--- /dev/null
+ /*
+ Unix SMB/CIFS implementation.
+
+ trivial database library
+
+ Copyright (C) Andrew Tridgell 1999-2005
+ Copyright (C) Paul `Rusty' Russell 2000
+ Copyright (C) Jeremy Allison 2000-2003
+ Copyright (C) Rusty Russell 2010
+
+ ** NOTE! The following LGPL license applies to the ntdb
+ ** library. This does NOT imply that all of Samba is released
+ ** under the LGPL
+
+ This library is free software; you can redistribute it and/or
+ modify it under the terms of the GNU Lesser General Public
+ License as published by the Free Software Foundation; either
+ version 3 of the License, or (at your option) any later version.
+
+ This library is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
+ Lesser General Public License for more details.
+
+ You should have received a copy of the GNU Lesser General Public
+ License along with this library; if not, see <http://www.gnu.org/licenses/>.
+*/
+#include "private.h"
+#include <ccan/likely/likely.h>
+
+static void free_old_mmaps(struct ntdb_context *ntdb)
+{
+ struct ntdb_old_mmap *i;
+
+ assert(ntdb->file->direct_count == 0);
+
+ while ((i = ntdb->file->old_mmaps) != NULL) {
+ ntdb->file->old_mmaps = i->next;
+ if (ntdb->flags & NTDB_INTERNAL) {
+ ntdb->free_fn(i->map_ptr, ntdb->alloc_data);
+ } else {
+ munmap(i->map_ptr, i->map_size);
+ }
+ ntdb->free_fn(i, ntdb->alloc_data);
+ }
+}
+
+static enum NTDB_ERROR save_old_map(struct ntdb_context *ntdb)
+{
+ struct ntdb_old_mmap *old;
+
+ assert(ntdb->file->direct_count);
+
+ old = ntdb->alloc_fn(ntdb->file, sizeof(*old), ntdb->alloc_data);
+ if (!old) {
+ return ntdb_logerr(ntdb, NTDB_ERR_OOM, NTDB_LOG_ERROR,
+ "save_old_map alloc failed");
+ }
+ old->next = ntdb->file->old_mmaps;
+ old->map_ptr = ntdb->file->map_ptr;
+ old->map_size = ntdb->file->map_size;
+ ntdb->file->old_mmaps = old;
+
+ return NTDB_SUCCESS;
+}
+
+enum NTDB_ERROR ntdb_munmap(struct ntdb_context *ntdb)
+{
+ if (ntdb->file->fd == -1) {
+ return NTDB_SUCCESS;
+ }
+
+ if (!ntdb->file->map_ptr) {
+ return NTDB_SUCCESS;
+ }
+
+ /* We can't unmap now if there are accessors. */
+ if (ntdb->file->direct_count) {
+ return save_old_map(ntdb);
+ } else {
+ munmap(ntdb->file->map_ptr, ntdb->file->map_size);
+ ntdb->file->map_ptr = NULL;
+ }
+ return NTDB_SUCCESS;
+}
+
+enum NTDB_ERROR ntdb_mmap(struct ntdb_context *ntdb)
+{
+ int mmap_flags;
+
+ if (ntdb->flags & NTDB_INTERNAL)
+ return NTDB_SUCCESS;
+
+#ifndef HAVE_INCOHERENT_MMAP
+ if (ntdb->flags & NTDB_NOMMAP)
+ return NTDB_SUCCESS;
+#endif
+
+ if ((ntdb->open_flags & O_ACCMODE) == O_RDONLY)
+ mmap_flags = PROT_READ;
+ else
+ mmap_flags = PROT_READ | PROT_WRITE;
+
+ /* size_t can be smaller than off_t. */
+ if ((size_t)ntdb->file->map_size == ntdb->file->map_size) {
+ ntdb->file->map_ptr = mmap(NULL, ntdb->file->map_size,
+ mmap_flags,
+ MAP_SHARED, ntdb->file->fd, 0);
+ } else
+ ntdb->file->map_ptr = MAP_FAILED;
+
+ /*
+ * NB. When mmap fails it returns MAP_FAILED *NOT* NULL !!!!
+ */
+ if (ntdb->file->map_ptr == MAP_FAILED) {
+ ntdb->file->map_ptr = NULL;
+#ifdef HAVE_INCOHERENT_MMAP
+ /* Incoherent mmap means everyone must mmap! */
+ return ntdb_logerr(ntdb, NTDB_ERR_IO, NTDB_LOG_ERROR,
+ "ntdb_mmap failed for size %lld (%s)",
+ (long long)ntdb->file->map_size,
+ strerror(errno));
+#else
+ ntdb_logerr(ntdb, NTDB_SUCCESS, NTDB_LOG_WARNING,
+ "ntdb_mmap failed for size %lld (%s)",
+ (long long)ntdb->file->map_size, strerror(errno));
+#endif
+ }
+ return NTDB_SUCCESS;
+}
+
+/* check for an out of bounds access - if it is out of bounds then
+ see if the database has been expanded by someone else and expand
+ if necessary
+ note that "len" is the minimum length needed for the db.
+
+ If probe is true, len being too large isn't a failure.
+*/
+static enum NTDB_ERROR ntdb_normal_oob(struct ntdb_context *ntdb,
+ ntdb_off_t off, ntdb_len_t len,
+ bool probe)
+{
+ struct stat st;
+ enum NTDB_ERROR ecode;
+
+ if (len + off < len) {
+ if (probe)
+ return NTDB_SUCCESS;
+
+ return ntdb_logerr(ntdb, NTDB_ERR_IO, NTDB_LOG_ERROR,
+ "ntdb_oob off %llu len %llu wrap\n",
+ (long long)off, (long long)len);
+ }
+
+ if (ntdb->flags & NTDB_INTERNAL) {
+ if (probe)
+ return NTDB_SUCCESS;
+
+ ntdb_logerr(ntdb, NTDB_ERR_IO, NTDB_LOG_ERROR,
+ "ntdb_oob len %lld beyond internal"
+ " alloc size %lld",
+ (long long)(off + len),
+ (long long)ntdb->file->map_size);
+ return NTDB_ERR_IO;
+ }
+
+ ecode = ntdb_lock_expand(ntdb, F_RDLCK);
+ if (ecode != NTDB_SUCCESS) {
+ return ecode;
+ }
+
+ if (fstat(ntdb->file->fd, &st) != 0) {
+ ntdb_logerr(ntdb, NTDB_ERR_IO, NTDB_LOG_ERROR,
+ "Failed to fstat file: %s", strerror(errno));
+ ntdb_unlock_expand(ntdb, F_RDLCK);
+ return NTDB_ERR_IO;
+ }
+
+ ntdb_unlock_expand(ntdb, F_RDLCK);
+
+ if (st.st_size < off + len) {
+ if (probe)
+ return NTDB_SUCCESS;
+
+ ntdb_logerr(ntdb, NTDB_ERR_IO, NTDB_LOG_ERROR,
+ "ntdb_oob len %llu beyond eof at %llu",
+ (long long)(off + len), (long long)st.st_size);
+ return NTDB_ERR_IO;
+ }
+
+ /* Unmap, update size, remap */
+ ecode = ntdb_munmap(ntdb);
+ if (ecode) {
+ return ecode;
+ }
+
+ ntdb->file->map_size = st.st_size;
+ return ntdb_mmap(ntdb);
+}
+
+/* Endian conversion: we only ever deal with 8 byte quantities */
+void *ntdb_convert(const struct ntdb_context *ntdb, void *buf, ntdb_len_t size)
+{
+ assert(size % 8 == 0);
+ if (unlikely((ntdb->flags & NTDB_CONVERT)) && buf) {
+ uint64_t i, *p = (uint64_t *)buf;
+ for (i = 0; i < size / 8; i++)
+ p[i] = bswap_64(p[i]);
+ }
+ return buf;
+}
+
+/* Return first non-zero offset in offset array, or end, or -ve error. */
+/* FIXME: Return the off? */
+uint64_t ntdb_find_nonzero_off(struct ntdb_context *ntdb,
+ ntdb_off_t base, uint64_t start, uint64_t end)
+{
+ uint64_t i;
+ const uint64_t *val;
+
+ /* Zero vs non-zero is the same unconverted: minor optimization. */
+ val = ntdb_access_read(ntdb, base + start * sizeof(ntdb_off_t),
+ (end - start) * sizeof(ntdb_off_t), false);
+ if (NTDB_PTR_IS_ERR(val)) {
+ return NTDB_ERR_TO_OFF(NTDB_PTR_ERR(val));
+ }
+
+ for (i = 0; i < (end - start); i++) {
+ if (val[i])
+ break;
+ }
+ ntdb_access_release(ntdb, val);
+ return start + i;
+}
+
+/* Return first zero offset in num offset array, or num, or -ve error. */
+uint64_t ntdb_find_zero_off(struct ntdb_context *ntdb, ntdb_off_t off,
+ uint64_t num)
+{
+ uint64_t i;
+ const uint64_t *val;
+
+ /* Zero vs non-zero is the same unconverted: minor optimization. */
+ val = ntdb_access_read(ntdb, off, num * sizeof(ntdb_off_t), false);
+ if (NTDB_PTR_IS_ERR(val)) {
+ return NTDB_ERR_TO_OFF(NTDB_PTR_ERR(val));
+ }
+
+ for (i = 0; i < num; i++) {
+ if (!val[i])
+ break;
+ }
+ ntdb_access_release(ntdb, val);
+ return i;
+}
+
+enum NTDB_ERROR zero_out(struct ntdb_context *ntdb, ntdb_off_t off, ntdb_len_t len)
+{
+ char buf[8192] = { 0 };
+ void *p = ntdb->io->direct(ntdb, off, len, true);
+ enum NTDB_ERROR ecode = NTDB_SUCCESS;
+
+ assert(!(ntdb->flags & NTDB_RDONLY));
+ if (NTDB_PTR_IS_ERR(p)) {
+ return NTDB_PTR_ERR(p);
+ }
+ if (p) {
+ memset(p, 0, len);
+ return ecode;
+ }
+ while (len) {
+ unsigned todo = len < sizeof(buf) ? len : sizeof(buf);
+ ecode = ntdb->io->twrite(ntdb, off, buf, todo);
+ if (ecode != NTDB_SUCCESS) {
+ break;
+ }
+ len -= todo;
+ off += todo;
+ }
+ return ecode;
+}
+
+/* write a lump of data at a specified offset */
+static enum NTDB_ERROR ntdb_write(struct ntdb_context *ntdb, ntdb_off_t off,
+ const void *buf, ntdb_len_t len)
+{
+ enum NTDB_ERROR ecode;
+
+ if (ntdb->flags & NTDB_RDONLY) {
+ return ntdb_logerr(ntdb, NTDB_ERR_RDONLY, NTDB_LOG_USE_ERROR,
+ "Write to read-only database");
+ }
+
+ ecode = ntdb_oob(ntdb, off, len, false);
+ if (ecode != NTDB_SUCCESS) {
+ return ecode;
+ }
+
+ if (ntdb->file->map_ptr) {
+ memcpy(off + (char *)ntdb->file->map_ptr, buf, len);
+ } else {
+#ifdef HAVE_INCOHERENT_MMAP
+ return NTDB_ERR_IO;
+#else
+ ssize_t ret;
+ ret = pwrite(ntdb->file->fd, buf, len, off);
+ if (ret != len) {
+ /* This shouldn't happen: we avoid sparse files. */
+ if (ret >= 0)
+ errno = ENOSPC;
+
+ return ntdb_logerr(ntdb, NTDB_ERR_IO, NTDB_LOG_ERROR,
+ "ntdb_write: %zi at %zu len=%zu (%s)",
+ ret, (size_t)off, (size_t)len,
+ strerror(errno));
+ }
+#endif
+ }
+ return NTDB_SUCCESS;
+}
+
+/* read a lump of data at a specified offset */
+static enum NTDB_ERROR ntdb_read(struct ntdb_context *ntdb, ntdb_off_t off,
+ void *buf, ntdb_len_t len)
+{
+ enum NTDB_ERROR ecode;
+
+ ecode = ntdb_oob(ntdb, off, len, false);
+ if (ecode != NTDB_SUCCESS) {
+ return ecode;
+ }
+
+ if (ntdb->file->map_ptr) {
+ memcpy(buf, off + (char *)ntdb->file->map_ptr, len);
+ } else {
+#ifdef HAVE_INCOHERENT_MMAP
+ return NTDB_ERR_IO;
+#else
+ ssize_t r = pread(ntdb->file->fd, buf, len, off);
+ if (r != len) {
+ return ntdb_logerr(ntdb, NTDB_ERR_IO, NTDB_LOG_ERROR,
+ "ntdb_read failed with %zi at %zu "
+ "len=%zu (%s) map_size=%zu",
+ r, (size_t)off, (size_t)len,
+ strerror(errno),
+ (size_t)ntdb->file->map_size);
+ }
+#endif
+ }
+ return NTDB_SUCCESS;
+}
+
+enum NTDB_ERROR ntdb_write_convert(struct ntdb_context *ntdb, ntdb_off_t off,
+ const void *rec, size_t len)
+{
+ enum NTDB_ERROR ecode;
+
+ if (unlikely((ntdb->flags & NTDB_CONVERT))) {
+ void *conv = ntdb->alloc_fn(ntdb, len, ntdb->alloc_data);
+ if (!conv) {
+ return ntdb_logerr(ntdb, NTDB_ERR_OOM, NTDB_LOG_ERROR,
+ "ntdb_write: no memory converting"
+ " %zu bytes", len);
+ }
+ memcpy(conv, rec, len);
+ ecode = ntdb->io->twrite(ntdb, off,
+ ntdb_convert(ntdb, conv, len), len);
+ ntdb->free_fn(conv, ntdb->alloc_data);
+ } else {
+ ecode = ntdb->io->twrite(ntdb, off, rec, len);
+ }
+ return ecode;
+}
+
+enum NTDB_ERROR ntdb_read_convert(struct ntdb_context *ntdb, ntdb_off_t off,
+ void *rec, size_t len)
+{
+ enum NTDB_ERROR ecode = ntdb->io->tread(ntdb, off, rec, len);
+ ntdb_convert(ntdb, rec, len);
+ return ecode;
+}
+
+static void *_ntdb_alloc_read(struct ntdb_context *ntdb, ntdb_off_t offset,
+ ntdb_len_t len, unsigned int prefix)
+{
+ unsigned char *buf;
+ enum NTDB_ERROR ecode;
+
+ /* some systems don't like zero length malloc */
+ buf = ntdb->alloc_fn(ntdb, prefix + len ? prefix + len : 1,
+ ntdb->alloc_data);
+ if (!buf) {
+ ntdb_logerr(ntdb, NTDB_ERR_OOM, NTDB_LOG_ERROR,
+ "ntdb_alloc_read alloc failed len=%zu",
+ (size_t)(prefix + len));
+ return NTDB_ERR_PTR(NTDB_ERR_OOM);
+ } else {
+ ecode = ntdb->io->tread(ntdb, offset, buf+prefix, len);
+ if (unlikely(ecode != NTDB_SUCCESS)) {
+ ntdb->free_fn(buf, ntdb->alloc_data);
+ return NTDB_ERR_PTR(ecode);
+ }
+ }
+ return buf;
+}
+
+/* read a lump of data, allocating the space for it */
+void *ntdb_alloc_read(struct ntdb_context *ntdb, ntdb_off_t offset, ntdb_len_t len)
+{
+ return _ntdb_alloc_read(ntdb, offset, len, 0);
+}
+
+static enum NTDB_ERROR fill(struct ntdb_context *ntdb,
+ const void *buf, size_t size,
+ ntdb_off_t off, ntdb_len_t len)
+{
+ while (len) {
+ size_t n = len > size ? size : len;
+ ssize_t ret = pwrite(ntdb->file->fd, buf, n, off);
+ if (ret != n) {
+ if (ret >= 0)
+ errno = ENOSPC;
+
+ return ntdb_logerr(ntdb, NTDB_ERR_IO, NTDB_LOG_ERROR,
+ "fill failed:"
+ " %zi at %zu len=%zu (%s)",
+ ret, (size_t)off, (size_t)len,
+ strerror(errno));
+ }
+ len -= n;
+ off += n;
+ }
+ return NTDB_SUCCESS;
+}
+
+/* expand a file. we prefer to use ftruncate, as that is what posix
+ says to use for mmap expansion */
+static enum NTDB_ERROR ntdb_expand_file(struct ntdb_context *ntdb,
+ ntdb_len_t addition)
+{
+ char buf[8192];
+ enum NTDB_ERROR ecode;
+
+ assert((ntdb->file->map_size + addition) % NTDB_PGSIZE == 0);
+ if (ntdb->flags & NTDB_RDONLY) {
+ return ntdb_logerr(ntdb, NTDB_ERR_RDONLY, NTDB_LOG_USE_ERROR,
+ "Expand on read-only database");
+ }
+
+ if (ntdb->flags & NTDB_INTERNAL) {
+ char *new;
+
+ /* Can't free it if we have direct accesses. */
+ if (ntdb->file->direct_count) {
+ ecode = save_old_map(ntdb);
+ if (ecode) {
+ return ecode;
+ }
+ new = ntdb->alloc_fn(ntdb->file,
+ ntdb->file->map_size + addition,
+ ntdb->alloc_data);
+ if (new) {
+ memcpy(new, ntdb->file->map_ptr,
+ ntdb->file->map_size);
+ }
+ } else {
+ new = ntdb->expand_fn(ntdb->file->map_ptr,
+ ntdb->file->map_size + addition,
+ ntdb->alloc_data);
+ }
+ if (!new) {
+ return ntdb_logerr(ntdb, NTDB_ERR_OOM, NTDB_LOG_ERROR,
+ "No memory to expand database");
+ }
+ ntdb->file->map_ptr = new;
+ ntdb->file->map_size += addition;
+ return NTDB_SUCCESS;
+ } else {
+ /* Unmap before trying to write; old NTDB claimed OpenBSD had
+ * problem with this otherwise. */
+ ecode = ntdb_munmap(ntdb);
+ if (ecode) {
+ return ecode;
+ }
+
+ /* If this fails, we try to fill anyway. */
+ if (ftruncate(ntdb->file->fd, ntdb->file->map_size + addition))
+ ;
+
+ /* now fill the file with something. This ensures that the
+ file isn't sparse, which would be very bad if we ran out of
+ disk. This must be done with write, not via mmap */
+ memset(buf, 0x43, sizeof(buf));
+ ecode = fill(ntdb, buf, sizeof(buf), ntdb->file->map_size,
+ addition);
+ if (ecode != NTDB_SUCCESS)
+ return ecode;
+ ntdb->file->map_size += addition;
+ return ntdb_mmap(ntdb);
+ }
+}
+
+const void *ntdb_access_read(struct ntdb_context *ntdb,
+ ntdb_off_t off, ntdb_len_t len, bool convert)
+{
+ void *ret = NULL;
+
+ if (likely(!(ntdb->flags & NTDB_CONVERT))) {
+ ret = ntdb->io->direct(ntdb, off, len, false);
+
+ if (NTDB_PTR_IS_ERR(ret)) {
+ return ret;
+ }
+ }
+ if (!ret) {
+ struct ntdb_access_hdr *hdr;
+ hdr = _ntdb_alloc_read(ntdb, off, len, sizeof(*hdr));
+ if (NTDB_PTR_IS_ERR(hdr)) {
+ return hdr;
+ }
+ hdr->next = ntdb->access;
+ ntdb->access = hdr;
+ ret = hdr + 1;
+ if (convert) {
+ ntdb_convert(ntdb, (void *)ret, len);
+ }
+ } else {
+ ntdb->file->direct_count++;
+ }
+
+ return ret;
+}
+
+void *ntdb_access_write(struct ntdb_context *ntdb,
+ ntdb_off_t off, ntdb_len_t len, bool convert)
+{
+ void *ret = NULL;
+
+ if (ntdb->flags & NTDB_RDONLY) {
+ ntdb_logerr(ntdb, NTDB_ERR_RDONLY, NTDB_LOG_USE_ERROR,
+ "Write to read-only database");
+ return NTDB_ERR_PTR(NTDB_ERR_RDONLY);
+ }
+
+ if (likely(!(ntdb->flags & NTDB_CONVERT))) {
+ ret = ntdb->io->direct(ntdb, off, len, true);
+
+ if (NTDB_PTR_IS_ERR(ret)) {
+ return ret;
+ }
+ }
+
+ if (!ret) {
+ struct ntdb_access_hdr *hdr;
+ hdr = _ntdb_alloc_read(ntdb, off, len, sizeof(*hdr));
+ if (NTDB_PTR_IS_ERR(hdr)) {
+ return hdr;
+ }
+ hdr->next = ntdb->access;
+ ntdb->access = hdr;
+ hdr->off = off;
+ hdr->len = len;
+ hdr->convert = convert;
+ ret = hdr + 1;
+ if (convert)
+ ntdb_convert(ntdb, (void *)ret, len);
+ } else {
+ ntdb->file->direct_count++;
+ }
+ return ret;
+}
+
+static struct ntdb_access_hdr **find_hdr(struct ntdb_context *ntdb, const void *p)
+{
+ struct ntdb_access_hdr **hp;
+
+ for (hp = &ntdb->access; *hp; hp = &(*hp)->next) {
+ if (*hp + 1 == p)
+ return hp;
+ }
+ return NULL;
+}
+
+void ntdb_access_release(struct ntdb_context *ntdb, const void *p)
+{
+ struct ntdb_access_hdr *hdr, **hp = find_hdr(ntdb, p);
+
+ if (hp) {
+ hdr = *hp;
+ *hp = hdr->next;
+ ntdb->free_fn(hdr, ntdb->alloc_data);
+ } else {
+ if (--ntdb->file->direct_count == 0) {
+ free_old_mmaps(ntdb);
+ }
+ }
+}
+
+enum NTDB_ERROR ntdb_access_commit(struct ntdb_context *ntdb, void *p)
+{
+ struct ntdb_access_hdr *hdr, **hp = find_hdr(ntdb, p);
+ enum NTDB_ERROR ecode;
+
+ if (hp) {
+ hdr = *hp;
+ if (hdr->convert)
+ ecode = ntdb_write_convert(ntdb, hdr->off, p, hdr->len);
+ else
+ ecode = ntdb_write(ntdb, hdr->off, p, hdr->len);
+ *hp = hdr->next;
+ ntdb->free_fn(hdr, ntdb->alloc_data);
+ } else {
+ if (--ntdb->file->direct_count == 0) {
+ free_old_mmaps(ntdb);
+ }
+ ecode = NTDB_SUCCESS;
+ }
+
+ return ecode;
+}
+
+static void *ntdb_direct(struct ntdb_context *ntdb, ntdb_off_t off, size_t len,
+ bool write_mode)
+{
+ enum NTDB_ERROR ecode;
+
+ if (unlikely(!ntdb->file->map_ptr))
+ return NULL;
+
+ ecode = ntdb_oob(ntdb, off, len, false);
+ if (unlikely(ecode != NTDB_SUCCESS))
+ return NTDB_ERR_PTR(ecode);
+ return (char *)ntdb->file->map_ptr + off;
+}
+
+static ntdb_off_t ntdb_read_normal_off(struct ntdb_context *ntdb,
+ ntdb_off_t off)
+{
+ ntdb_off_t ret;
+ enum NTDB_ERROR ecode;
+ ntdb_off_t *p;
+
+ p = ntdb_direct(ntdb, off, sizeof(*p), false);
+ if (NTDB_PTR_IS_ERR(p)) {
+ return NTDB_ERR_TO_OFF(NTDB_PTR_ERR(p));
+ }
+ if (likely(p)) {
+ return *p;
+ }
+
+ ecode = ntdb_read(ntdb, off, &ret, sizeof(ret));
+ if (ecode != NTDB_SUCCESS) {
+ return NTDB_ERR_TO_OFF(ecode);
+ }
+ return ret;
+}
+
+static ntdb_off_t ntdb_read_convert_off(struct ntdb_context *ntdb,
+ ntdb_off_t off)
+{
+ ntdb_off_t ret;
+ enum NTDB_ERROR ecode;
+
+ ecode = ntdb_read_convert(ntdb, off, &ret, sizeof(ret));
+ if (ecode != NTDB_SUCCESS) {
+ return NTDB_ERR_TO_OFF(ecode);
+ }
+ return ret;
+}
+
+static enum NTDB_ERROR ntdb_write_normal_off(struct ntdb_context *ntdb,
+ ntdb_off_t off, ntdb_off_t val)
+{
+ ntdb_off_t *p;
+
+ p = ntdb_direct(ntdb, off, sizeof(*p), true);
+ if (NTDB_PTR_IS_ERR(p)) {
+ return NTDB_PTR_ERR(p);
+ }
+ if (likely(p)) {
+ *p = val;
+ return NTDB_SUCCESS;
+ }
+ return ntdb_write(ntdb, off, &val, sizeof(val));
+}
+
+static enum NTDB_ERROR ntdb_write_convert_off(struct ntdb_context *ntdb,
+ ntdb_off_t off, ntdb_off_t val)
+{
+ return ntdb_write_convert(ntdb, off, &val, sizeof(val));
+}
+
+void ntdb_inc_seqnum(struct ntdb_context *ntdb)
+{
+ ntdb_off_t seq;
+
+ if (likely(!(ntdb->flags & NTDB_CONVERT))) {
+ int64_t *direct;
+
+ direct = ntdb->io->direct(ntdb,
+ offsetof(struct ntdb_header, seqnum),
+ sizeof(*direct), true);
+ if (likely(direct)) {
+ /* Don't let it go negative, even briefly */
+ if (unlikely((*direct) + 1) < 0)
+ *direct = 0;
+ (*direct)++;
+ return;
+ }
+ }
+
+ seq = ntdb_read_off(ntdb, offsetof(struct ntdb_header, seqnum));
+ if (!NTDB_OFF_IS_ERR(seq)) {
+ seq++;
+ if (unlikely((int64_t)seq < 0))
+ seq = 0;
+ ntdb_write_off(ntdb, offsetof(struct ntdb_header, seqnum), seq);
+ }
+}
+
+static const struct ntdb_methods io_methods = {
+ ntdb_read,
+ ntdb_write,
+ ntdb_normal_oob,
+ ntdb_expand_file,
+ ntdb_direct,
+ ntdb_read_normal_off,
+ ntdb_write_normal_off,
+};
+
+static const struct ntdb_methods io_convert_methods = {
+ ntdb_read,
+ ntdb_write,
+ ntdb_normal_oob,
+ ntdb_expand_file,
+ ntdb_direct,
+ ntdb_read_convert_off,
+ ntdb_write_convert_off,
+};
+
+/*
+ initialise the default methods table
+*/
+void ntdb_io_init(struct ntdb_context *ntdb)
+{
+ if (ntdb->flags & NTDB_CONVERT)
+ ntdb->io = &io_convert_methods;
+ else
+ ntdb->io = &io_methods;
+}
projects / ccan / blobdiff