]> git.ozlabs.org Git - ccan/blobdiff - ccan/tdb2/open.c
tdb2: actually implement tdb_error().
[ccan] / ccan / tdb2 / open.c
index 21881c350e084dcc5751c395a773ec974662244b..7bb50f1db5964ae13687f0c792fab5a8603e8481 100644 (file)
@@ -1,19 +1,20 @@
 #include "private.h"
+#include <assert.h>
 
-/* all contexts, to ensure no double-opens (fcntl locks don't nest!) */
-static struct tdb_context *tdbs = NULL;
+/* all lock info, to detect double-opens (fcntl file don't nest!) */
+static struct tdb_file *files = NULL;
 
-static bool tdb_already_open(dev_t device, ino_t ino)
+static struct tdb_file *find_file(dev_t device, ino_t ino)
 {
-       struct tdb_context *i;
+       struct tdb_file *i;
 
-       for (i = tdbs; i; i = i->next) {
+       for (i = files; i; i = i->next) {
                if (i->device == device && i->inode == ino) {
-                       return true;
+                       i->refcnt++;
+                       break;
                }
        }
-
-       return false;
+       return i;
 }
 
 static bool read_all(int fd, void *buf, size_t len)
@@ -106,6 +107,7 @@ static enum TDB_ERROR tdb_new_database(struct tdb_context *tdb,
                                         tdb->hash_priv);
        newdb.hdr.recovery = 0;
        newdb.hdr.features_used = newdb.hdr.features_offered = TDB_FEATURE_MASK;
+       newdb.hdr.seqnum = 0;
        memset(newdb.hdr.reserved, 0, sizeof(newdb.hdr.reserved));
        /* Initial hashes are empty. */
        memset(newdb.hdr.hashtable, 0, sizeof(newdb.hdr.hashtable));
@@ -133,29 +135,29 @@ static enum TDB_ERROR tdb_new_database(struct tdb_context *tdb,
        *hdr = newdb.hdr;
 
        if (tdb->flags & TDB_INTERNAL) {
-               tdb->map_size = sizeof(newdb);
-               tdb->map_ptr = malloc(tdb->map_size);
-               if (!tdb->map_ptr) {
+               tdb->file->map_size = sizeof(newdb);
+               tdb->file->map_ptr = malloc(tdb->file->map_size);
+               if (!tdb->file->map_ptr) {
                        return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
                                          "tdb_new_database:"
                                          " failed to allocate");
                }
-               memcpy(tdb->map_ptr, &newdb, tdb->map_size);
+               memcpy(tdb->file->map_ptr, &newdb, tdb->file->map_size);
                return TDB_SUCCESS;
        }
-       if (lseek(tdb->fd, 0, SEEK_SET) == -1) {
+       if (lseek(tdb->file->fd, 0, SEEK_SET) == -1) {
                return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
                                  "tdb_new_database:"
                                  " failed to seek: %s", strerror(errno));
        }
 
-       if (ftruncate(tdb->fd, 0) == -1) {
+       if (ftruncate(tdb->file->fd, 0) == -1) {
                return tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
                                  "tdb_new_database:"
                                  " failed to truncate: %s", strerror(errno));
        }
 
-       rlen = write(tdb->fd, &newdb, sizeof(newdb));
+       rlen = write(tdb->file->fd, &newdb, sizeof(newdb));
        if (rlen != sizeof(newdb)) {
                if (rlen >= 0)
                        errno = ENOSPC;
@@ -166,6 +168,19 @@ static enum TDB_ERROR tdb_new_database(struct tdb_context *tdb,
        return TDB_SUCCESS;
 }
 
+static enum TDB_ERROR tdb_new_file(struct tdb_context *tdb)
+{
+       tdb->file = malloc(sizeof(*tdb->file));
+       if (!tdb->file)
+               return tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
+                                 "tdb_open: could alloc tdb_file structure");
+       tdb->file->num_lockrecs = 0;
+       tdb->file->lockrecs = NULL;
+       tdb->file->allrecord_lock.count = 0;
+       tdb->file->refcnt = 1;
+       return TDB_SUCCESS;
+}
+
 struct tdb_context *tdb_open(const char *name, int tdb_flags,
                             int open_flags, mode_t mode,
                             union tdb_attribute *attr)
@@ -188,18 +203,16 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
                return NULL;
        }
        tdb->name = NULL;
-       tdb->map_ptr = NULL;
        tdb->direct_access = 0;
-       tdb->fd = -1;
-       tdb->map_size = sizeof(struct tdb_header);
        tdb->flags = tdb_flags;
        tdb->logfn = NULL;
        tdb->transaction = NULL;
        tdb->stats = NULL;
        tdb->access = NULL;
+       tdb->last_error = TDB_SUCCESS;
+       tdb->file = NULL;
        tdb_hash_init(tdb);
        tdb_io_init(tdb);
-       tdb_lock_init(tdb);
 
        while (attr) {
                switch (attr->base.attr) {
@@ -232,7 +245,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
        }
 
        if (tdb_flags & ~(TDB_INTERNAL | TDB_NOLOCK | TDB_NOMMAP | TDB_CONVERT
-                         | TDB_NOSYNC)) {
+                         | TDB_NOSYNC | TDB_SEQNUM)) {
                ecode = tdb_logerr(tdb, TDB_ERR_EINVAL, TDB_LOG_USE_ERROR,
                                   "tdb_open: unknown flags %u", tdb_flags);
                goto fail;
@@ -256,28 +269,69 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
        /* internal databases don't need any of the rest. */
        if (tdb->flags & TDB_INTERNAL) {
                tdb->flags |= (TDB_NOLOCK | TDB_NOMMAP);
+               ecode = tdb_new_file(tdb);
+               if (ecode != TDB_SUCCESS) {
+                       goto fail;
+               }
+               tdb->file->fd = -1;
                ecode = tdb_new_database(tdb, seed, &hdr);
                if (ecode != TDB_SUCCESS) {
                        goto fail;
                }
+               if (name) {
+                       tdb->name = strdup(name);
+                       if (!tdb->name) {
+                               ecode = tdb_logerr(tdb, TDB_ERR_OOM,
+                                                  TDB_LOG_ERROR,
+                                                  "tdb_open: failed to"
+                                                  " allocate name");
+                               goto fail;
+                       }
+               }
                tdb_convert(tdb, &hdr.hash_seed, sizeof(hdr.hash_seed));
                tdb->hash_seed = hdr.hash_seed;
                tdb_ftable_init(tdb);
                return tdb;
        }
 
-       if ((tdb->fd = open(name, open_flags, mode)) == -1) {
-               /* errno set by open(2) */
-               saved_errno = errno;
-               ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+       if (stat(name, &st) != -1)
+               tdb->file = find_file(st.st_dev, st.st_ino);
+
+       if (!tdb->file) {
+               int fd;
+
+               if ((fd = open(name, open_flags, mode)) == -1) {
+                       /* errno set by open(2) */
+                       saved_errno = errno;
+                       tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
                                   "tdb_open: could not open file %s: %s",
                                   name, strerror(errno));
-               goto fail;
-       }
+                       goto fail_errno;
+               }
 
-       /* on exec, don't inherit the fd */
-       v = fcntl(tdb->fd, F_GETFD, 0);
-        fcntl(tdb->fd, F_SETFD, v | FD_CLOEXEC);
+               /* on exec, don't inherit the fd */
+               v = fcntl(fd, F_GETFD, 0);
+               fcntl(fd, F_SETFD, v | FD_CLOEXEC);
+
+               if (fstat(fd, &st) == -1) {
+                       saved_errno = errno;
+                       tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+                                  "tdb_open: could not stat open %s: %s",
+                                  name, strerror(errno));
+                       goto fail_errno;
+               }
+
+               ecode = tdb_new_file(tdb);
+               if (ecode != TDB_SUCCESS)
+                       goto fail;
+
+               tdb->file->next = files;
+               tdb->file->fd = fd;
+               tdb->file->device = st.st_dev;
+               tdb->file->inode = st.st_ino;
+               tdb->file->map_ptr = NULL;
+               tdb->file->map_size = sizeof(struct tdb_header);
+       }
 
        /* ensure there is only one process initialising at once */
        ecode = tdb_lock_open(tdb, TDB_LOCK_WAIT|TDB_LOCK_NOCHECK);
@@ -286,7 +340,7 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
        }
 
        /* If they used O_TRUNC, read will return 0. */
-       rlen = read(tdb->fd, &hdr, sizeof(hdr));
+       rlen = pread(tdb->file->fd, &hdr, sizeof(hdr), 0);
        if (rlen == 0 && (open_flags & O_CREAT)) {
                ecode = tdb_new_database(tdb, seed, &hdr);
                if (ecode != TDB_SUCCESS) {
@@ -330,24 +384,6 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
                goto fail;
        }
 
-       if (fstat(tdb->fd, &st) == -1) {
-               saved_errno = errno;
-               ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-                                  "tdb_open: could not stat open %s: %s",
-                                  name, strerror(errno));
-               goto fail;
-       }
-
-       /* Is it already in the open list?  If so, fail. */
-       if (tdb_already_open(st.st_dev, st.st_ino)) {
-               /* FIXME */
-               ecode = tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_USE_ERROR,
-                                  "tdb_open: %s (%d,%d) is already open"
-                                  " in this process",
-                                  name, (int)st.st_dev, (int)st.st_ino);
-               goto fail;
-       }
-
        tdb->name = strdup(name);
        if (!tdb->name) {
                ecode = tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_ERROR,
@@ -365,12 +401,10 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
                        goto fail;
        }
 
-       tdb->device = st.st_dev;
-       tdb->inode = st.st_ino;
        tdb_unlock_open(tdb);
 
        /* This make sure we have current map_size and mmap. */
-       tdb->methods->oob(tdb, tdb->map_size + 1, true);
+       tdb->methods->oob(tdb, tdb->file->map_size + 1, true);
 
        /* Now it's fully formed, recover if necessary. */
        berr = tdb_needs_recovery(tdb);
@@ -390,49 +424,56 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
                goto fail;
        }
 
-       tdb->next = tdbs;
-       tdbs = tdb;
+       /* Add to linked list if we're new. */
+       if (tdb->file->refcnt == 1)
+               files = tdb->file;
        return tdb;
 
  fail:
        /* Map ecode to some logical errno. */
-       if (!saved_errno) {
-               switch (ecode) {
-               case TDB_ERR_CORRUPT:
-               case TDB_ERR_IO:
-                       saved_errno = EIO;
-                       break;
-               case TDB_ERR_LOCK:
-                       saved_errno = EWOULDBLOCK;
-                       break;
-               case TDB_ERR_OOM:
-                       saved_errno = ENOMEM;
-                       break;
-               case TDB_ERR_EINVAL:
-                       saved_errno = EINVAL;
-                       break;
-               default:
-                       saved_errno = EINVAL;
-                       break;
-               }
-       }
-
+       switch (ecode) {
+       case TDB_ERR_CORRUPT:
+       case TDB_ERR_IO:
+               saved_errno = EIO;
+               break;
+       case TDB_ERR_LOCK:
+               saved_errno = EWOULDBLOCK;
+               break;
+       case TDB_ERR_OOM:
+               saved_errno = ENOMEM;
+               break;
+       case TDB_ERR_EINVAL:
+               saved_errno = EINVAL;
+               break;
+       default:
+               saved_errno = EINVAL;
+               break;
+       }
+
+fail_errno:
 #ifdef TDB_TRACE
        close(tdb->tracefd);
 #endif
-       if (tdb->map_ptr) {
-               if (tdb->flags & TDB_INTERNAL) {
-                       free(tdb->map_ptr);
-               } else
-                       tdb_munmap(tdb);
+       free(cast_const(char *, tdb->name));
+       if (tdb->file) {
+               tdb_lock_cleanup(tdb);
+               if (--tdb->file->refcnt == 0) {
+                       assert(tdb->file->num_lockrecs == 0);
+                       if (tdb->file->map_ptr) {
+                               if (tdb->flags & TDB_INTERNAL) {
+                                       free(tdb->file->map_ptr);
+                               } else
+                                       tdb_munmap(tdb->file);
+                       }
+                       if (close(tdb->file->fd) != 0)
+                               tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
+                                          "tdb_open: failed to close tdb fd"
+                                          " on error: %s", strerror(errno));
+                       free(tdb->file->lockrecs);
+                       free(tdb->file);
+               }
        }
-       free(tdb->lockrecs);
-       free((char *)tdb->name);
-       if (tdb->fd != -1)
-               if (close(tdb->fd) != 0)
-                       tdb_logerr(tdb, TDB_ERR_IO, TDB_LOG_ERROR,
-                                  "tdb_open: failed to close tdb->fd"
-                                  " on error: %s", strerror(errno));
+
        free(tdb);
        errno = saved_errno;
        return NULL;
@@ -440,7 +481,6 @@ struct tdb_context *tdb_open(const char *name, int tdb_flags,
 
 int tdb_close(struct tdb_context *tdb)
 {
-       struct tdb_context **i;
        int ret = 0;
 
        tdb_trace(tdb, "tdb_close");
@@ -449,24 +489,29 @@ int tdb_close(struct tdb_context *tdb)
                tdb_transaction_cancel(tdb);
        }
 
-       if (tdb->map_ptr) {
+       if (tdb->file->map_ptr) {
                if (tdb->flags & TDB_INTERNAL)
-                       free(tdb->map_ptr);
+                       free(tdb->file->map_ptr);
                else
-                       tdb_munmap(tdb);
-       }
-       free((char *)tdb->name);
-       if (tdb->fd != -1) {
-               ret = close(tdb->fd);
-               tdb->fd = -1;
+                       tdb_munmap(tdb->file);
        }
-       free(tdb->lockrecs);
+       free(cast_const(char *, tdb->name));
+       if (tdb->file) {
+               struct tdb_file **i;
 
-       /* Remove from contexts list */
-       for (i = &tdbs; *i; i = &(*i)->next) {
-               if (*i == tdb) {
-                       *i = tdb->next;
-                       break;
+               tdb_lock_cleanup(tdb);
+               if (--tdb->file->refcnt == 0) {
+                       ret = close(tdb->file->fd);
+
+                       /* Remove from files list */
+                       for (i = &files; *i; i = &(*i)->next) {
+                               if (*i == tdb->file) {
+                                       *i = tdb->file->next;
+                                       break;
+                               }
+                       }
+                       free(tdb->file->lockrecs);
+                       free(tdb->file);
                }
        }