From b79d9a09ae23c7047bdce3a15e284398334198ea Mon Sep 17 00:00:00 2001 From: Ming Lei Date: Thu, 6 Jun 2019 16:34:08 +0800 Subject: scsi: lib/sg_pool.c: clear 'first_chunk' in case of no preallocation If user doesn't ask to preallocate by passing zero 'nents_first_chunk' to sg_alloc_table_chained, we need to make sure that 'first_chunk' is cleared. Otherwise, __sg_alloc_table() still may think that the 1st SGL should be from the preallocation. Fixes the issue by clearing 'first_chunk' in sg_alloc_table_chained() if 'nents_first_chunk' is zero. Cc: Christoph Hellwig Cc: Bart Van Assche Cc: Ewan D. Milne Cc: Hannes Reinecke Cc: Guenter Roeck Reported-by: Guenter Roeck Tested-by: Guenter Roeck Signed-off-by: Ming Lei Signed-off-by: Martin K. Petersen --- lib/sg_pool.c | 6 ++++-- 1 file changed, 4 insertions(+), 2 deletions(-) (limited to 'lib/sg_pool.c') diff --git a/lib/sg_pool.c b/lib/sg_pool.c index b3b8cf62ff49..f1cc8372df67 100644 --- a/lib/sg_pool.c +++ b/lib/sg_pool.c @@ -102,7 +102,9 @@ EXPORT_SYMBOL_GPL(sg_free_table_chained); * * Description: * Allocate and chain SGLs in an sg table. If @nents@ is larger than - * @nents_first_chunk a chained sg table will be setup. + * @nents_first_chunk a chained sg table will be setup. @first_chunk is + * ignored if nents_first_chunk <= 1 because user expects the SGL points + * non-chain SGL. * **/ int sg_alloc_table_chained(struct sg_table *table, int nents, @@ -121,7 +123,7 @@ int sg_alloc_table_chained(struct sg_table *table, int nents, } /* User supposes that the 1st SGL includes real entry */ - if (nents_first_chunk == 1) { + if (nents_first_chunk <= 1) { first_chunk = NULL; nents_first_chunk = 0; } -- cgit