btrfs: new ioctls to do logical->inode and inode->path resolving
these ioctls make use of the new functions initially added for scrub. they
return all inodes belonging to a logical address (BTRFS_IOC_LOGICAL_INO) and
all paths belonging to an inode (BTRFS_IOC_INO_PATHS).
Signed-off-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
index 538f65a..7f57efa 100644
--- a/fs/btrfs/ioctl.c
+++ b/fs/btrfs/ioctl.c
@@ -51,6 +51,7 @@
#include "volumes.h"
#include "locking.h"
#include "inode-map.h"
+#include "backref.h"
/* Mask out flags that are inappropriate for the given type of inode. */
static inline __u32 btrfs_mask_flags(umode_t mode, __u32 flags)
@@ -2855,6 +2856,144 @@
return ret;
}
+static long btrfs_ioctl_ino_to_path(struct btrfs_root *root, void __user *arg)
+{
+ int ret = 0;
+ int i;
+ unsigned long rel_ptr;
+ int size;
+ struct btrfs_ioctl_ino_path_args *ipa;
+ struct inode_fs_paths *ipath = NULL;
+ struct btrfs_path *path;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ ipa = memdup_user(arg, sizeof(*ipa));
+ if (IS_ERR(ipa)) {
+ ret = PTR_ERR(ipa);
+ ipa = NULL;
+ goto out;
+ }
+
+ size = min_t(u32, ipa->size, 4096);
+ ipath = init_ipath(size, root, path);
+ if (IS_ERR(ipath)) {
+ ret = PTR_ERR(ipath);
+ ipath = NULL;
+ goto out;
+ }
+
+ ret = paths_from_inode(ipa->inum, ipath);
+ if (ret < 0)
+ goto out;
+
+ for (i = 0; i < ipath->fspath->elem_cnt; ++i) {
+ rel_ptr = ipath->fspath->str[i] - (char *)ipath->fspath->str;
+ ipath->fspath->str[i] = (void *)rel_ptr;
+ }
+
+ ret = copy_to_user(ipa->fspath, ipath->fspath, size);
+ if (ret) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+out:
+ btrfs_free_path(path);
+ free_ipath(ipath);
+ kfree(ipa);
+
+ return ret;
+}
+
+static int build_ino_list(u64 inum, u64 offset, u64 root, void *ctx)
+{
+ struct btrfs_data_container *inodes = ctx;
+ const size_t c = 3 * sizeof(u64);
+
+ if (inodes->bytes_left >= c) {
+ inodes->bytes_left -= c;
+ inodes->val[inodes->elem_cnt] = inum;
+ inodes->val[inodes->elem_cnt + 1] = offset;
+ inodes->val[inodes->elem_cnt + 2] = root;
+ inodes->elem_cnt += 3;
+ } else {
+ inodes->bytes_missing += c - inodes->bytes_left;
+ inodes->bytes_left = 0;
+ inodes->elem_missed += 3;
+ }
+
+ return 0;
+}
+
+static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
+ void __user *arg)
+{
+ int ret = 0;
+ int size;
+ u64 extent_offset;
+ struct btrfs_ioctl_logical_ino_args *loi;
+ struct btrfs_data_container *inodes = NULL;
+ struct btrfs_path *path = NULL;
+ struct btrfs_key key;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ loi = memdup_user(arg, sizeof(*loi));
+ if (IS_ERR(loi)) {
+ ret = PTR_ERR(loi);
+ loi = NULL;
+ goto out;
+ }
+
+ path = btrfs_alloc_path();
+ if (!path) {
+ ret = -ENOMEM;
+ goto out;
+ }
+
+ size = min_t(u32, loi->size, 4096);
+ inodes = init_data_container(size);
+ if (IS_ERR(inodes)) {
+ ret = PTR_ERR(inodes);
+ inodes = NULL;
+ goto out;
+ }
+
+ ret = extent_from_logical(root->fs_info, loi->logical, path, &key);
+
+ if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK)
+ ret = -ENOENT;
+ if (ret < 0)
+ goto out;
+
+ extent_offset = loi->logical - key.objectid;
+ ret = iterate_extent_inodes(root->fs_info, path, key.objectid,
+ extent_offset, build_ino_list, inodes);
+
+ if (ret < 0)
+ goto out;
+
+ ret = copy_to_user(loi->inodes, inodes, size);
+ if (ret)
+ ret = -EFAULT;
+
+out:
+ btrfs_free_path(path);
+ kfree(inodes);
+ kfree(loi);
+
+ return ret;
+}
+
long btrfs_ioctl(struct file *file, unsigned int
cmd, unsigned long arg)
{
@@ -2912,6 +3051,10 @@
return btrfs_ioctl_tree_search(file, argp);
case BTRFS_IOC_INO_LOOKUP:
return btrfs_ioctl_ino_lookup(file, argp);
+ case BTRFS_IOC_INO_PATHS:
+ return btrfs_ioctl_ino_to_path(root, argp);
+ case BTRFS_IOC_LOGICAL_INO:
+ return btrfs_ioctl_logical_to_ino(root, argp);
case BTRFS_IOC_SPACE_INFO:
return btrfs_ioctl_space_info(root, argp);
case BTRFS_IOC_SYNC:
diff --git a/fs/btrfs/ioctl.h b/fs/btrfs/ioctl.h
index 1857e38..2da30d4 100644
--- a/fs/btrfs/ioctl.h
+++ b/fs/btrfs/ioctl.h
@@ -204,6 +204,20 @@
};
};
+struct btrfs_ioctl_ino_path_args {
+ __u64 inum; /* in */
+ __u32 size; /* in */
+ __u64 reserved[4];
+ struct btrfs_data_container *fspath; /* out */
+};
+
+struct btrfs_ioctl_logical_ino_args {
+ __u64 logical; /* in */
+ __u32 size; /* in */
+ __u64 reserved[4];
+ struct btrfs_data_container *inodes; /* out */
+};
+
#define BTRFS_IOC_SNAP_CREATE _IOW(BTRFS_IOCTL_MAGIC, 1, \
struct btrfs_ioctl_vol_args)
#define BTRFS_IOC_DEFRAG _IOW(BTRFS_IOCTL_MAGIC, 2, \
@@ -259,4 +273,9 @@
struct btrfs_ioctl_dev_info_args)
#define BTRFS_IOC_FS_INFO _IOR(BTRFS_IOCTL_MAGIC, 31, \
struct btrfs_ioctl_fs_info_args)
+#define BTRFS_IOC_INO_PATHS _IOWR(BTRFS_IOCTL_MAGIC, 35, \
+ struct btrfs_ioctl_ino_path_args)
+#define BTRFS_IOC_LOGICAL_INO _IOWR(BTRFS_IOCTL_MAGIC, 36, \
+ struct btrfs_ioctl_ino_path_args)
+
#endif