/*
* Sherlock Library -- Object Buckets
*
- * (c) 2001 Martin Mares <mj@ucw.cz>
+ * (c) 2001--2004 Martin Mares <mj@ucw.cz>
+ * (c) 2004 Robert Spalek <robert@ucw.cz>
*
- * Warning: Touches internals of the fb-file module!
+ * This software may be freely distributed and used according to the terms
+ * of the GNU Lesser General Public License.
*/
+#undef LOCAL_DEBUG
+
#include "lib/lib.h"
#include "lib/bucket.h"
#include "lib/fastbuf.h"
+#include "lib/lfs.h"
+#include "lib/conf.h"
#include <string.h>
+#include <stdlib.h>
#include <fcntl.h>
#include <unistd.h>
#include <sys/file.h>
+#include <alloca.h>
static int obuck_fd;
-static struct fastbuf *obuck_fb;
-static struct obuck_header obuck_hdr;
-static sh_off_t start_of_this, start_of_next;
-static char *obuck_name = "db/objects"; /* FIXME */
+static struct obuck_header obuck_hdr, obuck_create_hdr;
+static sh_off_t bucket_find_pos;
+static struct fastbuf *obuck_write_fb;
-void
-obuck_init(int writeable)
-{
- obuck_fb = bopen(obuck_name, (writeable ? O_RDWR | O_CREAT : O_RDONLY), 65536);
- obuck_fd = obuck_fb->fd;
-}
+/*** Configuration ***/
-void
-obuck_cleanup(void)
+byte *obuck_name = "not/configured";
+static uns obuck_io_buflen = 65536;
+static int obuck_shake_buflen = 1048576;
+static uns obuck_shake_security;
+static uns obuck_slurp_buflen = 65536;
+
+static struct cfitem obuck_config[] = {
+ { "Buckets", CT_SECTION, NULL },
+ { "BucketFile", CT_STRING, &obuck_name },
+ { "BufSize", CT_INT, &obuck_io_buflen },
+ { "ShakeBufSize", CT_INT, &obuck_shake_buflen },
+ { "ShakeSecurity", CT_INT, &obuck_shake_security },
+ { "SlurpBufSize", CT_INT, &obuck_slurp_buflen },
+ { NULL, CT_STOP, NULL }
+};
+
+static void CONSTRUCTOR obuck_init_config(void)
{
- bclose(obuck_fb);
+ cf_register(obuck_config);
}
+/*** Internal operations ***/
+
static void
-obuck_broken(char *msg)
+obuck_broken(char *msg, sh_off_t pos)
{
- die("Object pool corrupted: %s", msg); /* FIXME */
+ die("Object pool corrupted: %s (pos=%Lx)", msg, (long long) pos);
}
+/*
+ * We need several types of locks:
+ *
+ * Read lock reading parts of bucket file
+ * Write lock any write operations
+ * Append lock appending to the end of the file
+ * Scan lock reading parts which we are certain they exist
+ *
+ * Multiple read and scan locks can co-exist together.
+ * Scan locks can co-exist with an append lock.
+ * There can be at most one write/append lock at a time.
+ *
+ * These lock types map to a pair of normal read-write locks which
+ * we represent as fcntl() locks on the first and second byte of the
+ * bucket file. [We cannot use flock() since it happily permits
+ * locking a shared fd (e.g., after fork()) multiple times at it also
+ * doesn't offer multiple locks on a single file.]
+ *
+ * byte0 byte1
+ * Read <read> <read>
+ * Write <write> <write>
+ * Append <write> -
+ * Scan - <read>
+ */
+
static inline void
+obuck_do_lock(int type, int start, int len)
+{
+ struct flock fl;
+
+ fl.l_type = type;
+ fl.l_whence = SEEK_SET;
+ fl.l_start = start;
+ fl.l_len = len;
+ if (fcntl(obuck_fd, F_SETLKW, &fl) < 0)
+ die("fcntl lock: %m");
+}
+
+inline void
obuck_lock_read(void)
{
- flock(obuck_fd, LOCK_SH);
+ obuck_do_lock(F_RDLCK, 0, 2);
}
-static inline void
+inline void
obuck_lock_write(void)
{
- flock(obuck_fd, LOCK_EX);
+ obuck_do_lock(F_WRLCK, 0, 2);
+}
+
+static inline void
+obuck_lock_append(void)
+{
+ obuck_do_lock(F_WRLCK, 0, 1);
}
static inline void
+obuck_lock_read_to_scan(void)
+{
+ obuck_do_lock(F_UNLCK, 0, 1);
+}
+
+inline void
obuck_unlock(void)
{
- flock(obuck_fd, LOCK_UN);
+ obuck_do_lock(F_UNLCK, 0, 2);
+}
+
+/*** FastIO emulation ***/
+
+struct fb_bucket {
+ struct fastbuf fb;
+ sh_off_t start_pos;
+ uns bucket_size;
+ byte buffer[0];
+};
+#define FB_BUCKET(f) ((struct fb_bucket *)(f)->is_fastbuf)
+
+static int obuck_fb_count;
+
+static void
+obuck_fb_close(struct fastbuf *f)
+{
+ obuck_fb_count--;
+ xfree(f);
+}
+
+/* We need to use pread/pwrite since we work on fd's shared between processes */
+
+static int
+obuck_fb_refill(struct fastbuf *f)
+{
+ uns remains, bufsize, size, datasize;
+
+ remains = FB_BUCKET(f)->bucket_size - (uns)f->pos;
+ if (!remains)
+ return 0;
+ f->buffer = FB_BUCKET(f)->buffer; /* Could have been trimmed by bdirect_read_commit_modified() */
+ bufsize = f->bufend - f->buffer;
+ sh_off_t start = FB_BUCKET(f)->start_pos;
+ sh_off_t pos = start + sizeof(struct obuck_header) + f->pos;
+ if (remains <= bufsize)
+ {
+ datasize = remains;
+ size = start + obuck_bucket_size(FB_BUCKET(f)->bucket_size) - pos;
+ }
+ else
+ size = datasize = bufsize;
+ int l = sh_pread(obuck_fd, f->buffer, size, pos);
+ if (l < 0)
+ die("Error reading bucket: %m");
+ if ((unsigned) l != size)
+ obuck_broken("Short read", FB_BUCKET(f)->start_pos);
+ f->bptr = f->buffer;
+ f->bstop = f->buffer + datasize;
+ f->pos += datasize;
+ if (datasize < size)
+ {
+ if (GET_U32(f->buffer + size - 4) != OBUCK_TRAILER)
+ obuck_broken("Missing trailer", FB_BUCKET(f)->start_pos);
+ }
+ return datasize;
+}
+
+static void
+obuck_fb_spout(struct fastbuf *f)
+{
+ int l = f->bptr - f->buffer;
+ char *c = f->buffer;
+
+ while (l)
+ {
+ int z = sh_pwrite(obuck_fd, c, l, FB_BUCKET(f)->start_pos + sizeof(struct obuck_header) + f->pos);
+ if (z <= 0)
+ die("Error writing bucket: %m");
+ f->pos += z;
+ l -= z;
+ c += z;
+ }
+ f->bptr = f->buffer;
+}
+
+/*** Exported functions ***/
+
+void
+obuck_init(int writeable)
+{
+ sh_off_t size;
+
+ obuck_fd = sh_open(obuck_name, (writeable ? O_RDWR | O_CREAT : O_RDONLY), 0666);
+ if (obuck_fd < 0)
+ die("Unable to open bucket file %s: %m", obuck_name);
+ obuck_lock_read();
+ size = sh_seek(obuck_fd, 0, SEEK_END);
+ if (size)
+ {
+ /* If the bucket pool is not empty, check consistency of its end */
+ u32 check;
+ if (sh_pread(obuck_fd, &check, 4, size-4) != 4 ||
+ check != OBUCK_TRAILER)
+ obuck_broken("Missing trailer of last object", size - 4);
+ }
+ obuck_unlock();
+}
+
+void
+obuck_cleanup(void)
+{
+ close(obuck_fd);
+ if (obuck_fb_count)
+ log(L_ERROR, "Bug: Unbalanced bucket opens/closes: %d streams remain", obuck_fb_count);
+ if (obuck_write_fb)
+ log(L_ERROR, "Bug: Forgot to close bucket write stream");
+}
+
+void
+obuck_sync(void)
+{
+ if (obuck_write_fb)
+ bflush(obuck_write_fb);
+ fsync(obuck_fd);
}
static void
-obuck_fetch_header(oid_t oid)
+obuck_get(oid_t oid)
{
- start_of_this = ((sh_off_t) oid) << OBUCK_SHIFT;
- bsetpos(obuck_fb, start_of_this);
- bread(obuck_fb, &obuck_hdr, sizeof(obuck_hdr));
+ bucket_find_pos = obuck_get_pos(oid);
+ if (sh_pread(obuck_fd, &obuck_hdr, sizeof(obuck_hdr), bucket_find_pos) != sizeof(obuck_hdr))
+ obuck_broken("Short header read", bucket_find_pos);
if (obuck_hdr.magic != OBUCK_MAGIC)
- obuck_broken("Missing magic number");
+ obuck_broken("Missing magic number", bucket_find_pos);
if (obuck_hdr.oid == OBUCK_OID_DELETED)
- obuck_broken("Access to deleted bucket");
+ obuck_broken("Access to deleted bucket", bucket_find_pos);
if (obuck_hdr.oid != oid)
- obuck_broken("Invalid backlink");
+ obuck_broken("Invalid backlink", bucket_find_pos);
}
-struct fastbuf *
-obuck_fetch(struct obuck_header *hdrp)
+void
+obuck_find_by_oid(struct obuck_header *hdrp)
{
+ oid_t oid = hdrp->oid;
+
+ ASSERT(oid < OBUCK_OID_FIRST_SPECIAL);
obuck_lock_read();
- obuck_fetch_header(hdrp->oid);
+ obuck_get(oid);
+ obuck_unlock();
memcpy(hdrp, &obuck_hdr, sizeof(obuck_hdr));
- return obuck_fb;
}
-void
-obuck_fetch_abort(struct fastbuf *b UNUSED)
+int
+obuck_find_first(struct obuck_header *hdrp, int full)
{
- obuck_unlock();
+ bucket_find_pos = 0;
+ obuck_hdr.magic = 0;
+ return obuck_find_next(hdrp, full);
}
-void
-obuck_fetch_end(struct fastbuf *b UNUSED)
+int
+obuck_find_next(struct obuck_header *hdrp, int full)
{
- if (bgetl(b) != OBUCK_TRAILER)
- obuck_broken("Corrupted trailer");
- obuck_unlock();
+ int c;
+
+ for(;;)
+ {
+ if (obuck_hdr.magic)
+ bucket_find_pos += obuck_bucket_size(obuck_hdr.length);
+ obuck_lock_read();
+ c = sh_pread(obuck_fd, &obuck_hdr, sizeof(obuck_hdr), bucket_find_pos);
+ obuck_unlock();
+ if (!c)
+ return 0;
+ if (c != sizeof(obuck_hdr))
+ obuck_broken("Short header read", bucket_find_pos);
+ if (obuck_hdr.magic != OBUCK_MAGIC)
+ obuck_broken("Missing magic number", bucket_find_pos);
+ if (obuck_hdr.oid != OBUCK_OID_DELETED || full)
+ {
+ memcpy(hdrp, &obuck_hdr, sizeof(obuck_hdr));
+ return 1;
+ }
+ }
}
struct fastbuf *
-obuck_write(void)
+obuck_fetch(void)
{
- obuck_lock_write();
- bseek(obuck_fb, 0, SEEK_END);
- start_of_this = btell(obuck_fb);
- if (start_of_this & (OBUCK_ALIGN - 1))
- obuck_broken("Misaligned file");
- obuck_hdr.magic = 0;
- obuck_hdr.oid = start_of_this >> OBUCK_SHIFT;
- obuck_hdr.length = obuck_hdr.orig_length = 0;
- bwrite(obuck_fb, &obuck_hdr, sizeof(obuck_hdr));
- return obuck_fb;
+ struct fastbuf *b;
+ uns official_buflen = ALIGN(MIN(obuck_hdr.length, obuck_io_buflen), OBUCK_ALIGN);
+ uns real_buflen = official_buflen + OBUCK_ALIGN;
+
+ b = xmalloc(sizeof(struct fb_bucket) + real_buflen);
+ b->buffer = b->bptr = b->bstop = FB_BUCKET(b)->buffer;
+ b->bufend = b->buffer + official_buflen;
+ b->name = "bucket-read";
+ b->pos = 0;
+ b->refill = obuck_fb_refill;
+ b->spout = NULL;
+ b->seek = NULL;
+ b->close = obuck_fb_close;
+ b->config = NULL;
+ b->can_overwrite_buffer = 2;
+ FB_BUCKET(b)->start_pos = bucket_find_pos;
+ FB_BUCKET(b)->bucket_size = obuck_hdr.length;
+ obuck_fb_count++;
+ return b;
+}
+
+oid_t
+obuck_predict_last_oid(void)
+{
+ sh_off_t size = sh_seek(obuck_fd, 0, SEEK_END);
+ return (oid_t)(size >> OBUCK_SHIFT);
+}
+
+struct fastbuf *
+obuck_create(u32 type)
+{
+ ASSERT(!obuck_write_fb);
+
+ obuck_lock_append();
+ sh_off_t start = sh_seek(obuck_fd, 0, SEEK_END);
+ if (start & (OBUCK_ALIGN - 1))
+ obuck_broken("Misaligned file", start);
+ obuck_create_hdr.magic = OBUCK_INCOMPLETE_MAGIC;
+ obuck_create_hdr.oid = start >> OBUCK_SHIFT;
+ obuck_create_hdr.length = 0;
+ obuck_create_hdr.type = type;
+
+ struct fastbuf *b = xmalloc(sizeof(struct fb_bucket) + obuck_io_buflen);
+ obuck_write_fb = b;
+ b->buffer = FB_BUCKET(b)->buffer;
+ b->bptr = b->bstop = b->buffer;
+ b->bufend = b->buffer + obuck_io_buflen;
+ b->pos = -(int)sizeof(obuck_create_hdr);
+ b->name = "bucket-write";
+ b->refill = NULL;
+ b->spout = obuck_fb_spout;
+ b->seek = NULL;
+ b->close = NULL;
+ b->config = NULL;
+ b->can_overwrite_buffer = 0;
+ FB_BUCKET(b)->start_pos = start;
+ FB_BUCKET(b)->bucket_size = 0;
+ bwrite(b, &obuck_create_hdr, sizeof(obuck_create_hdr));
+
+ return b;
}
void
-obuck_write_end(struct fastbuf *b UNUSED, struct obuck_header *hdrp)
+obuck_create_end(struct fastbuf *b, struct obuck_header *hdrp)
{
- int pad;
- obuck_hdr.magic = OBUCK_MAGIC;
- obuck_hdr.length = obuck_hdr.orig_length = btell(obuck_fb) - start_of_this - sizeof(obuck_hdr);
- bputl(obuck_fb, OBUCK_TRAILER);
- pad = (OBUCK_ALIGN - sizeof(obuck_hdr) - obuck_hdr.length - 4) & (OBUCK_ALIGN - 1);
+ ASSERT(b == obuck_write_fb);
+ obuck_write_fb = NULL;
+
+ obuck_create_hdr.magic = OBUCK_MAGIC;
+ obuck_create_hdr.length = btell(b);
+ int pad = (OBUCK_ALIGN - sizeof(obuck_create_hdr) - obuck_create_hdr.length - 4) & (OBUCK_ALIGN - 1);
while (pad--)
- bputc(obuck_fb, 0);
- bflush(obuck_fb);
- bsetpos(obuck_fb, start_of_this);
- /* FIXME: Can be replaced with single pwrite */
- bwrite(obuck_fb, &obuck_hdr, sizeof(obuck_hdr));
- bflush(obuck_fb);
+ bputc(b, 0);
+ bputl(b, OBUCK_TRAILER);
+ bflush(b);
+ ASSERT(!((FB_BUCKET(b)->start_pos + sizeof(obuck_create_hdr) + b->pos) & (OBUCK_ALIGN - 1)));
+ if (sh_pwrite(obuck_fd, &obuck_create_hdr, sizeof(obuck_create_hdr), FB_BUCKET(b)->start_pos) != sizeof(obuck_create_hdr))
+ die("Bucket header update failed: %m");
obuck_unlock();
- memcpy(hdrp, &obuck_hdr, sizeof(obuck_hdr));
+ memcpy(hdrp, &obuck_create_hdr, sizeof(obuck_create_hdr));
+ xfree(b);
}
void
obuck_delete(oid_t oid)
{
obuck_lock_write();
- obuck_fetch_header(oid);
+ obuck_get(oid);
obuck_hdr.oid = OBUCK_OID_DELETED;
- bflush(obuck_fb);
- bsetpos(obuck_fb, start_of_this);
- bwrite(obuck_fb, &obuck_hdr, sizeof(obuck_hdr));
- bflush(obuck_fb);
+ sh_pwrite(obuck_fd, &obuck_hdr, sizeof(obuck_hdr), bucket_find_pos);
obuck_unlock();
}
-struct fastbuf *
-obuck_walk_init(void)
+/*** Fast reading of the whole pool ***/
+
+static struct fastbuf *obuck_rpf;
+static uns slurp_remains;
+static sh_off_t slurp_start, slurp_current, slurp_end;
+
+static int
+obuck_slurp_refill(struct fastbuf *f)
{
- start_of_this = start_of_next = 0;
- obuck_lock_read();
- return obuck_fb;
+ if (!slurp_remains)
+ return 0;
+ uns l = bdirect_read_prepare(obuck_rpf, &f->buffer);
+ if (!l)
+ obuck_broken("Incomplete object", slurp_start);
+ l = MIN(l, slurp_remains);
+ /* XXX: This probably should be bdirect_read_commit_modified() in some cases,
+ * but it doesn't hurt since we aren't going to seek.
+ */
+ bdirect_read_commit(obuck_rpf, f->buffer + l);
+ slurp_remains -= l;
+ f->bptr = f->buffer;
+ f->bufend = f->bstop = f->buffer + l;
+ return 1;
}
struct fastbuf *
-obuck_walk_next(struct fastbuf *b, struct obuck_header *hdrp)
+obuck_slurp_pool(struct obuck_header *hdrp)
{
- int c;
+ static struct fastbuf limiter;
+ uns l;
-restart:
- start_of_this = start_of_next;
- bsetpos(b, start_of_this);
- c = bgetc(b);
- if (c < 0)
- return NULL;
- bungetc(b, c);
- bread(b, &obuck_hdr, sizeof(obuck_hdr));
- if (obuck_hdr.magic != OBUCK_MAGIC)
- obuck_broken("Missing magic number");
- start_of_next = (start_of_this + sizeof(obuck_hdr) + obuck_hdr.orig_length +
- 4 + OBUCK_ALIGN - 1) & ~((sh_off_t)(OBUCK_ALIGN - 1));
- if (obuck_hdr.oid == OBUCK_OID_DELETED)
- goto restart;
- memcpy(hdrp, &obuck_hdr, sizeof(obuck_hdr));
- return b;
+ do
+ {
+ if (!obuck_rpf)
+ {
+ obuck_lock_read();
+ obuck_rpf = bopen(obuck_name, O_RDONLY, obuck_slurp_buflen);
+ slurp_end = bfilesize(obuck_rpf);
+ obuck_lock_read_to_scan();
+ }
+ else
+ {
+ bsetpos(obuck_rpf, slurp_current - 4);
+ if (bgetl(obuck_rpf) != OBUCK_TRAILER)
+ obuck_broken("Missing trailer", slurp_start);
+ }
+ slurp_start = btell(obuck_rpf);
+ if (slurp_start < slurp_end)
+ l = bread(obuck_rpf, hdrp, sizeof(struct obuck_header));
+ else
+ l = 0;
+ if (!l)
+ {
+ bclose(obuck_rpf);
+ obuck_rpf = NULL;
+ obuck_unlock();
+ return NULL;
+ }
+ if (l != sizeof(struct obuck_header))
+ obuck_broken("Short header read", slurp_start);
+ if (hdrp->magic != OBUCK_MAGIC)
+ obuck_broken("Missing magic number", slurp_start);
+ slurp_current = slurp_start + obuck_bucket_size(hdrp->length);
+ }
+ while (hdrp->oid == OBUCK_OID_DELETED);
+ if (obuck_get_pos(hdrp->oid) != slurp_start)
+ obuck_broken("Invalid backlink", slurp_start);
+ slurp_remains = hdrp->length;
+ limiter.bptr = limiter.bstop = limiter.buffer = limiter.bufend = NULL;
+ limiter.name = "Bucket";
+ limiter.pos = 0;
+ limiter.refill = obuck_slurp_refill;
+ limiter.can_overwrite_buffer = obuck_rpf->can_overwrite_buffer;
+ return &limiter;
+}
+
+/*** Shakedown ***/
+
+static inline void
+shake_write(void *addr, int len, sh_off_t pos)
+{
+ int l = sh_pwrite(obuck_fd, addr, len, pos);
+ if (l != len)
+ {
+ if (l < 0)
+ die("obuck_shakedown write error: %m");
+ else
+ die("obuck_shakedown write error: disk full");
+ }
+}
+
+static inline void
+shake_sync(void)
+{
+ if (obuck_shake_security > 1)
+ fdatasync(obuck_fd);
+}
+
+static void
+shake_write_backup(sh_off_t bpos, byte *norm_buf, int norm_size, byte *fragment, int frag_size, sh_off_t frag_pos, int more_size)
+{
+ struct obuck_header *bhdr;
+ int boff = 0;
+ int l;
+ oid_t old_oid;
+
+ /* First of all, the "normal" part -- everything that will be written in this pass */
+ DBG("Backing up first round of changes at position %Lx + %x", (long long) bpos, norm_size);
+ while (boff < norm_size)
+ {
+ /* This needn't be optimized for speed. */
+ bhdr = (struct obuck_header *) (norm_buf + boff);
+ ASSERT(bhdr->magic == OBUCK_MAGIC);
+ l = obuck_bucket_size(bhdr->length);
+ old_oid = bhdr->oid;
+ bhdr->oid = bpos >> OBUCK_SHIFT;
+ shake_write(bhdr, l, bpos);
+ bhdr->oid = old_oid;
+ boff += l;
+ bpos += l;
+ }
+
+ /* If we have an incomplete bucket at the end of the buffer, we must copy it as well. */
+ if (more_size)
+ {
+ DBG("Backing up fragment of size %x and %x more", frag_size, more_size);
+
+ /* First the part we already have in the buffer */
+ bhdr = (struct obuck_header *) fragment;
+ ASSERT(bhdr->magic == OBUCK_MAGIC);
+ old_oid = bhdr->oid;
+ bhdr->oid = bpos >> OBUCK_SHIFT;
+ shake_write(bhdr, frag_size, bpos);
+ bhdr->oid = old_oid;
+ bpos += frag_size;
+
+ /* And then the rest, using a small 64K buffer */
+ byte *auxbuf = alloca(65536);
+ l = 0;
+ while (l < more_size)
+ {
+ int j = MIN(more_size-l, 65536);
+ if (sh_pread(obuck_fd, auxbuf, j, frag_pos + frag_size + l) != j)
+ die("obuck_shakedown read error: %m");
+ shake_write(auxbuf, j, bpos);
+ bpos += j;
+ l += j;
+ }
+ }
+}
+
+static void
+shake_erase(sh_off_t start, sh_off_t end)
+{
+ if (start > end)
+ die("shake_erase called with negative length, that's a bug");
+ ASSERT(!(start & (OBUCK_ALIGN-1)) && !(end & (OBUCK_ALIGN-1)));
+ while (start < end)
+ {
+ u32 check = OBUCK_TRAILER;
+ obuck_hdr.magic = OBUCK_MAGIC;
+ obuck_hdr.oid = OBUCK_OID_DELETED;
+ uns len = MIN(0x40000000, end-start);
+ obuck_hdr.length = len - sizeof(obuck_hdr) - 4;
+ DBG("Erasing %08x bytes at %Lx", len, (long long) start);
+ shake_write(&obuck_hdr, sizeof(obuck_hdr), start);
+ start += len;
+ shake_write(&check, 4, start-4);
+ }
}
void
-obuck_walk_end(struct fastbuf *b UNUSED)
+obuck_shakedown(int (*kibitz)(struct obuck_header *old, oid_t new, byte *buck))
{
+ byte *buf; /* Shakedown buffer and its size */
+ int buflen = ALIGN(obuck_shake_buflen, OBUCK_ALIGN);
+ byte *msg; /* Error message we will print */
+ sh_off_t rstart, wstart; /* Original and new position of buffer start */
+ sh_off_t r_bucket_start, w_bucket_start; /* Original and new position of the current bucket */
+ int roff, woff; /* Orig/new position of the current bucket relative to buffer start */
+ int rsize; /* Number of original bytes in the buffer */
+ int l; /* Raw size of the current bucket */
+ int changed = 0; /* "Something has been altered" flag */
+ int wrote_anything = 0; /* We already did a write to the bucket file */
+ struct obuck_header *rhdr, *whdr; /* Original and new address of header of the current bucket */
+ sh_off_t r_file_size; /* Original size of the bucket file */
+ int more; /* How much does the last bucket overlap the buffer */
+
+ buf = xmalloc(buflen);
+ rstart = wstart = 0;
+ roff = woff = rsize = 0;
+
+ /* We need to be the only accessor, all the object ID's are becoming invalid */
+ obuck_lock_write();
+ r_file_size = sh_seek(obuck_fd, 0, SEEK_END);
+ ASSERT(!(r_file_size & (OBUCK_ALIGN - 1)));
+ if (r_file_size >= (0x100000000 << OBUCK_SHIFT) - buflen)
+ die("Bucket file is too large for safe shakedown. Shaking down with Bucket.ShakeSecurity=0 will still work.");
+
+ DBG("Starting shakedown. Buffer size is %d, original length %Lx", buflen, (long long) r_file_size);
+
+ for(;;)
+ {
+ r_bucket_start = rstart + roff;
+ w_bucket_start = wstart + woff;
+ rhdr = (struct obuck_header *)(buf + roff);
+ whdr = (struct obuck_header *)(buf + woff);
+ if (roff == rsize)
+ {
+ more = 0;
+ goto next;
+ }
+ if (rhdr->magic != OBUCK_MAGIC ||
+ rhdr->oid != OBUCK_OID_DELETED && rhdr->oid != (oid_t)(r_bucket_start >> OBUCK_SHIFT))
+ {
+ msg = "header mismatch";
+ goto broken;
+ }
+ l = obuck_bucket_size(rhdr->length);
+ if (l > buflen)
+ {
+ if (rhdr->oid != OBUCK_OID_DELETED)
+ {
+ msg = "bucket longer than ShakeBufSize";
+ goto broken;
+ }
+ /* Empty buckets are allowed to be large, but we need to handle them extra */
+ DBG("Tricking around an extra-large empty bucket at %Lx + %x", (long long)r_bucket_start, l);
+ rsize = roff + l;
+ }
+ else
+ {
+ if (rsize - roff < l)
+ {
+ more = l - (rsize - roff);
+ goto next;
+ }
+ if (GET_U32((byte *)rhdr + l - 4) != OBUCK_TRAILER)
+ {
+ msg = "missing trailer";
+ goto broken;
+ }
+ }
+ if (rhdr->oid != OBUCK_OID_DELETED)
+ {
+ int status = kibitz(rhdr, w_bucket_start >> OBUCK_SHIFT, (byte *)(rhdr+1));
+ if (status)
+ {
+ int lnew = l;
+ if (status > 1)
+ {
+ /* Changed! Reconstruct the trailer. */
+ lnew = obuck_bucket_size(rhdr->length);
+ ASSERT(lnew <= l);
+ PUT_U32((byte *)rhdr + lnew - 4, OBUCK_TRAILER);
+ changed = 1;
+ }
+ whdr = (struct obuck_header *)(buf+woff);
+ if (rhdr != whdr)
+ memmove(whdr, rhdr, lnew);
+ whdr->oid = w_bucket_start >> OBUCK_SHIFT;
+ woff += lnew;
+ }
+ else
+ changed = 1;
+ }
+ else
+ {
+ kibitz(rhdr, OBUCK_OID_DELETED, NULL);
+ changed = 1;
+ }
+ roff += l;
+ continue;
+
+ next:
+ if (changed)
+ {
+ /* Write the new contents of the bucket file */
+ if (!wrote_anything)
+ {
+ if (obuck_shake_security)
+ {
+ /* But first write a backup at the end of the file to ensure nothing can be lost. */
+ shake_write_backup(r_file_size, buf, woff, buf+roff, rsize-roff, rstart+roff, more);
+ shake_sync();
+ }
+ wrote_anything = 1;
+ }
+ if (woff)
+ {
+ DBG("Write %Lx %x", wstart, woff);
+ shake_write(buf, woff, wstart);
+ shake_sync();
+ }
+ }
+ else
+ ASSERT(wstart == rstart);
+
+ /* In any case, update the write position */
+ wstart += woff;
+ woff = 0;
+
+ /* Skip what's been read and if there is any fragment at the end of the buffer, move it to the start */
+ rstart += roff;
+ if (more)
+ {
+ memmove(buf, buf+roff, rsize-roff);
+ rsize = rsize-roff;
+ }
+ else
+ rsize = 0;
+
+ /* And refill the buffer */
+ r_bucket_start = rstart+rsize; /* Also needed for error messages */
+ l = sh_pread(obuck_fd, buf+rsize, MIN(buflen-rsize, r_file_size - r_bucket_start), r_bucket_start);
+ DBG("Read %Lx %x (%x inherited)", (long long)r_bucket_start, l, rsize);
+ if (l < 0)
+ die("obuck_shakedown read error: %m");
+ if (!l)
+ {
+ if (!more)
+ break;
+ msg = "unexpected EOF";
+ goto broken;
+ }
+ if (l & (OBUCK_ALIGN-1))
+ {
+ msg = "garbage at the end of file";
+ goto broken;
+ }
+ rsize += l;
+ roff = 0;
+ }
+
+ DBG("Finished at position %Lx", (long long) wstart);
+ sh_ftruncate(obuck_fd, wstart);
+ shake_sync();
+
obuck_unlock();
+ xfree(buf);
+ return;
+
+ broken:
+ log(L_ERROR, "Error during object pool shakedown: %s (pos=%Ld, id=%x), gathering debris",
+ msg, (long long) r_bucket_start, (uns)(r_bucket_start >> OBUCK_SHIFT));
+ /*
+ * We can attempt to clean up the bucket file by erasing everything between the last
+ * byte written and the next byte to be read. If the secure mode is switched on, we can
+ * guarantee that no data are lost, only some might be duplicated.
+ */
+ shake_erase(wstart, rstart);
+ die("Fatal error during object pool shakedown");
}
+/*** Testing ***/
+
#ifdef TEST
-int main(void)
+
+#define COUNT 5000
+#define MAXLEN 10000
+#define KILLPERC 13
+#define LEN(i) ((259309*(i))%MAXLEN)
+
+static int test_kibitz(struct obuck_header *h, oid_t new, byte *buck)
+{
+ return 1;
+}
+
+int main(int argc, char **argv)
{
- int i, j;
+ int ids[COUNT];
+ unsigned int i, j, cnt;
struct obuck_header h;
struct fastbuf *b;
+
+ log_init(NULL);
+ if (cf_getopt(argc, argv, CF_SHORT_OPTS, CF_NO_LONG_OPTS, NULL) >= 0 ||
+ optind < argc)
+ {
+ fputs("This program supports only the following command-line arguments:\n" CF_USAGE, stderr);
+ exit(1);
+ }
+
+ unlink(obuck_name);
obuck_init(1);
- for(j=0; j<100; j++)
+ for(j=0; j<COUNT; j++)
{
- b = obuck_write();
- for(i=0; i<100*j; i++)
- bputc(b, i);
- obuck_write_end(b, &h);
- printf("%d\t%08x\t%d\n", j, h.oid, h.orig_length);
+ b = obuck_create(BUCKET_TYPE_PLAIN);
+ for(i=0; i<LEN(j); i++)
+ bputc(b, (i+j) % 256);
+ obuck_create_end(b, &h);
+ printf("Writing %08x %d\n", h.oid, h.length);
+ ids[j] = h.oid;
}
- obuck_delete(0);
- b = obuck_walk_init();
- while (b = obuck_walk_next(b, &h))
- {
- printf("<<< %08x\t%d\n", h.oid, h.orig_length);
- }
- obuck_walk_end(b);
+ for(j=0; j<COUNT; j++)
+ if (j % 100 < KILLPERC)
+ {
+ printf("Deleting %08x\n", ids[j]);
+ obuck_delete(ids[j]);
+ }
+ cnt = 0;
+ for(j=0; j<COUNT; j++)
+ if (j % 100 >= KILLPERC)
+ {
+ cnt++;
+ h.oid = ids[j];
+ obuck_find_by_oid(&h);
+ b = obuck_fetch();
+ printf("Reading %08x %d\n", h.oid, h.length);
+ if (h.length != LEN(j))
+ die("Invalid length");
+ for(i=0; i<h.length; i++)
+ if ((unsigned) bgetc(b) != (i+j) % 256)
+ die("Contents mismatch");
+ if (bgetc(b) != EOF)
+ die("EOF mismatch");
+ bclose(b);
+ }
+ obuck_shakedown(test_kibitz);
+ if (obuck_find_first(&h, 0))
+ do
+ {
+ printf("<<< %08x\t%d\n", h.oid, h.length);
+ cnt--;
+ }
+ while (obuck_find_next(&h, 0));
+ if (cnt)
+ die("Walk mismatch");
obuck_cleanup();
return 0;
}
+
#endif
projects / libucw.git / blobdiff