[Tarantool-patches] [PATCH] fio/coio: handle partial writes
Cyrill Gorcunov
gorcunov at gmail.com
Wed Apr 22 00:39:30 MSK 2020
Writting less bytes than requested is perfectly fine.
In turn our fio.write/pwrite api simply returns 'true'
even if only some part of a buffer has been written.
Thus make coio_write and coio_pwrite to write the
whole data in a cycle. Note in most situations there
will be only one pass, partial writes are really the
rare cases.
Fixes #4651
Signed-off-by: Cyrill Gorcunov <gorcunov at gmail.com>
---
issue https://github.com/tarantool/tarantool/issues/4651
branch gorcunov/gh-4651-partial-write
src/lib/core/coio_file.c | 62 ++++++++++++++++++++++++++++------
src/lib/core/errinj.h | 1 +
test/app/fio.result | 73 ++++++++++++++++++++++++++++++++++++++++
test/app/fio.test.lua | 21 ++++++++++++
test/box/errinj.result | 1 +
5 files changed, 147 insertions(+), 11 deletions(-)
diff --git a/src/lib/core/coio_file.c b/src/lib/core/coio_file.c
index e2345567c..e290214bc 100644
--- a/src/lib/core/coio_file.c
+++ b/src/lib/core/coio_file.c
@@ -164,10 +164,30 @@ coio_file_close(int fd)
ssize_t
coio_pwrite(int fd, const void *buf, size_t count, off_t offset)
{
- INIT_COEIO_FILE(eio);
- eio_req *req = eio_write(fd, (void *) buf, count, offset,
- 0, coio_complete, &eio);
- return coio_wait_done(req, &eio);
+ ssize_t left = count, pos = 0, res, chunk;
+ eio_req *req;
+
+ while (left > 0) {
+ INIT_COEIO_FILE(eio);
+ chunk = left;
+
+ ERROR_INJECT(ERRINJ_COIO_WRITE_CHUNK, {
+ chunk = 1;
+ });
+
+ req = eio_write(fd, (void *)buf + pos, chunk,
+ offset + pos, EIO_PRI_DEFAULT,
+ coio_complete, &eio);
+ res = coio_wait_done(req, &eio);
+ if (res < 0) {
+ pos = -1;
+ break;
+ } else {
+ left -= res;
+ pos += res;
+ }
+ }
+ return pos;
}
ssize_t
@@ -201,6 +221,11 @@ static void
coio_do_write(eio_req *req)
{
struct coio_file_task *eio = (struct coio_file_task *)req->data;
+
+ ERROR_INJECT(ERRINJ_COIO_WRITE_CHUNK, {
+ eio->write.count = 1;
+ });
+
req->result = write(eio->write.fd, eio->write.buf, eio->write.count);
eio->errorno = errno;
}
@@ -208,13 +233,28 @@ coio_do_write(eio_req *req)
ssize_t
coio_write(int fd, const void *buf, size_t count)
{
- INIT_COEIO_FILE(eio);
- eio.write.buf = buf;
- eio.write.count = count;
- eio.write.fd = fd;
- eio_req *req = eio_custom(coio_do_write, 0,
- coio_complete, &eio);
- return coio_wait_done(req, &eio);
+ ssize_t left = count, pos = 0, res;
+ eio_req *req;
+
+ while (left > 0) {
+ INIT_COEIO_FILE(eio);
+
+ eio.write.buf = buf + pos;
+ eio.write.count = left;
+ eio.write.fd = fd;
+
+ req = eio_custom(coio_do_write, EIO_PRI_DEFAULT,
+ coio_complete, &eio);
+ res = coio_wait_done(req, &eio);
+ if (res < 0) {
+ pos = -1;
+ break;
+ } else {
+ left -= res;
+ pos += res;
+ }
+ }
+ return pos;
}
static void
diff --git a/src/lib/core/errinj.h b/src/lib/core/errinj.h
index 7577ed11a..e95611c1e 100644
--- a/src/lib/core/errinj.h
+++ b/src/lib/core/errinj.h
@@ -140,6 +140,7 @@ struct errinj {
_(ERRINJ_RELAY_FASTER_THAN_TX, ERRINJ_BOOL, {.bparam = false}) \
_(ERRINJ_INDEX_RESERVE, ERRINJ_BOOL, {.bparam = false})\
_(ERRINJ_TXN_COMMIT_ASYNC, ERRINJ_BOOL, {.bparam = false})\
+ _(ERRINJ_COIO_WRITE_CHUNK, ERRINJ_BOOL, {.bparam = false}) \
ENUM0(errinj_id, ERRINJ_LIST);
extern struct errinj errinjs[];
diff --git a/test/app/fio.result b/test/app/fio.result
index 783fa4fab..73fbd29e5 100644
--- a/test/app/fio.result
+++ b/test/app/fio.result
@@ -776,6 +776,12 @@ file5 = fio.pathjoin(tree, 'file.5')
file6 = fio.pathjoin(tree, 'file.6')
---
...
+file7 = fio.pathjoin(tree, 'file.7')
+---
+...
+file8 = fio.pathjoin(tree, 'file.8')
+---
+...
fh1 = fio.open(file1, { 'O_RDWR', 'O_TRUNC', 'O_CREAT' }, tonumber('0777', 8))
---
...
@@ -865,6 +871,73 @@ fh6:close()
---
- true
...
+-- test partial write/pwrite via one byte transfer
+fh7 = fio.open(file7, { 'O_RDWR', 'O_TRUNC', 'O_CREAT' }, tonumber('0644', 8))
+---
+...
+errinj.set('ERRINJ_COIO_WRITE_CHUNK', true)
+---
+- ok
+...
+fh7:write("one byte transfer, write")
+---
+- true
+...
+errinj.set('ERRINJ_COIO_WRITE_CHUNK', false)
+---
+- ok
+...
+fh7:seek(0)
+---
+- 0
+...
+fh7:read()
+---
+- one byte transfer, write
+...
+fh7:close()
+---
+- true
+...
+fh8 = fio.open(file8, { 'O_RDWR', 'O_TRUNC', 'O_CREAT' }, tonumber('0644', 8))
+---
+...
+errinj.set('ERRINJ_COIO_WRITE_CHUNK', true)
+---
+- ok
+...
+fh8:pwrite("one byte transfer, ", 0)
+---
+- true
+...
+fh8:seek(0)
+---
+- 0
+...
+fh8:read()
+---
+- 'one byte transfer, '
+...
+fh8:pwrite("pwrite", 19)
+---
+- true
+...
+errinj.set('ERRINJ_COIO_WRITE_CHUNK', false)
+---
+- ok
+...
+fh8:seek(0)
+---
+- 0
+...
+fh8:read()
+---
+- one byte transfer, pwrite
+...
+fh8:close()
+---
+- true
+...
res, err = fio.copyfile(fio.pathjoin(tmp1, 'not_exists.txt'), tmp1)
---
...
diff --git a/test/app/fio.test.lua b/test/app/fio.test.lua
index 6825b882f..733e0f25f 100644
--- a/test/app/fio.test.lua
+++ b/test/app/fio.test.lua
@@ -251,6 +251,8 @@ file3 = fio.pathjoin(tree, 'file.3')
file4 = fio.pathjoin(tree, 'file.4')
file5 = fio.pathjoin(tree, 'file.5')
file6 = fio.pathjoin(tree, 'file.6')
+file7 = fio.pathjoin(tree, 'file.7')
+file8 = fio.pathjoin(tree, 'file.8')
fh1 = fio.open(file1, { 'O_RDWR', 'O_TRUNC', 'O_CREAT' }, tonumber('0777', 8))
fh1:write("gogo")
@@ -280,6 +282,25 @@ fh6:seek(0)
fh6:read()
fh6:close()
+-- test partial write/pwrite via one byte transfer
+fh7 = fio.open(file7, { 'O_RDWR', 'O_TRUNC', 'O_CREAT' }, tonumber('0644', 8))
+errinj.set('ERRINJ_COIO_WRITE_CHUNK', true)
+fh7:write("one byte transfer, write")
+errinj.set('ERRINJ_COIO_WRITE_CHUNK', false)
+fh7:seek(0)
+fh7:read()
+fh7:close()
+fh8 = fio.open(file8, { 'O_RDWR', 'O_TRUNC', 'O_CREAT' }, tonumber('0644', 8))
+errinj.set('ERRINJ_COIO_WRITE_CHUNK', true)
+fh8:pwrite("one byte transfer, ", 0)
+fh8:seek(0)
+fh8:read()
+fh8:pwrite("pwrite", 19)
+errinj.set('ERRINJ_COIO_WRITE_CHUNK', false)
+fh8:seek(0)
+fh8:read()
+fh8:close()
+
res, err = fio.copyfile(fio.pathjoin(tmp1, 'not_exists.txt'), tmp1)
res
err:match("failed to copy") ~= nil
diff --git a/test/box/errinj.result b/test/box/errinj.result
index de877b708..6b4892500 100644
--- a/test/box/errinj.result
+++ b/test/box/errinj.result
@@ -47,6 +47,7 @@ evals
- ERRINJ_BUILD_INDEX_DELAY: false
- ERRINJ_CHECK_FORMAT_DELAY: false
- ERRINJ_COIO_SENDFILE_CHUNK: -1
+ - ERRINJ_COIO_WRITE_CHUNK: false
- ERRINJ_DYN_MODULE_COUNT: 0
- ERRINJ_FIBER_MADVISE: false
- ERRINJ_FIBER_MPROTECT: -1
--
2.20.1
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