From a9b2e0de92cbed84b9bca1464babaf1d67a5542b Mon Sep 17 00:00:00 2001 From: Omar Sandoval Date: Fri, 21 Aug 2020 00:39:51 -0700 Subject: btrfs: send: get rid of i_size logic in send_write() send_write()/fill_read_buf() have some logic for avoiding reading past i_size. However, everywhere that we call send_write()/send_extent_data(), we've already clamped the length down to i_size. Get rid of the i_size handling, which simplifies the next change. Reviewed-by: Filipe Manana Reviewed-by: Josef Bacik Signed-off-by: Omar Sandoval Signed-off-by: David Sterba --- fs/btrfs/send.c | 37 ++++++++++--------------------------- 1 file changed, 10 insertions(+), 27 deletions(-) diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c index 7c7c09fc65e8..8af5e867e4ca 100644 --- a/fs/btrfs/send.c +++ b/fs/btrfs/send.c @@ -4794,7 +4794,7 @@ out: return ret; } -static ssize_t fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len) +static int fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len) { struct btrfs_root *root = sctx->send_root; struct btrfs_fs_info *fs_info = root->fs_info; @@ -4804,21 +4804,13 @@ static ssize_t fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len) pgoff_t index = offset >> PAGE_SHIFT; pgoff_t last_index; unsigned pg_offset = offset_in_page(offset); - ssize_t ret = 0; + int ret = 0; + size_t read = 0; inode = btrfs_iget(fs_info->sb, sctx->cur_ino, root); if (IS_ERR(inode)) return PTR_ERR(inode); - if (offset + len > i_size_read(inode)) { - if (offset > i_size_read(inode)) - len = 0; - else - len = offset - i_size_read(inode); - } - if (len == 0) - goto out; - last_index = (offset + len - 1) >> PAGE_SHIFT; /* initial readahead */ @@ -4859,16 +4851,15 @@ static ssize_t fill_read_buf(struct send_ctx *sctx, u64 offset, u32 len) } addr = kmap(page); - memcpy(sctx->read_buf + ret, addr + pg_offset, cur_len); + memcpy(sctx->read_buf + read, addr + pg_offset, cur_len); kunmap(page); unlock_page(page); put_page(page); index++; pg_offset = 0; len -= cur_len; - ret += cur_len; + read += cur_len; } -out: iput(inode); return ret; } @@ -4882,7 +4873,6 @@ static int send_write(struct send_ctx *sctx, u64 offset, u32 len) struct btrfs_fs_info *fs_info = sctx->send_root->fs_info; int ret = 0; struct fs_path *p; - ssize_t num_read = 0; p = fs_path_alloc(); if (!p) @@ -4890,12 +4880,9 @@ static int send_write(struct send_ctx *sctx, u64 offset, u32 len) btrfs_debug(fs_info, "send_write offset=%llu, len=%d", offset, len); - num_read = fill_read_buf(sctx, offset, len); - if (num_read <= 0) { - if (num_read < 0) - ret = num_read; + ret = fill_read_buf(sctx, offset, len); + if (ret < 0) goto out; - } ret = begin_cmd(sctx, BTRFS_SEND_C_WRITE); if (ret < 0) @@ -4907,16 +4894,14 @@ static int send_write(struct send_ctx *sctx, u64 offset, u32 len) TLV_PUT_PATH(sctx, BTRFS_SEND_A_PATH, p); TLV_PUT_U64(sctx, BTRFS_SEND_A_FILE_OFFSET, offset); - TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, num_read); + TLV_PUT(sctx, BTRFS_SEND_A_DATA, sctx->read_buf, len); ret = send_cmd(sctx); tlv_put_failure: out: fs_path_free(p); - if (ret < 0) - return ret; - return num_read; + return ret; } /* @@ -5095,9 +5080,7 @@ static int send_extent_data(struct send_ctx *sctx, ret = send_write(sctx, offset + sent, size); if (ret < 0) return ret; - if (!ret) - break; - sent += ret; + sent += size; } return 0; } -- cgit v1.2.3