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[Deepin-Kernel-SIG] [linux 6.6-y] [Upstream] fs: backport VFS-related patches in preparation for EROFS file-backed mount #966

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Merged
opsiff merged 3 commits into from
Aug 5, 2025
Merged

[Deepin-Kernel-SIG] [linux 6.6-y] [Upstream] fs: backport VFS-related patches in preparation for EROFS file-backed mount #966

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b8ae17a
fs: super_set_uuid()
Feb 7, 2024
c9493cf
fs: FS_IOC_GETUUID
Feb 7, 2024
d047b31
fs: add FS_IOC_GETFSSYSFSPATH
Feb 7, 2024
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3 changes: 2 additions & 1 deletion Documentation/userspace-api/ioctl/ioctl-number.rst
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Expand Up @@ -82,8 +82,9 @@ Code Seq# Include File Comments
0x10 00-0F drivers/char/s390/vmcp.h
0x10 10-1F arch/s390/include/uapi/sclp_ctl.h
0x10 20-2F arch/s390/include/uapi/asm/hypfs.h
0x12 all linux/fs.h
0x12 all linux/fs.h BLK* ioctls
linux/blkpg.h
0x15 all linux/fs.h FS_IOC_* ioctls
0x1b all InfiniBand Subsystem
<http://infiniband.sourceforge.net/>
0x20 all drivers/cdrom/cm206.h
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2 changes: 1 addition & 1 deletion fs/ext4/super.c
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Expand Up @@ -5368,7 +5368,7 @@ static int __ext4_fill_super(struct fs_context *fc, struct super_block *sb)
sb->s_qcop = &ext4_qctl_operations;
sb->s_quota_types = QTYPE_MASK_USR | QTYPE_MASK_GRP | QTYPE_MASK_PRJ;
#endif
memcpy(&sb->s_uuid, es->s_uuid, sizeof(es->s_uuid));
super_set_uuid(sb, es->s_uuid, sizeof(es->s_uuid));

INIT_LIST_HEAD(&sbi->s_orphan); /* unlinked but open files */
mutex_init(&sbi->s_orphan_lock);
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2 changes: 1 addition & 1 deletion fs/f2fs/super.c
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Expand Up @@ -4468,7 +4468,7 @@ static int f2fs_fill_super(struct super_block *sb, void *data, int silent)
sb->s_time_gran = 1;
sb->s_flags = (sb->s_flags & ~SB_POSIXACL) |
(test_opt(sbi, POSIX_ACL) ? SB_POSIXACL : 0);
memcpy(&sb->s_uuid, raw_super->uuid, sizeof(raw_super->uuid));
super_set_uuid(sb, (void *) raw_super->uuid, sizeof(raw_super->uuid));
sb->s_iflags |= SB_I_CGROUPWB;

/* init f2fs-specific super block info */
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2 changes: 1 addition & 1 deletion fs/gfs2/ops_fstype.c
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Expand Up @@ -215,7 +215,7 @@ static void gfs2_sb_in(struct gfs2_sbd *sdp, const void *buf)

memcpy(sb->sb_lockproto, str->sb_lockproto, GFS2_LOCKNAME_LEN);
memcpy(sb->sb_locktable, str->sb_locktable, GFS2_LOCKNAME_LEN);
memcpy(&s->s_uuid, str->sb_uuid, 16);
super_set_uuid(s, str->sb_uuid, 16);
}

/**
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33 changes: 33 additions & 0 deletions fs/ioctl.c
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Expand Up @@ -763,6 +763,33 @@ static int ioctl_fssetxattr(struct file *file, void __user *argp)
return err;
}

static int ioctl_getfsuuid(struct file *file, void __user *argp)
{
struct super_block *sb = file_inode(file)->i_sb;
struct fsuuid2 u = { .len = sb->s_uuid_len, };

if (!sb->s_uuid_len)
return -ENOIOCTLCMD;

memcpy(&u.uuid[0], &sb->s_uuid, sb->s_uuid_len);

return copy_to_user(argp, &u, sizeof(u)) ? -EFAULT : 0;
}

static int ioctl_get_fs_sysfs_path(struct file *file, void __user *argp)
{
struct super_block *sb = file_inode(file)->i_sb;

if (!strlen(sb->s_sysfs_name))
return -ENOIOCTLCMD;

struct fs_sysfs_path u = {};

Comment on lines +782 to +787
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Copilot AI Jul 22, 2025

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Variable declaration should be at the beginning of the function scope for C89 compatibility, not in the middle of the function after other statements.

Suggested change
if (!strlen(sb->s_sysfs_name))
return -ENOIOCTLCMD;
struct fs_sysfs_path u = {};
struct fs_sysfs_path u = {};
if (!strlen(sb->s_sysfs_name))
return -ENOIOCTLCMD;

Copilot uses AI. Check for mistakes.
u.len = scnprintf(u.name, sizeof(u.name), "%s/%s", sb->s_type->name, sb->s_sysfs_name);

return copy_to_user(argp, &u, sizeof(u)) ? -EFAULT : 0;
}

/*
* do_vfs_ioctl() is not for drivers and not intended to be EXPORT_SYMBOL()'d.
* It's just a simple helper for sys_ioctl and compat_sys_ioctl.
Expand Down Expand Up @@ -845,6 +872,12 @@ static int do_vfs_ioctl(struct file *filp, unsigned int fd,
case FS_IOC_FSSETXATTR:
return ioctl_fssetxattr(filp, argp);

case FS_IOC_GETFSUUID:
return ioctl_getfsuuid(filp, argp);

case FS_IOC_GETFSSYSFSPATH:
return ioctl_get_fs_sysfs_path(filp, argp);

default:
if (S_ISREG(inode->i_mode))
return file_ioctl(filp, cmd, argp);
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4 changes: 3 additions & 1 deletion fs/kernfs/mount.c
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Expand Up @@ -361,7 +361,9 @@ int kernfs_get_tree(struct fs_context *fc)
}
sb->s_flags |= SB_ACTIVE;

uuid_gen(&sb->s_uuid);
uuid_t uuid;
uuid_gen(&uuid);
super_set_uuid(sb, uuid.b, sizeof(uuid));

down_write(&root->kernfs_supers_rwsem);
list_add(&info->node, &info->root->supers);
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4 changes: 2 additions & 2 deletions fs/ocfs2/super.c
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Expand Up @@ -2032,8 +2032,8 @@ static int ocfs2_initialize_super(struct super_block *sb,
cbits = le32_to_cpu(di->id2.i_super.s_clustersize_bits);
bbits = le32_to_cpu(di->id2.i_super.s_blocksize_bits);
sb->s_maxbytes = ocfs2_max_file_offset(bbits, cbits);
memcpy(&sb->s_uuid, di->id2.i_super.s_uuid,
sizeof(di->id2.i_super.s_uuid));
super_set_uuid(sb, di->id2.i_super.s_uuid,
sizeof(di->id2.i_super.s_uuid));

osb->osb_dx_mask = (1 << (cbits - bbits)) - 1;

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2 changes: 1 addition & 1 deletion fs/ubifs/super.c
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Expand Up @@ -2246,7 +2246,7 @@ static int ubifs_fill_super(struct super_block *sb, void *data, int silent)
goto out_umount;
}

import_uuid(&sb->s_uuid, c->uuid);
super_set_uuid(sb, c->uuid, sizeof(c->uuid));

mutex_unlock(&c->umount_mutex);
return 0;
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2 changes: 1 addition & 1 deletion fs/xfs/xfs_mount.c
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Expand Up @@ -62,7 +62,7 @@ xfs_uuid_mount(
int hole, i;

/* Publish UUID in struct super_block */
uuid_copy(&mp->m_super->s_uuid, uuid);
super_set_uuid(mp->m_super, uuid->b, sizeof(*uuid));

if (xfs_has_nouuid(mp))
return 0;
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52 changes: 52 additions & 0 deletions include/linux/fs.h
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Expand Up @@ -1267,8 +1267,22 @@ struct super_block {
struct fsnotify_mark_connector __rcu *s_fsnotify_marks;
#endif

/*
* q: why are s_id and s_sysfs_name not the same? both are human
* readable strings that identify the filesystem
* a: s_id is allowed to change at runtime; it's used in log messages,
* and we want to when a device starts out as single device (s_id is dev
* name) but then a device is hot added and we have to switch to
* identifying it by UUID
* but s_sysfs_name is a handle for programmatic access, and can't
* change at runtime
*/
char s_id[32]; /* Informational name */
uuid_t s_uuid; /* UUID */
u8 s_uuid_len; /* Default 16, possibly smaller for weird filesystems */

/* if set, fs shows up under sysfs at /sys/fs/$FSTYP/s_sysfs_name */
char s_sysfs_name[UUID_STRING_LEN + 1];

unsigned int s_max_links;

Expand Down Expand Up @@ -2474,6 +2488,44 @@ extern __printf(2, 3)
int super_setup_bdi_name(struct super_block *sb, char *fmt, ...);
extern int super_setup_bdi(struct super_block *sb);

static inline void super_set_uuid(struct super_block *sb, const u8 *uuid, unsigned len)
{
if (WARN_ON(len > sizeof(sb->s_uuid)))
len = sizeof(sb->s_uuid);
sb->s_uuid_len = len;
memcpy(&sb->s_uuid, uuid, len);
}

/* set sb sysfs name based on sb->s_bdev */
static inline void super_set_sysfs_name_bdev(struct super_block *sb)
{
snprintf(sb->s_sysfs_name, sizeof(sb->s_sysfs_name), "%pg", sb->s_bdev);
}

/* set sb sysfs name based on sb->s_uuid */
static inline void super_set_sysfs_name_uuid(struct super_block *sb)
{
WARN_ON(sb->s_uuid_len != sizeof(sb->s_uuid));
snprintf(sb->s_sysfs_name, sizeof(sb->s_sysfs_name), "%pU", sb->s_uuid.b);
}

/* set sb sysfs name based on sb->s_id */
static inline void super_set_sysfs_name_id(struct super_block *sb)
{
strscpy(sb->s_sysfs_name, sb->s_id, sizeof(sb->s_sysfs_name));
}

/* try to use something standard before you use this */
__printf(2, 3)
static inline void super_set_sysfs_name_generic(struct super_block *sb, const char *fmt, ...)
{
va_list args;

va_start(args, fmt);
vsnprintf(sb->s_sysfs_name, sizeof(sb->s_sysfs_name), fmt, args);
va_end(args);
}

extern int current_umask(void);

extern void ihold(struct inode * inode);
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25 changes: 25 additions & 0 deletions include/uapi/linux/fs.h
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Expand Up @@ -64,6 +64,24 @@ struct fstrim_range {
__u64 minlen;
};

/*
* We include a length field because some filesystems (vfat) have an identifier
* that we do want to expose as a UUID, but doesn't have the standard length.
*
* We use a fixed size buffer beacuse this interface will, by fiat, never
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Copilot AI Jul 22, 2025

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Spelling error: 'beacuse' should be 'because'.

Suggested change
* We use a fixed size buffer beacuse this interface will, by fiat, never
* We use a fixed size buffer because this interface will, by fiat, never

Copilot uses AI. Check for mistakes.
* support "UUIDs" longer than 16 bytes; we don't want to force all downstream
* users to have to deal with that.
*/
struct fsuuid2 {
__u8 len;
__u8 uuid[16];
};

struct fs_sysfs_path {
__u8 len;
__u8 name[128];
};

/* extent-same (dedupe) ioctls; these MUST match the btrfs ioctl definitions */
#define FILE_DEDUPE_RANGE_SAME 0
#define FILE_DEDUPE_RANGE_DIFFERS 1
Expand Down Expand Up @@ -215,6 +233,13 @@ struct fsxattr {
#define FS_IOC_FSSETXATTR _IOW('X', 32, struct fsxattr)
#define FS_IOC_GETFSLABEL _IOR(0x94, 49, char[FSLABEL_MAX])
#define FS_IOC_SETFSLABEL _IOW(0x94, 50, char[FSLABEL_MAX])
/* Returns the external filesystem UUID, the same one blkid returns */
#define FS_IOC_GETFSUUID _IOR(0x15, 0, struct fsuuid2)
/*
* Returns the path component under /sys/fs/ that refers to this filesystem;
* also /sys/kernel/debug/ for filesystems with debugfs exports
*/
#define FS_IOC_GETFSSYSFSPATH _IOR(0x15, 1, struct fs_sysfs_path)

/*
* Inode flags (FS_IOC_GETFLAGS / FS_IOC_SETFLAGS)
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4 changes: 3 additions & 1 deletion mm/shmem.c
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Expand Up @@ -4352,7 +4352,9 @@ static int shmem_fill_super(struct super_block *sb, struct fs_context *fc)
#ifdef CONFIG_TMPFS_POSIX_ACL
sb->s_flags |= SB_POSIXACL;
#endif
uuid_gen(&sb->s_uuid);
uuid_t uuid;
uuid_gen(&uuid);
super_set_uuid(sb, uuid.b, sizeof(uuid));

#ifdef CONFIG_TMPFS_QUOTA
if (ctx->seen & SHMEM_SEEN_QUOTA) {
Expand Down
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