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Commit 7a787c25 authored by Hongchao Zhang's avatar Hongchao Zhang Committed by Greg Kroah-Hartman
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staging: lustre: obdclass: guarantee all keys filled 



In keys_fill, the key_set_version could be changed after
the keys are filled, then the keys in this context won't
be refilled by the following lu_context_refill for its
version is equal to the current key_set_version.

In lu_context_refill, the key_set_version should be protected
before comparing it to version stored in the lu_context.

Signed-off-by: default avatarHongchao Zhang <hongchao.zhang@intel.com>
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-8346
Reviewed-on: https://review.whamcloud.com/26099
Reviewed-on: https://review.whamcloud.com/27448
Reviewed-on: https://review.whamcloud.com/27994


Reviewed-by: default avatarPatrick Farrell <paf@cray.com>
Reviewed-by: default avatarJinshan Xiong <jinshan.xiong@intel.com>
Reviewed-by: default avatarMike Pershin <mike.pershin@intel.com>
Reviewed-by: default avatarFan Yong <fan.yong@intel.com>
Reviewed-by: default avatarOleg Drokin <oleg.drokin@intel.com>
Signed-off-by: default avatarJames Simmons <jsimmons@infradead.org>
Signed-off-by: default avatarGreg Kroah-Hartman <gregkh@linuxfoundation.org>
parent 369a6fec

drivers/staging/lustre/lustre/obdclass/lu_object.c

+25 −4
Original line number Diff line number Diff line
@@ -1396,8 +1396,8 @@ void lu_context_key_degister(struct lu_context_key *key) 


	lu_context_key_quiesce(key);



	++key_set_version;

	write_lock(&lu_keys_guard);

	++key_set_version;

	key_fini(&lu_shrink_env.le_ctx, key->lct_index);



	/**
@@ -1556,15 +1556,18 @@ void lu_context_key_quiesce(struct lu_context_key *key) 


		list_for_each_entry(ctx, &lu_context_remembered, lc_remember)

			key_fini(ctx, key->lct_index);

		write_unlock(&lu_keys_guard);



		++key_set_version;

		write_unlock(&lu_keys_guard);

	}

}



void lu_context_key_revive(struct lu_context_key *key)

{

	write_lock(&lu_keys_guard);

	key->lct_tags &= ~LCT_QUIESCENT;

	++key_set_version;

	write_unlock(&lu_keys_guard);

}



static void keys_fini(struct lu_context *ctx)
@@ -1583,6 +1586,7 @@ static void keys_fini(struct lu_context *ctx) 


static int keys_fill(struct lu_context *ctx)

{

	unsigned int pre_version;

	unsigned int i;



	/*
@@ -1596,8 +1600,10 @@ static int keys_fill(struct lu_context *ctx) 
	 */

	read_lock(&lu_keys_guard);

	atomic_inc(&lu_key_initing_cnt);

	pre_version = key_set_version;

	read_unlock(&lu_keys_guard);



refill:

	LINVRNT(ctx->lc_value);

	for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {

		struct lu_context_key *key;
@@ -1638,9 +1644,17 @@ static int keys_fill(struct lu_context *ctx) 
			if (key->lct_exit)

				ctx->lc_tags |= LCT_HAS_EXIT;

		}

		ctx->lc_version = key_set_version;

	}



	read_lock(&lu_keys_guard);

	if (pre_version != key_set_version) {

		pre_version = key_set_version;

		read_unlock(&lu_keys_guard);

		goto refill;

	}

	ctx->lc_version = key_set_version;

	atomic_dec(&lu_key_initing_cnt);

	read_unlock(&lu_keys_guard);

	return 0;

}
@@ -1749,7 +1763,14 @@ EXPORT_SYMBOL(lu_context_exit); 
 */

int lu_context_refill(struct lu_context *ctx)

{

	return likely(ctx->lc_version == key_set_version) ? 0 : keys_fill(ctx);

	read_lock(&lu_keys_guard);

	if (likely(ctx->lc_version == key_set_version)) {

		read_unlock(&lu_keys_guard);

		return 0;

	}



	read_unlock(&lu_keys_guard);

	return keys_fill(ctx);

}



/**