From 9c76e95dbecdfb5440a16b7770ecc0525db3236c Mon Sep 17 00:00:00 2001
From: Hallvard Furuseth <hallvard@openldap.org>
Date: Tue, 27 Sep 2016 07:03:34 +0200
Subject: [PATCH] Move opening files to mdb_fopen()
No change in functionality.
---
libraries/liblmdb/mdb.c | 220 +++++++++++++++++++++++-----------------
1 file changed, 125 insertions(+), 95 deletions(-)
diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index af0e9364a0..9516252cc5 100644
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -4142,16 +4142,122 @@ mdb_fname_init(const char *path, unsigned envflags, MDB_name *fname)
#define mdb_fname_destroy(fname) \
do { if ((fname).mn_alloced) free((fname).mn_val); } while (0)
+#ifdef O_CLOEXEC /* POSIX.1-2008: Set FD_CLOEXEC atomically at open() */
+# define MDB_CLOEXEC O_CLOEXEC
+#else
+# define MDB_CLOEXEC 0
+#endif
+
+/** File type, access mode etc. for #mdb_fopen() */
enum mdb_fopen_type {
- MDB_O_DATA, MDB_O_LOCKS
+#ifdef _WIN32
+ MDB_O_RDONLY, MDB_O_RDWR, MDB_O_META, MDB_O_COPY, MDB_O_LOCKS
+#else
+ /* A comment in mdb_fopen() explains some O_* flag choices. */
+ MDB_O_RDONLY= O_RDONLY, /**< for RDONLY me_fd */
+ MDB_O_RDWR = O_RDWR |O_CREAT, /**< for me_fd */
+ MDB_O_META = O_RDWR |MDB_DSYNC, /**< for me_mfd */
+ MDB_O_COPY = O_WRONLY|O_CREAT|O_EXCL, /**< for #mdb_env_copy() */
+ /** Bitmask for open() flags in enum #mdb_fopen_type. The other bits
+ * distinguish otherwise-equal MDB_O_* constants from each other.
+ */
+ MDB_O_MASK = MDB_O_RDWR|MDB_CLOEXEC | MDB_O_RDONLY|MDB_O_META|MDB_O_COPY,
+ MDB_O_LOCKS = MDB_O_RDWR|MDB_CLOEXEC | ((MDB_O_MASK+1) & ~MDB_O_MASK) /**< for me_lfd */
+#endif
};
-static void ESECT
-mdb_fname_suffix_set(MDB_env *env, MDB_name *fname, enum mdb_fopen_type which)
+/** Open an LMDB file.
+ * @param[in] env The LMDB environment.
+ * @param[in,out] fname Path from from #mdb_fname_init(). A suffix is
+ * appended if necessary to create the filename, without changing mn_len.
+ * @param[in] which Determines file type, access mode, etc.
+ * @param[in] mode The Unix permissions for the file, if we create it.
+ * @param[out] res Resulting file handle.
+ * @return 0 on success, non-zero on failure.
+ */
+static int ESECT
+mdb_fopen(const MDB_env *env, MDB_name *fname,
+ enum mdb_fopen_type which, mdb_mode_t mode,
+ HANDLE *res)
{
+ int rc = MDB_SUCCESS;
+ HANDLE fd;
+#ifdef _WIN32
+ DWORD acc, share, disp, attrs;
+#else
+ int flags;
+#endif
+
if (fname->mn_alloced) /* modifiable copy */
mdb_name_cpy(fname->mn_val + fname->mn_len,
mdb_suffixes[which==MDB_O_LOCKS][F_ISSET(env->me_flags, MDB_NOSUBDIR)]);
+
+ /* The directory must already exist. Usually the file need not.
+ * MDB_O_META requires the file because we already created it using
+ * MDB_O_RDWR. MDB_O_COPY must not overwrite an existing file.
+ *
+ * With MDB_O_COPY we do not want the OS to cache the writes, since
+ * the source data is already in the OS cache.
+ *
+ * The lockfile needs FD_CLOEXEC (close file descriptor on exec*())
+ * to avoid the flock() issues noted under Caveats in lmdb.h.
+ */
+
+#ifdef _WIN32
+ acc = GENERIC_READ|GENERIC_WRITE;
+ share = FILE_SHARE_READ|FILE_SHARE_WRITE;
+ disp = OPEN_ALWAYS;
+ attrs = FILE_ATTRIBUTE_NORMAL;
+ switch (which) {
+ case MDB_O_RDONLY: /* read-only datafile */
+ acc = GENERIC_READ;
+ disp = OPEN_EXISTING;
+ break;
+ case MDB_O_META: /* for writing metapages */
+ disp = OPEN_EXISTING;
+ attrs = FILE_ATTRIBUTE_NORMAL|FILE_FLAG_WRITE_THROUGH;
+ break;
+ case MDB_O_COPY: /* mdb_env_copy() & co */
+ acc = GENERIC_WRITE;
+ share = 0;
+ disp = CREATE_NEW;
+ attrs = FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH;
+ break;
+ default: break; /* silence gcc -Wswitch (not all enum values handled) */
+ }
+ fd = CreateFileW(fname->mn_val, acc, share, NULL, disp, attrs, NULL);
+#else
+ fd = open(fname->mn_val, which & MDB_O_MASK, mode);
+#endif
+
+ if (fd == INVALID_HANDLE_VALUE)
+ rc = ErrCode();
+#ifndef _WIN32
+ else {
+ if (which == MDB_O_LOCKS) {
+ /* Set CLOEXEC if we could not pass it to open() */
+ if (!MDB_CLOEXEC && (flags = fcntl(fd, F_GETFD)) != -1)
+ (void) fcntl(fd, F_SETFD, flags | FD_CLOEXEC);
+ }
+ if (which == MDB_O_COPY && env->me_psize >= env->me_os_psize) {
+ /* This may require buffer alignment. There is no portable
+ * way to ask how much, so we require OS pagesize alignment.
+ */
+# ifdef F_NOCACHE /* __APPLE__ */
+ (void) fcntl(fd, F_NOCACHE, 1);
+# elif defined O_DIRECT
+ /* open(...O_DIRECT...) would break on filesystems without
+ * O_DIRECT support (ITS#7682). Try to set it here instead.
+ */
+ if ((flags = fcntl(fd, F_GETFL)) != -1)
+ (void) fcntl(fd, F_SETFL, flags | O_DIRECT);
+# endif
+ }
+ }
+#endif /* !_WIN32 */
+
+ *res = fd;
+ return rc;
}
@@ -4572,36 +4678,18 @@ mdb_env_setup_locks(MDB_env *env, MDB_name *fname, int mode, int *excl)
# define MDB_ERRCODE_ROFS ERROR_WRITE_PROTECT
#else
# define MDB_ERRCODE_ROFS EROFS
-#ifdef O_CLOEXEC /* Linux: Open file and set FD_CLOEXEC atomically */
-# define MDB_CLOEXEC O_CLOEXEC
-#else
-# define MDB_CLOEXEC 0
-#endif
- int fdflags;
#endif
int rc;
off_t size, rsize;
- mdb_fname_suffix_set(env, fname, MDB_O_LOCKS);
-#ifdef _WIN32
- env->me_lfd = CreateFileW(fname->mn_val, GENERIC_READ|GENERIC_WRITE,
- FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
- FILE_ATTRIBUTE_NORMAL, NULL);
-#else
- env->me_lfd = open(fname->mn_val, O_RDWR|O_CREAT|MDB_CLOEXEC, mode);
-#endif
- if (env->me_lfd == INVALID_HANDLE_VALUE) {
- rc = ErrCode();
+ rc = mdb_fopen(env, fname, MDB_O_LOCKS, mode, &env->me_lfd);
+ if (rc) {
+ /* Omit lockfile if read-only env on read-only filesystem */
if (rc == MDB_ERRCODE_ROFS && (env->me_flags & MDB_RDONLY)) {
return MDB_SUCCESS;
}
goto fail;
}
-#ifndef _WIN32
- /* Lose record locks when exec*() */
- if (!(MDB_CLOEXEC) && (fdflags = fcntl(env->me_lfd, F_GETFD)) != -1)
- fcntl(env->me_lfd, F_SETFD, fdflags | FD_CLOEXEC);
-#endif
if (!(env->me_flags & MDB_NOTLS)) {
rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
@@ -4806,7 +4894,7 @@ fail:
int ESECT
mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode)
{
- int oflags, rc, len, excl = -1;
+ int rc, excl = -1;
MDB_name fname;
if (env->me_fd!=INVALID_HANDLE_VALUE || (flags & ~(CHANGEABLE|CHANGELESS)))
@@ -4847,30 +4935,11 @@ mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode
goto leave;
}
- mdb_fname_suffix_set(env, &fname, MDB_O_DATA);
-#ifdef _WIN32
- if (F_ISSET(flags, MDB_RDONLY)) {
- oflags = GENERIC_READ;
- len = OPEN_EXISTING;
- } else {
- oflags = GENERIC_READ|GENERIC_WRITE;
- len = OPEN_ALWAYS;
- }
- mode = FILE_ATTRIBUTE_NORMAL;
- env->me_fd = CreateFileW(fname.mn_val, oflags, FILE_SHARE_READ|FILE_SHARE_WRITE,
- NULL, len, mode, NULL);
-#else
- if (F_ISSET(flags, MDB_RDONLY))
- oflags = O_RDONLY;
- else
- oflags = O_RDWR | O_CREAT;
-
- env->me_fd = open(fname.mn_val, oflags, mode);
-#endif
- if (env->me_fd == INVALID_HANDLE_VALUE) {
- rc = ErrCode();
+ rc = mdb_fopen(env, &fname,
+ (flags & MDB_RDONLY) ? MDB_O_RDONLY : MDB_O_RDWR,
+ mode, &env->me_fd);
+ if (rc)
goto leave;
- }
if ((flags & (MDB_RDONLY|MDB_NOLOCK)) == MDB_RDONLY) {
rc = mdb_env_setup_locks(env, &fname, mode, &excl);
@@ -4885,20 +4954,9 @@ mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mdb_mode_t mode
/* Synchronous fd for meta writes. Needed even with
* MDB_NOSYNC/MDB_NOMETASYNC, in case these get reset.
*/
- mdb_fname_suffix_set(env, &fname, MDB_O_DATA);
-#ifdef _WIN32
- len = OPEN_EXISTING;
- env->me_mfd = CreateFileW(fname.mn_val, oflags,
- FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, len,
- mode | FILE_FLAG_WRITE_THROUGH, NULL);
-#else
- oflags &= ~O_CREAT;
- env->me_mfd = open(fname.mn_val, oflags | MDB_DSYNC, mode);
-#endif
- if (env->me_mfd == INVALID_HANDLE_VALUE) {
- rc = ErrCode();
+ rc = mdb_fopen(env, &fname, MDB_O_META, mode, &env->me_mfd);
+ if (rc)
goto leave;
- }
}
DPRINTF(("opened dbenv %p", (void *) env));
if (excl > 0) {
@@ -9403,43 +9461,15 @@ mdb_env_copy2(MDB_env *env, const char *path, unsigned int flags)
HANDLE newfd = INVALID_HANDLE_VALUE;
rc = mdb_fname_init(path, env->me_flags | MDB_NOLOCK, &fname);
- if (rc)
- return rc;
- mdb_fname_suffix_set(env, &fname, MDB_O_DATA);
-
- /* The destination path must exist, but the destination file must not.
- * We don't want the OS to cache the writes, since the source data is
- * already in the OS cache.
- */
-#ifdef _WIN32
- newfd = CreateFileW(fname.mn_val, GENERIC_WRITE, 0, NULL, CREATE_NEW,
- FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
-#else
- newfd = open(fname.mn_val, O_WRONLY|O_CREAT|O_EXCL, 0666);
-#endif
- if (newfd == INVALID_HANDLE_VALUE) {
- rc = ErrCode();
- goto leave;
- }
-
- if (env->me_psize >= env->me_os_psize) {
-#ifdef F_NOCACHE /* __APPLE__ */
- (void) fcntl(newfd, F_NOCACHE, 1);
-#elif defined O_DIRECT
- /* Set O_DIRECT if the file system supports it */
- if ((rc = fcntl(newfd, F_GETFL)) != -1)
- (void) fcntl(newfd, F_SETFL, rc | O_DIRECT);
-#endif
+ if (rc == MDB_SUCCESS) {
+ rc = mdb_fopen(env, &fname, MDB_O_COPY, 0666, &newfd);
+ mdb_fname_destroy(fname);
}
-
- rc = mdb_env_copyfd2(env, newfd, flags);
-
-leave:
- mdb_fname_destroy(fname);
- if (newfd != INVALID_HANDLE_VALUE)
+ if (rc == MDB_SUCCESS) {
+ rc = mdb_env_copyfd2(env, newfd, flags);
if (close(newfd) < 0 && rc == MDB_SUCCESS)
rc = ErrCode();
-
+ }
return rc;
}
--
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