Just alloc the bio_vec array if we exceed the inline limit.
Signed-off-by: Jens Axboe <ax...@fb.com>
---
fs/block_dev.c | 17 ++++++++++++++---
1 file changed, 14 insertions(+), 3 deletions(-)
diff --git a/fs/block_dev.c b/fs/block_dev.c
index 7c3ec6049073..2010997fd326 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -193,7 +193,7 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct
iov_iter *iter,
struct file *file = iocb->ki_filp;
struct block_device *bdev = I_BDEV(bdev_file_inode(file));
unsigned blkbits = blksize_bits(bdev_logical_block_size(bdev));
- struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *bvec;
+ struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs, *bvec;
loff_t pos = iocb->ki_pos;
bool should_dirty = false;
struct bio bio;
@@ -204,9 +204,17 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct
iov_iter *iter,
if ((pos | iov_iter_alignment(iter)) & ((1 << blkbits) - 1))
return -EINVAL;
+ if (nr_pages <= DIO_INLINE_BIO_VECS)
+ vecs = inline_vecs;
+ else {
+ vecs = kmalloc(nr_pages * sizeof(struct bio_vec), GFP_KERNEL);
+ if (!vecs)
+ return -ENOMEM;
+ }
+
bio_init(&bio);
bio.bi_max_vecs = nr_pages;
- bio.bi_io_vec = inline_vecs;
+ bio.bi_io_vec = vecs;
bio.bi_bdev = bdev;
bio.bi_iter.bi_sector = pos >> blkbits;
bio.bi_private = current;
@@ -243,6 +251,9 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct
iov_iter *iter,
put_page(bvec->bv_page);
}
+ if (vecs != inline_vecs)
+ kfree(vecs);
+
if (unlikely(bio.bi_error))
return bio.bi_error;
iocb->ki_pos += ret;
@@ -259,7 +270,7 @@ blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES);
if (!nr_pages)
return 0;
- if (is_sync_kiocb(iocb) && nr_pages <= DIO_INLINE_BIO_VECS)
+ if (is_sync_kiocb(iocb))
return __blkdev_direct_IO_simple(iocb, iter, nr_pages);
return __blockdev_direct_IO(iocb, inode, I_BDEV(inode), iter,
blkdev_get_block, NULL, NULL,
--
2.7.4
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