From: Filipe David Borba Manana <fdman...@gmail.com> Instead of sending a write command with a data buffer filled with 0 value bytes, use the fallocate command, introduced in the send stream version 2, to tell the receiver to punch a file hole using the fallocate system call.
[Howard: rebased on 4.17-rc4] Signed-off-by: Howard McLauchlan <hmclauch...@fb.com> Signed-off-by: Filipe David Borba Manana <fdman...@gmail.com> --- fs/btrfs/send.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++--- fs/btrfs/send.h | 4 ++++ 2 files changed, 55 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 7b184831812b..328c7a2857ae 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -581,6 +581,7 @@ static int tlv_put(struct send_ctx *sctx, u16 attr, const void *data, int len) return tlv_put(sctx, attr, &__tmp, sizeof(__tmp)); \ } +TLV_PUT_DEFINE_INT(32) TLV_PUT_DEFINE_INT(64) static int tlv_put_string(struct send_ctx *sctx, u16 attr, @@ -5047,17 +5048,57 @@ static int send_update_extent(struct send_ctx *sctx, return ret; } +static int send_fallocate(struct send_ctx *sctx, u32 flags, + u64 offset, u64 len) +{ + struct fs_path *p = NULL; + int ret = 0; + + ASSERT(sctx->flags & BTRFS_SEND_FLAG_STREAM_V2); + + if (sctx->phase == SEND_PHASE_COMPUTE_DATA_SIZE) { + sctx->total_data_size += len; + return 0; + } + + p = fs_path_alloc(); + if (!p) + return -ENOMEM; + ret = get_cur_path(sctx, sctx->cur_ino, sctx->cur_inode_gen, p); + if (ret < 0) + goto out; + + ret = begin_cmd(sctx, BTRFS_SEND_C_FALLOCATE); + if (ret < 0) + goto out; + TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); + TLV_PUT_U32(sctx, BTRFS_SEND_A_FALLOCATE_FLAGS, flags); + TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset); + TLV_PUT_U64(sctx, BTRFS_SEND_A_SIZE, len); + ret = send_cmd(sctx); + +tlv_put_failure: +out: + fs_path_free(p); + return ret; +} + + static int send_hole(struct send_ctx *sctx, u64 end) { struct fs_path *p = NULL; u64 offset = sctx->cur_inode_last_extent; - u64 len; + u64 len = end - offset; int ret = 0; if (sctx->phase == SEND_PHASE_COMPUTE_DATA_SIZE) { - sctx->total_data_size += end - offset; + sctx->total_data_size += len; return 0; } + if (sctx->flags & BTRFS_SEND_FLAG_STREAM_V2) + return send_fallocate(sctx, BTRFS_SEND_PUNCH_HOLE_FALLOC_FLAGS, + offset, len); + if (sctx->flags & BTRFS_SEND_FLAG_NO_FILE_DATA) return send_update_extent(sctx, offset, end - offset); @@ -5304,7 +5345,8 @@ static int send_write_or_clone(struct send_ctx *sctx, ret = 0; goto out; } - if (offset + len > sctx->cur_inode_size) + if (offset < sctx->cur_inode_size && + offset + len > sctx->cur_inode_size) len = sctx->cur_inode_size - offset; if (len == 0) { ret = 0; @@ -5325,6 +5367,12 @@ static int send_write_or_clone(struct send_ctx *sctx, data_offset = btrfs_file_extent_offset(path->nodes[0], ei); ret = clone_range(sctx, clone_root, disk_byte, data_offset, offset, len); + } else if (btrfs_file_extent_disk_bytenr(path->nodes[0], ei) == 0 && + type != BTRFS_FILE_EXTENT_INLINE && + (sctx->flags & BTRFS_SEND_FLAG_STREAM_V2) && + offset < sctx->cur_inode_size) { + ret = send_fallocate(sctx, BTRFS_SEND_PUNCH_HOLE_FALLOC_FLAGS, + offset, len); } else { ret = send_extent_data(sctx, offset, len); } diff --git a/fs/btrfs/send.h b/fs/btrfs/send.h index a9b5489d690e..a5830d216ac1 100644 --- a/fs/btrfs/send.h +++ b/fs/btrfs/send.h @@ -138,6 +138,10 @@ enum { #define BTRFS_SEND_A_FALLOCATE_FLAG_KEEP_SIZE (1 << 0) #define BTRFS_SEND_A_FALLOCATE_FLAG_PUNCH_HOLE (1 << 1) +#define BTRFS_SEND_PUNCH_HOLE_FALLOC_FLAGS \ + (BTRFS_SEND_A_FALLOCATE_FLAG_KEEP_SIZE | \ + BTRFS_SEND_A_FALLOCATE_FLAG_PUNCH_HOLE) + #ifdef __KERNEL__ long btrfs_ioctl_send(struct file *mnt_file, struct btrfs_ioctl_send_args *arg); #endif -- 2.17.0 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html