On 04/17/2018 04:39 PM, Howard McLauchlan wrote:
> Presently btrfs send/receive does not propagate inode attribute flags;
> all chattr operations are effectively discarded upon transmission.
>
> This patch adds kernel support for inode attribute flags. Userspace
> support can be found under the commit:
>
> btrfs-progs: add chattr support for send/receive
>
> An associated xfstest can be found at:
>
> btrfs: add verify chattr support for send/receive test
>
> A caveat is that a user with an updated kernel (aware of chattrs) and an
> older version of btrfs-progs (unaware of chattrs) will fail to receive
> if a chattr is included in the send stream.
>
> Signed-off-by: Howard McLauchlan <hmclauchlan@xxxxxx>
> ---
> Based on 4.17-rc1
>
> fs/btrfs/ctree.h | 2 +
> fs/btrfs/ioctl.c | 2 +-
> fs/btrfs/send.c | 176 +++++++++++++++++++++++++++++++++++++++--------
> fs/btrfs/send.h | 2 +
> 4 files changed, 154 insertions(+), 28 deletions(-)
>
> diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h
> index 5474ef14d6e6..a0dc6a8a37eb 100644
> --- a/fs/btrfs/ctree.h
> +++ b/fs/btrfs/ctree.h
> @@ -1436,6 +1436,8 @@ struct btrfs_map_token {
> unsigned long offset;
> };
>
> +unsigned int btrfs_flags_to_ioctl(unsigned int flags);
> +
> #define BTRFS_BYTES_TO_BLKS(fs_info, bytes) \
> ((bytes) >> (fs_info)->sb->s_blocksize_bits)
>
> diff --git a/fs/btrfs/ioctl.c b/fs/btrfs/ioctl.c
> index 632e26d6f7ce..36ce1e589f9e 100644
> --- a/fs/btrfs/ioctl.c
> +++ b/fs/btrfs/ioctl.c
> @@ -106,7 +106,7 @@ static unsigned int btrfs_mask_flags(umode_t mode, unsigned int flags)
> /*
> * Export inode flags to the format expected by the FS_IOC_GETFLAGS ioctl.
> */
> -static unsigned int btrfs_flags_to_ioctl(unsigned int flags)
> +unsigned int btrfs_flags_to_ioctl(unsigned int flags)
> {
> unsigned int iflags = 0;
>
> diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
> index 221e5cdb060b..da521a5a1843 100644
> --- a/fs/btrfs/send.c
> +++ b/fs/btrfs/send.c
> @@ -101,6 +101,13 @@ struct send_ctx {
> u64 cur_inode_last_extent;
> u64 cur_inode_next_write_offset;
>
> + /*
> + * state for chattr purposes
> + */
> + u64 cur_inode_flip_flags;
> + u64 cur_inode_receive_flags;
> + int receive_flags_valid;
> +
> u64 send_progress;
>
> struct list_head new_refs;
> @@ -798,7 +805,7 @@ static int send_rmdir(struct send_ctx *sctx, struct fs_path *path)
> */
> static int __get_inode_info(struct btrfs_root *root, struct btrfs_path *path,
> u64 ino, u64 *size, u64 *gen, u64 *mode, u64 *uid,
> - u64 *gid, u64 *rdev)
> + u64 *gid, u64 *rdev, u64 *flags)
> {
> int ret;
> struct btrfs_inode_item *ii;
> @@ -828,6 +835,8 @@ static int __get_inode_info(struct btrfs_root *root, struct btrfs_path *path,
> *gid = btrfs_inode_gid(path->nodes[0], ii);
> if (rdev)
> *rdev = btrfs_inode_rdev(path->nodes[0], ii);
> + if (flags)
> + *flags = btrfs_inode_flags(path->nodes[0], ii);
>
> return ret;
> }
> @@ -835,7 +844,7 @@ static int __get_inode_info(struct btrfs_root *root, struct btrfs_path *path,
> static int get_inode_info(struct btrfs_root *root,
> u64 ino, u64 *size, u64 *gen,
> u64 *mode, u64 *uid, u64 *gid,
> - u64 *rdev)
> + u64 *rdev, u64 *flags)
> {
> struct btrfs_path *path;
> int ret;
> @@ -844,7 +853,7 @@ static int get_inode_info(struct btrfs_root *root,
> if (!path)
> return -ENOMEM;
> ret = __get_inode_info(root, path, ino, size, gen, mode, uid, gid,
> - rdev);
> + rdev, flags);
> btrfs_free_path(path);
> return ret;
> }
> @@ -1233,7 +1242,7 @@ static int __iterate_backrefs(u64 ino, u64 offset, u64 root, void *ctx_)
> * accept clones from these extents.
> */
> ret = __get_inode_info(found->root, bctx->path, ino, &i_size, NULL, NULL,
> - NULL, NULL, NULL);
> + NULL, NULL, NULL, NULL);
> btrfs_release_path(bctx->path);
> if (ret < 0)
> return ret;
> @@ -1593,7 +1602,7 @@ static int get_cur_inode_state(struct send_ctx *sctx, u64 ino, u64 gen)
> u64 right_gen;
>
> ret = get_inode_info(sctx->send_root, ino, NULL, &left_gen, NULL, NULL,
> - NULL, NULL);
> + NULL, NULL, NULL);
> if (ret < 0 && ret != -ENOENT)
> goto out;
> left_ret = ret;
> @@ -1602,7 +1611,7 @@ static int get_cur_inode_state(struct send_ctx *sctx, u64 ino, u64 gen)
> right_ret = -ENOENT;
> } else {
> ret = get_inode_info(sctx->parent_root, ino, NULL, &right_gen,
> - NULL, NULL, NULL, NULL);
> + NULL, NULL, NULL, NULL, NULL);
> if (ret < 0 && ret != -ENOENT)
> goto out;
> right_ret = ret;
> @@ -1771,7 +1780,7 @@ static int get_first_ref(struct btrfs_root *root, u64 ino,
>
> if (dir_gen) {
> ret = get_inode_info(root, parent_dir, NULL, dir_gen, NULL,
> - NULL, NULL, NULL);
> + NULL, NULL, NULL, NULL);
> if (ret < 0)
> goto out;
> }
> @@ -1844,7 +1853,7 @@ static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen,
> */
> if (sctx->parent_root && dir != BTRFS_FIRST_FREE_OBJECTID) {
> ret = get_inode_info(sctx->parent_root, dir, NULL, &gen, NULL,
> - NULL, NULL, NULL);
> + NULL, NULL, NULL, NULL);
> if (ret < 0 && ret != -ENOENT)
> goto out;
> if (ret) {
> @@ -1872,7 +1881,7 @@ static int will_overwrite_ref(struct send_ctx *sctx, u64 dir, u64 dir_gen,
> if (other_inode > sctx->send_progress ||
> is_waiting_for_move(sctx, other_inode)) {
> ret = get_inode_info(sctx->parent_root, other_inode, NULL,
> - who_gen, who_mode, NULL, NULL, NULL);
> + who_gen, who_mode, NULL, NULL, NULL, NULL);
> if (ret < 0)
> goto out;
>
> @@ -1912,7 +1921,7 @@ static int did_overwrite_ref(struct send_ctx *sctx,
>
> if (dir != BTRFS_FIRST_FREE_OBJECTID) {
> ret = get_inode_info(sctx->send_root, dir, NULL, &gen, NULL,
> - NULL, NULL, NULL);
> + NULL, NULL, NULL, NULL);
> if (ret < 0 && ret != -ENOENT)
> goto out;
> if (ret) {
> @@ -1935,7 +1944,7 @@ static int did_overwrite_ref(struct send_ctx *sctx,
> }
>
> ret = get_inode_info(sctx->send_root, ow_inode, NULL, &gen, NULL, NULL,
> - NULL, NULL);
> + NULL, NULL, NULL);
> if (ret < 0)
> goto out;
>
> @@ -2502,6 +2511,39 @@ static int send_chown(struct send_ctx *sctx, u64 ino, u64 gen, u64 uid, u64 gid)
> return ret;
> }
>
> +static int send_chattr(struct send_ctx *sctx, u64 ino, u64 gen, u64 flags)
> +{
> + struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
> + int ret = 0;
> + int __flags;
> + struct fs_path *p;
> +
> + __flags = btrfs_flags_to_ioctl(flags);
> +
> + btrfs_debug(fs_info, "send_chattr %llu flags=%llu", ino, flags);
> +
> + p = fs_path_alloc();
> + if (!p)
> + return -ENOMEM;
> +
> + ret = begin_cmd(sctx, BTRFS_SEND_C_CHATTR);
> + if (ret < 0)
> + goto out;
> +
> + ret = get_cur_path(sctx, ino, gen, p);
> + if (ret < 0)
> + goto out;
> + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p);
> + TLV_PUT_U64(sctx, BTRFS_SEND_A_CHATTR, __flags);
> +
> + ret = send_cmd(sctx);
> +
> +tlv_put_failure:
> +out:
> + fs_path_free(p);
> + return ret;
> +}
> +
> static int send_utimes(struct send_ctx *sctx, u64 ino, u64 gen)
> {
> struct btrfs_fs_info *fs_info = sctx->send_root->fs_info;
> @@ -2583,7 +2625,7 @@ static int send_create_inode(struct send_ctx *sctx, u64 ino)
>
> if (ino != sctx->cur_ino) {
> ret = get_inode_info(sctx->send_root, ino, NULL, &gen, &mode,
> - NULL, NULL, &rdev);
> + NULL, NULL, &rdev, NULL);
> if (ret < 0)
> goto out;
> } else {
> @@ -3299,7 +3341,7 @@ static int apply_dir_move(struct send_ctx *sctx, struct pending_dir_move *pm)
> * The parent inode might have been deleted in the send snapshot
> */
> ret = get_inode_info(sctx->send_root, cur->dir, NULL,
> - NULL, NULL, NULL, NULL, NULL);
> + NULL, NULL, NULL, NULL, NULL, NULL);
> if (ret == -ENOENT) {
> ret = 0;
> continue;
> @@ -3469,11 +3511,11 @@ static int wait_for_dest_dir_move(struct send_ctx *sctx,
> }
>
> ret = get_inode_info(sctx->parent_root, di_key.objectid, NULL,
> - &left_gen, NULL, NULL, NULL, NULL);
> + &left_gen, NULL, NULL, NULL, NULL, NULL);
> if (ret < 0)
> goto out;
> ret = get_inode_info(sctx->send_root, di_key.objectid, NULL,
> - &right_gen, NULL, NULL, NULL, NULL);
> + &right_gen, NULL, NULL, NULL, NULL, NULL);
> if (ret < 0) {
> if (ret == -ENOENT)
> ret = 0;
> @@ -3617,7 +3659,7 @@ static int is_ancestor(struct btrfs_root *root,
> }
>
> ret = get_inode_info(root, parent, NULL, &parent_gen,
> - NULL, NULL, NULL, NULL);
> + NULL, NULL, NULL, NULL, NULL);
> if (ret < 0)
> goto out;
> ret = check_ino_in_path(root, ino1, ino1_gen,
> @@ -3707,7 +3749,7 @@ static int wait_for_parent_move(struct send_ctx *sctx,
>
> ret = get_inode_info(sctx->parent_root, ino, NULL,
> &parent_ino_gen, NULL, NULL, NULL,
> - NULL);
> + NULL, NULL);
> if (ret < 0)
> goto out;
> if (ino_gen == parent_ino_gen) {
> @@ -4184,7 +4226,7 @@ static int record_ref(struct btrfs_root *root, u64 dir, struct fs_path *name,
> return -ENOMEM;
>
> ret = get_inode_info(root, dir, NULL, &gen, NULL, NULL,
> - NULL, NULL);
> + NULL, NULL, NULL);
> if (ret < 0)
> goto out;
>
> @@ -4272,7 +4314,7 @@ static int __find_iref(int num, u64 dir, int index,
> * else matches.
> */
> ret = get_inode_info(ctx->root, dir, NULL, &dir_gen, NULL,
> - NULL, NULL, NULL);
> + NULL, NULL, NULL, NULL);
> if (ret)
> return ret;
> if (dir_gen != ctx->dir_gen)
> @@ -4316,7 +4358,7 @@ static int __record_changed_new_ref(int num, u64 dir, int index,
> struct send_ctx *sctx = ctx;
>
> ret = get_inode_info(sctx->send_root, dir, NULL, &dir_gen, NULL,
> - NULL, NULL, NULL);
> + NULL, NULL, NULL, NULL);
> if (ret)
> return ret;
>
> @@ -4339,7 +4381,7 @@ static int __record_changed_deleted_ref(int num, u64 dir, int index,
> struct send_ctx *sctx = ctx;
>
> ret = get_inode_info(sctx->parent_root, dir, NULL, &dir_gen, NULL,
> - NULL, NULL, NULL);
> + NULL, NULL, NULL, NULL);
> if (ret)
> return ret;
>
> @@ -4915,7 +4957,7 @@ static int send_clone(struct send_ctx *sctx,
>
> if (clone_root->root == sctx->send_root) {
> ret = get_inode_info(sctx->send_root, clone_root->ino, NULL,
> - &gen, NULL, NULL, NULL, NULL);
> + &gen, NULL, NULL, NULL, NULL, NULL);
> if (ret < 0)
> goto out;
> ret = get_cur_path(sctx, clone_root->ino, gen, p);
> @@ -5777,9 +5819,11 @@ static int finish_inode_if_needed(struct send_ctx *sctx, int at_end)
> u64 right_mode;
> u64 right_uid;
> u64 right_gid;
> + u64 left_flags;
> int need_chmod = 0;
> int need_chown = 0;
> int need_truncate = 1;
> + int need_chattr = 0;
> int pending_move = 0;
> int refs_processed = 0;
>
> @@ -5787,7 +5831,6 @@ static int finish_inode_if_needed(struct send_ctx *sctx, int at_end)
> &refs_processed);
> if (ret < 0)
> goto out;
> -
> /*
> * We have processed the refs and thus need to advance send_progress.
> * Now, calls to get_cur_xxx will take the updated refs of the current
> @@ -5805,11 +5848,67 @@ static int finish_inode_if_needed(struct send_ctx *sctx, int at_end)
>
> if (sctx->cur_ino == 0 || sctx->cur_inode_deleted)
> goto out;
> +
> + /*
> + * If possible, we want to know what flags are set for this inode on the
> + * receiving end.
> + */
> + if (sctx->parent_root && !sctx->receive_flags_valid) {
> + ret = get_inode_info(sctx->parent_root, sctx->cur_ino, NULL,
> + NULL, NULL, NULL, NULL, NULL,
> + &sctx->cur_inode_receive_flags);
> + if (ret < 0)
> + goto out;
> + sctx->receive_flags_valid = 1;
> + }
> +
> + /*
> + * The change is going to modify data and the inode already exists
> + * !at_end prevents unnecessary chattr.
> + */
> + if (!at_end && sctx->parent_root && !sctx->cur_inode_new &&
> + (sctx->cmp_key->type == BTRFS_EXTENT_DATA_KEY ||
> + sctx->cmp_key->type == BTRFS_XATTR_ITEM_KEY)) {
> +
> + ret = get_inode_info(sctx->send_root, sctx->cur_ino, NULL, NULL,
> + NULL, NULL, NULL, NULL, &left_flags);
> + if (ret < 0)
> + goto out;
> + /*
> + * We check against the receive flags first; then check against
> + * the left flags to see if we can save a chattr later on
> + */
> + if (sctx->cur_inode_receive_flags & BTRFS_INODE_IMMUTABLE) {
> + sctx->cur_inode_flip_flags |= (left_flags &
> + BTRFS_INODE_IMMUTABLE);
> + left_flags &= ~BTRFS_INODE_IMMUTABLE;
> + need_chattr = 1;
> + }
> + if (sctx->cur_inode_receive_flags & BTRFS_INODE_APPEND) {
> + sctx->cur_inode_flip_flags |= (left_flags &
> + BTRFS_INODE_APPEND);
> + left_flags &= ~BTRFS_INODE_APPEND;
> + need_chattr = 1;
> + }
> + if (need_chattr) {
> + need_chattr = 0;
> + ret = send_chattr(sctx, sctx->cur_ino,
> + sctx->cur_inode_gen, left_flags);
> + if (ret < 0)
> + goto out;
> + /*
> + * left_flags is now an accurate rep of what the
> + * receiving inode's flags are
> + */
> + sctx->cur_inode_receive_flags = left_flags;
> + }
> + }
> +
> if (!at_end && sctx->cmp_key->objectid == sctx->cur_ino)
> goto out;
>
> ret = get_inode_info(sctx->send_root, sctx->cur_ino, NULL, NULL,
> - &left_mode, &left_uid, &left_gid, NULL);
> + &left_mode, &left_uid, &left_gid, NULL, &left_flags);
> if (ret < 0)
> goto out;
>
> @@ -5819,12 +5918,14 @@ static int finish_inode_if_needed(struct send_ctx *sctx, int at_end)
> need_chmod = 1;
> if (sctx->cur_inode_next_write_offset == sctx->cur_inode_size)
> need_truncate = 0;
> + if (left_flags)
> + need_chattr = 1;
> } else {
> u64 old_size;
>
> ret = get_inode_info(sctx->parent_root, sctx->cur_ino,
> &old_size, NULL, &right_mode, &right_uid,
> - &right_gid, NULL);
> + &right_gid, NULL, NULL);
> if (ret < 0)
> goto out;
>
> @@ -5897,6 +5998,27 @@ static int finish_inode_if_needed(struct send_ctx *sctx, int at_end)
> goto out;
> }
>
> + /*
> + * At this point, if we toggled stuff earlier, untoggle it
> + * force a chattr and fix the flags
> + */
> + if (sctx->cur_inode_flip_flags) {
> + left_flags |= sctx->cur_inode_flip_flags;
> + }
> +
Just noticed I have some extra braces here. Will fix in V2 along with other feedback.
> + /*
> + * We either need a chattr because this inode is new, or we need to make
> + * a change due to a discrepancy between left_flags and receive_flags
> + */
> + if (need_chattr || (sctx->cur_inode_receive_flags != left_flags)) {
> + ret = send_chattr(sctx, sctx->cur_ino, sctx->cur_inode_gen,
> + left_flags);
> + if (ret < 0)
> + goto out;
> + }
> + sctx->cur_inode_flip_flags = 0;
> + sctx->cur_inode_receive_flags = 0;
> + sctx->receive_flags_valid = 0;
> out:
> return ret;
> }
> @@ -6198,12 +6320,12 @@ static int dir_changed(struct send_ctx *sctx, u64 dir)
> int ret;
>
> ret = get_inode_info(sctx->send_root, dir, NULL, &new_gen, NULL, NULL,
> - NULL, NULL);
> + NULL, NULL, NULL);
> if (ret)
> return ret;
>
> ret = get_inode_info(sctx->parent_root, dir, NULL, &orig_gen, NULL,
> - NULL, NULL, NULL);
> + NULL, NULL, NULL, NULL);
> if (ret)
> return ret;
>
> diff --git a/fs/btrfs/send.h b/fs/btrfs/send.h
> index ead397f7034f..b6e6dcc3db70 100644
> --- a/fs/btrfs/send.h
> +++ b/fs/btrfs/send.h
> @@ -77,6 +77,7 @@ enum btrfs_send_cmd {
>
> BTRFS_SEND_C_END,
> BTRFS_SEND_C_UPDATE_EXTENT,
> + BTRFS_SEND_C_CHATTR,
> __BTRFS_SEND_C_MAX,
> };
> #define BTRFS_SEND_C_MAX (__BTRFS_SEND_C_MAX - 1)
> @@ -114,6 +115,7 @@ enum {
> BTRFS_SEND_A_CLONE_PATH,
> BTRFS_SEND_A_CLONE_OFFSET,
> BTRFS_SEND_A_CLONE_LEN,
> + BTRFS_SEND_A_CHATTR,
>
> __BTRFS_SEND_A_MAX,
> };
--
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