[ovs-dev] [PATCH 10/14] ovsdb: Allow ovsdb_log_open()'s caller to choose whether to lock.
Ben Pfaff
blp at nicira.com
Fri Feb 12 19:37:30 UTC 2010
The current callers of ovsdb_log_open() always want to log the file if
they are accessing it for read/write access. An upcoming commit will add
a new caller that does not fit this model (it wants to lock the file
across a wider region) and so the caller should be able to choose whether
to do locking. This commit adds that ability.
Also, get rid of the use of <fcntl.h> flags to choose the open mode, which
has always seemed somewhat crude and which this change would make even
cruder.
---
ovsdb/file.c | 4 ++-
ovsdb/log.c | 35 +++++++++++++++++++++++-------
ovsdb/log.h | 14 +++++++++--
ovsdb/ovsdb-tool.c | 7 +++--
tests/ovsdb-log.at | 60 ++++++++++++++++++++++++++--------------------------
tests/test-ovsdb.c | 32 +++++++++------------------
6 files changed, 86 insertions(+), 66 deletions(-)
diff --git a/ovsdb/file.c b/ovsdb/file.c
index 31086af..3e07b84 100644
--- a/ovsdb/file.c
+++ b/ovsdb/file.c
@@ -43,13 +43,15 @@ static void ovsdb_file_replica_create(struct ovsdb *, struct ovsdb_log *);
struct ovsdb_error *
ovsdb_file_open(const char *file_name, bool read_only, struct ovsdb **dbp)
{
+ enum ovsdb_log_open_mode open_mode;
struct ovsdb_schema *schema;
struct ovsdb_error *error;
struct ovsdb_log *log;
struct json *json;
struct ovsdb *db;
- error = ovsdb_log_open(file_name, read_only ? O_RDONLY : O_RDWR, &log);
+ open_mode = read_only ? OVSDB_LOG_READ_ONLY : OVSDB_LOG_READ_WRITE;
+ error = ovsdb_log_open(file_name, open_mode, -1, &log);
if (error) {
return error;
}
diff --git a/ovsdb/log.c b/ovsdb/log.c
index 837f215..6d07aca 100644
--- a/ovsdb/log.c
+++ b/ovsdb/log.c
@@ -50,21 +50,33 @@ struct ovsdb_log {
enum ovsdb_log_mode mode;
};
+/* Attempts to open 'name' with the specified 'open_mode'. On success, stores
+ * the new log into '*filep' and returns NULL; otherwise returns NULL and
+ * stores NULL into '*filep'.
+ *
+ * Whether the file will be locked using lockfile_lock() depends on 'locking':
+ * use true to lock it, false not to lock it, or -1 to lock it only if
+ * 'open_mode' is a mode that allows writing.
+ */
struct ovsdb_error *
-ovsdb_log_open(const char *name, int flags, struct ovsdb_log **filep)
+ovsdb_log_open(const char *name, enum ovsdb_log_open_mode open_mode,
+ int locking, struct ovsdb_log **filep)
{
struct lockfile *lockfile;
struct ovsdb_error *error;
struct ovsdb_log *file;
struct stat s;
FILE *stream;
- int accmode;
+ int flags;
int fd;
*filep = NULL;
- accmode = flags & O_ACCMODE;
- if (accmode == O_RDWR || accmode == O_WRONLY) {
+ assert(locking == -1 || locking == false || locking == true);
+ if (locking < 0) {
+ locking = open_mode != OVSDB_LOG_READ_ONLY;
+ }
+ if (locking) {
int retval = lockfile_lock(name, 0, &lockfile);
if (retval) {
error = ovsdb_io_error(retval, "%s: failed to lock lockfile",
@@ -75,9 +87,18 @@ ovsdb_log_open(const char *name, int flags, struct ovsdb_log **filep)
lockfile = NULL;
}
+ if (open_mode == OVSDB_LOG_READ_ONLY) {
+ flags = O_RDONLY;
+ } else if (open_mode == OVSDB_LOG_READ_WRITE) {
+ flags = O_RDWR;
+ } else if (open_mode == OVSDB_LOG_CREATE) {
+ flags = O_RDWR | O_CREAT | O_EXCL;
+ } else {
+ NOT_REACHED();
+ }
fd = open(name, flags, 0666);
if (fd < 0) {
- const char *op = flags & O_CREAT && flags & O_EXCL ? "create" : "open";
+ const char *op = open_mode == OVSDB_LOG_CREATE ? "create" : "open";
error = ovsdb_io_error(errno, "%s: %s failed", op, name);
goto error_unlock;
}
@@ -98,9 +119,7 @@ ovsdb_log_open(const char *name, int flags, struct ovsdb_log **filep)
free(dir);
}
- stream = fdopen(fd, (accmode == O_RDONLY ? "rb"
- : accmode == O_WRONLY ? "wb"
- : "w+b"));
+ stream = fdopen(fd, open_mode == OVSDB_LOG_READ_ONLY ? "rb" : "w+b");
if (!stream) {
error = ovsdb_io_error(errno, "%s: fdopen failed", name);
goto error_close;
diff --git a/ovsdb/log.h b/ovsdb/log.h
index 2daa635..045740b 100644
--- a/ovsdb/log.h
+++ b/ovsdb/log.h
@@ -1,4 +1,4 @@
-/* Copyright (c) 2009 Nicira Networks
+/* Copyright (c) 2009, 2010 Nicira Networks
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
@@ -22,8 +22,16 @@
struct json;
struct ovsdb_log;
-struct ovsdb_error *ovsdb_log_open(const char *name, int flags,
- struct ovsdb_log **) WARN_UNUSED_RESULT;
+/* Access mode for opening an OVSDB log. */
+enum ovsdb_log_open_mode {
+ OVSDB_LOG_READ_ONLY, /* Open existing file, read-only. */
+ OVSDB_LOG_READ_WRITE, /* Open existing file, read/write. */
+ OVSDB_LOG_CREATE /* Create new file, read/write. */
+};
+
+struct ovsdb_error *ovsdb_log_open(const char *name, enum ovsdb_log_open_mode,
+ int locking, struct ovsdb_log **)
+ WARN_UNUSED_RESULT;
void ovsdb_log_close(struct ovsdb_log *);
struct ovsdb_error *ovsdb_log_read(struct ovsdb_log *, struct json **)
diff --git a/ovsdb/ovsdb-tool.c b/ovsdb/ovsdb-tool.c
index 34c7676..f419fb8 100644
--- a/ovsdb/ovsdb-tool.c
+++ b/ovsdb/ovsdb-tool.c
@@ -164,8 +164,8 @@ do_create(int argc OVS_UNUSED, char *argv[])
ovsdb_schema_destroy(schema);
/* Create database file. */
- check_ovsdb_error(ovsdb_log_open(db_file_name, O_RDWR | O_CREAT | O_EXCL,
- &log));
+ check_ovsdb_error(ovsdb_log_open(db_file_name, OVSDB_LOG_CREATE,
+ -1, &log));
check_ovsdb_error(ovsdb_log_write(log, json));
check_ovsdb_error(ovsdb_log_commit(log));
ovsdb_log_close(log);
@@ -288,7 +288,8 @@ do_show_log(int argc OVS_UNUSED, char *argv[])
struct ovsdb_log *log;
unsigned int i;
- check_ovsdb_error(ovsdb_log_open(db_file_name, O_RDONLY, &log));
+ check_ovsdb_error(ovsdb_log_open(db_file_name, OVSDB_LOG_READ_ONLY,
+ -1, &log));
shash_init(&names);
for (i = 0; ; i++) {
struct json *json;
diff --git a/tests/ovsdb-log.at b/tests/ovsdb-log.at
index 8aeb33b..507ef8e 100644
--- a/tests/ovsdb-log.at
+++ b/tests/ovsdb-log.at
@@ -4,11 +4,11 @@ AT_SETUP([create empty, reread])
AT_KEYWORDS([ovsdb log])
AT_CAPTURE_FILE([log])
AT_CHECK(
- [test-ovsdb log-io file 'O_CREAT|O_RDWR'], [0],
+ [test-ovsdb log-io file create], [0],
[file: open successful
], [ignore])
AT_CHECK(
- [test-ovsdb log-io file 'O_RDONLY' read], [0],
+ [test-ovsdb log-io file read-only read], [0],
[file: open successful
file: read: end of log
], [ignore])
@@ -19,12 +19,12 @@ AT_SETUP([write one, reread])
AT_KEYWORDS([ovsdb log])
AT_CAPTURE_FILE([file])
AT_CHECK(
- [[test-ovsdb log-io file 'O_CREAT|O_RDWR' 'write:[0]']], [0],
+ [[test-ovsdb log-io file create 'write:[0]']], [0],
[[file: open successful
file: write:[0] successful
]], [ignore])
AT_CHECK(
- [test-ovsdb log-io file 'O_RDONLY' read read], [0],
+ [test-ovsdb log-io file read-only read read], [0],
[[file: open successful
file: read: [0]
file: read: end of log
@@ -32,21 +32,21 @@ file: read: end of log
AT_CHECK([test -f .file.~lock~])
AT_CLEANUP
-AT_SETUP([check that O_EXCL works])
+AT_SETUP([check that create fails if file exists])
AT_KEYWORDS([ovsdb log])
AT_CAPTURE_FILE([file])
AT_CHECK(
- [[test-ovsdb log-io file 'O_CREAT|O_RDWR' 'write:[1]']], [0],
+ [[test-ovsdb log-io file create 'write:[1]']], [0],
[[file: open successful
file: write:[1] successful
]], [ignore])
AT_CHECK(
- [test-ovsdb log-io file 'O_RDONLY' read], [0],
+ [test-ovsdb log-io file read-only read], [0],
[[file: open successful
file: read: [1]
]], [ignore])
AT_CHECK(
- [test-ovsdb -vlockfile:console:emer log-io file 'O_CREAT|O_RDWR|O_EXCL' read], [1],
+ [test-ovsdb -vlockfile:console:emer log-io file create read], [1],
[], [test-ovsdb: I/O error: create: file failed (File exists)
])
AT_CHECK([test -f .file.~lock~])
@@ -56,14 +56,14 @@ AT_SETUP([write one, reread])
AT_KEYWORDS([ovsdb log])
AT_CAPTURE_FILE([file])
AT_CHECK(
- [[test-ovsdb log-io file 'O_CREAT|O_RDWR' 'write:[0]' 'write:[1]' 'write:[2]']], [0],
+ [[test-ovsdb log-io file create 'write:[0]' 'write:[1]' 'write:[2]']], [0],
[[file: open successful
file: write:[0] successful
file: write:[1] successful
file: write:[2] successful
]], [ignore])
AT_CHECK(
- [test-ovsdb log-io file 'O_RDONLY' read read read read], [0],
+ [test-ovsdb log-io file read-only read read read read], [0],
[[file: open successful
file: read: [0]
file: read: [1]
@@ -77,14 +77,14 @@ AT_SETUP([write one, reread, append])
AT_KEYWORDS([ovsdb log])
AT_CAPTURE_FILE([file])
AT_CHECK(
- [[test-ovsdb log-io file 'O_CREAT|O_RDWR' 'write:[0]' 'write:[1]' 'write:[2]']], [0],
+ [[test-ovsdb log-io file create 'write:[0]' 'write:[1]' 'write:[2]']], [0],
[[file: open successful
file: write:[0] successful
file: write:[1] successful
file: write:[2] successful
]], [ignore])
AT_CHECK(
- [[test-ovsdb log-io file 'O_RDWR' read read read 'write:["append"]']], [0],
+ [[test-ovsdb log-io file read/write read read read 'write:["append"]']], [0],
[[file: open successful
file: read: [0]
file: read: [1]
@@ -92,7 +92,7 @@ file: read: [2]
file: write:["append"] successful
]], [ignore])
AT_CHECK(
- [test-ovsdb log-io file 'O_RDONLY' read read read read read], [0],
+ [test-ovsdb log-io file read-only read read read read read], [0],
[[file: open successful
file: read: [0]
file: read: [1]
@@ -107,20 +107,20 @@ AT_SETUP([write, reread one, overwrite])
AT_KEYWORDS([ovsdb log])
AT_CAPTURE_FILE([file])
AT_CHECK(
- [[test-ovsdb log-io file 'O_CREAT|O_RDWR' 'write:[0]' 'write:[1]' 'write:[2]']], [0],
+ [[test-ovsdb log-io file create 'write:[0]' 'write:[1]' 'write:[2]']], [0],
[[file: open successful
file: write:[0] successful
file: write:[1] successful
file: write:[2] successful
]], [ignore])
AT_CHECK(
- [[test-ovsdb log-io file 'O_RDWR' read 'write:["more data"]']], [0],
+ [[test-ovsdb log-io file read/write read 'write:["more data"]']], [0],
[[file: open successful
file: read: [0]
file: write:["more data"] successful
]], [ignore])
AT_CHECK(
- [test-ovsdb log-io file 'O_RDONLY' read read read], [0],
+ [test-ovsdb log-io file read-only read read read], [0],
[[file: open successful
file: read: [0]
file: read: ["more data"]
@@ -133,7 +133,7 @@ AT_SETUP([write, add corrupted data, read])
AT_KEYWORDS([ovsdb log])
AT_CAPTURE_FILE([file])
AT_CHECK(
- [[test-ovsdb log-io file 'O_CREAT|O_RDWR' 'write:[0]' 'write:[1]' 'write:[2]']], [0],
+ [[test-ovsdb log-io file create 'write:[0]' 'write:[1]' 'write:[2]']], [0],
[[file: open successful
file: write:[0] successful
file: write:[1] successful
@@ -141,7 +141,7 @@ file: write:[2] successful
]], [ignore])
AT_CHECK([echo 'xxx' >> file])
AT_CHECK(
- [test-ovsdb log-io file 'O_RDONLY' read read read read], [0],
+ [test-ovsdb log-io file read-only read read read read], [0],
[[file: open successful
file: read: [0]
file: read: [1]
@@ -155,7 +155,7 @@ AT_SETUP([write, add corrupted data, read, overwrite])
AT_KEYWORDS([ovsdb log])
AT_CAPTURE_FILE([file])
AT_CHECK(
- [[test-ovsdb log-io file 'O_CREAT|O_RDWR' 'write:[0]' 'write:[1]' 'write:[2]']], [0],
+ [[test-ovsdb log-io file create 'write:[0]' 'write:[1]' 'write:[2]']], [0],
[[file: open successful
file: write:[0] successful
file: write:[1] successful
@@ -163,7 +163,7 @@ file: write:[2] successful
]], [ignore])
AT_CHECK([echo 'xxx' >> file])
AT_CHECK(
- [[test-ovsdb log-io file 'O_RDWR' read read read read 'write:[3]']], [0],
+ [[test-ovsdb log-io file read/write read read read read 'write:[3]']], [0],
[[file: open successful
file: read: [0]
file: read: [1]
@@ -172,7 +172,7 @@ file: read failed: syntax error: file: parse error at offset 174 in header line
file: write:[3] successful
]], [ignore])
AT_CHECK(
- [test-ovsdb log-io file 'O_RDONLY' read read read read read], [0],
+ [test-ovsdb log-io file read-only read read read read read], [0],
[[file: open successful
file: read: [0]
file: read: [1]
@@ -187,7 +187,7 @@ AT_SETUP([write, corrupt some data, read, overwrite])
AT_KEYWORDS([ovsdb log])
AT_CAPTURE_FILE([file])
AT_CHECK(
- [[test-ovsdb log-io file 'O_CREAT|O_RDWR' 'write:[0]' 'write:[1]' 'write:[2]']], [0],
+ [[test-ovsdb log-io file create 'write:[0]' 'write:[1]' 'write:[2]']], [0],
[[file: open successful
file: write:[0] successful
file: write:[1] successful
@@ -198,7 +198,7 @@ AT_CHECK([mv file.tmp file])
AT_CHECK([[grep -c '\[3]' file]], [0], [1
])
AT_CHECK(
- [[test-ovsdb log-io file 'O_RDWR' read read read 'write:["longer data"]']], [0],
+ [[test-ovsdb log-io file read/write read read read 'write:["longer data"]']], [0],
[[file: open successful
file: read: [0]
file: read: [1]
@@ -206,7 +206,7 @@ file: read failed: syntax error: file: 4 bytes starting at offset 170 have SHA-1
file: write:["longer data"] successful
]], [ignore])
AT_CHECK(
- [test-ovsdb log-io file 'O_RDONLY' read read read read], [0],
+ [test-ovsdb log-io file read-only read read read read], [0],
[[file: open successful
file: read: [0]
file: read: [1]
@@ -220,7 +220,7 @@ AT_SETUP([write, truncate file, read, overwrite])
AT_KEYWORDS([ovsdb log])
AT_CAPTURE_FILE([file])
AT_CHECK(
- [[test-ovsdb log-io file 'O_CREAT|O_RDWR' 'write:[0]' 'write:[1]' 'write:[2]']], [0],
+ [[test-ovsdb log-io file create 'write:[0]' 'write:[1]' 'write:[2]']], [0],
[[file: open successful
file: write:[0] successful
file: write:[1] successful
@@ -231,7 +231,7 @@ AT_CHECK([mv file.tmp file])
AT_CHECK([[grep -c '^2$' file]], [0], [1
])
AT_CHECK(
- [[test-ovsdb log-io file 'O_RDWR' read read read 'write:["longer data"]']], [0],
+ [[test-ovsdb log-io file read/write read read read 'write:["longer data"]']], [0],
[[file: open successful
file: read: [0]
file: read: [1]
@@ -239,7 +239,7 @@ file: read failed: I/O error: file: error reading 4 bytes starting at offset 170
file: write:["longer data"] successful
]], [ignore])
AT_CHECK(
- [test-ovsdb log-io file 'O_RDONLY' read read read read], [0],
+ [test-ovsdb log-io file read-only read read read read], [0],
[[file: open successful
file: read: [0]
file: read: [1]
@@ -253,7 +253,7 @@ AT_SETUP([write bad JSON, read, overwrite])
AT_KEYWORDS([ovsdb log])
AT_CAPTURE_FILE([file])
AT_CHECK(
- [[test-ovsdb log-io file 'O_CREAT|O_RDWR' 'write:[0]' 'write:[1]' 'write:[2]']], [0],
+ [[test-ovsdb log-io file create 'write:[0]' 'write:[1]' 'write:[2]']], [0],
[[file: open successful
file: write:[0] successful
file: write:[1] successful
@@ -261,7 +261,7 @@ file: write:[2] successful
]], [ignore])
AT_CHECK([[printf '%s\n%s\n' 'OVSDB JSON 5 d910b02871075d3156ec8675dfc95b7d5d640aa6' 'null' >> file]])
AT_CHECK(
- [[test-ovsdb log-io file 'O_RDWR' read read read read 'write:["replacement data"]']], [0],
+ [[test-ovsdb log-io file read/write read read read read 'write:["replacement data"]']], [0],
[[file: open successful
file: read: [0]
file: read: [1]
@@ -270,7 +270,7 @@ file: read failed: syntax error: file: 5 bytes starting at offset 228 are not va
file: write:["replacement data"] successful
]], [ignore])
AT_CHECK(
- [test-ovsdb log-io file 'O_RDONLY' read read read read read], [0],
+ [test-ovsdb log-io file read-only read read read read read], [0],
[[file: open successful
file: read: [0]
file: read: [1]
diff --git a/tests/test-ovsdb.c b/tests/test-ovsdb.c
index 2e12d49..48a5007 100644
--- a/tests/test-ovsdb.c
+++ b/tests/test-ovsdb.c
@@ -257,34 +257,24 @@ static void
do_log_io(int argc, char *argv[])
{
const char *name = argv[1];
- char *mode = argv[2];
+ char *mode_string = argv[2];
struct ovsdb_error *error;
+ enum ovsdb_log_open_mode mode;
struct ovsdb_log *log;
- char *save_ptr = NULL;
- const char *token;
- int flags;
int i;
- for (flags = 0, token = strtok_r(mode, " |", &save_ptr); token != NULL;
- token = strtok_r(NULL, " |", &save_ptr))
- {
- if (!strcmp(token, "O_RDONLY")) {
- flags |= O_RDONLY;
- } else if (!strcmp(token, "O_RDWR")) {
- flags |= O_RDWR;
- } else if (!strcmp(token, "O_TRUNC")) {
- flags |= O_TRUNC;
- } else if (!strcmp(token, "O_CREAT")) {
- flags |= O_CREAT;
- } else if (!strcmp(token, "O_EXCL")) {
- flags |= O_EXCL;
- } else if (!strcmp(token, "O_TRUNC")) {
- flags |= O_TRUNC;
- }
+ if (!strcmp(mode_string, "read-only")) {
+ mode = OVSDB_LOG_READ_ONLY;
+ } else if (!strcmp(mode_string, "read/write")) {
+ mode = OVSDB_LOG_READ_WRITE;
+ } else if (!strcmp(mode_string, "create")) {
+ mode = OVSDB_LOG_CREATE;
+ } else {
+ ovs_fatal(0, "unknown log-io open mode \"%s\"", mode_string);
}
- check_ovsdb_error(ovsdb_log_open(name, flags, &log));
+ check_ovsdb_error(ovsdb_log_open(name, mode, -1, &log));
printf("%s: open successful\n", name);
for (i = 3; i < argc; i++) {
--
1.6.6.1
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