Whenever we fail to read from a device it's pointless to
continue with probing; we should be failing immediately.
Otherwise the system will continue logging I/O errors.
This patch updates the probe functions to return -1
on error and 1 if not found.
Signed-off-by: Hannes Reinecke <hare@xxxxxxx>
---
libblkid/src/partitions/partitions.c | 13 +++++++++----
libblkid/src/probe.c | 13 +++++++++++--
libblkid/src/superblocks/superblocks.c | 13 ++++++++++---
3 files changed, 30 insertions(+), 9 deletions(-)
diff --git a/libblkid/src/partitions/partitions.c b/libblkid/src/partitions/partitions.c
index d9419f2..53e5009 100644
--- a/libblkid/src/partitions/partitions.c
+++ b/libblkid/src/partitions/partitions.c
@@ -540,7 +540,8 @@ static int idinfo_probe(blkid_probe pr, const struct blkid_idinfo *id,
if (pr->size <= 0 || (id->minsz && id->minsz > pr->size))
goto nothing; /* the device is too small */
- if (blkid_probe_get_idmag(pr, id, &off, &mag))
+ rc = blkid_probe_get_idmag(pr, id, &off, &mag);
+ if (rc != 0)
goto nothing;
/* final check by probing function */
@@ -548,12 +549,13 @@ static int idinfo_probe(blkid_probe pr, const struct blkid_idinfo *id,
DBG(LOWPROBE, blkid_debug(
"%s: ---> call probefunc()", id->name));
rc = id->probefunc(pr, mag);
- if (rc == -1) {
+ if (rc != 0) {
/* reset after error */
reset_partlist(blkid_probe_get_partlist(pr));
if (chn && !chn->binary)
blkid_probe_chain_reset_vals(pr, chn);
- DBG(LOWPROBE, blkid_debug("%s probefunc failed", id->name));
+ DBG(LOWPROBE, blkid_debug("%s probefunc failed, rc %d",
+ id->name, rc));
}
if (rc == 0 && mag && chn && !chn->binary)
rc = blkid_probe_set_magic(pr, off, mag->len,
@@ -599,7 +601,10 @@ static int partitions_probe(blkid_probe pr, struct blkid_chain *chn)
continue;
/* apply checks from idinfo */
- if (idinfo_probe(pr, idinfos[i], chn) != 0)
+ rc = idinfo_probe(pr, idinfos[i], chn);
+ if (rc < 0)
+ return rc;
+ if (rc > 0)
continue;
name = idinfos[i]->name;
diff --git a/libblkid/src/probe.c b/libblkid/src/probe.c
index e20c61b..e68e1dc 100644
--- a/libblkid/src/probe.c
+++ b/libblkid/src/probe.c
@@ -569,13 +569,17 @@ unsigned char *blkid_probe_get_buffer(blkid_probe pr,
if (!bf) {
ssize_t ret;
- if (blkid_llseek(pr->fd, pr->off + off, SEEK_SET) < 0)
+ if (blkid_llseek(pr->fd, pr->off + off, SEEK_SET) < 0) {
+ errno = 0;
return NULL;
+ }
/* allocate info and space for data by why call */
bf = calloc(1, sizeof(struct blkid_bufinfo) + len);
- if (!bf)
+ if (!bf) {
+ errno = 0;
return NULL;
+ }
bf->data = ((unsigned char *) bf) + sizeof(struct blkid_bufinfo);
bf->len = len;
@@ -587,7 +591,10 @@ unsigned char *blkid_probe_get_buffer(blkid_probe pr,
ret = read(pr->fd, bf->data, len);
if (ret != (ssize_t) len) {
+ DBG(LOWPROBE, blkid_debug("\tbuffer read: return %d error %d", ret, errno));
free(bf);
+ if (ret >= 0)
+ errno = 0;
return NULL;
}
list_add_tail(&bf->bufs, &pr->buffers);
@@ -794,6 +801,8 @@ int blkid_probe_get_idmag(blkid_probe pr, const struct blkid_idinfo *id,
off = (mag->kboff + (mag->sboff >> 10)) << 10;
buf = blkid_probe_get_buffer(pr, off, 1024);
+ if (!buf && errno)
+ return -1;
if (buf && !memcmp(mag->magic,
buf + (mag->sboff & 0x3ff), mag->len)) {
DBG(LOWPROBE, blkid_debug("\tmagic sboff=%u, kboff=%ld",
diff --git a/libblkid/src/superblocks/superblocks.c b/libblkid/src/superblocks/superblocks.c
index c6394c4..35cfd50 100644
--- a/libblkid/src/superblocks/superblocks.c
+++ b/libblkid/src/superblocks/superblocks.c
@@ -379,15 +379,22 @@ static int superblocks_probe(blkid_probe pr, struct blkid_chain *chn)
DBG(LOWPROBE, blkid_debug("[%zd] %s:", i, id->name));
- if (blkid_probe_get_idmag(pr, id, &off, &mag))
+ rc = blkid_probe_get_idmag(pr, id, &off, &mag);
+ if (rc < 0)
+ break;
+ if (rc > 0)
continue;
/* final check by probing function */
if (id->probefunc) {
DBG(LOWPROBE, blkid_debug("\tcall probefunc()"));
- if (id->probefunc(pr, mag) != 0) {
+ rc = id->probefunc(pr, mag);
+ if (rc != 0) {
blkid_probe_chain_reset_vals(pr, chn);
- continue;
+ if (rc < 0)
+ break;
+ else
+ continue;
}
}
--
1.8.1.4
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