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authorGiuseppe Scrivano <gscrivan@redhat.com>2023-01-20 10:43:46 +0100
committerChristian Brauner (Microsoft) <brauner@kernel.org>2023-01-20 18:46:56 +0100
commit7a80e5b8c6fa7d0ae6624bd6aedc4a6a1cfc62fa (patch)
treed47a4b0a14834cf5a89a17c13e5199b46a7db2c3 /mm/shmem.c
parent3707d84c13670bf09b4a9a4dc6733326d8344b31 (diff)
shmem: support idmapped mounts for tmpfs
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>
Diffstat (limited to 'mm/shmem.c')
-rw-r--r--mm/shmem.c47
1 files changed, 28 insertions, 19 deletions
diff --git a/mm/shmem.c b/mm/shmem.c
index 028675cd97d4..2fdd76ab337f 100644
--- a/mm/shmem.c
+++ b/mm/shmem.c
@@ -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);