dm crypt: remove io_pending refcount member from dm_crypt_io

Commit "dm crypt: don't allocate pages for a partial request" changed
the code to allocate all pages for one request.  There is always just
one pending request, so the io_pending refcount may be removed.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index ae9764e16f6fe1d4af3ef189678852b7162332df..628a8cbaf26f7df687e1897a8beea482e4b67c05 100644 (file)
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -55,7 +55,6 @@ struct dm_crypt_io {
 
        struct convert_context ctx;
 
-       atomic_t io_pending;
        int error;
        sector_t sector;
 } CRYPTO_MINALIGN_ATTR;
@@ -1037,27 +1036,18 @@ static void crypt_io_init(struct dm_crypt_io *io, struct crypt_config *cc,
        io->sector = sector;
        io->error = 0;
        io->ctx.req = NULL;
-       atomic_set(&io->io_pending, 0);
-}
-
-static void crypt_inc_pending(struct dm_crypt_io *io)
-{
-       atomic_inc(&io->io_pending);
 }
 
 /*
  * One of the bios was finished. Check for completion of
  * the whole request and correctly clean up the buffer.
  */
-static void crypt_dec_pending(struct dm_crypt_io *io)
+static void crypt_end_io(struct dm_crypt_io *io)
 {
        struct crypt_config *cc = io->cc;
        struct bio *base_bio = io->base_bio;
        int error = io->error;
 
-       if (!atomic_dec_and_test(&io->io_pending))
-               return;
-
        if (io->ctx.req)
                crypt_free_req(cc, io->ctx.req, base_bio);
 
@@ -1106,7 +1096,7 @@ static void crypt_endio(struct bio *clone, int error)
        if (unlikely(error))
                io->error = error;
 
-       crypt_dec_pending(io);
+       crypt_end_io(io);
 }
 
 static void clone_init(struct dm_crypt_io *io, struct bio *clone)
@@ -1134,8 +1124,6 @@ static int kcryptd_io_read(struct dm_crypt_io *io, gfp_t gfp)
        if (!clone)
                return 1;
 
-       crypt_inc_pending(io);
-
        clone_init(io, clone);
        clone->bi_iter.bi_sector = cc->start + io->sector;
 
@@ -1154,10 +1142,10 @@ static void kcryptd_io(struct work_struct *work)
        struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
 
        if (bio_data_dir(io->base_bio) == READ) {
-               crypt_inc_pending(io);
-               if (kcryptd_io_read(io, GFP_NOIO))
+               if (kcryptd_io_read(io, GFP_NOIO)) {
                        io->error = -ENOMEM;
-               crypt_dec_pending(io);
+                       crypt_end_io(io);
+               }
        } else
                kcryptd_io_write(io);
 }
@@ -1178,7 +1166,7 @@ static void kcryptd_crypt_write_io_submit(struct dm_crypt_io *io, int async)
        if (unlikely(io->error < 0)) {
                crypt_free_buffer_pages(cc, clone);
                bio_put(clone);
-               crypt_dec_pending(io);
+               crypt_end_io(io);
                return;
        }
 
@@ -1201,16 +1189,13 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
        sector_t sector = io->sector;
        int r;
 
-       /*
-        * Prevent io from disappearing until this function completes.
-        */
-       crypt_inc_pending(io);
        crypt_convert_init(cc, &io->ctx, NULL, io->base_bio, sector);
 
        clone = crypt_alloc_buffer(io, io->base_bio->bi_iter.bi_size);
        if (unlikely(!clone)) {
                io->error = -EIO;
-               goto dec;
+               crypt_end_io(io);
+               return;
        }
 
        io->ctx.bio_out = clone;
@@ -1218,7 +1203,6 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
 
        sector += bio_sectors(clone);
 
-       crypt_inc_pending(io);
        r = crypt_convert(cc, &io->ctx);
        if (r)
                io->error = -EIO;
@@ -1229,14 +1213,11 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
                kcryptd_crypt_write_io_submit(io, 0);
                io->sector = sector;
        }
-
-dec:
-       crypt_dec_pending(io);
 }
 
 static void kcryptd_crypt_read_done(struct dm_crypt_io *io)
 {
-       crypt_dec_pending(io);
+       crypt_end_io(io);
 }
 
 static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
@@ -1244,8 +1225,6 @@ static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
        struct crypt_config *cc = io->cc;
        int r = 0;
 
-       crypt_inc_pending(io);
-
        crypt_convert_init(cc, &io->ctx, io->base_bio, io->base_bio,
                           io->sector);
 
@@ -1255,8 +1234,6 @@ static void kcryptd_crypt_read_convert(struct dm_crypt_io *io)
 
        if (atomic_dec_and_test(&io->ctx.cc_pending))
                kcryptd_crypt_read_done(io);
-
-       crypt_dec_pending(io);
 }
 
 static void kcryptd_async_done(struct crypto_async_request *async_req,