOR) &&
> + (params.errors_behavior > EXT4_ERRORS_PANIC))
> + return -EINVAL;
> +
> + if ((params.set_flags & EXT4_TUNE_FL_RESERVED_BLOCKS) &&
> + (params.reserved_blocks > ext4_blocks_count(sbi->s_es) / 2))
> + return -EINVAL;
> + if ((params.set_flags & EXT4_TUNE_FL_DEF_HASH_ALG) &&
> + ((params.def_hash_alg > DX_HASH_LAST) ||
> + (params.def_hash_alg == DX_HASH_SIPHASH)))
> + return -EINVAL;
> + if ((params.set_flags & EXT4_TUNE_FL_FEATURES) &&
> + (params.set_flags & EXT4_TUNE_FL_EDIT_FEATURES))
> + return -EINVAL;
> +
> + if (params.set_flags & EXT4_TUNE_FL_FEATURES) {
> + params.set_feature_compat_mask =
> + params.feature_compat &
> + ~le32_to_cpu(es->s_feature_compat);
> + params.set_feature_incompat_mask =
> + params.feature_incompat &
> + ~le32_to_cpu(es->s_feature_incompat);
> + params.set_feature_ro_compat_mask =
> + params.feature_ro_compat &
> + ~le32_to_cpu(es->s_feature_ro_compat);
> + params.clear_feature_compat_mask =
> + ~params.feature_compat &
> + le32_to_cpu(es->s_feature_compat);
> + params.clear_feature_incompat_mask =
> + ~params.feature_incompat &
> + le32_to_cpu(es->s_feature_incompat);
> + params.clear_feature_ro_compat_mask =
> + ~params.feature_ro_compat &
> + le32_to_cpu(es->s_feature_ro_compat);
> + params.set_flags |= EXT4_TUNE_FL_EDIT_FEATURES;
> + }
> + if (params.set_flags & EXT4_TUNE_FL_EDIT_FEATURES) {
> + if ((params.set_feature_compat_mask &
> + ~EXT4_TUNE_SET_COMPAT_SUPP) ||
> + (params.set_feature_incompat_mask &
> + ~EXT4_TUNE_SET_INCOMPAT_SUPP) ||
> + (params.set_feature_ro_compat_mask &
> + ~EXT4_TUNE_SET_RO_COMPAT_SUPP) ||
> + (params.clear_feature_compat_mask &
> + ~EXT4_TUNE_CLEAR_COMPAT_SUPP) ||
> + (params.clear_feature_incompat_mask &
> + ~EXT4_TUNE_CLEAR_INCOMPAT_SUPP) ||
> + (params.clear_feature_ro_compat_mask &
> + ~EXT4_TUNE_CLEAR_RO_COMPAT_SUPP))
> + return -EOPNOTSUPP;
> +
> + /*
> + * Filter out the features that are already set from
> + * the set_mask.
> + */
> + params.set_feature_compat_mask &=
> + ~le32_to_cpu(es->s_feature_compat);
> + params.set_feature_incompat_mask &=
> + ~le32_to_cpu(es->s_feature_incompat);
> + params.set_feature_ro_compat_mask &=
> + ~le32_to_cpu(es->s_feature_ro_compat);
> + if ((params.set_feature_incompat_mask &
> + EXT4_FEATURE_INCOMPAT_CASEFOLD)) {
> + enabling_casefold = 1;
> + if (!(params.set_flags & EXT4_TUNE_FL_ENCODING)) {
> + params.encoding = EXT4_ENC_UTF8_12_1;
> + params.set_flags |= EXT4_TUNE_FL_ENCODING;
> + }
> + if (!(params.set_flags & EXT4_TUNE_FL_ENCODING_FLAGS)) {
> + params.encoding_flags = 0;
> + params.set_flags |= EXT4_TUNE_FL_ENCODING_FLAGS;
> + }
> + }
> + if ((params.set_feature_compat_mask &
> + EXT4_FEATURE_COMPAT_DIR_INDEX)) {
> + uuid_t uu;
> +
> + memcpy(&uu, sbi->s_hash_seed, UUID_SIZE);
> + if (uuid_is_null(&uu))
> + generate_random_uuid((char *)
> + &sbi->s_hash_seed);
> + if (params.set_flags & EXT4_TUNE_FL_DEF_HASH_ALG)
> + sbi->s_def_hash_version = params.def_hash_alg;
> + else if (sbi->s_def_hash_version == 0)
> + sbi->s_def_hash_version = DX_HASH_HALF_MD4;
> + if (!(es->s_flags &
> + cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH)) &&
> + !(es->s_flags &
> + cpu_to_le32(EXT2_FLAGS_SIGNED_HASH))) {
> +#ifdef __CHAR_UNSIGNED__
> + sbi->s_hash_unsigned = 3;
> +#else
> + sbi->s_hash_unsigned = 0;
> +#endif
> + }
> + }
> + }
> + if (params.set_flags & EXT4_TUNE_FL_ENCODING) {
> + if (!enabling_casefold)
> + return -EINVAL;
> + if (params.encoding == 0)
> + params.encoding = EXT4_ENC_UTF8_12_1;
> + else if (params.encoding != EXT4_ENC_UTF8_12_1)
> + return -EINVAL;
> + }
> + if (params.set_flags & EXT4_TUNE_FL_ENCODING_FLAGS) {
> + if (!enabling_casefold)
> + return -EINVAL;
> + if (params.encoding_flags & ~SB_ENC_SUPP_MASK)
> + return -EINVAL;
> + }
> +
> + ret = mnt_want_write_file(filp);
> + if (ret)
> + return ret;
> +
> + ret = ext4_update_superblocks_fn(sb, ext4_sb_setparams, ¶ms);
> + mnt_drop_write_file(filp);
> +
> + if (params.set_flags & EXT4_TUNE_FL_DEF_HASH_ALG)
> + sbi->s_def_hash_version = params.def_hash_alg;
> +
> + return ret;
> +}
> +
> static long __ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> {
> struct inode *inode = file_inode(filp);
> @@ -1616,6 +1908,11 @@ static long __ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> return ext4_ioctl_getuuid(EXT4_SB(sb), (void __user *)arg);
> case EXT4_IOC_SETFSUUID:
> return ext4_ioctl_setuuid(filp, (const void __user *)arg);
> + case EXT4_IOC_GET_TUNE_SB_PARAM:
> + return ext4_ioctl_get_tune_sb(EXT4_SB(sb),
> + (void __user *)arg);
> + case EXT4_IOC_SET_TUNE_SB_PARAM:
> + return ext4_ioctl_set_tune_sb(filp, (void __user *)arg);
> default:
> return -ENOTTY;
> }
> @@ -1703,7 +2000,8 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> }
> #endif
>
> -static void set_overhead(struct ext4_super_block *es, const void *arg)
> +static void set_overhead(struct ext4_sb_info *sbi,
> + struct ext4_super_block *es, const void *arg)
> {
> es->s_overhead_clusters = cpu_to_le32(*((unsigned long *) arg));
> }
> diff --git a/include/uapi/linux/ext4.h b/include/uapi/linux/ext4.h
> index 1c4c2dd29112cda9f7dc91d917492cffc33ee524..411dcc1e4a35c8c6a10f3768d17b8cc50cff4c34 100644
> --- a/include/uapi/linux/ext4.h
> +++ b/include/uapi/linux/ext4.h
> @@ -33,6 +33,8 @@
> #define EXT4_IOC_CHECKPOINT _IOW('f', 43, __u32)
> #define EXT4_IOC_GETFSUUID _IOR('f', 44, struct fsuuid)
> #define EXT4_IOC_SETFSUUID _IOW('f', 44, struct fsuuid)
> +#define EXT4_IOC_GET_TUNE_SB_PARAM _IOR('f', 45, struct ext4_tune_sb_params)
> +#define EXT4_IOC_SET_TUNE_SB_PARAM _IOW('f', 46, struct ext4_tune_sb_params)
>
> #define EXT4_IOC_SHUTDOWN _IOR('X', 125, __u32)
>
> @@ -108,6 +110,57 @@ struct ext4_new_group_input {
> __u16 unused;
> };
>
> +struct ext4_tune_sb_params {
> + __u32 set_flags;
> + __u32 checkinterval;
> + __u16 errors_behavior;
> + __u16 mnt_count;
> + __u16 max_mnt_count;
> + __u16 raid_stride;
> + __u64 last_check_time;
> + __u64 reserved_blocks;
> + __u64 blocks_count;
> + __u32 default_mnt_opts;
> + __u32 reserved_uid;
> + __u32 reserved_gid;
> + __u32 raid_stripe_width;
> + __u16 encoding;
> + __u16 encoding_flags;
> + __u8 def_hash_alg;
> + __u8 pad_1;
> + __u16 pad_2;
> + __u32 feature_compat;
> + __u32 feature_incompat;
> + __u32 feature_ro_compat;
> + __u32 set_feature_compat_mask;
> + __u32 set_feature_incompat_mask;
> + __u32 set_feature_ro_compat_mask;
> + __u32 clear_feature_compat_mask;
> + __u32 clear_feature_incompat_mask;
> + __u32 clear_feature_ro_compat_mask;
> + __u8 mount_opts[64];
> + __u8 pad[64];
> +};
> +
> +#define EXT4_TUNE_FL_ERRORS_BEHAVIOR 0x00000001
> +#define EXT4_TUNE_FL_MNT_COUNT 0x00000002
> +#define EXT4_TUNE_FL_MAX_MNT_COUNT 0x00000004
> +#define EXT4_TUNE_FL_CHECKINTRVAL 0x00000008
> +#define EXT4_TUNE_FL_LAST_CHECK_TIME 0x00000010
> +#define EXT4_TUNE_FL_RESERVED_BLOCKS 0x00000020
> +#define EXT4_TUNE_FL_RESERVED_UID 0x00000040
> +#define EXT4_TUNE_FL_RESERVED_GID 0x00000080
> +#define EXT4_TUNE_FL_DEFAULT_MNT_OPTS 0x00000100
> +#define EXT4_TUNE_FL_DEF_HASH_ALG 0x00000200
> +#define EXT4_TUNE_FL_RAID_STRIDE 0x00000400
> +#define EXT4_TUNE_FL_RAID_STRIPE_WIDTH 0x00000800
> +#define EXT4_TUNE_FL_MOUNT_OPTS 0x00001000
> +#define EXT4_TUNE_FL_FEATURES 0x00002000
> +#define EXT4_TUNE_FL_EDIT_FEATURES 0x00004000
> +#define EXT4_TUNE_FL_FORCE_FSCK 0x00008000
> +#define EXT4_TUNE_FL_ENCODING 0x00010000
> +#define EXT4_TUNE_FL_ENCODING_FLAGS 0x00020000
> +
> /*
> * Returned by EXT4_IOC_GET_ES_CACHE as an additional possible flag.
> * It indicates that the entry in extent status cache is for a hole.
>
> --
> 2.51.0
>
>
>
--
Jan Kara <jack@suse.com>
SUSE Labs, CR
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2 1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options()
2025-09-17 16:05 ` Jan Kara
@ 2025-09-18 16:55 ` Darrick J. Wong
0 siblings, 0 replies; 10+ messages in thread
From: Darrick J. Wong @ 2025-09-18 16:55 UTC (permalink / raw)
To: Jan Kara; +Cc: tytso, linux-ext4, linux-api, stable
On Wed, Sep 17, 2025 at 06:05:06PM +0200, Jan Kara wrote:
> On Tue 16-09-25 23:22:47, Theodore Ts'o via B4 Relay wrote:
> > From: Theodore Ts'o <tytso@mit.edu>
> >
> > Unlike other strings in the ext4 superblock, we rely on tune2fs to
> > make sure s_mount_opts is NUL terminated. Harden
> > parse_apply_sb_mount_options() by treating s_mount_opts as a potential
> > __nonstring.
> >
> > Cc: stable@vger.kernel.org
> > Fixes: 8b67f04ab9de ("ext4: Add mount options in superblock")
> > Signed-off-by: Theodore Ts'o <tytso@mit.edu>
>
> Looks good. Feel free to add:
>
> Reviewed-by: Jan Kara <jack@suse.cz>
Looks fine to me too,
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
--D
>
> Honza
>
> > ---
> > fs/ext4/super.c | 17 +++++------------
> > 1 file changed, 5 insertions(+), 12 deletions(-)
> >
> > diff --git a/fs/ext4/super.c b/fs/ext4/super.c
> > index 699c15db28a82f26809bf68533454a242596f0fd..94c98446c84f9a4614971d246ca7f001de610a8a 100644
> > --- a/fs/ext4/super.c
> > +++ b/fs/ext4/super.c
> > @@ -2460,7 +2460,7 @@ static int parse_apply_sb_mount_options(struct super_block *sb,
> > struct ext4_fs_context *m_ctx)
> > {
> > struct ext4_sb_info *sbi = EXT4_SB(sb);
> > - char *s_mount_opts = NULL;
> > + char s_mount_opts[65];
> > struct ext4_fs_context *s_ctx = NULL;
> > struct fs_context *fc = NULL;
> > int ret = -ENOMEM;
> > @@ -2468,15 +2468,11 @@ static int parse_apply_sb_mount_options(struct super_block *sb,
> > if (!sbi->s_es->s_mount_opts[0])
> > return 0;
> >
> > - s_mount_opts = kstrndup(sbi->s_es->s_mount_opts,
> > - sizeof(sbi->s_es->s_mount_opts),
> > - GFP_KERNEL);
> > - if (!s_mount_opts)
> > - return ret;
> > + strscpy_pad(s_mount_opts, sbi->s_es->s_mount_opts);
> >
> > fc = kzalloc(sizeof(struct fs_context), GFP_KERNEL);
> > if (!fc)
> > - goto out_free;
> > + return -ENOMEM;
> >
> > s_ctx = kzalloc(sizeof(struct ext4_fs_context), GFP_KERNEL);
> > if (!s_ctx)
> > @@ -2508,11 +2504,8 @@ static int parse_apply_sb_mount_options(struct super_block *sb,
> > ret = 0;
> >
> > out_free:
> > - if (fc) {
> > - ext4_fc_free(fc);
> > - kfree(fc);
> > - }
> > - kfree(s_mount_opts);
> > + ext4_fc_free(fc);
> > + kfree(fc);
> > return ret;
> > }
> >
> >
> > --
> > 2.51.0
> >
> >
> >
> --
> Jan Kara <jack@suse.com>
> SUSE Labs, CR
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2 3/3] ext4: implemet new ioctls to set and get superblock parameters
2025-09-17 3:22 ` [PATCH v2 3/3] ext4: implemet new ioctls to set and get superblock parameters Theodore Ts'o via B4 Relay
2025-09-17 16:22 ` Jan Kara
@ 2025-09-18 16:57 ` Darrick J. Wong
1 sibling, 0 replies; 10+ messages in thread
From: Darrick J. Wong @ 2025-09-18 16:57 UTC (permalink / raw)
To: tytso; +Cc: linux-ext4, linux-api
On Tue, Sep 16, 2025 at 11:22:49PM -0400, Theodore Ts'o via B4 Relay wrote:
> From: Theodore Ts'o <tytso@mit.edu>
>
> Implement the EXT4_IOC_GET_TUNE_SB_PARAM and
> EXT4_IOC_SET_TUNE_SB_PARAM ioctls, which allow certains superblock
> parameters to be set while the file system is mounted, without needing
> write access to the block device.
>
> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Looks good to me now,
Reviewed-by: "Darrick J. Wong" <djwong@kernel.org>
--D
> ---
> fs/ext4/ioctl.c | 312 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--
> include/uapi/linux/ext4.h | 53 +++++++++++++
> 2 files changed, 358 insertions(+), 7 deletions(-)
>
> diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
> index 84e3c73952d72e436429489f5fc8b7ae1c01c7a1..a93a7baae990cc5580d2ddb3ffcc72fe15246978 100644
> --- a/fs/ext4/ioctl.c
> +++ b/fs/ext4/ioctl.c
> @@ -27,14 +27,16 @@
> #include "fsmap.h"
> #include <trace/events/ext4.h>
>
> -typedef void ext4_update_sb_callback(struct ext4_super_block *es,
> - const void *arg);
> +typedef void ext4_update_sb_callback(struct ext4_sb_info *sbi,
> + struct ext4_super_block *es,
> + const void *arg);
>
> /*
> * Superblock modification callback function for changing file system
> * label
> */
> -static void ext4_sb_setlabel(struct ext4_super_block *es, const void *arg)
> +static void ext4_sb_setlabel(struct ext4_sb_info *sbi,
> + struct ext4_super_block *es, const void *arg)
> {
> /* Sanity check, this should never happen */
> BUILD_BUG_ON(sizeof(es->s_volume_name) < EXT4_LABEL_MAX);
> @@ -46,7 +48,8 @@ static void ext4_sb_setlabel(struct ext4_super_block *es, const void *arg)
> * Superblock modification callback function for changing file system
> * UUID.
> */
> -static void ext4_sb_setuuid(struct ext4_super_block *es, const void *arg)
> +static void ext4_sb_setuuid(struct ext4_sb_info *sbi,
> + struct ext4_super_block *es, const void *arg)
> {
> memcpy(es->s_uuid, (__u8 *)arg, UUID_SIZE);
> }
> @@ -71,7 +74,7 @@ int ext4_update_primary_sb(struct super_block *sb, handle_t *handle,
> goto out_err;
>
> lock_buffer(bh);
> - func(es, arg);
> + func(sbi, es, arg);
> ext4_superblock_csum_set(sb);
> unlock_buffer(bh);
>
> @@ -149,7 +152,7 @@ static int ext4_update_backup_sb(struct super_block *sb,
> unlock_buffer(bh);
> goto out_bh;
> }
> - func(es, arg);
> + func(EXT4_SB(sb), es, arg);
> if (ext4_has_feature_metadata_csum(sb))
> es->s_checksum = ext4_superblock_csum(es);
> set_buffer_uptodate(bh);
> @@ -1230,6 +1233,295 @@ static int ext4_ioctl_setuuid(struct file *filp,
> return ret;
> }
>
> +
> +#define TUNE_OPS_SUPPORTED (EXT4_TUNE_FL_ERRORS_BEHAVIOR | \
> + EXT4_TUNE_FL_MNT_COUNT | EXT4_TUNE_FL_MAX_MNT_COUNT | \
> + EXT4_TUNE_FL_CHECKINTRVAL | EXT4_TUNE_FL_LAST_CHECK_TIME | \
> + EXT4_TUNE_FL_RESERVED_BLOCKS | EXT4_TUNE_FL_RESERVED_UID | \
> + EXT4_TUNE_FL_RESERVED_GID | EXT4_TUNE_FL_DEFAULT_MNT_OPTS | \
> + EXT4_TUNE_FL_DEF_HASH_ALG | EXT4_TUNE_FL_RAID_STRIDE | \
> + EXT4_TUNE_FL_RAID_STRIPE_WIDTH | EXT4_TUNE_FL_MOUNT_OPTS | \
> + EXT4_TUNE_FL_FEATURES | EXT4_TUNE_FL_EDIT_FEATURES | \
> + EXT4_TUNE_FL_FORCE_FSCK | EXT4_TUNE_FL_ENCODING | \
> + EXT4_TUNE_FL_ENCODING_FLAGS)
> +
> +#define EXT4_TUNE_SET_COMPAT_SUPP \
> + (EXT4_FEATURE_COMPAT_DIR_INDEX | \
> + EXT4_FEATURE_COMPAT_STABLE_INODES)
> +#define EXT4_TUNE_SET_INCOMPAT_SUPP \
> + (EXT4_FEATURE_INCOMPAT_EXTENTS | \
> + EXT4_FEATURE_INCOMPAT_EA_INODE | \
> + EXT4_FEATURE_INCOMPAT_ENCRYPT | \
> + EXT4_FEATURE_INCOMPAT_CSUM_SEED | \
> + EXT4_FEATURE_INCOMPAT_LARGEDIR | \
> + EXT4_FEATURE_INCOMPAT_CASEFOLD)
> +#define EXT4_TUNE_SET_RO_COMPAT_SUPP \
> + (EXT4_FEATURE_RO_COMPAT_LARGE_FILE | \
> + EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \
> + EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \
> + EXT4_FEATURE_RO_COMPAT_PROJECT | \
> + EXT4_FEATURE_RO_COMPAT_VERITY)
> +
> +#define EXT4_TUNE_CLEAR_COMPAT_SUPP (0)
> +#define EXT4_TUNE_CLEAR_INCOMPAT_SUPP (0)
> +#define EXT4_TUNE_CLEAR_RO_COMPAT_SUPP (0)
> +
> +#define SB_ENC_SUPP_MASK (SB_ENC_STRICT_MODE_FL | \
> + SB_ENC_NO_COMPAT_FALLBACK_FL)
> +
> +static int ext4_ioctl_get_tune_sb(struct ext4_sb_info *sbi,
> + struct ext4_tune_sb_params __user *params)
> +{
> + struct ext4_tune_sb_params ret;
> + struct ext4_super_block *es = sbi->s_es;
> +
> + memset(&ret, 0, sizeof(ret));
> + ret.set_flags = TUNE_OPS_SUPPORTED;
> + ret.errors_behavior = le16_to_cpu(es->s_errors);
> + ret.mnt_count = le16_to_cpu(es->s_mnt_count);
> + ret.max_mnt_count = le16_to_cpu(es->s_max_mnt_count);
> + ret.checkinterval = le32_to_cpu(es->s_checkinterval);
> + ret.last_check_time = le32_to_cpu(es->s_lastcheck);
> + ret.reserved_blocks = ext4_r_blocks_count(es);
> + ret.blocks_count = ext4_blocks_count(es);
> + ret.reserved_uid = ext4_get_resuid(es);
> + ret.reserved_gid = ext4_get_resgid(es);
> + ret.default_mnt_opts = le32_to_cpu(es->s_default_mount_opts);
> + ret.def_hash_alg = es->s_def_hash_version;
> + ret.raid_stride = le16_to_cpu(es->s_raid_stride);
> + ret.raid_stripe_width = le32_to_cpu(es->s_raid_stripe_width);
> + ret.encoding = le16_to_cpu(es->s_encoding);
> + ret.encoding_flags = le16_to_cpu(es->s_encoding_flags);
> + strscpy_pad(ret.mount_opts, es->s_mount_opts);
> + ret.feature_compat = le32_to_cpu(es->s_feature_compat);
> + ret.feature_incompat = le32_to_cpu(es->s_feature_incompat);
> + ret.feature_ro_compat = le32_to_cpu(es->s_feature_ro_compat);
> + ret.set_feature_compat_mask = EXT4_TUNE_SET_COMPAT_SUPP;
> + ret.set_feature_incompat_mask = EXT4_TUNE_SET_INCOMPAT_SUPP;
> + ret.set_feature_ro_compat_mask = EXT4_TUNE_SET_RO_COMPAT_SUPP;
> + ret.clear_feature_compat_mask = EXT4_TUNE_CLEAR_COMPAT_SUPP;
> + ret.clear_feature_incompat_mask = EXT4_TUNE_CLEAR_INCOMPAT_SUPP;
> + ret.clear_feature_ro_compat_mask = EXT4_TUNE_CLEAR_RO_COMPAT_SUPP;
> + if (copy_to_user(params, &ret, sizeof(ret)))
> + return -EFAULT;
> + return 0;
> +}
> +
> +static void ext4_sb_setparams(struct ext4_sb_info *sbi,
> + struct ext4_super_block *es, const void *arg)
> +{
> + const struct ext4_tune_sb_params *params = arg;
> +
> + if (params->set_flags & EXT4_TUNE_FL_ERRORS_BEHAVIOR)
> + es->s_errors = cpu_to_le16(params->errors_behavior);
> + if (params->set_flags & EXT4_TUNE_FL_MNT_COUNT)
> + es->s_mnt_count = cpu_to_le16(params->mnt_count);
> + if (params->set_flags & EXT4_TUNE_FL_MAX_MNT_COUNT)
> + es->s_max_mnt_count = cpu_to_le16(params->max_mnt_count);
> + if (params->set_flags & EXT4_TUNE_FL_CHECKINTRVAL)
> + es->s_checkinterval = cpu_to_le32(params->checkinterval);
> + if (params->set_flags & EXT4_TUNE_FL_LAST_CHECK_TIME)
> + es->s_lastcheck = cpu_to_le32(params->last_check_time);
> + if (params->set_flags & EXT4_TUNE_FL_RESERVED_BLOCKS) {
> + ext4_fsblk_t blk = params->reserved_blocks;
> +
> + es->s_r_blocks_count_lo = cpu_to_le32((u32)blk);
> + es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32);
> + }
> + if (params->set_flags & EXT4_TUNE_FL_RESERVED_UID) {
> + int uid = params->reserved_uid;
> +
> + es->s_def_resuid = cpu_to_le16(uid & 0xFFFF);
> + es->s_def_resuid_hi = cpu_to_le16(uid >> 16);
> + }
> + if (params->set_flags & EXT4_TUNE_FL_RESERVED_GID) {
> + int gid = params->reserved_gid;
> +
> + es->s_def_resgid = cpu_to_le16(gid & 0xFFFF);
> + es->s_def_resgid_hi = cpu_to_le16(gid >> 16);
> + }
> + if (params->set_flags & EXT4_TUNE_FL_DEFAULT_MNT_OPTS)
> + es->s_default_mount_opts = cpu_to_le32(params->default_mnt_opts);
> + if (params->set_flags & EXT4_TUNE_FL_DEF_HASH_ALG)
> + es->s_def_hash_version = params->def_hash_alg;
> + if (params->set_flags & EXT4_TUNE_FL_RAID_STRIDE)
> + es->s_raid_stride = cpu_to_le16(params->raid_stride);
> + if (params->set_flags & EXT4_TUNE_FL_RAID_STRIPE_WIDTH)
> + es->s_raid_stripe_width =
> + cpu_to_le32(params->raid_stripe_width);
> + if (params->set_flags & EXT4_TUNE_FL_ENCODING)
> + es->s_encoding = cpu_to_le16(params->encoding);
> + if (params->set_flags & EXT4_TUNE_FL_ENCODING_FLAGS)
> + es->s_encoding_flags = cpu_to_le16(params->encoding_flags);
> + strscpy_pad(es->s_mount_opts, params->mount_opts);
> + if (params->set_flags & EXT4_TUNE_FL_EDIT_FEATURES) {
> + es->s_feature_compat |=
> + cpu_to_le32(params->set_feature_compat_mask);
> + es->s_feature_incompat |=
> + cpu_to_le32(params->set_feature_incompat_mask);
> + es->s_feature_ro_compat |=
> + cpu_to_le32(params->set_feature_ro_compat_mask);
> + es->s_feature_compat &=
> + ~cpu_to_le32(params->clear_feature_compat_mask);
> + es->s_feature_incompat &=
> + ~cpu_to_le32(params->clear_feature_incompat_mask);
> + es->s_feature_ro_compat &=
> + ~cpu_to_le32(params->clear_feature_ro_compat_mask);
> + if (params->set_feature_compat_mask &
> + EXT4_FEATURE_COMPAT_DIR_INDEX)
> + es->s_def_hash_version = sbi->s_def_hash_version;
> + if (params->set_feature_incompat_mask &
> + EXT4_FEATURE_INCOMPAT_CSUM_SEED)
> + es->s_checksum_seed = cpu_to_le32(sbi->s_csum_seed);
> + }
> + if (params->set_flags & EXT4_TUNE_FL_FORCE_FSCK)
> + es->s_state |= cpu_to_le16(EXT4_ERROR_FS);
> +}
> +
> +static int ext4_ioctl_set_tune_sb(struct file *filp,
> + struct ext4_tune_sb_params __user *in)
> +{
> + struct ext4_tune_sb_params params;
> + struct super_block *sb = file_inode(filp)->i_sb;
> + struct ext4_sb_info *sbi = EXT4_SB(sb);
> + struct ext4_super_block *es = sbi->s_es;
> + int enabling_casefold = 0;
> + int ret;
> +
> + if (!capable(CAP_SYS_ADMIN))
> + return -EPERM;
> +
> + if (copy_from_user(¶ms, in, sizeof(params)))
> + return -EFAULT;
> +
> + if ((params.set_flags & ~TUNE_OPS_SUPPORTED) != 0)
> + return -EOPNOTSUPP;
> +
> + if ((params.set_flags & EXT4_TUNE_FL_ERRORS_BEHAVIOR) &&
> + (params.errors_behavior > EXT4_ERRORS_PANIC))
> + return -EINVAL;
> +
> + if ((params.set_flags & EXT4_TUNE_FL_RESERVED_BLOCKS) &&
> + (params.reserved_blocks > ext4_blocks_count(sbi->s_es) / 2))
> + return -EINVAL;
> + if ((params.set_flags & EXT4_TUNE_FL_DEF_HASH_ALG) &&
> + ((params.def_hash_alg > DX_HASH_LAST) ||
> + (params.def_hash_alg == DX_HASH_SIPHASH)))
> + return -EINVAL;
> + if ((params.set_flags & EXT4_TUNE_FL_FEATURES) &&
> + (params.set_flags & EXT4_TUNE_FL_EDIT_FEATURES))
> + return -EINVAL;
> +
> + if (params.set_flags & EXT4_TUNE_FL_FEATURES) {
> + params.set_feature_compat_mask =
> + params.feature_compat &
> + ~le32_to_cpu(es->s_feature_compat);
> + params.set_feature_incompat_mask =
> + params.feature_incompat &
> + ~le32_to_cpu(es->s_feature_incompat);
> + params.set_feature_ro_compat_mask =
> + params.feature_ro_compat &
> + ~le32_to_cpu(es->s_feature_ro_compat);
> + params.clear_feature_compat_mask =
> + ~params.feature_compat &
> + le32_to_cpu(es->s_feature_compat);
> + params.clear_feature_incompat_mask =
> + ~params.feature_incompat &
> + le32_to_cpu(es->s_feature_incompat);
> + params.clear_feature_ro_compat_mask =
> + ~params.feature_ro_compat &
> + le32_to_cpu(es->s_feature_ro_compat);
> + params.set_flags |= EXT4_TUNE_FL_EDIT_FEATURES;
> + }
> + if (params.set_flags & EXT4_TUNE_FL_EDIT_FEATURES) {
> + if ((params.set_feature_compat_mask &
> + ~EXT4_TUNE_SET_COMPAT_SUPP) ||
> + (params.set_feature_incompat_mask &
> + ~EXT4_TUNE_SET_INCOMPAT_SUPP) ||
> + (params.set_feature_ro_compat_mask &
> + ~EXT4_TUNE_SET_RO_COMPAT_SUPP) ||
> + (params.clear_feature_compat_mask &
> + ~EXT4_TUNE_CLEAR_COMPAT_SUPP) ||
> + (params.clear_feature_incompat_mask &
> + ~EXT4_TUNE_CLEAR_INCOMPAT_SUPP) ||
> + (params.clear_feature_ro_compat_mask &
> + ~EXT4_TUNE_CLEAR_RO_COMPAT_SUPP))
> + return -EOPNOTSUPP;
> +
> + /*
> + * Filter out the features that are already set from
> + * the set_mask.
> + */
> + params.set_feature_compat_mask &=
> + ~le32_to_cpu(es->s_feature_compat);
> + params.set_feature_incompat_mask &=
> + ~le32_to_cpu(es->s_feature_incompat);
> + params.set_feature_ro_compat_mask &=
> + ~le32_to_cpu(es->s_feature_ro_compat);
> + if ((params.set_feature_incompat_mask &
> + EXT4_FEATURE_INCOMPAT_CASEFOLD)) {
> + enabling_casefold = 1;
> + if (!(params.set_flags & EXT4_TUNE_FL_ENCODING)) {
> + params.encoding = EXT4_ENC_UTF8_12_1;
> + params.set_flags |= EXT4_TUNE_FL_ENCODING;
> + }
> + if (!(params.set_flags & EXT4_TUNE_FL_ENCODING_FLAGS)) {
> + params.encoding_flags = 0;
> + params.set_flags |= EXT4_TUNE_FL_ENCODING_FLAGS;
> + }
> + }
> + if ((params.set_feature_compat_mask &
> + EXT4_FEATURE_COMPAT_DIR_INDEX)) {
> + uuid_t uu;
> +
> + memcpy(&uu, sbi->s_hash_seed, UUID_SIZE);
> + if (uuid_is_null(&uu))
> + generate_random_uuid((char *)
> + &sbi->s_hash_seed);
> + if (params.set_flags & EXT4_TUNE_FL_DEF_HASH_ALG)
> + sbi->s_def_hash_version = params.def_hash_alg;
> + else if (sbi->s_def_hash_version == 0)
> + sbi->s_def_hash_version = DX_HASH_HALF_MD4;
> + if (!(es->s_flags &
> + cpu_to_le32(EXT2_FLAGS_UNSIGNED_HASH)) &&
> + !(es->s_flags &
> + cpu_to_le32(EXT2_FLAGS_SIGNED_HASH))) {
> +#ifdef __CHAR_UNSIGNED__
> + sbi->s_hash_unsigned = 3;
> +#else
> + sbi->s_hash_unsigned = 0;
> +#endif
> + }
> + }
> + }
> + if (params.set_flags & EXT4_TUNE_FL_ENCODING) {
> + if (!enabling_casefold)
> + return -EINVAL;
> + if (params.encoding == 0)
> + params.encoding = EXT4_ENC_UTF8_12_1;
> + else if (params.encoding != EXT4_ENC_UTF8_12_1)
> + return -EINVAL;
> + }
> + if (params.set_flags & EXT4_TUNE_FL_ENCODING_FLAGS) {
> + if (!enabling_casefold)
> + return -EINVAL;
> + if (params.encoding_flags & ~SB_ENC_SUPP_MASK)
> + return -EINVAL;
> + }
> +
> + ret = mnt_want_write_file(filp);
> + if (ret)
> + return ret;
> +
> + ret = ext4_update_superblocks_fn(sb, ext4_sb_setparams, ¶ms);
> + mnt_drop_write_file(filp);
> +
> + if (params.set_flags & EXT4_TUNE_FL_DEF_HASH_ALG)
> + sbi->s_def_hash_version = params.def_hash_alg;
> +
> + return ret;
> +}
> +
> static long __ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> {
> struct inode *inode = file_inode(filp);
> @@ -1616,6 +1908,11 @@ static long __ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
> return ext4_ioctl_getuuid(EXT4_SB(sb), (void __user *)arg);
> case EXT4_IOC_SETFSUUID:
> return ext4_ioctl_setuuid(filp, (const void __user *)arg);
> + case EXT4_IOC_GET_TUNE_SB_PARAM:
> + return ext4_ioctl_get_tune_sb(EXT4_SB(sb),
> + (void __user *)arg);
> + case EXT4_IOC_SET_TUNE_SB_PARAM:
> + return ext4_ioctl_set_tune_sb(filp, (void __user *)arg);
> default:
> return -ENOTTY;
> }
> @@ -1703,7 +2000,8 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
> }
> #endif
>
> -static void set_overhead(struct ext4_super_block *es, const void *arg)
> +static void set_overhead(struct ext4_sb_info *sbi,
> + struct ext4_super_block *es, const void *arg)
> {
> es->s_overhead_clusters = cpu_to_le32(*((unsigned long *) arg));
> }
> diff --git a/include/uapi/linux/ext4.h b/include/uapi/linux/ext4.h
> index 1c4c2dd29112cda9f7dc91d917492cffc33ee524..411dcc1e4a35c8c6a10f3768d17b8cc50cff4c34 100644
> --- a/include/uapi/linux/ext4.h
> +++ b/include/uapi/linux/ext4.h
> @@ -33,6 +33,8 @@
> #define EXT4_IOC_CHECKPOINT _IOW('f', 43, __u32)
> #define EXT4_IOC_GETFSUUID _IOR('f', 44, struct fsuuid)
> #define EXT4_IOC_SETFSUUID _IOW('f', 44, struct fsuuid)
> +#define EXT4_IOC_GET_TUNE_SB_PARAM _IOR('f', 45, struct ext4_tune_sb_params)
> +#define EXT4_IOC_SET_TUNE_SB_PARAM _IOW('f', 46, struct ext4_tune_sb_params)
>
> #define EXT4_IOC_SHUTDOWN _IOR('X', 125, __u32)
>
> @@ -108,6 +110,57 @@ struct ext4_new_group_input {
> __u16 unused;
> };
>
> +struct ext4_tune_sb_params {
> + __u32 set_flags;
> + __u32 checkinterval;
> + __u16 errors_behavior;
> + __u16 mnt_count;
> + __u16 max_mnt_count;
> + __u16 raid_stride;
> + __u64 last_check_time;
> + __u64 reserved_blocks;
> + __u64 blocks_count;
> + __u32 default_mnt_opts;
> + __u32 reserved_uid;
> + __u32 reserved_gid;
> + __u32 raid_stripe_width;
> + __u16 encoding;
> + __u16 encoding_flags;
> + __u8 def_hash_alg;
> + __u8 pad_1;
> + __u16 pad_2;
> + __u32 feature_compat;
> + __u32 feature_incompat;
> + __u32 feature_ro_compat;
> + __u32 set_feature_compat_mask;
> + __u32 set_feature_incompat_mask;
> + __u32 set_feature_ro_compat_mask;
> + __u32 clear_feature_compat_mask;
> + __u32 clear_feature_incompat_mask;
> + __u32 clear_feature_ro_compat_mask;
> + __u8 mount_opts[64];
> + __u8 pad[64];
> +};
> +
> +#define EXT4_TUNE_FL_ERRORS_BEHAVIOR 0x00000001
> +#define EXT4_TUNE_FL_MNT_COUNT 0x00000002
> +#define EXT4_TUNE_FL_MAX_MNT_COUNT 0x00000004
> +#define EXT4_TUNE_FL_CHECKINTRVAL 0x00000008
> +#define EXT4_TUNE_FL_LAST_CHECK_TIME 0x00000010
> +#define EXT4_TUNE_FL_RESERVED_BLOCKS 0x00000020
> +#define EXT4_TUNE_FL_RESERVED_UID 0x00000040
> +#define EXT4_TUNE_FL_RESERVED_GID 0x00000080
> +#define EXT4_TUNE_FL_DEFAULT_MNT_OPTS 0x00000100
> +#define EXT4_TUNE_FL_DEF_HASH_ALG 0x00000200
> +#define EXT4_TUNE_FL_RAID_STRIDE 0x00000400
> +#define EXT4_TUNE_FL_RAID_STRIPE_WIDTH 0x00000800
> +#define EXT4_TUNE_FL_MOUNT_OPTS 0x00001000
> +#define EXT4_TUNE_FL_FEATURES 0x00002000
> +#define EXT4_TUNE_FL_EDIT_FEATURES 0x00004000
> +#define EXT4_TUNE_FL_FORCE_FSCK 0x00008000
> +#define EXT4_TUNE_FL_ENCODING 0x00010000
> +#define EXT4_TUNE_FL_ENCODING_FLAGS 0x00020000
> +
> /*
> * Returned by EXT4_IOC_GET_ES_CACHE as an additional possible flag.
> * It indicates that the entry in extent status cache is for a hole.
>
> --
> 2.51.0
>
>
>
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: [PATCH v2 0/3] ext4: Add support for mounted updates to the superblock via an ioctl
2025-09-17 3:22 [PATCH v2 0/3] ext4: Add support for mounted updates to the superblock via an ioctl Theodore Ts'o via B4 Relay
` (2 preceding siblings ...)
2025-09-17 3:22 ` [PATCH v2 3/3] ext4: implemet new ioctls to set and get superblock parameters Theodore Ts'o via B4 Relay
@ 2025-09-26 21:47 ` Theodore Ts'o
3 siblings, 0 replies; 10+ messages in thread
From: Theodore Ts'o @ 2025-09-26 21:47 UTC (permalink / raw)
To: Theodore Ts'o; +Cc: linux-ext4, linux-api, stable
On Tue, 16 Sep 2025 23:22:46 -0400, Theodore Ts'o wrote:
> This patch series enables a future version of tune2fs to be able to
> modify certain parts of the ext4 superblock without to write to the
> block device.
>
> The first patch fixes a potential buffer overrun caused by a
> maliciously moified superblock. The second patch adds support for
> 32-bit uid and gid's which can have access to the reserved blocks pool.
> The last patch adds the ioctl's which will be used by tune2fs.
>
> [...]
Applied, thanks!
[1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options()
commit: 8ecb790ea8c3fc69e77bace57f14cf0d7c177bd8
[2/3] ext4: add support for 32-bit default reserved uid and gid values
commit: 12c84dd4d308551568d85203fd6ed2685e861fda
[3/3] ext4: implemet new ioctls to set and get superblock parameters
commit: 04a91570ac67760301e5458d65eaf1342ecca314
Best regards,
--
Theodore Ts'o <tytso@mit.edu>
^ permalink raw reply [flat|nested] 10+ messages in thread
end of thread, other threads:[~2025-09-26 21:48 UTC | newest]
Thread overview: 10+ messages (download: mbox.gz follow: Atom feed
-- links below jump to the message on this page --
2025-09-17 3:22 [PATCH v2 0/3] ext4: Add support for mounted updates to the superblock via an ioctl Theodore Ts'o via B4 Relay
2025-09-17 3:22 ` [PATCH v2 1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() Theodore Ts'o via B4 Relay
2025-09-17 16:05 ` Jan Kara
2025-09-18 16:55 ` Darrick J. Wong
2025-09-17 3:22 ` [PATCH v2 2/3] ext4: add support for 32-bit default reserved uid and gid values Theodore Ts'o via B4 Relay
2025-09-17 16:10 ` Jan Kara
2025-09-17 3:22 ` [PATCH v2 3/3] ext4: implemet new ioctls to set and get superblock parameters Theodore Ts'o via B4 Relay
2025-09-17 16:22 ` Jan Kara
2025-09-18 16:57 ` Darrick J. Wong
2025-09-26 21:47 ` [PATCH v2 0/3] ext4: Add support for mounted updates to the superblock via an ioctl Theodore Ts'o
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).