mirror of
https://github.com/AuxXxilium/linux_dsm_epyc7002.git
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d99724c3c3
This patch closes a timing window in which two processes compete
and overlap in the execution of do_xmote for the same glock:
Process A Process B
------------------------------------ -----------------------------
1. Grabs gl_lockref and calls do_xmote
2. Grabs gl_lockref but is blocked
3. Sets GLF_INVALIDATE_IN_PROGRESS
4. Unlocks gl_lockref
5. Calls do_xmote
6. Call glops->go_sync
7. test_and_clear_bit GLF_DIRTY
8. Call gfs2_log_flush Call glops->go_sync
9. (slow IO, so it blocks a long time) test_and_clear_bit GLF_DIRTY
It's not dirty (step 7) returns
10. Tests GLF_INVALIDATE_IN_PROGRESS
11. Calls go_inval (rgrp_go_inval)
12. gfs2_rgrp_relse does brelse
13. truncate_inode_pages_range
14. Calls lm_lock UN
In step 14 we've just told dlm to give the glock to another node
when, in fact, process A has not finished the IO and synced all
buffer_heads to disk and make sure their revokes are done.
This patch fixes the problem by changing the GLF_INVALIDATE_IN_PROGRESS
to use test_and_set_bit, and if the bit is already set, process B just
ignores it and trusts that process A will do the do_xmote in the proper
order.
Signed-off-by: Bob Peterson <rpeterso@redhat.com>
Signed-off-by: Andreas Gruenbacher <agruenba@redhat.com>
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| .. | ||
| acl.c | ||
| acl.h | ||
| aops.c | ||
| aops.h | ||
| bmap.c | ||
| bmap.h | ||
| dentry.c | ||
| dir.c | ||
| dir.h | ||
| export.c | ||
| file.c | ||
| gfs2.h | ||
| glock.c | ||
| glock.h | ||
| glops.c | ||
| glops.h | ||
| incore.h | ||
| inode.c | ||
| inode.h | ||
| Kconfig | ||
| lock_dlm.c | ||
| log.c | ||
| log.h | ||
| lops.c | ||
| lops.h | ||
| main.c | ||
| Makefile | ||
| meta_io.c | ||
| meta_io.h | ||
| ops_fstype.c | ||
| quota.c | ||
| quota.h | ||
| recovery.c | ||
| recovery.h | ||
| rgrp.c | ||
| rgrp.h | ||
| super.c | ||
| super.h | ||
| sys.c | ||
| sys.h | ||
| trace_gfs2.h | ||
| trans.c | ||
| trans.h | ||
| util.c | ||
| util.h | ||
| xattr.c | ||
| xattr.h | ||