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authorChris Mason <chris.mason@oracle.com>2011-01-16 11:24:45 -0500
committerChris Mason <chris.mason@oracle.com>2011-01-16 11:24:45 -0500
commit26c79f6ba0ccdc4bbc8ef8721406d37e9178e30b (patch)
treec5bcbf8f605afdae1a89ea2617f29052ac8c6f18 /fs/btrfs
parent65e5341b9a0c39767ae1fecc727d70eda0dd6d83 (diff)
parent0caa102da82799efaba88e234484786a9591c797 (diff)
Merge branch 'readonly-snapshots' of git://repo.or.cz/linux-btrfs-devel into btrfs-38
Diffstat (limited to 'fs/btrfs')
-rw-r--r--fs/btrfs/ctree.h7
-rw-r--r--fs/btrfs/inode.c8
-rw-r--r--fs/btrfs/ioctl.c199
-rw-r--r--fs/btrfs/ioctl.h3
-rw-r--r--fs/btrfs/transaction.c8
-rw-r--r--fs/btrfs/transaction.h1
-rw-r--r--fs/btrfs/xattr.c18
7 files changed, 195 insertions, 49 deletions
diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
index af52f6d7a4d..4403e5643d4 100644
--- a/fs/btrfs/ctree.h
+++ b/fs/btrfs/ctree.h
@@ -597,6 +597,8 @@ struct btrfs_dir_item {
u8 type;
} __attribute__ ((__packed__));
+#define BTRFS_ROOT_SUBVOL_RDONLY (1ULL << 0)
+
struct btrfs_root_item {
struct btrfs_inode_item inode;
__le64 generation;
@@ -1893,6 +1895,11 @@ BTRFS_SETGET_STACK_FUNCS(root_limit, struct btrfs_root_item, byte_limit, 64);
BTRFS_SETGET_STACK_FUNCS(root_last_snapshot, struct btrfs_root_item,
last_snapshot, 64);
+static inline bool btrfs_root_readonly(struct btrfs_root *root)
+{
+ return root->root_item.flags & BTRFS_ROOT_SUBVOL_RDONLY;
+}
+
/* struct btrfs_super_block */
BTRFS_SETGET_STACK_FUNCS(super_bytenr, struct btrfs_super_block, bytenr, 64);
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index 5f9194438f7..956f1eb913b 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -3671,8 +3671,12 @@ static int btrfs_setattr_size(struct inode *inode, struct iattr *attr)
static int btrfs_setattr(struct dentry *dentry, struct iattr *attr)
{
struct inode *inode = dentry->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
int err;
+ if (btrfs_root_readonly(root))
+ return -EROFS;
+
err = inode_change_ok(inode, attr);
if (err)
return err;
@@ -7206,6 +7210,10 @@ static int btrfs_set_page_dirty(struct page *page)
static int btrfs_permission(struct inode *inode, int mask)
{
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+
+ if (btrfs_root_readonly(root) && (mask & MAY_WRITE))
+ return -EROFS;
if ((BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) && (mask & MAY_WRITE))
return -EACCES;
return generic_permission(inode, mask, btrfs_check_acl);
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index f87552a1d7e..ad1983524f9 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -147,6 +147,9 @@ static int btrfs_ioctl_setflags(struct file *file, void __user *arg)
unsigned int flags, oldflags;
int ret;
+ if (btrfs_root_readonly(root))
+ return -EROFS;
+
if (copy_from_user(&flags, arg, sizeof(flags)))
return -EFAULT;
@@ -360,7 +363,8 @@ fail:
}
static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
- char *name, int namelen, u64 *async_transid)
+ char *name, int namelen, u64 *async_transid,
+ bool readonly)
{
struct inode *inode;
struct dentry *parent;
@@ -378,6 +382,7 @@ static int create_snapshot(struct btrfs_root *root, struct dentry *dentry,
btrfs_init_block_rsv(&pending_snapshot->block_rsv);
pending_snapshot->dentry = dentry;
pending_snapshot->root = root;
+ pending_snapshot->readonly = readonly;
trans = btrfs_start_transaction(root->fs_info->extent_root, 5);
if (IS_ERR(trans)) {
@@ -509,7 +514,7 @@ static inline int btrfs_may_create(struct inode *dir, struct dentry *child)
static noinline int btrfs_mksubvol(struct path *parent,
char *name, int namelen,
struct btrfs_root *snap_src,
- u64 *async_transid)
+ u64 *async_transid, bool readonly)
{
struct inode *dir = parent->dentry->d_inode;
struct dentry *dentry;
@@ -541,7 +546,7 @@ static noinline int btrfs_mksubvol(struct path *parent,
if (snap_src) {
error = create_snapshot(snap_src, dentry,
- name, namelen, async_transid);
+ name, namelen, async_transid, readonly);
} else {
error = create_subvol(BTRFS_I(dir)->root, dentry,
name, namelen, async_transid);
@@ -901,7 +906,8 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
char *name,
unsigned long fd,
int subvol,
- u64 *transid)
+ u64 *transid,
+ bool readonly)
{
struct btrfs_root *root = BTRFS_I(fdentry(file)->d_inode)->root;
struct file *src_file;
@@ -919,7 +925,7 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
if (subvol) {
ret = btrfs_mksubvol(&file->f_path, name, namelen,
- NULL, transid);
+ NULL, transid, readonly);
} else {
struct inode *src_inode;
src_file = fget(fd);
@@ -938,7 +944,7 @@ static noinline int btrfs_ioctl_snap_create_transid(struct file *file,
}
ret = btrfs_mksubvol(&file->f_path, name, namelen,
BTRFS_I(src_inode)->root,
- transid);
+ transid, readonly);
fput(src_file);
}
out:
@@ -946,58 +952,139 @@ out:
}
static noinline int btrfs_ioctl_snap_create(struct file *file,
- void __user *arg, int subvol,
- int v2)
+ void __user *arg, int subvol)
{
- struct btrfs_ioctl_vol_args *vol_args = NULL;
- struct btrfs_ioctl_vol_args_v2 *vol_args_v2 = NULL;
- char *name;
- u64 fd;
+ struct btrfs_ioctl_vol_args *vol_args;
int ret;
- if (v2) {
- u64 transid = 0;
- u64 *ptr = NULL;
-
- vol_args_v2 = memdup_user(arg, sizeof(*vol_args_v2));
- if (IS_ERR(vol_args_v2))
- return PTR_ERR(vol_args_v2);
+ vol_args = memdup_user(arg, sizeof(*vol_args));
+ if (IS_ERR(vol_args))
+ return PTR_ERR(vol_args);
+ vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
- if (vol_args_v2->flags & ~BTRFS_SUBVOL_CREATE_ASYNC) {
- ret = -EINVAL;
- goto out;
- }
+ ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
+ vol_args->fd, subvol,
+ NULL, false);
- name = vol_args_v2->name;
- fd = vol_args_v2->fd;
- vol_args_v2->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
+ kfree(vol_args);
+ return ret;
+}
- if (vol_args_v2->flags & BTRFS_SUBVOL_CREATE_ASYNC)
- ptr = &transid;
+static noinline int btrfs_ioctl_snap_create_v2(struct file *file,
+ void __user *arg, int subvol)
+{
+ struct btrfs_ioctl_vol_args_v2 *vol_args;
+ int ret;
+ u64 transid = 0;
+ u64 *ptr = NULL;
+ bool readonly = false;
- ret = btrfs_ioctl_snap_create_transid(file, name, fd,
- subvol, ptr);
+ vol_args = memdup_user(arg, sizeof(*vol_args));
+ if (IS_ERR(vol_args))
+ return PTR_ERR(vol_args);
+ vol_args->name[BTRFS_SUBVOL_NAME_MAX] = '\0';
- if (ret == 0 && ptr &&
- copy_to_user(arg +
- offsetof(struct btrfs_ioctl_vol_args_v2,
- transid), ptr, sizeof(*ptr)))
- ret = -EFAULT;
- } else {
- vol_args = memdup_user(arg, sizeof(*vol_args));
- if (IS_ERR(vol_args))
- return PTR_ERR(vol_args);
- name = vol_args->name;
- fd = vol_args->fd;
- vol_args->name[BTRFS_PATH_NAME_MAX] = '\0';
-
- ret = btrfs_ioctl_snap_create_transid(file, name, fd,
- subvol, NULL);
+ if (vol_args->flags &
+ ~(BTRFS_SUBVOL_CREATE_ASYNC | BTRFS_SUBVOL_RDONLY)) {
+ ret = -EOPNOTSUPP;
+ goto out;
}
+
+ if (vol_args->flags & BTRFS_SUBVOL_CREATE_ASYNC)
+ ptr = &transid;
+ if (vol_args->flags & BTRFS_SUBVOL_RDONLY)
+ readonly = true;
+
+ ret = btrfs_ioctl_snap_create_transid(file, vol_args->name,
+ vol_args->fd, subvol,
+ ptr, readonly);
+
+ if (ret == 0 && ptr &&
+ copy_to_user(arg +
+ offsetof(struct btrfs_ioctl_vol_args_v2,
+ transid), ptr, sizeof(*ptr)))
+ ret = -EFAULT;
out:
kfree(vol_args);
- kfree(vol_args_v2);
+ return ret;
+}
+
+static noinline int btrfs_ioctl_subvol_getflags(struct file *file,
+ void __user *arg)
+{
+ struct inode *inode = fdentry(file)->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ int ret = 0;
+ u64 flags = 0;
+
+ if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID)
+ return -EINVAL;
+
+ down_read(&root->fs_info->subvol_sem);
+ if (btrfs_root_readonly(root))
+ flags |= BTRFS_SUBVOL_RDONLY;
+ up_read(&root->fs_info->subvol_sem);
+
+ if (copy_to_user(arg, &flags, sizeof(flags)))
+ ret = -EFAULT;
+
+ return ret;
+}
+
+static noinline int btrfs_ioctl_subvol_setflags(struct file *file,
+ void __user *arg)
+{
+ struct inode *inode = fdentry(file)->d_inode;
+ struct btrfs_root *root = BTRFS_I(inode)->root;
+ struct btrfs_trans_handle *trans;
+ u64 root_flags;
+ u64 flags;
+ int ret = 0;
+
+ if (root->fs_info->sb->s_flags & MS_RDONLY)
+ return -EROFS;
+
+ if (inode->i_ino != BTRFS_FIRST_FREE_OBJECTID)
+ return -EINVAL;
+
+ if (copy_from_user(&flags, arg, sizeof(flags)))
+ return -EFAULT;
+
+ if (flags & ~BTRFS_SUBVOL_CREATE_ASYNC)
+ return -EINVAL;
+
+ if (flags & ~BTRFS_SUBVOL_RDONLY)
+ return -EOPNOTSUPP;
+
+ down_write(&root->fs_info->subvol_sem);
+
+ /* nothing to do */
+ if (!!(flags & BTRFS_SUBVOL_RDONLY) == btrfs_root_readonly(root))
+ goto out;
+
+ root_flags = btrfs_root_flags(&root->root_item);
+ if (flags & BTRFS_SUBVOL_RDONLY)
+ btrfs_set_root_flags(&root->root_item,
+ root_flags | BTRFS_ROOT_SUBVOL_RDONLY);
+ else
+ btrfs_set_root_flags(&root->root_item,
+ root_flags & ~BTRFS_ROOT_SUBVOL_RDONLY);
+
+ trans = btrfs_start_transaction(root, 1);
+ if (IS_ERR(trans)) {
+ ret = PTR_ERR(trans);
+ goto out_reset;
+ }
+ ret = btrfs_update_root(trans, root,
+ &root->root_key, &root->root_item);
+
+ btrfs_commit_transaction(trans, root);
+out_reset:
+ if (ret)
+ btrfs_set_root_flags(&root->root_item, root_flags);
+out:
+ up_write(&root->fs_info->subvol_sem);
return ret;
}
@@ -1509,6 +1596,9 @@ static int btrfs_ioctl_defrag(struct file *file, void __user *argp)
struct btrfs_ioctl_defrag_range_args *range;
int ret;
+ if (btrfs_root_readonly(root))
+ return -EROFS;
+
ret = mnt_want_write(file->f_path.mnt);
if (ret)
return ret;
@@ -1637,6 +1727,9 @@ static noinline long btrfs_ioctl_clone(struct file *file, unsigned long srcfd,
if (!(file->f_mode & FMODE_WRITE) || (file->f_flags & O_APPEND))
return -EINVAL;
+ if (btrfs_root_readonly(root))
+ return -EROFS;
+
ret = mnt_want_write(file->f_path.mnt);
if (ret)
return ret;
@@ -1958,6 +2051,10 @@ static long btrfs_ioctl_trans_start(struct file *file)
if (file->private_data)
goto out;
+ ret = -EROFS;
+ if (btrfs_root_readonly(root))
+ goto out;
+
ret = mnt_want_write(file->f_path.mnt);
if (ret)
goto out;
@@ -2257,13 +2354,17 @@ long btrfs_ioctl(struct file *file, unsigned int
case FS_IOC_GETVERSION:
return btrfs_ioctl_getversion(file, argp);
case BTRFS_IOC_SNAP_CREATE:
- return btrfs_ioctl_snap_create(file, argp, 0, 0);
+ return btrfs_ioctl_snap_create(file, argp, 0);
case BTRFS_IOC_SNAP_CREATE_V2:
- return btrfs_ioctl_snap_create(file, argp, 0, 1);
+ return btrfs_ioctl_snap_create_v2(file, argp, 0);
case BTRFS_IOC_SUBVOL_CREATE:
- return btrfs_ioctl_snap_create(file, argp, 1, 0);
+ return btrfs_ioctl_snap_create(file, argp, 1);
case BTRFS_IOC_SNAP_DESTROY:
return btrfs_ioctl_snap_destroy(file, argp);
+ case BTRFS_IOC_SUBVOL_GETFLAGS:
+ return btrfs_ioctl_subvol_getflags(file, argp);
+ case BTRFS_IOC_SUBVOL_SETFLAGS:
+ return btrfs_ioctl_subvol_setflags(file, argp);
case BTRFS_IOC_DEFAULT_SUBVOL:
return btrfs_ioctl_default_subvol(file, argp);
case BTRFS_IOC_DEFRAG:
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index c344d12c646..1223223351f 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -31,6 +31,7 @@ struct btrfs_ioctl_vol_args {
};
#define BTRFS_SUBVOL_CREATE_ASYNC (1ULL << 0)
+#define BTRFS_SUBVOL_RDONLY (1ULL << 1)
#define BTRFS_SUBVOL_NAME_MAX 4039
struct btrfs_ioctl_vol_args_v2 {
@@ -193,4 +194,6 @@ struct btrfs_ioctl_space_args {
#define BTRFS_IOC_WAIT_SYNC _IOW(BTRFS_IOCTL_MAGIC, 22, __u64)
#define BTRFS_IOC_SNAP_CREATE_V2 _IOW(BTRFS_IOCTL_MAGIC, 23, \
struct btrfs_ioctl_vol_args_v2)
+#define BTRFS_IOC_SUBVOL_GETFLAGS _IOW(BTRFS_IOCTL_MAGIC, 25, __u64)
+#define BTRFS_IOC_SUBVOL_SETFLAGS _IOW(BTRFS_IOCTL_MAGIC, 26, __u64)
#endif
diff --git a/fs/btrfs/transaction.c b/fs/btrfs/transaction.c
index f50e931fc21..29e30d832ec 100644
--- a/fs/btrfs/transaction.c
+++ b/fs/btrfs/transaction.c
@@ -910,6 +910,7 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
u64 to_reserve = 0;
u64 index = 0;
u64 objectid;
+ u64 root_flags;
new_root_item = kmalloc(sizeof(*new_root_item), GFP_NOFS);
if (!new_root_item) {
@@ -967,6 +968,13 @@ static noinline int create_pending_snapshot(struct btrfs_trans_handle *trans,
btrfs_set_root_last_snapshot(&root->root_item, trans->transid);
memcpy(new_root_item, &root->root_item, sizeof(*new_root_item));
+ root_flags = btrfs_root_flags(new_root_item);
+ if (pending->readonly)
+ root_flags |= BTRFS_ROOT_SUBVOL_RDONLY;
+ else
+ root_flags &= ~BTRFS_ROOT_SUBVOL_RDONLY;
+ btrfs_set_root_flags(new_root_item, root_flags);
+
old = btrfs_lock_root_node(root);
btrfs_cow_block(trans, root, old, NULL, 0, &old);
btrfs_set_lock_blocking(old);
diff --git a/fs/btrfs/transaction.h b/fs/btrfs/transaction.h
index f104b57ad4e..229a594cacd 100644
--- a/fs/btrfs/transaction.h
+++ b/fs/btrfs/transaction.h
@@ -62,6 +62,7 @@ struct btrfs_pending_snapshot {
struct btrfs_block_rsv block_rsv;
/* extra metadata reseration for relocation */
int error;
+ bool readonly;
struct list_head list;
};
diff --git a/fs/btrfs/xattr.c b/fs/btrfs/xattr.c
index 698fdd2c739..a5776531dc2 100644
--- a/fs/btrfs/xattr.c
+++ b/fs/btrfs/xattr.c
@@ -316,6 +316,15 @@ ssize_t btrfs_getxattr(struct dentry *dentry, const char *name,
int btrfs_setxattr(struct dentry *dentry, const char *name, const void *value,
size_t size, int flags)
{
+ struct btrfs_root *root = BTRFS_I(dentry->d_inode)->root;
+
+ /*
+ * The permission on security.* and system.* is not checked
+ * in permission().
+ */
+ if (btrfs_root_readonly(root))
+ return -EROFS;
+
/*
* If this is a request for a synthetic attribute in the system.*
* namespace use the generic infrastructure to resolve a handler
@@ -336,6 +345,15 @@ int btrfs_setxattr(struct dentry *dentry, const char *name, const void *value,
int btrfs_removexattr(struct dentry *dentry, const char *name)
{
+ struct btrfs_root *root = BTRFS_I(dentry->d_inode)->root;
+
+ /*
+ * The permission on security.* and system.* is not checked
+ * in permission().
+ */
+ if (btrfs_root_readonly(root))
+ return -EROFS;
+
/*
* If this is a request for a synthetic attribute in the system.*
* namespace use the generic infrastructure to resolve a handler