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| author | Nick Mathewson <nickm@torproject.org> | 2013-06-12 12:04:33 -0400 |
|---|---|---|
| committer | Nick Mathewson <nickm@torproject.org> | 2013-06-12 12:04:33 -0400 |
| commit | f455686b77e4ac686251c6edf1f4a506a369866c (patch) | |
| tree | 72f904cc2464b984cc4c872c8e079abfa359bdf7 | |
| parent | fff9386af87bd0f54cda1ef4fe0bf131de7c3d8e (diff) | |
| download | tor-f455686b77e4ac686251c6edf1f4a506a369866c.tar.gz tor-f455686b77e4ac686251c6edf1f4a506a369866c.zip | |
Unmap the microdescriptor cache before replacing it.
This is a reprise of the fix in bdff7e3299d78; 6905c1f6 reintroduced
that bug. Briefly: windows doesn't seem to like deleting a mapped
file. I tried adding the PROT_SHARED_DELETE flag to the createfile
all, but that didn't actually fix this issue. Fortunately, the unit
test I added in 4f4fc63fea0589a4fa03f3859dc27860cdde75af should
prevent us from making this particular screw-up again.
This patch also tries to limit the crash potential of a failure to
write by a little bit, although it could do a better job of retaining
microdescriptor bodies.
Fix for bug 8822, bugfix on 0.2.4.12-alpha.
| -rw-r--r-- | changes/bug8822 | 5 | ||||
| -rw-r--r-- | src/or/microdesc.c | 20 |
2 files changed, 22 insertions, 3 deletions
diff --git a/changes/bug8822 b/changes/bug8822 new file mode 100644 index 0000000000..c6787afe06 --- /dev/null +++ b/changes/bug8822 @@ -0,0 +1,5 @@ + o Major bugfixes (windows): + - Prevent failures on Windows Vista and later when rebuilding the + microdescriptor cache. Diagnosed by Robert Ransom. Fixes bug 8822; + bugfix on 0.2.4.12-alpha. + diff --git a/src/or/microdesc.c b/src/or/microdesc.c index d9955c7b49..f99e1c88ad 100644 --- a/src/or/microdesc.c +++ b/src/or/microdesc.c @@ -474,15 +474,29 @@ microdesc_cache_rebuild(microdesc_cache_t *cache, int force) smartlist_add(wrote, md); } + /* We must do this unmap _before_ we call finish_writing_to_file(), or + * windows will not actually replace the file. */ + if (cache->cache_content) + tor_munmap_file(cache->cache_content); + if (finish_writing_to_file(open_file) < 0) { log_warn(LD_DIR, "Error rebuilding microdescriptor cache: %s", strerror(errno)); + /* Okay. Let's prevent from making things worse elsewhere. */ + cache->cache_content = NULL; + HT_FOREACH(mdp, microdesc_map, &cache->map) { + microdesc_t *md = *mdp; + if (md->saved_location == SAVED_IN_CACHE) { + md->off = 0; + md->saved_location = SAVED_NOWHERE; + md->body = NULL; + md->bodylen = 0; + md->no_save = 1; + } + } return -1; } - if (cache->cache_content) - tor_munmap_file(cache->cache_content); - cache->cache_content = tor_mmap_file(cache->cache_fname); if (!cache->cache_content && smartlist_len(wrote)) { |