From: Liu Yuan <[email protected]> For storing one object into backend store, either
a) no content change, then point to the same old sha1_file (no stale object) or b) content updated, then will point to a new object with a new sha1. So we need to remove stale object in case b), only in the assumption it is the object generated by recovery code. [*] When we try store new snapshot object into the backend store, it is safe and good timing for us to remove the old object with the same object ID. [*] Here I assume we don't need to restore to 'sys epoch' state. Signed-off-by: Liu Yuan <[email protected]> --- sheep/farm.h | 2 + sheep/farm/trunk.c | 149 +++++++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 149 insertions(+), 2 deletions(-) diff --git a/sheep/farm.h b/sheep/farm.h index 4f51ca6..be7df1c 100644 --- a/sheep/farm.h +++ b/sheep/farm.h @@ -64,5 +64,7 @@ extern int trunk_file_write(unsigned char *outsha1, int user); extern void *trunk_file_read(unsigned char *sha1, struct sha1_file_hdr *); extern int trunk_update_entry(uint64_t oid); extern void trunk_reset(void); +extern void trunk_put_entry(uint64_t oid); +extern void trunk_get_entry(uint64_t oid); #endif diff --git a/sheep/farm/trunk.c b/sheep/farm/trunk.c index 0506f3f..5731ae9 100644 --- a/sheep/farm/trunk.c +++ b/sheep/farm/trunk.c @@ -18,6 +18,8 @@ */ #include <pthread.h> #include <dirent.h> +#include <sys/stat.h> +#include <unistd.h> #include "farm.h" #include "strbuf.h" @@ -36,6 +38,11 @@ static struct hlist_head trunk_hashtable[HASH_SIZE]; static pthread_mutex_t hashtable_lock[HASH_SIZE] = { [0 ... HASH_SIZE - 1] = PTHREAD_MUTEX_INITIALIZER }; static unsigned int trunk_entry_active_nr; +struct omap_entry { + uint64_t oid; + unsigned char sha1[SHA1_LEN]; +}; + static inline int trunk_entry_is_dirty(struct trunk_entry_incore *entry) { return entry->flags & TRUNK_ENTRY_DIRTY; @@ -91,6 +98,27 @@ out: return entry; } +static int create_files(void) +{ + int fd, ret = 0; + struct strbuf buf = STRBUF_INIT; + + strbuf_addstr(&buf, farm_dir); + strbuf_addf(&buf, "/%s", "sys_omap"); + + fd = open(buf.buf, O_CREAT | O_EXCL, 0666); + if (fd < 0) { + if (errno != EEXIST) { + ret = -1; + goto out; + } + } + close(fd); +out: + strbuf_release(&buf); + return ret; +} + int trunk_init(void) { DIR *dir; @@ -109,6 +137,10 @@ int trunk_init(void) continue; lookup_trunk_entry(oid, 1); } + + if (create_files() < 0) + return -1; + closedir(dir); return 0; } @@ -142,7 +174,8 @@ static int fill_entry_new_sha1(struct trunk_entry_incore *entry) close(fd); goto out; } - dprintf("oid: %"PRIx64"\n", entry->raw.oid); + dprintf("data sha1:%s, %"PRIx64"\n", sha1_to_hex(entry->raw.sha1), + entry->raw.oid); out: strbuf_release(&buf); return ret; @@ -163,9 +196,91 @@ static void inline put_entry(struct trunk_entry_incore *entry) free(entry); } +static int omap_file_init(struct strbuf *outbuf) +{ + int fd; + int len = -1; + void *buffer = NULL; + struct strbuf buf = STRBUF_INIT; + struct stat st; + + strbuf_addf(&buf, "%s/%s", farm_dir, "sys_omap"); + fd = open(buf.buf, O_RDONLY); + if (fd < 0) + goto out; + + if (fstat(fd, &st) < 0) { + dprintf("%m\n"); + goto out_close; + } + + len = st.st_size; + if (len == 0) + goto out_close; + + buffer = xmalloc(len); + len = xread(fd, buffer, len); + if (len != st.st_size) { + len = -1; + goto out_close; + } + strbuf_add(outbuf, buffer, len); +out_close: + close(fd); +out: + strbuf_release(&buf); + free(buffer); + return len; +} + +static int omap_file_final(struct strbuf *omap_buf) +{ + int fd, ret = -1; + struct strbuf buf = STRBUF_INIT; + + if (omap_buf->len == 0) + return 0; + + strbuf_addf(&buf, "%s/%s", farm_dir, "sys_omap"); + fd = open(buf.buf, O_WRONLY | O_TRUNC); + if (fd < 0) { + dprintf("%m\n"); + goto out; + } + + ret = xwrite(fd, omap_buf->buf, omap_buf->len); + if (ret != omap_buf->len) + ret = -1; + + close(fd); +out: + strbuf_release(&buf); + return ret; +} + +static struct omap_entry *omap_file_insert(struct strbuf *buf, struct omap_entry *new) +{ + unsigned i, nr = buf->len / sizeof(struct omap_entry); + struct omap_entry *omap_buf = (struct omap_entry *)buf->buf; + for (i = 0; i < nr; i++, omap_buf++) + if (omap_buf->oid == new->oid) { + if (memcmp(omap_buf->sha1, new->sha1, SHA1_LEN) == 0) + return NULL; + else { + struct omap_entry *old = xmalloc(sizeof(*old)); + memcpy(old, omap_buf, sizeof(*old)); + memcpy(omap_buf->sha1, new->sha1, SHA1_LEN); + return old; + } + } + dprintf("oid, %"PRIx64"\n", new->oid); + strbuf_add(buf, new, sizeof(*new)); + return NULL; +} + int trunk_file_write(unsigned char *outsha1, int user) { - struct strbuf buf; + struct strbuf buf, omap_buf = STRBUF_INIT; uint64_t data_size = sizeof(struct trunk_entry) * trunk_entry_active_nr; struct sha1_file_hdr hdr = { .size = data_size, .priv = trunk_entry_active_nr }; @@ -174,6 +289,7 @@ int trunk_file_write(unsigned char *outsha1, int user) memcpy(hdr.tag, TAG_TRUNK, TAG_LEN); strbuf_init(&buf, sizeof(hdr) + data_size); + omap_file_init(&omap_buf); strbuf_add(&buf, &hdr, sizeof(hdr)); list_for_each_entry_safe(entry, t, &trunk_active_list, active_list) { @@ -184,8 +300,21 @@ int trunk_file_write(unsigned char *outsha1, int user) } } strbuf_add(&buf, &entry->raw, sizeof(struct trunk_entry)); + if (!user) { + struct omap_entry new = { .oid = entry->raw.oid }, *old; + memcpy(new.sha1, entry->raw.sha1, SHA1_LEN); + old = omap_file_insert(&omap_buf, &new); + if (old) { + dprintf("try delete stale snapshot object %"PRIx64"\n", old->oid); + sha1_file_delete(old->sha1); + free(old); + } + } undirty_trunk_entry(entry); } + if (omap_file_final(&omap_buf) < 0) + eprintf("omap_file_final failed\n"); + if (sha1_file_write((void *)buf.buf, buf.len, outsha1) < 0) { ret = -1; goto out; @@ -193,6 +322,7 @@ int trunk_file_write(unsigned char *outsha1, int user) dprintf("trunk sha1: %s\n", sha1_to_hex(outsha1)); out: strbuf_release(&buf); + strbuf_release(&omap_buf); return ret; } @@ -223,6 +353,21 @@ int trunk_update_entry(uint64_t oid) return 0; } +void trunk_put_entry(uint64_t oid) +{ + struct trunk_entry_incore *entry; + + entry = lookup_trunk_entry(oid, 0); + if (entry) + /* When it is supposed to be put, no IO requests for it */ + put_entry(entry); +} + +void trunk_get_entry(uint64_t oid) +{ + lookup_trunk_entry(oid, 1); +} + void trunk_reset(void) { struct trunk_entry_incore *entry, *t; -- 1.7.8.rc3 -- sheepdog mailing list [email protected] http://lists.wpkg.org/mailman/listinfo/sheepdog
