[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index] [Xen-devel] [PATCH v3 4/4] xenstore: cleanup tdb.c
Remove all unused functions from tdb.c. This will reduce code size of xenstored and - more important - of xenstore stubdom. tdb.c hasn't been updated to a newer version since its introduction in 2005. Any backport of bug fixes or update to a new version will need major work, so there is no real downside to remove not needed code. Signed-off-by: Juergen Gross <jgross@xxxxxxxx> Acked-by: Ian Jackson <ian.jackson@xxxxxxxxxxxxx> Acked-by: Wei Liu <wei.liu2@xxxxxxxxxx> --- tools/xenstore/tdb.c | 439 +-------------------------------------------------- tools/xenstore/tdb.h | 22 --- 2 files changed, 1 insertion(+), 460 deletions(-) diff --git a/tools/xenstore/tdb.c b/tools/xenstore/tdb.c index e26900e..29593b7 100644 --- a/tools/xenstore/tdb.c +++ b/tools/xenstore/tdb.c @@ -103,7 +103,7 @@ #endif #define BUCKET(hash) ((hash) % tdb->header.hash_size) -TDB_DATA tdb_null; +static TDB_DATA tdb_null; /* all contexts, to ensure no double-opens (fcntl locks don't nest!) */ static TDB_CONTEXT *tdbs = NULL; @@ -510,108 +510,6 @@ static int update_tailer(TDB_CONTEXT *tdb, tdb_off offset, &totalsize); } -static tdb_off tdb_dump_record(TDB_CONTEXT *tdb, tdb_off offset) -{ - struct list_struct rec; - tdb_off tailer_ofs, tailer; - - if (tdb_read(tdb, offset, (char *)&rec, sizeof(rec), DOCONV()) == -1) { - printf("ERROR: failed to read record at %u\n", offset); - return 0; - } - - printf(" rec: offset=0x%08x next=0x%08x rec_len=%d key_len=%d data_len=%d full_hash=0x%x magic=0x%x\n", - offset, rec.next, rec.rec_len, rec.key_len, rec.data_len, rec.full_hash, rec.magic); - - tailer_ofs = offset + sizeof(rec) + rec.rec_len - sizeof(tdb_off); - if (ofs_read(tdb, tailer_ofs, &tailer) == -1) { - printf("ERROR: failed to read tailer at %u\n", tailer_ofs); - return rec.next; - } - - if (tailer != rec.rec_len + sizeof(rec)) { - printf("ERROR: tailer does not match record! tailer=%u totalsize=%u\n", - (unsigned int)tailer, (unsigned int)(rec.rec_len + sizeof(rec))); - } - return rec.next; -} - -static int tdb_dump_chain(TDB_CONTEXT *tdb, int i) -{ - tdb_off rec_ptr, top; - - top = TDB_HASH_TOP(i); - - if (tdb_lock(tdb, i, F_WRLCK) != 0) - return -1; - - if (ofs_read(tdb, top, &rec_ptr) == -1) - return tdb_unlock(tdb, i, F_WRLCK); - - if (rec_ptr) - printf("hash=%d\n", i); - - while (rec_ptr) { - rec_ptr = tdb_dump_record(tdb, rec_ptr); - } - - return tdb_unlock(tdb, i, F_WRLCK); -} - -void tdb_dump_all(TDB_CONTEXT *tdb) -{ - unsigned int i; - for (i=0;i<tdb->header.hash_size;i++) { - tdb_dump_chain(tdb, i); - } - printf("freelist:\n"); - tdb_dump_chain(tdb, -1); -} - -int tdb_printfreelist(TDB_CONTEXT *tdb) -{ - int ret; - long total_free = 0; - tdb_off offset, rec_ptr; - struct list_struct rec; - - if ((ret = tdb_lock(tdb, -1, F_WRLCK)) != 0) - return ret; - - offset = FREELIST_TOP; - - /* read in the freelist top */ - if (ofs_read(tdb, offset, &rec_ptr) == -1) { - tdb_unlock(tdb, -1, F_WRLCK); - return 0; - } - - printf("freelist top=[0x%08x]\n", rec_ptr ); - while (rec_ptr) { - if (tdb_read(tdb, rec_ptr, (char *)&rec, sizeof(rec), DOCONV()) == -1) { - tdb_unlock(tdb, -1, F_WRLCK); - return -1; - } - - if (rec.magic != TDB_FREE_MAGIC) { - printf("bad magic 0x%08x in free list\n", rec.magic); - tdb_unlock(tdb, -1, F_WRLCK); - return -1; - } - - printf("entry offset=[0x%08x], rec.rec_len = [0x%08x (%d)] (end = 0x%08x)\n", - rec_ptr, rec.rec_len, rec.rec_len, rec_ptr + rec.rec_len); - total_free += rec.rec_len; - - /* move to the next record */ - rec_ptr = rec.next; - } - printf("total rec_len = [0x%08x (%d)]\n", (int)total_free, - (int)total_free); - - return tdb_unlock(tdb, -1, F_WRLCK); -} - /* Remove an element from the freelist. Must have alloc lock. */ static int remove_from_freelist(TDB_CONTEXT *tdb, tdb_off off, tdb_off next) { @@ -1170,12 +1068,6 @@ static int tdb_exists_hash(TDB_CONTEXT *tdb, TDB_DATA key, uint32_t hash) return 1; } -int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key) -{ - uint32_t hash = tdb->hash_fn(&key); - return tdb_exists_hash(tdb, key, hash); -} - /* record lock stops delete underneath */ static int lock_record(TDB_CONTEXT *tdb, tdb_off off) { @@ -1617,131 +1509,6 @@ fail: goto out; } -/* Attempt to append data to an entry in place - this only works if the new data size - is <= the old data size and the key exists. - on failure return -1. Record must be locked before calling. -*/ -static int tdb_append_inplace(TDB_CONTEXT *tdb, TDB_DATA key, uint32_t hash, TDB_DATA new_dbuf) -{ - struct list_struct rec; - tdb_off rec_ptr; - - /* find entry */ - if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) - return -1; - - /* Append of 0 is always ok. */ - if (new_dbuf.dsize == 0) - return 0; - - /* must be long enough for key, old data + new data and tailer */ - if (rec.rec_len < key.dsize + rec.data_len + new_dbuf.dsize + sizeof(tdb_off)) { - /* No room. */ - tdb->ecode = TDB_SUCCESS; /* Not really an error */ - return -1; - } - - if (tdb_write(tdb, rec_ptr + sizeof(rec) + rec.key_len + rec.data_len, - new_dbuf.dptr, new_dbuf.dsize) == -1) - return -1; - - /* update size */ - rec.data_len += new_dbuf.dsize; - return rec_write(tdb, rec_ptr, &rec); -} - -/* Append to an entry. Create if not exist. */ - -int tdb_append(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf) -{ - struct list_struct rec; - uint32_t hash; - tdb_off rec_ptr; - char *p = NULL; - int ret = 0; - size_t new_data_size = 0; - - /* find which hash bucket it is in */ - hash = tdb->hash_fn(&key); - if (tdb_lock(tdb, BUCKET(hash), F_WRLCK) == -1) - return -1; - - /* first try in-place. */ - if (tdb_append_inplace(tdb, key, hash, new_dbuf) == 0) - goto out; - - /* reset the error code potentially set by the tdb_append_inplace() */ - tdb->ecode = TDB_SUCCESS; - - /* find entry */ - if (!(rec_ptr = tdb_find(tdb, key, hash, &rec))) { - if (tdb->ecode != TDB_ERR_NOEXIST) - goto fail; - - /* Not found - create. */ - - ret = tdb_store(tdb, key, new_dbuf, TDB_INSERT); - goto out; - } - - new_data_size = rec.data_len + new_dbuf.dsize; - - /* Copy key+old_value+value *before* allocating free space in case malloc - fails and we are left with a dead spot in the tdb. */ - - if (!(p = (char *)talloc_size(tdb, key.dsize + new_data_size))) { - tdb->ecode = TDB_ERR_OOM; - goto fail; - } - - /* Copy the key in place. */ - memcpy(p, key.dptr, key.dsize); - - /* Now read the old data into place. */ - if (rec.data_len && - tdb_read(tdb, rec_ptr + sizeof(rec) + rec.key_len, p + key.dsize, rec.data_len, 0) == -1) - goto fail; - - /* Finally append the new data. */ - if (new_dbuf.dsize) - memcpy(p+key.dsize+rec.data_len, new_dbuf.dptr, new_dbuf.dsize); - - /* delete any existing record - if it doesn't exist we don't - care. Doing this first reduces fragmentation, and avoids - coalescing with `allocated' block before it's updated. */ - - tdb_delete_hash(tdb, key, hash); - - if (!(rec_ptr = tdb_allocate(tdb, key.dsize + new_data_size, &rec))) - goto fail; - - /* Read hash top into next ptr */ - if (ofs_read(tdb, TDB_HASH_TOP(hash), &rec.next) == -1) - goto fail; - - rec.key_len = key.dsize; - rec.data_len = new_data_size; - rec.full_hash = hash; - rec.magic = TDB_MAGIC; - - /* write out and point the top of the hash chain at it */ - if (rec_write(tdb, rec_ptr, &rec) == -1 - || tdb_write(tdb, rec_ptr+sizeof(rec), p, key.dsize+new_data_size)==-1 - || ofs_write(tdb, TDB_HASH_TOP(hash), &rec_ptr) == -1) { - /* Need to tdb_unallocate() here */ - goto fail; - } - - out: - SAFE_FREE(p); - tdb_unlock(tdb, BUCKET(hash), F_WRLCK); - return ret; - -fail: - ret = -1; - goto out; -} - static int tdb_already_open(dev_t device, ino_t ino) { @@ -1756,22 +1523,6 @@ static int tdb_already_open(dev_t device, return 0; } -/* open the database, creating it if necessary - - The open_flags and mode are passed straight to the open call on the - database file. A flags value of O_WRONLY is invalid. The hash size - is advisory, use zero for a default value. - - Return is NULL on error, in which case errno is also set. Don't - try to call tdb_error or tdb_errname, just do strerror(errno). - - @param name may be NULL for internal databases. */ -TDB_CONTEXT *tdb_open(const char *name, int hash_size, int tdb_flags, - int open_flags, mode_t mode) -{ - return tdb_open_ex(name, hash_size, tdb_flags, open_flags, mode, NULL, NULL); -} - /* a default logging function */ static void null_log_fn(TDB_CONTEXT *tdb __attribute__((unused)), int level __attribute__((unused)), @@ -1995,191 +1746,3 @@ int tdb_close(TDB_CONTEXT *tdb) return ret; } - -/* lock/unlock entire database */ -int tdb_lockall(TDB_CONTEXT *tdb) -{ - uint32_t i; - - /* There are no locks on read-only dbs */ - if (tdb->read_only) - return TDB_ERRCODE(TDB_ERR_LOCK, -1); - for (i = 0; i < tdb->header.hash_size; i++) - if (tdb_lock(tdb, i, F_WRLCK)) - break; - - /* If error, release locks we have... */ - if (i < tdb->header.hash_size) { - uint32_t j; - - for ( j = 0; j < i; j++) - tdb_unlock(tdb, j, F_WRLCK); - return TDB_ERRCODE(TDB_ERR_NOLOCK, -1); - } - - return 0; -} -void tdb_unlockall(TDB_CONTEXT *tdb) -{ - uint32_t i; - for (i=0; i < tdb->header.hash_size; i++) - tdb_unlock(tdb, i, F_WRLCK); -} - -/* lock/unlock one hash chain. This is meant to be used to reduce - contention - it cannot guarantee how many records will be locked */ -int tdb_chainlock(TDB_CONTEXT *tdb, TDB_DATA key) -{ - return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK); -} - -int tdb_chainunlock(TDB_CONTEXT *tdb, TDB_DATA key) -{ - return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_WRLCK); -} - -int tdb_chainlock_read(TDB_CONTEXT *tdb, TDB_DATA key) -{ - return tdb_lock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK); -} - -int tdb_chainunlock_read(TDB_CONTEXT *tdb, TDB_DATA key) -{ - return tdb_unlock(tdb, BUCKET(tdb->hash_fn(&key)), F_RDLCK); -} - - -/* register a loging function */ -void tdb_logging_function(TDB_CONTEXT *tdb, void (*fn)(TDB_CONTEXT *, int , const char *, ...)) -{ - tdb->log_fn = fn?fn:null_log_fn; -} - - -/* reopen a tdb - this can be used after a fork to ensure that we have an independent - seek pointer from our parent and to re-establish locks */ -int tdb_reopen(TDB_CONTEXT *tdb) -{ - struct stat st; - - if (tdb->flags & TDB_INTERNAL) - return 0; /* Nothing to do. */ - if (tdb_munmap(tdb) != 0) { - TDB_LOG((tdb, 0, "tdb_reopen: munmap failed (%s)\n", strerror(errno))); - goto fail; - } - if (close(tdb->fd) != 0) - TDB_LOG((tdb, 0, "tdb_reopen: WARNING closing tdb->fd failed!\n")); - tdb->fd = open(tdb->name, tdb->open_flags & ~(O_CREAT|O_TRUNC), 0); - if (tdb->fd == -1) { - TDB_LOG((tdb, 0, "tdb_reopen: open failed (%s)\n", strerror(errno))); - goto fail; - } - if (fstat(tdb->fd, &st) != 0) { - TDB_LOG((tdb, 0, "tdb_reopen: fstat failed (%s)\n", strerror(errno))); - goto fail; - } - if (st.st_ino != tdb->inode || st.st_dev != tdb->device) { - TDB_LOG((tdb, 0, "tdb_reopen: file dev/inode has changed!\n")); - goto fail; - } - tdb_mmap(tdb); - if ((tdb->flags & TDB_CLEAR_IF_FIRST) && (tdb_brlock(tdb, ACTIVE_LOCK, F_RDLCK, F_SETLKW, 0) == -1)) { - TDB_LOG((tdb, 0, "tdb_reopen: failed to obtain active lock\n")); - goto fail; - } - - return 0; - -fail: - tdb_close(tdb); - return -1; -} - -/* Not general: only works if single writer. */ -TDB_CONTEXT *tdb_copy(TDB_CONTEXT *tdb, const char *outfile) -{ - int fd, saved_errno; - TDB_CONTEXT *copy; - - if (tdb->flags & TDB_INTERNAL) { - struct tdb_header *copydb; - - copy = talloc_zero(outfile, TDB_CONTEXT); - if (copy == NULL) { - errno = ENOMEM; - goto intfail; - } - memcpy(copy, tdb, sizeof(TDB_CONTEXT)); - - if (copy->name || copy->locked || copy->device || copy->inode) { - fprintf(stderr, "tdb_copy assumption(s) failed\n"); - goto intfail; - } - - copydb = talloc_zero_size(copy, copy->map_size); - if (copydb == NULL) { - errno = ENOMEM; - goto intfail; - } - memcpy(copydb, copy->map_ptr, copy->map_size); - copy->map_ptr = (char*) copydb; - - if (tdb_brlock(tdb, GLOBAL_LOCK, F_UNLCK, F_SETLKW, 0) == -1) - goto intfail; - - copy->next = tdbs; - tdbs = copy; - - return copy; -intfail: - talloc_free(copy); - return NULL; - } - - fd = open(outfile, O_TRUNC|O_CREAT|O_WRONLY, 0640); - if (fd < 0) - return NULL; - if (tdb->map_ptr) { - if (write(fd,tdb->map_ptr,tdb->map_size) != (int)tdb->map_size) - goto fail; - } else { - char buf[65536]; - int r; - - lseek(tdb->fd, 0, SEEK_SET); - while ((r = read(tdb->fd, buf, sizeof(buf))) > 0) { - if (write(fd, buf, r) != r) - goto fail; - } - if (r < 0) - goto fail; - } - copy = tdb_open(outfile, 0, 0, O_RDWR, 0); - if (!copy) - goto fail; - close(fd); - return copy; - -fail: - saved_errno = errno; - close(fd); - unlink(outfile); - errno = saved_errno; - return NULL; -} - -/* reopen all tdb's */ -int tdb_reopen_all(void) -{ - TDB_CONTEXT *tdb; - - for (tdb=tdbs; tdb; tdb = tdb->next) { - /* Ensure no clear-if-first. */ - tdb->flags &= ~TDB_CLEAR_IF_FIRST; - if (tdb_reopen(tdb) != 0) - return -1; - } - - return 0; -} diff --git a/tools/xenstore/tdb.h b/tools/xenstore/tdb.h index 4187274..557cf72 100644 --- a/tools/xenstore/tdb.h +++ b/tools/xenstore/tdb.h @@ -112,42 +112,20 @@ typedef int (*tdb_traverse_func)(TDB_CONTEXT *, TDB_DATA, TDB_DATA, void *); typedef void (*tdb_log_func)(TDB_CONTEXT *, int , const char *, ...); typedef uint32_t (*tdb_hash_func)(TDB_DATA *key); -TDB_CONTEXT *tdb_open(const char *name, int hash_size, int tdb_flags, - int open_flags, mode_t mode); TDB_CONTEXT *tdb_open_ex(const char *name, int hash_size, int tdb_flags, int open_flags, mode_t mode, tdb_log_func log_fn, tdb_hash_func hash_fn); -int tdb_reopen(TDB_CONTEXT *tdb); -int tdb_reopen_all(void); -void tdb_logging_function(TDB_CONTEXT *tdb, tdb_log_func); enum TDB_ERROR tdb_error(TDB_CONTEXT *tdb); const char *tdb_errorstr(TDB_CONTEXT *tdb); TDB_DATA tdb_fetch(TDB_CONTEXT *tdb, TDB_DATA key); int tdb_delete(TDB_CONTEXT *tdb, TDB_DATA key); int tdb_store(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA dbuf, int flag); -int tdb_append(TDB_CONTEXT *tdb, TDB_DATA key, TDB_DATA new_dbuf); int tdb_close(TDB_CONTEXT *tdb); TDB_DATA tdb_firstkey(TDB_CONTEXT *tdb); TDB_DATA tdb_nextkey(TDB_CONTEXT *tdb, TDB_DATA key); int tdb_traverse(TDB_CONTEXT *tdb, tdb_traverse_func fn, void *); -int tdb_exists(TDB_CONTEXT *tdb, TDB_DATA key); -int tdb_lockall(TDB_CONTEXT *tdb); -void tdb_unlockall(TDB_CONTEXT *tdb); - -/* Low level locking functions: use with care */ -int tdb_chainlock(TDB_CONTEXT *tdb, TDB_DATA key); -int tdb_chainunlock(TDB_CONTEXT *tdb, TDB_DATA key); -int tdb_chainlock_read(TDB_CONTEXT *tdb, TDB_DATA key); -int tdb_chainunlock_read(TDB_CONTEXT *tdb, TDB_DATA key); -TDB_CONTEXT *tdb_copy(TDB_CONTEXT *tdb, const char *outfile); - -/* Debug functions. Not used in production. */ -void tdb_dump_all(TDB_CONTEXT *tdb); -int tdb_printfreelist(TDB_CONTEXT *tdb); - -extern TDB_DATA tdb_null; #ifdef __cplusplus } -- 2.10.2 _______________________________________________ Xen-devel mailing list Xen-devel@xxxxxxxxxxxxx https://lists.xen.org/xen-devel
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