Hi, Jan,
On Thu, Jul 07, 2011 at 05:48:33PM +0200, Jan Schmidt wrote:
> 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).
I've not read this patch in detail, so I may have missed something,
but why do we need new ioctls for these functions, when we have
BTRFS_IOC_TREE_SEARCH, which will allow us to perform the same two
operations using existing kernel-side infrastructure?
Hugo.
> Signed-off-by: Jan Schmidt <list.btrfs@xxxxxxxxxxxxx>
> ---
> fs/btrfs/ioctl.c | 134 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
> fs/btrfs/ioctl.h | 19 ++++++++
> 2 files changed, 153 insertions(+), 0 deletions(-)
>
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index a3c4751..5299b40 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)
> @@ -2836,6 +2837,135 @@ static long btrfs_ioctl_scrub_progress(struct btrfs_root *root,
> 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;
> +
> + 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(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;
> +
> + inodes->size -= 3 * sizeof(u64);
> + if (inodes->size > 0) {
> + 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->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;
> +
> + 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(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)
> {
> @@ -2893,6 +3023,10 @@ long btrfs_ioctl(struct file *file, unsigned int
> 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 4afb60b..10a0c10 100644
> --- a/fs/btrfs/ioctl.h
> +++ b/fs/btrfs/ioctl.h
> @@ -203,6 +203,20 @@ struct btrfs_data_container {
> };
> };
>
> +struct btrfs_ioctl_ino_path_args {
> + __u64 inum; /* in */
> + __s32 size; /* in */
> + __u64 reserved[4];
> + struct btrfs_data_container *fspath; /* out */
> +};
> +
> +struct btrfs_ioctl_logical_ino_args {
> + __u64 logical; /* in */
> + __s32 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, \
> @@ -258,4 +272,9 @@ struct btrfs_data_container {
> 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
--
=== Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk ===
PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk
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