From: Rusty Russell Date: Tue, 1 Mar 2011 12:49:19 +0000 (+1030) Subject: tdb2: rework some io.c functions to encode errors in their pointer returns. X-Git-Url: http://git.ozlabs.org/?p=ccan;a=commitdiff_plain;h=1d4d21dfb5ac43274afc125f132d196ce07f3177 tdb2: rework some io.c functions to encode errors in their pointer returns. This causes a subtle enhancement in tdb_direct(): it previously returned NULL on both "can't use direct access" or "some error occurred", as the caller always uses read/write functions as a fallback anyway. Now we distinguish the error case. --- diff --git a/ccan/tdb2/check.c b/ccan/tdb2/check.c index 2b7576e6..1b351672 100644 --- a/ccan/tdb2/check.c +++ b/ccan/tdb2/check.c @@ -237,8 +237,10 @@ static bool check_hash_tree(struct tdb_context *tdb, sizeof(tdb_off_t) << (group_bits + TDB_HASH_GROUP_BITS), true); - if (!hash) + if (TDB_PTR_IS_ERR(hash)) { + tdb->ecode = TDB_PTR_ERR(hash); return false; + } for (g = 0; g < (1 << group_bits); g++) { const tdb_off_t *group = hash + (g << TDB_HASH_GROUP_BITS); @@ -389,8 +391,10 @@ static bool check_hash_tree(struct tdb_context *tdb, off + sizeof(rec), key.dsize + data.dsize, false); - if (!key.dptr) + if (TDB_PTR_IS_ERR(key.dptr)) { + tdb->ecode = TDB_PTR_ERR(key.dptr); goto fail; + } data.dptr = key.dptr + key.dsize; if (check(key, data, private_data) != 0) goto fail; diff --git a/ccan/tdb2/free.c b/ccan/tdb2/free.c index fb45c80c..4f9a52a1 100644 --- a/ccan/tdb2/free.c +++ b/ccan/tdb2/free.c @@ -297,8 +297,10 @@ static int coalesce(struct tdb_context *tdb, unsigned ftable, bucket; r = tdb_access_read(tdb, end, sizeof(*r), true); - if (!r) + if (TDB_PTR_IS_ERR(r)) { + tdb->ecode = TDB_PTR_ERR(r); goto err; + } if (frec_magic(r) != TDB_FREE_MAGIC || frec_ftable(r) == TDB_FTABLE_NONE) { @@ -443,8 +445,10 @@ again: tdb_off_t next; r = tdb_access_read(tdb, off, sizeof(*r), true); - if (!r) + if (TDB_PTR_IS_ERR(r)) { + tdb->ecode = TDB_PTR_ERR(r); goto unlock_err; + } if (frec_magic(r) != TDB_FREE_MAGIC) { tdb_access_release(tdb, r); diff --git a/ccan/tdb2/hash.c b/ccan/tdb2/hash.c index 5b34fc06..260c36f2 100644 --- a/ccan/tdb2/hash.c +++ b/ccan/tdb2/hash.c @@ -47,16 +47,20 @@ uint64_t hash_record(struct tdb_context *tdb, tdb_off_t off) uint64_t klen, hash; r = tdb_access_read(tdb, off, sizeof(*r), true); - if (!r) + if (TDB_PTR_IS_ERR(r)) { + tdb->ecode = TDB_PTR_ERR(r); /* FIXME */ return 0; + } klen = rec_key_length(r); tdb_access_release(tdb, r); key = tdb_access_read(tdb, off + sizeof(*r), klen, false); - if (!key) + if (TDB_PTR_IS_ERR(key)) { + tdb->ecode = TDB_PTR_ERR(key); return 0; + } hash = tdb_hash(tdb, key, klen); tdb_access_release(tdb, key); @@ -92,8 +96,10 @@ static bool key_matches(struct tdb_context *tdb, } rkey = tdb_access_read(tdb, off + sizeof(*rec), key->dsize, false); - if (!rkey) + if (TDB_PTR_IS_ERR(rkey)) { + tdb->ecode = TDB_PTR_ERR(rkey); return ret; + } if (memcmp(rkey, key->dptr, key->dsize) == 0) ret = true; else @@ -490,8 +496,10 @@ static int add_to_subhash(struct tdb_context *tdb, tdb_off_t subhash, group = tdb_access_write(tdb, h.group_start, sizeof(*group) << TDB_HASH_GROUP_BITS, true); - if (!group) + if (TDB_PTR_IS_ERR(group)) { + tdb->ecode = TDB_PTR_ERR(group); return -1; + } force_into_group(group, h.home_bucket, encode_offset(off, &h)); ecode = tdb_access_commit(tdb, group); if (ecode != TDB_SUCCESS) { @@ -808,7 +816,11 @@ int next_in_hash(struct tdb_context *tdb, kbuf->dsize); } tdb_unlock_hashes(tdb, hl_start, hl_range, F_RDLCK); - return kbuf->dptr ? 1 : -1; + if (TDB_PTR_IS_ERR(kbuf->dptr)) { + tdb->ecode = TDB_PTR_ERR(kbuf->dptr); + return -1; + } + return 1; } tdb_unlock_hashes(tdb, hl_start, hl_range, F_RDLCK); diff --git a/ccan/tdb2/io.c b/ccan/tdb2/io.c index 71238afe..7d20f46a 100644 --- a/ccan/tdb2/io.c +++ b/ccan/tdb2/io.c @@ -143,8 +143,10 @@ uint64_t tdb_find_nonzero_off(struct tdb_context *tdb, /* Zero vs non-zero is the same unconverted: minor optimization. */ val = tdb_access_read(tdb, base + start * sizeof(tdb_off_t), (end - start) * sizeof(tdb_off_t), false); - if (!val) + if (TDB_PTR_IS_ERR(val)) { + tdb->ecode = TDB_PTR_ERR(val); return end; + } for (i = 0; i < (end - start); i++) { if (val[i]) @@ -163,8 +165,10 @@ uint64_t tdb_find_zero_off(struct tdb_context *tdb, tdb_off_t off, /* Zero vs non-zero is the same unconverted: minor optimization. */ val = tdb_access_read(tdb, off, num * sizeof(tdb_off_t), false); - if (!val) + if (TDB_PTR_IS_ERR(val)) { + tdb->ecode = TDB_PTR_ERR(val); return num; + } for (i = 0; i < num; i++) { if (!val[i]) @@ -181,6 +185,9 @@ enum TDB_ERROR zero_out(struct tdb_context *tdb, tdb_off_t off, tdb_len_t len) enum TDB_ERROR ecode = TDB_SUCCESS; assert(!tdb->read_only); + if (TDB_PTR_IS_ERR(p)) { + return TDB_PTR_ERR(p); + } if (p) { memset(p, 0, len); return ecode; @@ -205,6 +212,10 @@ tdb_off_t tdb_read_off(struct tdb_context *tdb, tdb_off_t off) if (likely(!(tdb->flags & TDB_CONVERT))) { tdb_off_t *p = tdb->methods->direct(tdb, off, sizeof(*p), false); + if (TDB_PTR_IS_ERR(p)) { + tdb->ecode = TDB_PTR_ERR(p); + return TDB_OFF_ERR; + } if (p) return *p; } @@ -325,6 +336,9 @@ enum TDB_ERROR tdb_write_off(struct tdb_context *tdb, if (likely(!(tdb->flags & TDB_CONVERT))) { tdb_off_t *p = tdb->methods->direct(tdb, off, sizeof(*p), true); + if (TDB_PTR_IS_ERR(p)) { + return TDB_PTR_ERR(p); + } if (p) { *p = val; return TDB_SUCCESS; @@ -345,12 +359,12 @@ static void *_tdb_alloc_read(struct tdb_context *tdb, tdb_off_t offset, tdb_logerr(tdb, TDB_ERR_OOM, TDB_LOG_USE_ERROR, "tdb_alloc_read malloc failed len=%zu", (size_t)(prefix + len)); + return TDB_ERR_PTR(TDB_ERR_OOM); } else { ecode = tdb->methods->tread(tdb, offset, buf+prefix, len); if (unlikely(ecode != TDB_SUCCESS)) { - tdb->ecode = ecode; free(buf); - buf = NULL; + return TDB_ERR_PTR(ecode); } } return buf; @@ -433,18 +447,24 @@ const void *tdb_access_read(struct tdb_context *tdb, { const void *ret = NULL; - if (likely(!(tdb->flags & TDB_CONVERT))) + if (likely(!(tdb->flags & TDB_CONVERT))) { ret = tdb->methods->direct(tdb, off, len, false); + if (TDB_PTR_IS_ERR(ret)) { + return ret; + } + } if (!ret) { struct tdb_access_hdr *hdr; hdr = _tdb_alloc_read(tdb, off, len, sizeof(*hdr)); - if (hdr) { - hdr->next = tdb->access; - tdb->access = hdr; - ret = hdr + 1; - if (convert) - tdb_convert(tdb, (void *)ret, len); + if (TDB_PTR_IS_ERR(hdr)) { + return hdr; + } + hdr->next = tdb->access; + tdb->access = hdr; + ret = hdr + 1; + if (convert) { + tdb_convert(tdb, (void *)ret, len); } } else tdb->direct_access++; @@ -460,25 +480,31 @@ void *tdb_access_write(struct tdb_context *tdb, if (tdb->read_only) { tdb_logerr(tdb, TDB_ERR_RDONLY, TDB_LOG_USE_ERROR, "Write to read-only database"); - return NULL; + return TDB_ERR_PTR(TDB_ERR_RDONLY); } - if (likely(!(tdb->flags & TDB_CONVERT))) + if (likely(!(tdb->flags & TDB_CONVERT))) { ret = tdb->methods->direct(tdb, off, len, true); + if (TDB_PTR_IS_ERR(ret)) { + return ret; + } + } + if (!ret) { struct tdb_access_hdr *hdr; hdr = _tdb_alloc_read(tdb, off, len, sizeof(*hdr)); - if (hdr) { - hdr->next = tdb->access; - tdb->access = hdr; - hdr->off = off; - hdr->len = len; - hdr->convert = convert; - ret = hdr + 1; - if (convert) - tdb_convert(tdb, (void *)ret, len); + if (TDB_PTR_IS_ERR(hdr)) { + return hdr; } + hdr->next = tdb->access; + tdb->access = hdr; + hdr->off = off; + hdr->len = len; + hdr->convert = convert; + ret = hdr + 1; + if (convert) + tdb_convert(tdb, (void *)ret, len); } else tdb->direct_access++; @@ -532,11 +558,14 @@ enum TDB_ERROR tdb_access_commit(struct tdb_context *tdb, void *p) static void *tdb_direct(struct tdb_context *tdb, tdb_off_t off, size_t len, bool write_mode) { + enum TDB_ERROR ecode; + if (unlikely(!tdb->map_ptr)) return NULL; - if (unlikely(tdb_oob(tdb, off + len, true) != TDB_SUCCESS)) - return NULL; + ecode = tdb_oob(tdb, off + len, true); + if (unlikely(ecode != TDB_SUCCESS)) + return TDB_ERR_PTR(ecode); return (char *)tdb->map_ptr + off; } diff --git a/ccan/tdb2/summary.c b/ccan/tdb2/summary.c index d279131d..61d76897 100644 --- a/ccan/tdb2/summary.c +++ b/ccan/tdb2/summary.c @@ -26,8 +26,10 @@ static int count_hash(struct tdb_context *tdb, unsigned int i, count = 0; h = tdb_access_read(tdb, hash_off, sizeof(*h) << bits, true); - if (!h) + if (TDB_PTR_IS_ERR(h)) { + tdb->ecode = TDB_PTR_ERR(h); return -1; + } for (i = 0; i < (1 << bits); i++) count += (h[i] != 0); @@ -58,8 +60,10 @@ static bool summarize(struct tdb_context *tdb, } *p; /* We might not be able to get the whole thing. */ p = tdb_access_read(tdb, off, sizeof(p->f), true); - if (!p) + if (TDB_PTR_IS_ERR(p)) { + tdb->ecode = TDB_PTR_ERR(p); return false; + } if (p->r.magic == TDB_RECOVERY_INVALID_MAGIC || p->r.magic == TDB_RECOVERY_MAGIC) { if (unc) { diff --git a/ccan/tdb2/tdb.c b/ccan/tdb2/tdb.c index 8079dad7..130bb6b5 100644 --- a/ccan/tdb2/tdb.c +++ b/ccan/tdb2/tdb.c @@ -631,6 +631,10 @@ struct tdb_data tdb_fetch(struct tdb_context *tdb, struct tdb_data key) ret.dsize = rec_data_length(&rec); ret.dptr = tdb_alloc_read(tdb, off + sizeof(rec) + key.dsize, ret.dsize); + if (TDB_PTR_IS_ERR(ret.dptr)) { + tdb->ecode = TDB_PTR_ERR(ret.dptr); + ret = tdb_null; + } } tdb_unlock_hashes(tdb, h.hlock_start, h.hlock_range, F_RDLCK);