Github/littlefs
1
Fork 0
Code Actions Activity

Fixed explicit trunks messing with canonical checksums

Browse Source 
Updating the canonical checksum should only depend on if the tag is a
trunkish tag (not a checksum tag), and not if the tag is in the current
trunk. The trunk parameter to lfsr_rbyd_fetch should have no effect on
the canonical checksum.

Fixed in boath lfsr_rbyd_fetch and scripts.

Curiously no code changes:

           code          stack
  before: 36416           2616
  after:  36416 (+0.0%)   2616 (+0.0%
This commit is contained in:
Christopher Haster
2024-08-20 01:26:32 -05:00
parent 2f11fa71f4
commit c00e0b2af6
6 changed files with 167 additions and 159 deletions
Download Patch File Download Diff File Expand all files Collapse all files
lfs.c
+34 -32
View File
@@ -3066,40 +3066,42 @@ static int lfsr_rbyd_fetch(lfs_t *lfs, lfsr_rbyd_t *rbyd,
}
}
// found a trunk of a tree?
if (lfsr_tag_istrunk(tag)
&& (!trunk || off <= trunk || trunk__)) {
// start of trunk?
if (!trunk__) {
// keep track of trunk's entry point
trunk__ = off;
// reset weight
weight_ = 0;
}
// derive weight of the tree from alt pointers
//
// NOTE we can't check for overflow/underflow here because we
// may be overeagerly parsing an invalid commit, it's ok for
// this to overflow/underflow as long as we throw it out later
// on a bad cksum
weight_ += weight__;
// end of trunk?
if (!lfsr_tag_isalt(tag)) {
// update canonical checksum, xoring out any perturb
// state, we don't want erased-state affecting our
// canonical checksum
cksum = cksum_ ^ ((lfsr_rbyd_isperturb(rbyd))
? LFS_CRC32C_ODDZERO
: LFS_CRC32C_EVENZERO);
// update trunk and weight, unless we are a shrub trunk
if (!lfsr_tag_isshrub(tag) || trunk__ == trunk) {
trunk_ = trunk__;
weight = weight_;
// found a trunk?
if (lfsr_tag_istrunk(tag)) {
if (!(trunk && off > trunk && !trunk__)) {
// start of trunk?
if (!trunk__) {
// keep track of trunk's entry point
trunk__ = off;
// reset weight
weight_ = 0;
}
// derive weight of the tree from alt pointers
//
// NOTE we can't check for overflow/underflow here because we
// may be overeagerly parsing an invalid commit, it's ok for
// this to overflow/underflow as long as we throw it out later
// on a bad cksum
weight_ += weight__;
// end of trunk?
if (!lfsr_tag_isalt(tag)) {
// update trunk and weight, unless we are a shrub trunk
if (!lfsr_tag_isshrub(tag) || trunk__ == trunk) {
trunk_ = trunk__;
weight = weight_;
}
trunk__ = 0;
}
trunk__ = 0;
}
// update canonical checksum, xoring out any perturb
// state, we don't want erased-state affecting our
// canonical checksum
cksum = cksum_ ^ ((lfsr_rbyd_isperturb(rbyd))
? LFS_CRC32C_ODDZERO
: LFS_CRC32C_EVENZERO);
}
// skip data
scripts/dbgbmap.py
+26 -25
View File
@@ -695,33 +695,34 @@ class Rbyd:
cksum__ = cksum_ ^ (0xfca42daf if perturb else 0)
# evaluate trunks
if (tag & 0xf000) != TAG_CKSUM and (
not trunk or j_-d <= trunk or trunk___):
# new trunk?
if not trunk___:
trunk___ = j_-d
weight__ = 0
if (tag & 0xf000) != TAG_CKSUM:
if not (trunk and j_-d > trunk and not trunk___):
# new trunk?
if not trunk___:
trunk___ = j_-d
weight__ = 0
# keep track of weight
weight__ += w
# keep track of weight
weight__ += w
# end of trunk?
if not tag & TAG_ALT:
# update canonical checksum, xoring out any perturb state
cksum_ = cksum__ ^ (0xfca42daf if perturb else 0)
# update trunk/weight unless we found a shrub or an
# explicit trunk (which may be a shrub) is requested
if not tag & TAG_SHRUB or trunk___ == trunk:
trunk__ = trunk___
weight_ = weight__
# keep track of eoff for best matching trunk
if trunk and j_ + size > trunk:
eoff_ = j_ + size
eoff = eoff_
cksum = cksum_
trunk_ = trunk__
weight = weight_
trunk___ = 0
# end of trunk?
if not tag & TAG_ALT:
# update trunk/weight unless we found a shrub or an
# explicit trunk (which may be a shrub) is requested
if not tag & TAG_SHRUB or trunk___ == trunk:
trunk__ = trunk___
weight_ = weight__
# keep track of eoff for best matching trunk
if trunk and j_ + size > trunk:
eoff_ = j_ + size
eoff = eoff_
cksum = cksum_
trunk_ = trunk__
weight = weight_
trunk___ = 0
# update canonical checksum, xoring out any perturb state
cksum_ = cksum__ ^ (0xfca42daf if perturb else 0)
if not tag & TAG_ALT:
j_ += size
scripts/dbgbtree.py
+26 -25
View File
@@ -368,33 +368,34 @@ class Rbyd:
cksum__ = cksum_ ^ (0xfca42daf if perturb else 0)
# evaluate trunks
if (tag & 0xf000) != TAG_CKSUM and (
not trunk or j_-d <= trunk or trunk___):
# new trunk?
if not trunk___:
trunk___ = j_-d
weight__ = 0
if (tag & 0xf000) != TAG_CKSUM:
if not (trunk and j_-d > trunk and not trunk___):
# new trunk?
if not trunk___:
trunk___ = j_-d
weight__ = 0
# keep track of weight
weight__ += w
# keep track of weight
weight__ += w
# end of trunk?
if not tag & TAG_ALT:
# update canonical checksum, xoring out any perturb state
cksum_ = cksum__ ^ (0xfca42daf if perturb else 0)
# update trunk/weight unless we found a shrub or an
# explicit trunk (which may be a shrub) is requested
if not tag & TAG_SHRUB or trunk___ == trunk:
trunk__ = trunk___
weight_ = weight__
# keep track of eoff for best matching trunk
if trunk and j_ + size > trunk:
eoff_ = j_ + size
eoff = eoff_
cksum = cksum_
trunk_ = trunk__
weight = weight_
trunk___ = 0
# end of trunk?
if not tag & TAG_ALT:
# update trunk/weight unless we found a shrub or an
# explicit trunk (which may be a shrub) is requested
if not tag & TAG_SHRUB or trunk___ == trunk:
trunk__ = trunk___
weight_ = weight__
# keep track of eoff for best matching trunk
if trunk and j_ + size > trunk:
eoff_ = j_ + size
eoff = eoff_
cksum = cksum_
trunk_ = trunk__
weight = weight_
trunk___ = 0
# update canonical checksum, xoring out any perturb state
cksum_ = cksum__ ^ (0xfca42daf if perturb else 0)
if not tag & TAG_ALT:
j_ += size
scripts/dbglfs.py
+26 -25
View File
@@ -399,33 +399,34 @@ class Rbyd:
cksum__ = cksum_ ^ (0xfca42daf if perturb else 0)
# evaluate trunks
if (tag & 0xf000) != TAG_CKSUM and (
not trunk or j_-d <= trunk or trunk___):
# new trunk?
if not trunk___:
trunk___ = j_-d
weight__ = 0
if (tag & 0xf000) != TAG_CKSUM:
if not (trunk and j_-d > trunk and not trunk___):
# new trunk?
if not trunk___:
trunk___ = j_-d
weight__ = 0
# keep track of weight
weight__ += w
# keep track of weight
weight__ += w
# end of trunk?
if not tag & TAG_ALT:
# update canonical checksum, xoring out any perturb state
cksum_ = cksum__ ^ (0xfca42daf if perturb else 0)
# update trunk/weight unless we found a shrub or an
# explicit trunk (which may be a shrub) is requested
if not tag & TAG_SHRUB or trunk___ == trunk:
trunk__ = trunk___
weight_ = weight__
# keep track of eoff for best matching trunk
if trunk and j_ + size > trunk:
eoff_ = j_ + size
eoff = eoff_
cksum = cksum_
trunk_ = trunk__
weight = weight_
trunk___ = 0
# end of trunk?
if not tag & TAG_ALT:
# update trunk/weight unless we found a shrub or an
# explicit trunk (which may be a shrub) is requested
if not tag & TAG_SHRUB or trunk___ == trunk:
trunk__ = trunk___
weight_ = weight__
# keep track of eoff for best matching trunk
if trunk and j_ + size > trunk:
eoff_ = j_ + size
eoff = eoff_
cksum = cksum_
trunk_ = trunk__
weight = weight_
trunk___ = 0
# update canonical checksum, xoring out any perturb state
cksum_ = cksum__ ^ (0xfca42daf if perturb else 0)
if not tag & TAG_ALT:
j_ += size
scripts/dbgmtree.py
+26 -25
View File
@@ -383,33 +383,34 @@ class Rbyd:
cksum__ = cksum_ ^ (0xfca42daf if perturb else 0)
# evaluate trunks
if (tag & 0xf000) != TAG_CKSUM and (
not trunk or j_-d <= trunk or trunk___):
# new trunk?
if not trunk___:
trunk___ = j_-d
weight__ = 0
if (tag & 0xf000) != TAG_CKSUM:
if not (trunk and j_-d > trunk and not trunk___):
# new trunk?
if not trunk___:
trunk___ = j_-d
weight__ = 0
# keep track of weight
weight__ += w
# keep track of weight
weight__ += w
# end of trunk?
if not tag & TAG_ALT:
# update canonical checksum, xoring out any perturb state
cksum_ = cksum__ ^ (0xfca42daf if perturb else 0)
# update trunk/weight unless we found a shrub or an
# explicit trunk (which may be a shrub) is requested
if not tag & TAG_SHRUB or trunk___ == trunk:
trunk__ = trunk___
weight_ = weight__
# keep track of eoff for best matching trunk
if trunk and j_ + size > trunk:
eoff_ = j_ + size
eoff = eoff_
cksum = cksum_
trunk_ = trunk__
weight = weight_
trunk___ = 0
# end of trunk?
if not tag & TAG_ALT:
# update trunk/weight unless we found a shrub or an
# explicit trunk (which may be a shrub) is requested
if not tag & TAG_SHRUB or trunk___ == trunk:
trunk__ = trunk___
weight_ = weight__
# keep track of eoff for best matching trunk
if trunk and j_ + size > trunk:
eoff_ = j_ + size
eoff = eoff_
cksum = cksum_
trunk_ = trunk__
weight = weight_
trunk___ = 0
# update canonical checksum, xoring out any perturb state
cksum_ = cksum__ ^ (0xfca42daf if perturb else 0)
if not tag & TAG_ALT:
j_ += size
scripts/dbgrbyd.py
+29 -27
View File
@@ -577,12 +577,13 @@ def dbg_log(data, block_size, rev, eoff, weight, *,
# end of trunk?
if not tag & TAG_ALT:
# update canonical checksum, xoring out any perturb state
cksum = cksum_ ^ (0xfca42daf if perturb else 0)
# derive the current tag's rid from alt weights
rid = lower_ + w-1
trunk_ = 0
# update canonical checksum, xoring out any perturb state
cksum = cksum_ ^ (0xfca42daf if perturb else 0)
# show human-readable tag representation
print('%s%08x:%s %*s%s%*s %-*s%s%s%s' % (
'\x1b[90m' if color and j >= eoff else '',
@@ -976,33 +977,34 @@ def main(disk, blocks=None, *,
cksum__ = cksum_ ^ (0xfca42daf if perturb else 0)
# evaluate trunks
if (tag & 0xf000) != TAG_CKSUM and (
not trunk or j_-d <= trunk or trunk___):
# new trunk?
if not trunk___:
trunk___ = j_-d
weight__ = 0
if (tag & 0xf000) != TAG_CKSUM:
if not (trunk and j_-d > trunk and not trunk___):
# new trunk?
if not trunk___:
trunk___ = j_-d
weight__ = 0
# keep track of weight
weight__ += w
# keep track of weight
weight__ += w
# end of trunk?
if not tag & TAG_ALT:
# update canonical checksum, xoring out any perturb state
cksum_ = cksum__ ^ (0xfca42daf if perturb else 0)
# update trunk/weight unless we found a shrub or an
# explicit trunk (which may be a shrub) is requested
if not tag & TAG_SHRUB or trunk___ == trunk:
trunk__ = trunk___
weight_ = weight__
# keep track of eoff for best matching trunk
if trunk and j_ + size > trunk:
eoff_ = j_ + size
eoff = eoff_
cksum = cksum_
trunk_ = trunk__
weight = weight_
trunk___ = 0
# end of trunk?
if not tag & TAG_ALT:
# update trunk/weight unless we found a shrub or an
# explicit trunk (which may be a shrub) is requested
if not tag & TAG_SHRUB or trunk___ == trunk:
trunk__ = trunk___
weight_ = weight__
# keep track of eoff for best matching trunk
if trunk and j_ + size > trunk:
eoff_ = j_ + size
eoff = eoff_
cksum = cksum_
trunk_ = trunk__
weight = weight_
trunk___ = 0
# update canonical checksum, xoring out any perturb state
cksum_ = cksum__ ^ (0xfca42daf if perturb else 0)
if not tag & TAG_ALT:
j_ += size