[LU-8371] Optimize open of known negative dentry Created: 06/Jul/16 Updated: 22/Aug/16 Resolved: 22/Aug/16 |
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| Status: | Resolved |
| Project: | Lustre |
| Component/s: | None |
| Affects Version/s: | None |
| Fix Version/s: | Lustre 2.9.0 |
| Type: | Bug | Priority: | Minor |
| Reporter: | Oleg Drokin | Assignee: | Oleg Drokin |
| Resolution: | Fixed | Votes: | 0 |
| Labels: | None | ||
| Severity: | 3 |
| Rank (Obsolete): | 9223372036854775807 |
| Description |
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While working with Al Viro on some corner cases in atomic open, I noticed that we are doing a lot more work than necessary there. If we were called with a negative dentry - that means just now we revalidated that dentry so there's no point in contacting MDS to open that file (unless it's a create request), we can just return ENOENT and be done with it which speeds up 99.9% of all usecases and the remaining 0.15 where it's a valid race, we just resolve it the other way as is perfectly fine for us to do. |
| Comments |
| Comment by Gerrit Updater [ 06/Jul/16 ] |
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Oleg Drokin (oleg.drokin@intel.com) uploaded a new patch: http://review.whamcloud.com/21161 |
| Comment by Gerrit Updater [ 06/Jul/16 ] |
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Oleg Drokin (oleg.drokin@intel.com) uploaded a new patch: http://review.whamcloud.com/21168 |
| Comment by Gerrit Updater [ 11/Aug/16 ] |
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Oleg Drokin (oleg.drokin@intel.com) merged in patch http://review.whamcloud.com/21161/ |
| Comment by Gerrit Updater [ 22/Aug/16 ] |
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Oleg Drokin (oleg.drokin@intel.com) merged in patch http://review.whamcloud.com/21168/ |
| Comment by Peter Jones [ 22/Aug/16 ] |
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Landed for 2.9 |