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authorLinus Torvalds <torvalds@linux-foundation.org>2023-06-27 17:10:27 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2023-06-27 17:10:27 -0700
commit26642864f8b212964f80fbd69685eb850ced5f45 (patch)
tree1f5928998519b5f8a0ce909ebdd8d92b4236291c /fs/hostfs
parent6e2332e0ab532eb01f1fde39080dbfa9bf65c4cf (diff)
parent35ca4239929737bdc021ee923f97ebe7aff8fcc4 (diff)
Merge tag 'landlock-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux
Pull landlock updates from Mickaël Salaün: "Add support for Landlock to UML. To do this, this fixes the way hostfs manages inodes according to the underlying filesystem [1]. They are now properly handled as for other filesystems, which enables Landlock support (and probably other features). This also extends Landlock's tests with 6 pseudo filesystems, including hostfs" [1] https://lore.kernel.org/all/20230612191430.339153-1-mic@digikod.net/ * tag 'landlock-6.5-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/mic/linux: selftests/landlock: Add hostfs tests selftests/landlock: Add tests for pseudo filesystems selftests/landlock: Make mounts configurable selftests/landlock: Add supports_filesystem() helper selftests/landlock: Don't create useless file layouts hostfs: Fix ephemeral inodes
Diffstat (limited to 'fs/hostfs')
-rw-r--r--fs/hostfs/hostfs.h1
-rw-r--r--fs/hostfs/hostfs_kern.c213
-rw-r--r--fs/hostfs/hostfs_user.c1
3 files changed, 108 insertions, 107 deletions
diff --git a/fs/hostfs/hostfs.h b/fs/hostfs/hostfs.h
index 69cb796f6270..0239e3af3945 100644
--- a/fs/hostfs/hostfs.h
+++ b/fs/hostfs/hostfs.h
@@ -65,6 +65,7 @@ struct hostfs_stat {
unsigned long long blocks;
unsigned int maj;
unsigned int min;
+ dev_t dev;
};
extern int stat_file(const char *path, struct hostfs_stat *p, int fd);
diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c
index 87998df499f4..46387090eb76 100644
--- a/fs/hostfs/hostfs_kern.c
+++ b/fs/hostfs/hostfs_kern.c
@@ -26,6 +26,7 @@ struct hostfs_inode_info {
fmode_t mode;
struct inode vfs_inode;
struct mutex open_mutex;
+ dev_t dev;
};
static inline struct hostfs_inode_info *HOSTFS_I(struct inode *inode)
@@ -182,14 +183,6 @@ static char *follow_link(char *link)
return ERR_PTR(n);
}
-static struct inode *hostfs_iget(struct super_block *sb)
-{
- struct inode *inode = new_inode(sb);
- if (!inode)
- return ERR_PTR(-ENOMEM);
- return inode;
-}
-
static int hostfs_statfs(struct dentry *dentry, struct kstatfs *sf)
{
/*
@@ -228,6 +221,7 @@ static struct inode *hostfs_alloc_inode(struct super_block *sb)
return NULL;
hi->fd = -1;
hi->mode = 0;
+ hi->dev = 0;
inode_init_once(&hi->vfs_inode);
mutex_init(&hi->open_mutex);
return &hi->vfs_inode;
@@ -240,6 +234,7 @@ static void hostfs_evict_inode(struct inode *inode)
if (HOSTFS_I(inode)->fd != -1) {
close_file(&HOSTFS_I(inode)->fd);
HOSTFS_I(inode)->fd = -1;
+ HOSTFS_I(inode)->dev = 0;
}
}
@@ -265,6 +260,7 @@ static int hostfs_show_options(struct seq_file *seq, struct dentry *root)
static const struct super_operations hostfs_sbops = {
.alloc_inode = hostfs_alloc_inode,
.free_inode = hostfs_free_inode,
+ .drop_inode = generic_delete_inode,
.evict_inode = hostfs_evict_inode,
.statfs = hostfs_statfs,
.show_options = hostfs_show_options,
@@ -512,18 +508,31 @@ static const struct address_space_operations hostfs_aops = {
.write_end = hostfs_write_end,
};
-static int read_name(struct inode *ino, char *name)
+static int hostfs_inode_update(struct inode *ino, const struct hostfs_stat *st)
+{
+ set_nlink(ino, st->nlink);
+ i_uid_write(ino, st->uid);
+ i_gid_write(ino, st->gid);
+ ino->i_atime =
+ (struct timespec64){ st->atime.tv_sec, st->atime.tv_nsec };
+ ino->i_mtime =
+ (struct timespec64){ st->mtime.tv_sec, st->mtime.tv_nsec };
+ ino->i_ctime =
+ (struct timespec64){ st->ctime.tv_sec, st->ctime.tv_nsec };
+ ino->i_size = st->size;
+ ino->i_blocks = st->blocks;
+ return 0;
+}
+
+static int hostfs_inode_set(struct inode *ino, void *data)
{
+ struct hostfs_stat *st = data;
dev_t rdev;
- struct hostfs_stat st;
- int err = stat_file(name, &st, -1);
- if (err)
- return err;
/* Reencode maj and min with the kernel encoding.*/
- rdev = MKDEV(st.maj, st.min);
+ rdev = MKDEV(st->maj, st->min);
- switch (st.mode & S_IFMT) {
+ switch (st->mode & S_IFMT) {
case S_IFLNK:
ino->i_op = &hostfs_link_iops;
break;
@@ -535,7 +544,7 @@ static int read_name(struct inode *ino, char *name)
case S_IFBLK:
case S_IFIFO:
case S_IFSOCK:
- init_special_inode(ino, st.mode & S_IFMT, rdev);
+ init_special_inode(ino, st->mode & S_IFMT, rdev);
ino->i_op = &hostfs_iops;
break;
case S_IFREG:
@@ -547,17 +556,42 @@ static int read_name(struct inode *ino, char *name)
return -EIO;
}
- ino->i_ino = st.ino;
- ino->i_mode = st.mode;
- set_nlink(ino, st.nlink);
- i_uid_write(ino, st.uid);
- i_gid_write(ino, st.gid);
- ino->i_atime = (struct timespec64){ st.atime.tv_sec, st.atime.tv_nsec };
- ino->i_mtime = (struct timespec64){ st.mtime.tv_sec, st.mtime.tv_nsec };
- ino->i_ctime = (struct timespec64){ st.ctime.tv_sec, st.ctime.tv_nsec };
- ino->i_size = st.size;
- ino->i_blocks = st.blocks;
- return 0;
+ HOSTFS_I(ino)->dev = st->dev;
+ ino->i_ino = st->ino;
+ ino->i_mode = st->mode;
+ return hostfs_inode_update(ino, st);
+}
+
+static int hostfs_inode_test(struct inode *inode, void *data)
+{
+ const struct hostfs_stat *st = data;
+
+ return inode->i_ino == st->ino && HOSTFS_I(inode)->dev == st->dev;
+}
+
+static struct inode *hostfs_iget(struct super_block *sb, char *name)
+{
+ struct inode *inode;
+ struct hostfs_stat st;
+ int err = stat_file(name, &st, -1);
+
+ if (err)
+ return ERR_PTR(err);
+
+ inode = iget5_locked(sb, st.ino, hostfs_inode_test, hostfs_inode_set,
+ &st);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ if (inode->i_state & I_NEW) {
+ unlock_new_inode(inode);
+ } else {
+ spin_lock(&inode->i_lock);
+ hostfs_inode_update(inode, &st);
+ spin_unlock(&inode->i_lock);
+ }
+
+ return inode;
}
static int hostfs_create(struct mnt_idmap *idmap, struct inode *dir,
@@ -565,62 +599,48 @@ static int hostfs_create(struct mnt_idmap *idmap, struct inode *dir,
{
struct inode *inode;
char *name;
- int error, fd;
-
- inode = hostfs_iget(dir->i_sb);
- if (IS_ERR(inode)) {
- error = PTR_ERR(inode);
- goto out;
- }
+ int fd;
- error = -ENOMEM;
name = dentry_name(dentry);
if (name == NULL)
- goto out_put;
+ return -ENOMEM;
fd = file_create(name, mode & 0777);
- if (fd < 0)
- error = fd;
- else
- error = read_name(inode, name);
+ if (fd < 0) {
+ __putname(name);
+ return fd;
+ }
+ inode = hostfs_iget(dir->i_sb, name);
__putname(name);
- if (error)
- goto out_put;
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
HOSTFS_I(inode)->fd = fd;
HOSTFS_I(inode)->mode = FMODE_READ | FMODE_WRITE;
d_instantiate(dentry, inode);
return 0;
-
- out_put:
- iput(inode);
- out:
- return error;
}
static struct dentry *hostfs_lookup(struct inode *ino, struct dentry *dentry,
unsigned int flags)
{
- struct inode *inode;
+ struct inode *inode = NULL;
char *name;
- int err;
-
- inode = hostfs_iget(ino->i_sb);
- if (IS_ERR(inode))
- goto out;
- err = -ENOMEM;
name = dentry_name(dentry);
- if (name) {
- err = read_name(inode, name);
- __putname(name);
- }
- if (err) {
- iput(inode);
- inode = (err == -ENOENT) ? NULL : ERR_PTR(err);
+ if (name == NULL)
+ return ERR_PTR(-ENOMEM);
+
+ inode = hostfs_iget(ino->i_sb, name);
+ __putname(name);
+ if (IS_ERR(inode)) {
+ if (PTR_ERR(inode) == -ENOENT)
+ inode = NULL;
+ else
+ return ERR_CAST(inode);
}
- out:
+
return d_splice_alias(inode, dentry);
}
@@ -704,35 +724,23 @@ static int hostfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
char *name;
int err;
- inode = hostfs_iget(dir->i_sb);
- if (IS_ERR(inode)) {
- err = PTR_ERR(inode);
- goto out;
- }
-
- err = -ENOMEM;
name = dentry_name(dentry);
if (name == NULL)
- goto out_put;
+ return -ENOMEM;
err = do_mknod(name, mode, MAJOR(dev), MINOR(dev));
- if (err)
- goto out_free;
+ if (err) {
+ __putname(name);
+ return err;
+ }
- err = read_name(inode, name);
+ inode = hostfs_iget(dir->i_sb, name);
__putname(name);
- if (err)
- goto out_put;
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
d_instantiate(dentry, inode);
return 0;
-
- out_free:
- __putname(name);
- out_put:
- iput(inode);
- out:
- return err;
}
static int hostfs_rename2(struct mnt_idmap *idmap,
@@ -929,49 +937,40 @@ static int hostfs_fill_sb_common(struct super_block *sb, void *d, int silent)
sb->s_maxbytes = MAX_LFS_FILESIZE;
err = super_setup_bdi(sb);
if (err)
- goto out;
+ return err;
/* NULL is printed as '(null)' by printf(): avoid that. */
if (req_root == NULL)
req_root = "";
- err = -ENOMEM;
sb->s_fs_info = host_root_path =
kasprintf(GFP_KERNEL, "%s/%s", root_ino, req_root);
if (host_root_path == NULL)
- goto out;
-
- root_inode = new_inode(sb);
- if (!root_inode)
- goto out;
+ return -ENOMEM;
- err = read_name(root_inode, host_root_path);
- if (err)
- goto out_put;
+ root_inode = hostfs_iget(sb, host_root_path);
+ if (IS_ERR(root_inode))
+ return PTR_ERR(root_inode);
if (S_ISLNK(root_inode->i_mode)) {
- char *name = follow_link(host_root_path);
- if (IS_ERR(name)) {
- err = PTR_ERR(name);
- goto out_put;
- }
- err = read_name(root_inode, name);
+ char *name;
+
+ iput(root_inode);
+ name = follow_link(host_root_path);
+ if (IS_ERR(name))
+ return PTR_ERR(name);
+
+ root_inode = hostfs_iget(sb, name);
kfree(name);
- if (err)
- goto out_put;
+ if (IS_ERR(root_inode))
+ return PTR_ERR(root_inode);
}
- err = -ENOMEM;
sb->s_root = d_make_root(root_inode);
if (sb->s_root == NULL)
- goto out;
+ return -ENOMEM;
return 0;
-
-out_put:
- iput(root_inode);
-out:
- return err;
}
static struct dentry *hostfs_read_sb(struct file_system_type *type,
diff --git a/fs/hostfs/hostfs_user.c b/fs/hostfs/hostfs_user.c
index 5ecc4706172b..840619e39a1a 100644
--- a/fs/hostfs/hostfs_user.c
+++ b/fs/hostfs/hostfs_user.c
@@ -36,6 +36,7 @@ static void stat64_to_hostfs(const struct stat64 *buf, struct hostfs_stat *p)
p->blocks = buf->st_blocks;
p->maj = os_major(buf->st_rdev);
p->min = os_minor(buf->st_rdev);
+ p->dev = buf->st_dev;
}
int stat_file(const char *path, struct hostfs_stat *p, int fd)