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cache: stop pre-checking seqc when starting the lookup

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Tested by:	pho
This commit is contained in:
Mateusz Guzik 2021-01-06 07:12:58 +01:00
parent c6d3272b73
commit deabdc6868
1 changed files with 8 additions and 5 deletions
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13
sys/kern/vfs_cache.c
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@ -5032,7 +5032,7 @@ cache_fplookup_skip_slashes(struct cache_fpl *fpl)
ndp->ni_next = cnp->cn_nameptr;
/*
* Retry the lookup, similar to dot lookups.
* See cache_fplookup_dot.
*/
fpl->tvp = fpl->dvp;
fpl->tvp_seqc = fpl->dvp_seqc;
@ -5139,11 +5139,14 @@ cache_fplookup_impl(struct vnode *dvp, struct cache_fpl *fpl)
cache_fpl_checkpoint(fpl, &fpl->snd);
/*
* The vnode is hand is almost always stable, skip checking for it.
* Worst case this postpones the check towards the end of the iteration
* of the main loop.
*/
fpl->dvp = dvp;
fpl->dvp_seqc = vn_seqc_read_any(fpl->dvp);
if (seqc_in_modify(fpl->dvp_seqc)) {
return (cache_fpl_aborted(fpl));
}
fpl->dvp_seqc = vn_seqc_read_notmodify(fpl->dvp);
mp = atomic_load_ptr(&dvp->v_mount);
if (__predict_false(mp == NULL || !cache_fplookup_mp_supported(mp))) {
return (cache_fpl_aborted(fpl));