* [PATCH 0/3] ext4: Add support for mounted updates to the superblock via an ioctl
@ 2025-09-09 3:15 Theodore Ts'o via B4 Relay
2025-09-09 3:15 ` [PATCH 1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() Theodore Ts'o via B4 Relay
` (2 more replies)
0 siblings, 3 replies; 11+ messages in thread
From: Theodore Ts'o via B4 Relay @ 2025-09-09 3:15 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>
---
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 | 256 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
fs/ext4/super.c | 25 +++-----
include/uapi/linux/ext4.h | 75 ++++++++++++++++++++++
4 files changed, 348 insertions(+), 24 deletions(-)
---
base-commit: b320789d6883cc00ac78ce83bccbfe7ed58afcf0
change-id: 20250830-tune2fs-3376beb72403
Best regards,
--
Theodore Ts'o <tytso@mit.edu>
^ permalink raw reply [flat|nested] 11+ messages in thread* [PATCH 1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() 2025-09-09 3:15 [PATCH 0/3] ext4: Add support for mounted updates to the superblock via an ioctl Theodore Ts'o via B4 Relay @ 2025-09-09 3:15 ` Theodore Ts'o via B4 Relay 2025-09-11 22:27 ` Darrick J. Wong 2025-09-09 3:15 ` [PATCH 2/3] ext4: add support for 32-bit default reserved uid and gid values Theodore Ts'o via B4 Relay 2025-09-09 3:15 ` [PATCH 3/3] ext4: implemet new ioctls to set and get superblock parameters Theodore Ts'o via B4 Relay 2 siblings, 1 reply; 11+ messages in thread From: Theodore Ts'o via B4 Relay @ 2025-09-09 3:15 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] 11+ messages in thread
* Re: [PATCH 1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() 2025-09-09 3:15 ` [PATCH 1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() Theodore Ts'o via B4 Relay @ 2025-09-11 22:27 ` Darrick J. Wong 2025-09-12 2:12 ` Theodore Ts'o 0 siblings, 1 reply; 11+ messages in thread From: Darrick J. Wong @ 2025-09-11 22:27 UTC (permalink / raw) To: tytso; +Cc: linux-ext4, linux-api, stable On Mon, Sep 08, 2025 at 11:15:48PM -0400, 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. Uh.... does that mean that a filesystem with exactly 64 bytes worth of mount option string (and no trailing null) could do something malicious? My guess is that s_usr_quota_inum mostly saves us, but a nastycrafted filesystem with more than 2^24 inodes could cause an out of bounds memory access? But that most likely will just fail the mount option parser anyway? --D > > 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 [flat|nested] 11+ messages in thread
* Re: [PATCH 1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() 2025-09-11 22:27 ` Darrick J. Wong @ 2025-09-12 2:12 ` Theodore Ts'o 0 siblings, 0 replies; 11+ messages in thread From: Theodore Ts'o @ 2025-09-12 2:12 UTC (permalink / raw) To: Darrick J. Wong; +Cc: linux-ext4, linux-api, stable, Kees Cook, jannh On Thu, Sep 11, 2025 at 03:27:00PM -0700, Darrick J. Wong wrote: > On Mon, Sep 08, 2025 at 11:15:48PM -0400, 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. > > Uh.... does that mean that a filesystem with exactly 64 bytes worth of > mount option string (and no trailing null) could do something malicious? Maybe.... I'm surprised syzkaller hasn't managed to create a maliciously fuzzed file system along these lines. This was one of the things that I found while I was poking about in code that I hadn't examined in years. And I guess the kernel hardening folks have been looking for strndup() as a deprecated interface, but apparently they haven't targetted kstrndup() yet. > My guess is that s_usr_quota_inum mostly saves us, but a nastycrafted > filesystem with more than 2^24 inodes could cause an out of bounds > memory access? But that most likely will just fail the mount option > parser anyway? Actually, s_usr_quota_inum won't help, because s_mount_opts is copied into allocated memory using kstrndup(). So the buffer overrun is going to be in the allocated memory buffer, and since parse_options() uses strsep() it could potentially modify an adajacent string/buffer by replacing ',' and '=' bytes with NUL characters. I'll leave to security engineers to see if they can turn it into a usuable exploit, although I've always said that mounting untrusted file systems isn't a wise thing for a paranoid system administrator to do/allow, which is why I'm a big fan of your fuse2fs work. :-) - Ted ^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 2/3] ext4: add support for 32-bit default reserved uid and gid values 2025-09-09 3:15 [PATCH 0/3] ext4: Add support for mounted updates to the superblock via an ioctl Theodore Ts'o via B4 Relay 2025-09-09 3:15 ` [PATCH 1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() Theodore Ts'o via B4 Relay @ 2025-09-09 3:15 ` Theodore Ts'o via B4 Relay 2025-09-11 22:31 ` Darrick J. Wong 2025-09-09 3:15 ` [PATCH 3/3] ext4: implemet new ioctls to set and get superblock parameters Theodore Ts'o via B4 Relay 2 siblings, 1 reply; 11+ messages in thread From: Theodore Ts'o via B4 Relay @ 2025-09-09 3:15 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] 11+ messages in thread
* Re: [PATCH 2/3] ext4: add support for 32-bit default reserved uid and gid values 2025-09-09 3:15 ` [PATCH 2/3] ext4: add support for 32-bit default reserved uid and gid values Theodore Ts'o via B4 Relay @ 2025-09-11 22:31 ` Darrick J. Wong 2025-09-12 2:57 ` Theodore Ts'o 0 siblings, 1 reply; 11+ messages in thread From: Darrick J. Wong @ 2025-09-11 22:31 UTC (permalink / raw) To: tytso; +Cc: linux-ext4, linux-api On Mon, Sep 08, 2025 at 11:15:49PM -0400, 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 */ Does anything actually check that s_reserved is zero? I couldn't find any: $ git grep -w s_reserved fs/ext4 fs/ext2 fs/ext2/ext2.h:480: __u32 s_reserved[190]; /* Padding to the end of the block */ fs/ext4/ext4.h:1445: __le32 s_reserved[94]; /* Padding to the end of the block */ $ git grep -w s_reserved lib/ext2fs/ e2fsck/ lib/ext2fs/ext2_fs.h:777: __le32 s_reserved[94]; /* Padding to the end of the block */ lib/ext2fs/swapfs.c:135: /* catch when new fields are used from s_reserved */ lib/ext2fs/swapfs.c:136: EXT2FS_BUILD_BUG_ON(sizeof(sb->s_reserved) != 94 * sizeof(__le32)); lib/ext2fs/tst_super_size.c:156: check_field(s_reserved, 94 * 4); Is there a risk that some garbage written to s_reserved (and not caught by either the kernel or e2fsck) will now appear as a "legitimate" resuid value? --D > __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 [flat|nested] 11+ messages in thread
* Re: [PATCH 2/3] ext4: add support for 32-bit default reserved uid and gid values 2025-09-11 22:31 ` Darrick J. Wong @ 2025-09-12 2:57 ` Theodore Ts'o 0 siblings, 0 replies; 11+ messages in thread From: Theodore Ts'o @ 2025-09-12 2:57 UTC (permalink / raw) To: Darrick J. Wong, G; +Cc: linux-ext4, linux-api On Thu, Sep 11, 2025 at 03:31:21PM -0700, Darrick J. Wong wrote: > > Is there a risk that some garbage written to s_reserved (and not caught > by either the kernel or e2fsck) will now appear as a "legitimate" resuid > value? The superblock is checksumed, so the risk would be that some impleentation modifies the superblock and updates s_reserved for some reason. But they could do that to any superblock field, or to the low 16 bits of s_resuid/s_resgid today, and that's something that neither the kernel or e2fsck could check. The mke2fs program zeroes all of the unused/reserved portions of the superblock, so the risk is some random non-Linux implementation (e.g., GNU Hurd or BSD) had hijacked some reserved field without coordinating with upstream ext4. I thought about using some kind of compat feature flag, but it probably wouldn't help since the other implementation would likely not bother to use their own feature flag since that would prevent the file system to be mounted with Linux. Currently, someone tried to run "tune2fs -u 146878 /tmp/foo.img" we'll silently drop the high 16 bits: % tune2fs -u 146878 /tmp/foo.img tune2fs 1.47.3-rc2 (12-Jun-2025) Setting reserved blocks uid to 146878 % dumpe2fs -h /tmp/foo.img | grep uid dumpe2fs 1.47.3-rc2 (12-Jun-2025) Reserved blocks uid: 15806 (user tytso) And if we have implementations that support 32-bit reserved uid's/gid's, and the file system is mounted on an older kernel, it will simply use a different reserved uid (e.g., 15806 instead of 146878). But we're kind of confused today, and in practice most of the time people will be using low reserved uid's/gid's (e.g., 1 for daemon, etc.). - Ted ^ permalink raw reply [flat|nested] 11+ messages in thread
* [PATCH 3/3] ext4: implemet new ioctls to set and get superblock parameters 2025-09-09 3:15 [PATCH 0/3] ext4: Add support for mounted updates to the superblock via an ioctl Theodore Ts'o via B4 Relay 2025-09-09 3:15 ` [PATCH 1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() Theodore Ts'o via B4 Relay 2025-09-09 3:15 ` [PATCH 2/3] ext4: add support for 32-bit default reserved uid and gid values Theodore Ts'o via B4 Relay @ 2025-09-09 3:15 ` Theodore Ts'o via B4 Relay 2025-09-09 21:33 ` kernel test robot 2025-09-11 22:40 ` Darrick J. Wong 2 siblings, 2 replies; 11+ messages in thread From: Theodore Ts'o via B4 Relay @ 2025-09-09 3:15 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 | 256 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--- include/uapi/linux/ext4.h | 75 ++++++++++++++++++++++ 2 files changed, 324 insertions(+), 7 deletions(-) diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c index 84e3c73952d72e436429489f5fc8b7ae1c01c7a1..569c98c962af63130c0119f60788a26a2807bd86 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 +1233,239 @@ 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) + +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 = 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 = le16_to_cpu(es->s_raid_stripe_width); + 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_le16(params->raid_stripe_width); + 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 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_compat_mask & + EXT4_FEATURE_COMPAT_DIR_INDEX) && + !ext4_has_feature_dir_index(sb)) { + 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 + } + } + } + + + 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 +1852,11 @@ 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 +1944,8 @@ 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..145875fd633772e76ce7fd8bc0fef136ff620d2d 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 +110,79 @@ 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; + __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_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_READONLY | \ + 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 \ + (EXT4_FEATURE_RO_COMPAT_LARGE_FILE | \ + EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \ + EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \ + EXT4_FEATURE_RO_COMPAT_PROJECT) + /* * 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] 11+ messages in thread
* Re: [PATCH 3/3] ext4: implemet new ioctls to set and get superblock parameters 2025-09-09 3:15 ` [PATCH 3/3] ext4: implemet new ioctls to set and get superblock parameters Theodore Ts'o via B4 Relay @ 2025-09-09 21:33 ` kernel test robot 2025-09-11 22:40 ` Darrick J. Wong 1 sibling, 0 replies; 11+ messages in thread From: kernel test robot @ 2025-09-09 21:33 UTC (permalink / raw) To: Theodore Ts'o via B4 Relay, tytso Cc: oe-kbuild-all, linux-ext4, linux-api Hi Theodore, kernel test robot noticed the following build warnings: [auto build test WARNING on b320789d6883cc00ac78ce83bccbfe7ed58afcf0] url: https://github.com/intel-lab-lkp/linux/commits/Theodore-Ts-o-via-B4-Relay/ext4-avoid-potential-buffer-over-read-in-parse_apply_sb_mount_options/20250909-111746 base: b320789d6883cc00ac78ce83bccbfe7ed58afcf0 patch link: https://lore.kernel.org/r/20250908-tune2fs-v1-3-e3a6929f3355%40mit.edu patch subject: [PATCH 3/3] ext4: implemet new ioctls to set and get superblock parameters config: csky-randconfig-r123-20250910 (https://download.01.org/0day-ci/archive/20250910/202509100550.fj5qrPH5-lkp@intel.com/config) compiler: csky-linux-gcc (GCC) 10.5.0 reproduce: (https://download.01.org/0day-ci/archive/20250910/202509100550.fj5qrPH5-lkp@intel.com/reproduce) If you fix the issue in a separate patch/commit (i.e. not just a new version of the same patch/commit), kindly add following tags | Reported-by: kernel test robot <lkp@intel.com> | Closes: https://lore.kernel.org/oe-kbuild-all/202509100550.fj5qrPH5-lkp@intel.com/ sparse warnings: (new ones prefixed by >>) >> fs/ext4/ioctl.c:1255:29: sparse: sparse: incorrect type in assignment (different base types) @@ expected unsigned short [addressable] [assigned] [usertype] errors_behavior @@ got restricted __le16 [usertype] s_errors @@ fs/ext4/ioctl.c:1255:29: sparse: expected unsigned short [addressable] [assigned] [usertype] errors_behavior fs/ext4/ioctl.c:1255:29: sparse: got restricted __le16 [usertype] s_errors >> fs/ext4/ioctl.c:1267:33: sparse: sparse: cast to restricted __le16 >> fs/ext4/ioctl.c:1267:33: sparse: sparse: cast from restricted __le32 >> fs/ext4/ioctl.c:1323:41: sparse: sparse: incorrect type in assignment (different base types) @@ expected restricted __le32 [usertype] s_raid_stripe_width @@ got restricted __le16 [usertype] @@ fs/ext4/ioctl.c:1323:41: sparse: expected restricted __le32 [usertype] s_raid_stripe_width fs/ext4/ioctl.c:1323:41: sparse: got restricted __le16 [usertype] fs/ext4/ioctl.c: note: in included file (through include/linux/uaccess.h, include/linux/sched/task.h, include/linux/sched/signal.h, ...): arch/csky/include/asm/uaccess.h:110:17: sparse: sparse: cast removes address space '__user' of expression arch/csky/include/asm/uaccess.h:110:17: sparse: sparse: asm output is not an lvalue arch/csky/include/asm/uaccess.h:110:17: sparse: sparse: cast removes address space '__user' of expression arch/csky/include/asm/uaccess.h:110:17: sparse: sparse: cast removes address space '__user' of expression arch/csky/include/asm/uaccess.h:110:17: sparse: sparse: asm output is not an lvalue arch/csky/include/asm/uaccess.h:110:17: sparse: sparse: cast removes address space '__user' of expression arch/csky/include/asm/uaccess.h:110:17: sparse: sparse: generating address of non-lvalue (11) arch/csky/include/asm/uaccess.h:110:17: sparse: sparse: generating address of non-lvalue (11) vim +1255 fs/ext4/ioctl.c 1235 1236 1237 #define TUNE_OPS_SUPPORTED (EXT4_TUNE_FL_ERRORS_BEHAVIOR | \ 1238 EXT4_TUNE_FL_MNT_COUNT | EXT4_TUNE_FL_MAX_MNT_COUNT | \ 1239 EXT4_TUNE_FL_CHECKINTRVAL | EXT4_TUNE_FL_LAST_CHECK_TIME | \ 1240 EXT4_TUNE_FL_RESERVED_BLOCKS | EXT4_TUNE_FL_RESERVED_UID | \ 1241 EXT4_TUNE_FL_RESERVED_GID | EXT4_TUNE_FL_DEFAULT_MNT_OPTS | \ 1242 EXT4_TUNE_FL_DEF_HASH_ALG | EXT4_TUNE_FL_RAID_STRIDE | \ 1243 EXT4_TUNE_FL_RAID_STRIPE_WIDTH | EXT4_TUNE_FL_MOUNT_OPTS | \ 1244 EXT4_TUNE_FL_FEATURES | EXT4_TUNE_FL_EDIT_FEATURES | \ 1245 EXT4_TUNE_FL_FORCE_FSCK) 1246 1247 static int ext4_ioctl_get_tune_sb(struct ext4_sb_info *sbi, 1248 struct ext4_tune_sb_params __user *params) 1249 { 1250 struct ext4_tune_sb_params ret; 1251 struct ext4_super_block *es = sbi->s_es; 1252 1253 memset(&ret, 0, sizeof(ret)); 1254 ret.set_flags = TUNE_OPS_SUPPORTED; > 1255 ret.errors_behavior = es->s_errors; 1256 ret.mnt_count = le16_to_cpu(es->s_mnt_count); 1257 ret.max_mnt_count = le16_to_cpu(es->s_max_mnt_count); 1258 ret.checkinterval = le32_to_cpu(es->s_checkinterval); 1259 ret.last_check_time = le32_to_cpu(es->s_lastcheck); 1260 ret.reserved_blocks = ext4_r_blocks_count(es); 1261 ret.blocks_count = ext4_blocks_count(es); 1262 ret.reserved_uid = ext4_get_resuid(es); 1263 ret.reserved_gid = ext4_get_resgid(es); 1264 ret.default_mnt_opts = le32_to_cpu(es->s_default_mount_opts); 1265 ret.def_hash_alg = es->s_def_hash_version; 1266 ret.raid_stride = le16_to_cpu(es->s_raid_stride); > 1267 ret.raid_stripe_width = le16_to_cpu(es->s_raid_stripe_width); 1268 strscpy_pad(ret.mount_opts, es->s_mount_opts); 1269 ret.feature_compat = le32_to_cpu(es->s_feature_compat); 1270 ret.feature_incompat = le32_to_cpu(es->s_feature_incompat); 1271 ret.feature_ro_compat = le32_to_cpu(es->s_feature_ro_compat); 1272 ret.set_feature_compat_mask = EXT4_TUNE_SET_COMPAT_SUPP; 1273 ret.set_feature_incompat_mask = EXT4_TUNE_SET_INCOMPAT_SUPP; 1274 ret.set_feature_ro_compat_mask = EXT4_TUNE_SET_RO_COMPAT_SUPP; 1275 ret.clear_feature_compat_mask = EXT4_TUNE_CLEAR_COMPAT_SUPP; 1276 ret.clear_feature_incompat_mask = EXT4_TUNE_CLEAR_INCOMPAT_SUPP; 1277 ret.clear_feature_ro_compat_mask = EXT4_TUNE_CLEAR_RO_COMPAT_SUPP; 1278 if (copy_to_user(params, &ret, sizeof(ret))) 1279 return -EFAULT; 1280 return 0; 1281 } 1282 1283 static void ext4_sb_setparams(struct ext4_sb_info *sbi, 1284 struct ext4_super_block *es, const void *arg) 1285 { 1286 const struct ext4_tune_sb_params *params = arg; 1287 1288 if (params->set_flags & EXT4_TUNE_FL_ERRORS_BEHAVIOR) 1289 es->s_errors = cpu_to_le16(params->errors_behavior); 1290 if (params->set_flags & EXT4_TUNE_FL_MNT_COUNT) 1291 es->s_mnt_count = cpu_to_le16(params->mnt_count); 1292 if (params->set_flags & EXT4_TUNE_FL_MAX_MNT_COUNT) 1293 es->s_max_mnt_count = cpu_to_le16(params->max_mnt_count); 1294 if (params->set_flags & EXT4_TUNE_FL_CHECKINTRVAL) 1295 es->s_checkinterval = cpu_to_le32(params->checkinterval); 1296 if (params->set_flags & EXT4_TUNE_FL_LAST_CHECK_TIME) 1297 es->s_lastcheck = cpu_to_le32(params->last_check_time); 1298 if (params->set_flags & EXT4_TUNE_FL_RESERVED_BLOCKS) { 1299 ext4_fsblk_t blk = params->reserved_blocks; 1300 1301 es->s_r_blocks_count_lo = cpu_to_le32((u32)blk); 1302 es->s_r_blocks_count_hi = cpu_to_le32(blk >> 32); 1303 } 1304 if (params->set_flags & EXT4_TUNE_FL_RESERVED_UID) { 1305 int uid = params->reserved_uid; 1306 1307 es->s_def_resuid = cpu_to_le16(uid & 0xFFFF); 1308 es->s_def_resuid_hi = cpu_to_le16(uid >> 16); 1309 } 1310 if (params->set_flags & EXT4_TUNE_FL_RESERVED_GID) { 1311 int gid = params->reserved_gid; 1312 1313 es->s_def_resgid = cpu_to_le16(gid & 0xFFFF); 1314 es->s_def_resgid_hi = cpu_to_le16(gid >> 16); 1315 } 1316 if (params->set_flags & EXT4_TUNE_FL_DEFAULT_MNT_OPTS) 1317 es->s_default_mount_opts = cpu_to_le32(params->default_mnt_opts); 1318 if (params->set_flags & EXT4_TUNE_FL_DEF_HASH_ALG) 1319 es->s_def_hash_version = params->def_hash_alg; 1320 if (params->set_flags & EXT4_TUNE_FL_RAID_STRIDE) 1321 es->s_raid_stride = cpu_to_le16(params->raid_stride); 1322 if (params->set_flags & EXT4_TUNE_FL_RAID_STRIPE_WIDTH) > 1323 es->s_raid_stripe_width = 1324 cpu_to_le16(params->raid_stripe_width); 1325 strscpy_pad(es->s_mount_opts, params->mount_opts); 1326 if (params->set_flags & EXT4_TUNE_FL_EDIT_FEATURES) { 1327 es->s_feature_compat |= 1328 cpu_to_le32(params->set_feature_compat_mask); 1329 es->s_feature_incompat |= 1330 cpu_to_le32(params->set_feature_incompat_mask); 1331 es->s_feature_ro_compat |= 1332 cpu_to_le32(params->set_feature_ro_compat_mask); 1333 es->s_feature_compat &= 1334 ~cpu_to_le32(params->clear_feature_compat_mask); 1335 es->s_feature_incompat &= 1336 ~cpu_to_le32(params->clear_feature_incompat_mask); 1337 es->s_feature_ro_compat &= 1338 ~cpu_to_le32(params->clear_feature_ro_compat_mask); 1339 if (params->set_feature_compat_mask & 1340 EXT4_FEATURE_COMPAT_DIR_INDEX) 1341 es->s_def_hash_version = sbi->s_def_hash_version; 1342 if (params->set_feature_incompat_mask & 1343 EXT4_FEATURE_INCOMPAT_CSUM_SEED) 1344 es->s_checksum_seed = cpu_to_le32(sbi->s_csum_seed); 1345 } 1346 if (params->set_flags & EXT4_TUNE_FL_FORCE_FSCK) 1347 es->s_state |= cpu_to_le16(EXT4_ERROR_FS); 1348 } 1349 -- 0-DAY CI Kernel Test Service https://github.com/intel/lkp-tests/wiki ^ permalink raw reply [flat|nested] 11+ messages in thread
* Re: [PATCH 3/3] ext4: implemet new ioctls to set and get superblock parameters 2025-09-09 3:15 ` [PATCH 3/3] ext4: implemet new ioctls to set and get superblock parameters Theodore Ts'o via B4 Relay 2025-09-09 21:33 ` kernel test robot @ 2025-09-11 22:40 ` Darrick J. Wong 2025-09-12 3:14 ` Theodore Ts'o 1 sibling, 1 reply; 11+ messages in thread From: Darrick J. Wong @ 2025-09-11 22:40 UTC (permalink / raw) To: tytso; +Cc: linux-ext4, linux-api On Mon, Sep 08, 2025 at 11:15:50PM -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> > --- > fs/ext4/ioctl.c | 256 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++--- > include/uapi/linux/ext4.h | 75 ++++++++++++++++++++++ > 2 files changed, 324 insertions(+), 7 deletions(-) > > diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c > index 84e3c73952d72e436429489f5fc8b7ae1c01c7a1..569c98c962af63130c0119f60788a26a2807bd86 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 +1233,239 @@ 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) > + > +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 = 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 = le16_to_cpu(es->s_raid_stripe_width); > + 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_le16(params->raid_stripe_width); > + 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 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; What's the difference between _FL_FEATURES and _FL_EDIT_FEATURES? > + > + 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_compat_mask & > + EXT4_FEATURE_COMPAT_DIR_INDEX) && > + !ext4_has_feature_dir_index(sb)) { > + 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 > + } > + } > + } > + > + > + 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 +1852,11 @@ 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 +1944,8 @@ 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..145875fd633772e76ce7fd8bc0fef136ff620d2d 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 +110,79 @@ 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; > + __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_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_READONLY | \ > + 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 \ > + (EXT4_FEATURE_RO_COMPAT_LARGE_FILE | \ > + EXT4_FEATURE_RO_COMPAT_DIR_NLINK | \ > + EXT4_FEATURE_RO_COMPAT_EXTRA_ISIZE | \ > + EXT4_FEATURE_RO_COMPAT_PROJECT) Is it actually safe to clear these without scanning the filesystem to make sure nobody's using these features? --D > + > /* > * 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] 11+ messages in thread
* Re: [PATCH 3/3] ext4: implemet new ioctls to set and get superblock parameters 2025-09-11 22:40 ` Darrick J. Wong @ 2025-09-12 3:14 ` Theodore Ts'o 0 siblings, 0 replies; 11+ messages in thread From: Theodore Ts'o @ 2025-09-12 3:14 UTC (permalink / raw) To: Darrick J. Wong; +Cc: linux-ext4, linux-api On Thu, Sep 11, 2025 at 03:40:19PM -0700, Darrick J. Wong wrote: > > What's the difference between _FL_FEATURES and _FL_EDIT_FEATURES? We have three sets of _FL_FEATURES allows the user to set the features via: __u32 feature_compat; __u32 feature_incompat; __u32 feature_ro_compat; ... while _FS_EDIT_FEATURES allows the user to set or clear specific feature or feature(s) using these fields: __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; I originally only implemented _FS_EDIT_EFATURES but it turns out that given how tune2fs() and e2p_edit_feateurs2() was implemented, _FS_FEATURES was a lot more convenient. But I kept _FS_EDIT_FEATURES in case some other users wanted an easy way to, say, "just enable feature X" using a single ioctl. > > +#define EXT4_TUNE_CLEAR_COMPAT_SUPP (0) > > +#define EXT4_TUNE_CLEAR_INCOMPAT_SUPP (0) > > +#define EXT4_TUNE_CLEAR_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) > > Is it actually safe to clear these without scanning the filesystem to > make sure nobody's using these features? Hmm.... probably not. For some of these features, tune2fs will issue a "pleas run e2fsck -f" before mounting the file system. All of these featrues tune2fs will allow being cleared on a mounted file system, but looking at this more closely, I probably *shouldn't* have allowed tune2fs to remove the feature wile the file system is mounted. (For example, tune2fs -O ^project" will try to clear they project quota inode even if the file system is mounted, hilarity would soon follow...) - Ted ^ permalink raw reply [flat|nested] 11+ messages in thread
end of thread, other threads:[~2025-09-12 3:14 UTC | newest] Thread overview: 11+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2025-09-09 3:15 [PATCH 0/3] ext4: Add support for mounted updates to the superblock via an ioctl Theodore Ts'o via B4 Relay 2025-09-09 3:15 ` [PATCH 1/3] ext4: avoid potential buffer over-read in parse_apply_sb_mount_options() Theodore Ts'o via B4 Relay 2025-09-11 22:27 ` Darrick J. Wong 2025-09-12 2:12 ` Theodore Ts'o 2025-09-09 3:15 ` [PATCH 2/3] ext4: add support for 32-bit default reserved uid and gid values Theodore Ts'o via B4 Relay 2025-09-11 22:31 ` Darrick J. Wong 2025-09-12 2:57 ` Theodore Ts'o 2025-09-09 3:15 ` [PATCH 3/3] ext4: implemet new ioctls to set and get superblock parameters Theodore Ts'o via B4 Relay 2025-09-09 21:33 ` kernel test robot 2025-09-11 22:40 ` Darrick J. Wong 2025-09-12 3:14 ` Theodore Ts'o
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