30a9f0e2f9
- fix direct map cache locking. - fix patch "dont umount existing direct mount on reread" deadlock.
54 lines
1.8 KiB
Diff
54 lines
1.8 KiB
Diff
autofs-5.0.4 - fix dont umount existing direct mount on reread
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From: Ian Kent <raven@themaw.net>
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A recent problem where we incorrectly umounted direct mounts on map
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re-read, when the map name in the master map has changed, checks for
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the stale entry in an old map source and updates the new entry from
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information in the the stale entry. But this check can also match
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an entry that has been removed from a direct map whose name hasn't
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changed which leads to a deadlock when we try and take the cache
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write lock on the (alleged) stale cache to update the new entry.
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This is because, in this case, the cache we want to lock is in
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fact the one we are reading and we already hold a read lock on it.
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---
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CHANGELOG | 1 +
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daemon/state.c | 10 ++++++++++
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2 files changed, 11 insertions(+), 0 deletions(-)
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diff --git a/CHANGELOG b/CHANGELOG
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index 82ebc83..929a21f 100644
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--- a/CHANGELOG
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+++ b/CHANGELOG
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@@ -61,6 +61,7 @@
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- fix pthread push order in expire_proc_direct().
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- fix libxml2 non-thread-safe calls.
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- fix direct map cache locking.
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+- fix dont umount existing direct mount on reread.
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4/11/2008 autofs-5.0.4
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-----------------------
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diff --git a/daemon/state.c b/daemon/state.c
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index 84ccba3..71af46a 100644
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--- a/daemon/state.c
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+++ b/daemon/state.c
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@@ -389,6 +389,16 @@ static void do_readmap_mount(struct autofs_point *ap, struct mnt_list *mnts,
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* an empty cache awaiting a map re-load.
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*/
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valid = lookup_source_valid_mapent(ap, me->key, LKP_DISTINCT);
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+ if (valid && valid->mc == me->mc) {
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+ /*
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+ * We've found a map entry that has been removed from
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+ * the current cache so there is no need to update it.
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+ * The stale entry will be dealt with when we prune the
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+ * cache later.
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+ */
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+ cache_unlock(valid->mc);
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+ valid = NULL;
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+ }
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if (valid) {
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struct mapent_cache *vmc = valid->mc;
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cache_unlock(vmc);
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