tdb2: check PID if we are holding a lock.

[ccan] / ccan / tdb2 / private.h

diff --git a/ccan/tdb2/private.h b/ccan/tdb2/private.h
index 8e7df501b716a139c77e8de2ff673fe1afa55266..c95c7e05e59181f9d67c8131c7d813353a4c99af 100644 (file)
--- a/ccan/tdb2/private.h
+++ b/ccan/tdb2/private.h
@@ -75,7 +75,7 @@ typedef uint64_t tdb_off_t;
 
 /* Packing errors into pointers and v.v. */
 #define TDB_PTR_IS_ERR(ptr) \
-       unlikely((void *)(ptr) >= (void *)(long)TDB_ERR_LAST)
+       unlikely((unsigned long)(ptr) >= (unsigned long)TDB_ERR_LAST)
 #define TDB_PTR_ERR(p) ((enum TDB_ERROR)(long)(p))
 #define TDB_ERR_PTR(err) ((void *)(long)(err))
 
@@ -246,7 +246,9 @@ struct tdb_header {
        uint64_t features_used; /* Features all writers understand */
        uint64_t features_offered; /* Features offered */
 
-       tdb_off_t reserved[24];
+       uint64_t seqnum; /* Sequence number for TDB_SEQNUM */
+
+       tdb_off_t reserved[23];
 
        /* Top level hash table. */
        tdb_off_t hashtable[1ULL << TDB_TOPLEVEL_HASH_BITS];
@@ -300,7 +302,8 @@ enum tdb_lock_flags {
        TDB_LOCK_NOCHECK = 4,
 };
 
-struct tdb_lock_type {
+struct tdb_lock {
+       struct tdb_context *owner;
        uint32_t off;
        uint32_t count;
        uint32_t ltype;
@@ -315,21 +318,39 @@ struct tdb_access_hdr {
        bool convert;
 };
 
-struct tdb_context {
-       /* Filename of the database. */
-       const char *name;
+struct tdb_file {
+       /* Single list of all TDBs, to detect multiple opens. */
+       struct tdb_file *next;
+
+       /* How many are sharing us? */
+       unsigned int refcnt;
 
        /* Mmap (if any), or malloc (for TDB_INTERNAL). */
        void *map_ptr;
 
-       /* Are we accessing directly? (debugging check). */
-       int direct_access;
+       /* How much space has been mapped (<= current file size) */
+       tdb_len_t map_size;
 
-        /* Open file descriptor (undefined for TDB_INTERNAL). */
+       /* The file descriptor (-1 for TDB_INTERNAL). */
        int fd;
 
-       /* How much space has been mapped (<= current file size) */
-       tdb_len_t map_size;
+       /* Lock information */
+       pid_t locker;
+       struct tdb_lock allrecord_lock;
+       size_t num_lockrecs;
+       struct tdb_lock *lockrecs;
+
+       /* Identity of this file. */
+       dev_t device;
+       ino_t inode;
+};
+
+struct tdb_context {
+       /* Filename of the database. */
+       const char *name;
+
+       /* Are we accessing directly? (debugging check). */
+       int direct_access;
 
        /* Operating read-only? (Opened O_RDONLY, or in traverse_read) */
        bool read_only;
@@ -365,20 +386,16 @@ struct tdb_context {
        /* IO methods: changes for transactions. */
        const struct tdb_methods *methods;
 
-       /* Lock information */
-       struct tdb_lock_type allrecord_lock;
-       size_t num_lockrecs;
-       struct tdb_lock_type *lockrecs;
-
        struct tdb_attribute_stats *stats;
 
        /* Direct access information */
        struct tdb_access_hdr *access;
 
-       /* Single list of all TDBs, to avoid multiple opens. */
-       struct tdb_context *next;
-       dev_t device;
-       ino_t inode;
+       /* Last error we returned. */
+       enum TDB_ERROR last_error;
+
+       /* The actual file information */
+       struct tdb_file *file;
 };
 
 struct tdb_methods {
@@ -467,7 +484,7 @@ void tdb_io_init(struct tdb_context *tdb);
 void *tdb_convert(const struct tdb_context *tdb, void *buf, tdb_len_t size);
 
 /* Unmap and try to map the tdb. */
-void tdb_munmap(struct tdb_context *tdb);
+void tdb_munmap(struct tdb_file *file);
 void tdb_mmap(struct tdb_context *tdb);
 
 /* Either alloc a copy, or give direct access.  Release frees or noop. */
@@ -512,6 +529,9 @@ enum TDB_ERROR tdb_write_convert(struct tdb_context *tdb, tdb_off_t off,
 enum TDB_ERROR tdb_read_convert(struct tdb_context *tdb, tdb_off_t off,
                                void *rec, size_t len);
 
+/* Bump the seqnum (caller checks for tdb->flags & TDB_SEQNUM) */
+void tdb_inc_seqnum(struct tdb_context *tdb);
+
 /* Adds a stat, if it's in range. */
 void add_stat_(struct tdb_context *tdb, uint64_t *stat, size_t val);
 #define add_stat(tdb, statname, val)                                   \
@@ -521,8 +541,6 @@ void add_stat_(struct tdb_context *tdb, uint64_t *stat, size_t val);
        } while (0)
 
 /* lock.c: */
-void tdb_lock_init(struct tdb_context *tdb);
-
 /* Lock/unlock a range of hashes. */
 enum TDB_ERROR tdb_lock_hashes(struct tdb_context *tdb,
                               tdb_off_t hash_lock, tdb_len_t hash_range,
@@ -531,6 +549,9 @@ enum TDB_ERROR tdb_unlock_hashes(struct tdb_context *tdb,
                                 tdb_off_t hash_lock,
                                 tdb_len_t hash_range, int ltype);
 
+/* For closing the file. */
+void tdb_lock_cleanup(struct tdb_context *tdb);
+
 /* Lock/unlock a particular free bucket. */
 enum TDB_ERROR tdb_lock_free_bucket(struct tdb_context *tdb, tdb_off_t b_off,
                                    enum tdb_lock_flags waitflag);