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shmem: support idmapped mounts for tmpfs

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This patch enables idmapped mounts for tmpfs when CONFIG_SHMEM is defined.
Since all dedicated helpers for this functionality exist, in this
patch we just pass down the idmap argument from the VFS methods to the
relevant helpers.

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>
Tested-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Christian Brauner (Microsoft) <brauner@kernel.org>
Reviewed-by: Seth Forshee (DigitalOcean) <sforshee@kernel.org>
Signed-off-by: Christian Brauner (Microsoft) <brauner@kernel.org>
This commit is contained in:
Giuseppe Scrivano 2023-01-20 10:43:46 +01:00 committed by Christian Brauner (Microsoft)
parent 3707d84c13
commit 7a80e5b8c6
No known key found for this signature in database
GPG key ID: 91C61BC06578DCA2
1 changed files with 28 additions and 19 deletions
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47
mm/shmem.c
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@ -1068,7 +1068,7 @@ static int shmem_getattr(struct mnt_idmap *idmap,
stat->attributes_mask |= (STATX_ATTR_APPEND |
STATX_ATTR_IMMUTABLE |
STATX_ATTR_NODUMP);
generic_fillattr(&nop_mnt_idmap, inode, stat);
generic_fillattr(idmap, inode, stat);
if (shmem_is_huge(NULL, inode, 0, false))
stat->blksize = HPAGE_PMD_SIZE;
@ -1091,7 +1091,7 @@ static int shmem_setattr(struct mnt_idmap *idmap,
bool update_mtime = false;
bool update_ctime = true;
error = setattr_prepare(&nop_mnt_idmap, dentry, attr);
error = setattr_prepare(idmap, dentry, attr);
if (error)
return error;
@ -1129,9 +1129,9 @@ static int shmem_setattr(struct mnt_idmap *idmap,
}
}
setattr_copy(&nop_mnt_idmap, inode, attr);
setattr_copy(idmap, inode, attr);
if (attr->ia_valid & ATTR_MODE)
error = posix_acl_chmod(&nop_mnt_idmap, dentry, inode->i_mode);
error = posix_acl_chmod(idmap, dentry, inode->i_mode);
if (!error && update_ctime) {
inode->i_ctime = current_time(inode);
if (update_mtime)
@ -2329,8 +2329,9 @@ static void shmem_set_inode_flags(struct inode *inode, unsigned int fsflags)
#define shmem_initxattrs NULL
#endif
static struct inode *shmem_get_inode(struct super_block *sb, struct inode *dir,
umode_t mode, dev_t dev, unsigned long flags)
static struct inode *shmem_get_inode(struct mnt_idmap *idmap, struct super_block *sb,
struct inode *dir, umode_t mode, dev_t dev,
unsigned long flags)
{
struct inode *inode;
struct shmem_inode_info *info;
@ -2343,7 +2344,7 @@ static struct inode *shmem_get_inode(struct super_block *sb, struct inode *dir,
inode = new_inode(sb);
if (inode) {
inode->i_ino = ino;
inode_init_owner(&nop_mnt_idmap, inode, dir, mode);
inode_init_owner(idmap, inode, dir, mode);
inode->i_blocks = 0;
inode->i_atime = inode->i_mtime = inode->i_ctime = current_time(inode);
inode->i_generation = get_random_u32();
@ -2921,7 +2922,7 @@ shmem_mknod(struct mnt_idmap *idmap, struct inode *dir,
struct inode *inode;
int error = -ENOSPC;
inode = shmem_get_inode(dir->i_sb, dir, mode, dev, VM_NORESERVE);
inode = shmem_get_inode(idmap, dir->i_sb, dir, mode, dev, VM_NORESERVE);
if (inode) {
error = simple_acl_create(dir, inode);
if (error)
@ -2952,7 +2953,7 @@ shmem_tmpfile(struct mnt_idmap *idmap, struct inode *dir,
struct inode *inode;
int error = -ENOSPC;
inode = shmem_get_inode(dir->i_sb, dir, mode, 0, VM_NORESERVE);
inode = shmem_get_inode(idmap, dir->i_sb, dir, mode, 0, VM_NORESERVE);
if (inode) {
error = security_inode_init_security(inode, dir,
NULL,
@ -2975,8 +2976,8 @@ static int shmem_mkdir(struct mnt_idmap *idmap, struct inode *dir,
{
int error;
if ((error = shmem_mknod(&nop_mnt_idmap, dir, dentry,
mode | S_IFDIR, 0)))
error = shmem_mknod(idmap, dir, dentry, mode | S_IFDIR, 0);
if (error)
return error;
inc_nlink(dir);
return 0;
@ -2985,7 +2986,7 @@ static int shmem_mkdir(struct mnt_idmap *idmap, struct inode *dir,
static int shmem_create(struct mnt_idmap *idmap, struct inode *dir,
struct dentry *dentry, umode_t mode, bool excl)
{
return shmem_mknod(&nop_mnt_idmap, dir, dentry, mode | S_IFREG, 0);
return shmem_mknod(idmap, dir, dentry, mode | S_IFREG, 0);
}
/*
@ -3055,7 +3056,7 @@ static int shmem_whiteout(struct mnt_idmap *idmap,
if (!whiteout)
return -ENOMEM;
error = shmem_mknod(&nop_mnt_idmap, old_dir, whiteout,
error = shmem_mknod(idmap, old_dir, whiteout,
S_IFCHR | WHITEOUT_MODE, WHITEOUT_DEV);
dput(whiteout);
if (error)
@ -3098,7 +3099,7 @@ static int shmem_rename2(struct mnt_idmap *idmap,
if (flags & RENAME_WHITEOUT) {
int error;
error = shmem_whiteout(&nop_mnt_idmap, old_dir, old_dentry);
error = shmem_whiteout(idmap, old_dir, old_dentry);
if (error)
return error;
}
@ -3136,7 +3137,7 @@ static int shmem_symlink(struct mnt_idmap *idmap, struct inode *dir,
if (len > PAGE_SIZE)
return -ENAMETOOLONG;
inode = shmem_get_inode(dir->i_sb, dir, S_IFLNK | 0777, 0,
inode = shmem_get_inode(idmap, dir->i_sb, dir, S_IFLNK | 0777, 0,
VM_NORESERVE);
if (!inode)
return -ENOSPC;
@ -3819,7 +3820,8 @@ static int shmem_fill_super(struct super_block *sb, struct fs_context *fc)
#endif
uuid_gen(&sb->s_uuid);
inode = shmem_get_inode(sb, NULL, S_IFDIR | sbinfo->mode, 0, VM_NORESERVE);
inode = shmem_get_inode(&nop_mnt_idmap, sb, NULL, S_IFDIR | sbinfo->mode, 0,
VM_NORESERVE);
if (!inode)
goto failed;
inode->i_uid = sbinfo->uid;
@ -4044,7 +4046,11 @@ static struct file_system_type shmem_fs_type = {
.parameters = shmem_fs_parameters,
#endif
.kill_sb = kill_litter_super,
#ifdef CONFIG_SHMEM
.fs_flags = FS_USERNS_MOUNT | FS_ALLOW_IDMAP,
#else
.fs_flags = FS_USERNS_MOUNT,
#endif
};
void __init shmem_init(void)
@ -4196,7 +4202,7 @@ EXPORT_SYMBOL_GPL(shmem_truncate_range);
#define shmem_vm_ops generic_file_vm_ops
#define shmem_anon_vm_ops generic_file_vm_ops
#define shmem_file_operations ramfs_file_operations
#define shmem_get_inode(sb, dir, mode, dev, flags) ramfs_get_inode(sb, dir, mode, dev)
#define shmem_get_inode(idmap, sb, dir, mode, dev, flags) ramfs_get_inode(sb, dir, mode, dev)
#define shmem_acct_size(flags, size) 0
#define shmem_unacct_size(flags, size) do {} while (0)
@ -4219,8 +4225,11 @@ static struct file *__shmem_file_setup(struct vfsmount *mnt, const char *name, l
if (shmem_acct_size(flags, size))
return ERR_PTR(-ENOMEM);
inode = shmem_get_inode(mnt->mnt_sb, NULL, S_IFREG | S_IRWXUGO, 0,
flags);
if (is_idmapped_mnt(mnt))
return ERR_PTR(-EINVAL);
inode = shmem_get_inode(&nop_mnt_idmap, mnt->mnt_sb, NULL,
S_IFREG | S_IRWXUGO, 0, flags);
if (unlikely(!inode)) {
shmem_unacct_size(flags, size);
return ERR_PTR(-ENOSPC);