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 <fdmanana@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/send.c b/fs/btrfs/send.c
index 7c7c09f..8af5e86 100644
--- a/fs/btrfs/send.c
+++ b/fs/btrfs/send.c
@@ -4794,7 +4794,7 @@ static int process_all_new_xattrs(struct send_ctx *sctx)
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;
}