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exfat: handle idmapped mounts

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Pass the idmapped mount information to the different helper
functions. Adapt the uid/gid checks in exfat_setattr to use the
vfsuid/vfsgid helpers.

Based on the fat implementation in commit 4b78993681
("fat: handle idmapped mounts") by Christian Brauner.

Signed-off-by: Michael Jeanson <mjeanson@efficios.com>
Reviewed-by: Christian Brauner <brauner@kernel.org>
Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
This commit is contained in:
Michael Jeanson 2024-05-22 21:10:07 -04:00 committed by Namjae Jeon
parent 0c38364824
commit 224821766f
2 changed files with 14 additions and 10 deletions
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22
fs/exfat/file.c
View File

@ -89,12 +89,14 @@ free_clu:
return -EIO; return -EIO;
} }
static bool exfat_allow_set_time(struct exfat_sb_info *sbi, struct inode *inode) static bool exfat_allow_set_time(struct mnt_idmap *idmap,
struct exfat_sb_info *sbi, struct inode *inode)
{ {
mode_t allow_utime = sbi->options.allow_utime; mode_t allow_utime = sbi->options.allow_utime;
if (!uid_eq(current_fsuid(), inode->i_uid)) { if (!vfsuid_eq_kuid(i_uid_into_vfsuid(idmap, inode),
if (in_group_p(inode->i_gid)) current_fsuid())) {
if (vfsgid_in_group_p(i_gid_into_vfsgid(idmap, inode)))
allow_utime >>= 3; allow_utime >>= 3;
if (allow_utime & MAY_WRITE) if (allow_utime & MAY_WRITE)
return true; return true;
@ -283,7 +285,7 @@ int exfat_getattr(struct mnt_idmap *idmap, const struct path *path,
struct inode *inode = d_backing_inode(path->dentry); struct inode *inode = d_backing_inode(path->dentry);
struct exfat_inode_info *ei = EXFAT_I(inode); struct exfat_inode_info *ei = EXFAT_I(inode);
generic_fillattr(&nop_mnt_idmap, request_mask, inode, stat); generic_fillattr(idmap, request_mask, inode, stat);
exfat_truncate_atime(&stat->atime); exfat_truncate_atime(&stat->atime);
stat->result_mask |= STATX_BTIME; stat->result_mask |= STATX_BTIME;
stat->btime.tv_sec = ei->i_crtime.tv_sec; stat->btime.tv_sec = ei->i_crtime.tv_sec;
@ -311,20 +313,22 @@ int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
/* Check for setting the inode time. */ /* Check for setting the inode time. */
ia_valid = attr->ia_valid; ia_valid = attr->ia_valid;
if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) && if ((ia_valid & (ATTR_MTIME_SET | ATTR_ATIME_SET | ATTR_TIMES_SET)) &&
exfat_allow_set_time(sbi, inode)) { exfat_allow_set_time(idmap, sbi, inode)) {
attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET | attr->ia_valid &= ~(ATTR_MTIME_SET | ATTR_ATIME_SET |
ATTR_TIMES_SET); ATTR_TIMES_SET);
} }
error = setattr_prepare(&nop_mnt_idmap, dentry, attr); error = setattr_prepare(idmap, dentry, attr);
attr->ia_valid = ia_valid; attr->ia_valid = ia_valid;
if (error) if (error)
goto out; goto out;
if (((attr->ia_valid & ATTR_UID) && if (((attr->ia_valid & ATTR_UID) &&
!uid_eq(attr->ia_uid, sbi->options.fs_uid)) || (!uid_eq(from_vfsuid(idmap, i_user_ns(inode), attr->ia_vfsuid),
sbi->options.fs_uid))) ||
((attr->ia_valid & ATTR_GID) && ((attr->ia_valid & ATTR_GID) &&
!gid_eq(attr->ia_gid, sbi->options.fs_gid)) || (!gid_eq(from_vfsgid(idmap, i_user_ns(inode), attr->ia_vfsgid),
sbi->options.fs_gid))) ||
((attr->ia_valid & ATTR_MODE) && ((attr->ia_valid & ATTR_MODE) &&
(attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) { (attr->ia_mode & ~(S_IFREG | S_IFLNK | S_IFDIR | 0777)))) {
error = -EPERM; error = -EPERM;
@ -343,7 +347,7 @@ int exfat_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
if (attr->ia_valid & ATTR_SIZE) if (attr->ia_valid & ATTR_SIZE)
inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode)); inode_set_mtime_to_ts(inode, inode_set_ctime_current(inode));
setattr_copy(&nop_mnt_idmap, inode, attr); setattr_copy(idmap, inode, attr);
exfat_truncate_inode_atime(inode); exfat_truncate_inode_atime(inode);
if (attr->ia_valid & ATTR_SIZE) { if (attr->ia_valid & ATTR_SIZE) {

2
fs/exfat/super.c
View File

@ -788,7 +788,7 @@ static struct file_system_type exfat_fs_type = {
.init_fs_context = exfat_init_fs_context, .init_fs_context = exfat_init_fs_context,
.parameters = exfat_parameters, .parameters = exfat_parameters,
.kill_sb = exfat_kill_sb, .kill_sb = exfat_kill_sb,
.fs_flags = FS_REQUIRES_DEV, .fs_flags = FS_REQUIRES_DEV | FS_ALLOW_IDMAP,
}; };
static void exfat_inode_init_once(void *foo) static void exfat_inode_init_once(void *foo)