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| author | Ming Lei <ming.lei@redhat.com> | 2019-06-06 16:34:08 +0800 |
|---|---|---|
| committer | Martin K. Petersen <martin.petersen@oracle.com> | 2019-06-20 15:21:33 -0400 |
| commit | b79d9a09ae23c7047bdce3a15e284398334198ea (patch) | |
| tree | b2cdeab4564fdd2bc3706eb1aa0864e3e4ec1e6f /lib/sg_pool.c | |
| parent | 3dccdf53c2f38399b11085ded4447ce1467f006c (diff) | |
| download | lwn-b79d9a09ae23c7047bdce3a15e284398334198ea.tar.gz lwn-b79d9a09ae23c7047bdce3a15e284398334198ea.zip | |
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 <hch@lst.de>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Ewan D. Milne <emilne@redhat.com>
Cc: Hannes Reinecke <hare@suse.com>
Cc: Guenter Roeck <linux@roeck-us.net>
Reported-by: Guenter Roeck <linux@roeck-us.net>
Tested-by: Guenter Roeck <linux@roeck-us.net>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Diffstat (limited to 'lib/sg_pool.c')
| -rw-r--r-- | lib/sg_pool.c | 6 |
1 files changed, 4 insertions, 2 deletions
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; } |