From: Omar Sandoval <osandov@osandov.com>
To: linux-btrfs@vger.kernel.org
Cc: linux-fsdevel@vger.kernel.org
Subject: [PATCH 02/11] btrfs-progs: receive: dynamically allocate sctx->read_buf
Date: Fri, 21 Aug 2020 00:40:01 -0700 [thread overview]
Message-ID: <6e4ecaf9b4182ef9f1e3a18ad32c089d82f4d64c.1597994354.git.osandov@osandov.com> (raw)
In-Reply-To: <cover.1597994106.git.osandov@osandov.com>
From: Boris Burkov <boris@bur.io>
In send stream v2, write commands can now be an arbitrary size. For that
reason, we can no longer allocate a fixed array in sctx for read_cmd.
Instead, read_cmd dynamically allocates sctx->read_buf. To avoid
needless reallocations, we reuse read_buf between read_cmd calls by also
keeping track of the size of the allocated buffer in sctx->read_buf_sz.
We do the first allocation of the old default size at the start of
processing the stream, and we only reallocate if we encounter a command
that needs a larger buffer.
Signed-off-by: Boris Burkov <boris@bur.io>
---
common/send-stream.c | 55 ++++++++++++++++++++++++++++----------------
send.h | 2 +-
2 files changed, 36 insertions(+), 21 deletions(-)
diff --git a/common/send-stream.c b/common/send-stream.c
index 3bd21d3f..51a6a94a 100644
--- a/common/send-stream.c
+++ b/common/send-stream.c
@@ -36,10 +36,10 @@ struct btrfs_send_attribute {
struct btrfs_send_stream {
int fd;
- char read_buf[BTRFS_SEND_BUF_SIZE];
+ char *read_buf;
+ size_t read_buf_sz;
int cmd;
- struct btrfs_cmd_header *cmd_hdr;
struct btrfs_send_attribute cmd_attrs[BTRFS_SEND_A_MAX + 1];
u32 version;
@@ -111,11 +111,12 @@ static int read_cmd(struct btrfs_send_stream *sctx)
u32 pos;
u32 crc;
u32 crc2;
+ struct btrfs_cmd_header *cmd_hdr;
+ size_t buf_len;
memset(sctx->cmd_attrs, 0, sizeof(sctx->cmd_attrs));
- ASSERT(sizeof(*sctx->cmd_hdr) <= sizeof(sctx->read_buf));
- ret = read_buf(sctx, sctx->read_buf, sizeof(*sctx->cmd_hdr));
+ ret = read_buf(sctx, sctx->read_buf, sizeof(*cmd_hdr));
if (ret < 0)
goto out;
if (ret) {
@@ -124,18 +125,22 @@ static int read_cmd(struct btrfs_send_stream *sctx)
goto out;
}
- sctx->cmd_hdr = (struct btrfs_cmd_header *)sctx->read_buf;
- cmd = le16_to_cpu(sctx->cmd_hdr->cmd);
- cmd_len = le32_to_cpu(sctx->cmd_hdr->len);
-
- if (cmd_len + sizeof(*sctx->cmd_hdr) >= sizeof(sctx->read_buf)) {
- ret = -EINVAL;
- error("command length %u too big for buffer %zu",
- cmd_len, sizeof(sctx->read_buf));
- goto out;
+ cmd_hdr = (struct btrfs_cmd_header *)sctx->read_buf;
+ cmd_len = le32_to_cpu(cmd_hdr->len);
+ cmd = le16_to_cpu(cmd_hdr->cmd);
+ buf_len = sizeof(*cmd_hdr) + cmd_len;
+ if (sctx->read_buf_sz < buf_len) {
+ sctx->read_buf = realloc(sctx->read_buf, buf_len);
+ if (!sctx->read_buf) {
+ ret = -ENOMEM;
+ error("failed to reallocate read buffer for cmd");
+ goto out;
+ }
+ sctx->read_buf_sz = buf_len;
+ /* We need to reset cmd_hdr after realloc of sctx->read_buf */
+ cmd_hdr = (struct btrfs_cmd_header *)sctx->read_buf;
}
-
- data = sctx->read_buf + sizeof(*sctx->cmd_hdr);
+ data = sctx->read_buf + sizeof(*cmd_hdr);
ret = read_buf(sctx, data, cmd_len);
if (ret < 0)
goto out;
@@ -145,11 +150,12 @@ static int read_cmd(struct btrfs_send_stream *sctx)
goto out;
}
- crc = le32_to_cpu(sctx->cmd_hdr->crc);
- sctx->cmd_hdr->crc = 0;
+ crc = le32_to_cpu(cmd_hdr->crc);
+ /* in send, crc is computed with header crc = 0, replicate that */
+ cmd_hdr->crc = 0;
crc2 = crc32c(0, (unsigned char*)sctx->read_buf,
- sizeof(*sctx->cmd_hdr) + cmd_len);
+ sizeof(*cmd_hdr) + cmd_len);
if (crc != crc2) {
ret = -EINVAL;
@@ -524,19 +530,28 @@ int btrfs_read_and_process_send_stream(int fd,
goto out;
}
+ sctx.read_buf = malloc(BTRFS_SEND_BUF_SIZE_V1);
+ if (!sctx.read_buf) {
+ ret = -ENOMEM;
+ error("unable to allocate send stream read buffer");
+ goto out;
+ }
+ sctx.read_buf_sz = BTRFS_SEND_BUF_SIZE_V1;
+
while (1) {
ret = read_and_process_cmd(&sctx);
if (ret < 0) {
last_err = ret;
errors++;
if (max_errors > 0 && errors >= max_errors)
- goto out;
+ break;
} else if (ret > 0) {
if (!honor_end_cmd)
ret = 0;
- goto out;
+ break;
}
}
+ free(sctx.read_buf);
out:
if (last_err && !ret)
diff --git a/send.h b/send.h
index 8dd865ec..228928a0 100644
--- a/send.h
+++ b/send.h
@@ -33,7 +33,7 @@ extern "C" {
#define BTRFS_SEND_STREAM_MAGIC "btrfs-stream"
#define BTRFS_SEND_STREAM_VERSION 1
-#define BTRFS_SEND_BUF_SIZE SZ_64K
+#define BTRFS_SEND_BUF_SIZE_V1 SZ_64K
#define BTRFS_SEND_READ_SIZE (1024 * 48)
enum btrfs_tlv_type {
--
2.28.0
next prev parent reply other threads:[~2020-08-21 7:41 UTC|newest]
Thread overview: 37+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-08-21 7:39 [PATCH 0/9] btrfs: implement send/receive of compressed extents without decompressing Omar Sandoval
2020-08-21 7:39 ` [PATCH 1/9] btrfs: send: get rid of i_size logic in send_write() Omar Sandoval
2020-08-21 17:26 ` Filipe Manana
2020-08-24 17:39 ` Josef Bacik
2020-08-21 7:39 ` [PATCH 2/9] btrfs: send: avoid copying file data Omar Sandoval
2020-08-21 17:29 ` Filipe Manana
2020-08-24 21:34 ` Omar Sandoval
2020-08-24 17:47 ` Josef Bacik
2020-09-11 14:13 ` David Sterba
2020-09-14 22:04 ` Omar Sandoval
2020-09-15 8:14 ` David Sterba
2020-08-21 7:39 ` [PATCH 3/9] btrfs: send: use btrfs_file_extent_end() in send_write_or_clone() Omar Sandoval
2020-08-21 17:30 ` Filipe Manana
2020-08-21 7:39 ` [PATCH 4/9] btrfs: add send_stream_version attribute to sysfs Omar Sandoval
2020-08-21 7:39 ` [PATCH 5/9] btrfs: add send stream v2 definitions Omar Sandoval
2020-08-24 17:49 ` Josef Bacik
2020-08-21 7:39 ` [PATCH 6/9] btrfs: send: write larger chunks when using stream v2 Omar Sandoval
2020-08-24 17:57 ` Josef Bacik
2020-08-21 7:39 ` [PATCH 7/9] btrfs: send: allocate send buffer with alloc_page() and vmap() for v2 Omar Sandoval
2020-08-21 7:39 ` [PATCH 8/9] btrfs: send: send compressed extents with encoded writes Omar Sandoval
2020-08-24 17:32 ` Josef Bacik
2020-08-24 17:52 ` Omar Sandoval
2020-08-21 7:39 ` [PATCH 9/9] btrfs: send: enable support for stream v2 and compressed writes Omar Sandoval
2020-08-21 7:40 ` [PATCH 01/11] btrfs-progs: receive: support v2 send stream larger tlv_len Omar Sandoval
2020-08-21 7:40 ` Omar Sandoval [this message]
2020-08-21 7:40 ` [PATCH 03/11] btrfs-progs: receive: support v2 send stream DATA tlv format Omar Sandoval
2020-08-21 7:40 ` [PATCH 04/11] btrfs-progs: receive: add send stream v2 cmds and attrs to send.h Omar Sandoval
2020-08-21 7:40 ` [PATCH 05/11] btrfs-progs: receive: add stub implementation for pwritev2 Omar Sandoval
2020-08-21 7:40 ` [PATCH 06/11] btrfs-progs: receive: process encoded_write commands Omar Sandoval
2020-08-21 7:40 ` [PATCH 07/11] btrfs-progs: receive: encoded_write fallback to explicit decode and write Omar Sandoval
2020-08-21 7:40 ` [PATCH 08/11] btrfs-progs: receive: process fallocate commands Omar Sandoval
2020-08-21 7:40 ` [PATCH 09/11] btrfs-progs: receive: process setflags ioctl commands Omar Sandoval
2020-08-21 7:40 ` [PATCH 10/11] btrfs-progs: send: stream v2 ioctl flags Omar Sandoval
2020-08-21 7:40 ` [PATCH 11/11] btrfs-progs: receive: add tests for basic encoded_write send/receive Omar Sandoval
2020-08-24 19:57 ` [PATCH 0/9] btrfs: implement send/receive of compressed extents without decompressing David Sterba
2020-08-24 22:16 ` Omar Sandoval
2020-09-10 11:28 ` David Sterba
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