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Commit 59a8f43b authored by Matias Bjørling's avatar Matias Bjørling Committed by Jens Axboe
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lightnvm: limit get chunk meta request size 



For devices that does not specify a limit on its transfer size, the
get_chk_meta command may send down a single I/O retrieving the full
chunk metadata table. Resulting in large 2-4MB I/O requests. Instead,
split up the I/Os to a maximum of 256KB and issue them separately to
reduce memory requirements.

Signed-off-by: default avatarMatias Bjørling <mb@lightnvm.io>
Reviewed-by: default avatarJavier González <javier@cnexlabs.com>
Signed-off-by: default avatarJens Axboe <axboe@kernel.dk>
parent 921aebfa

drivers/nvme/host/lightnvm.c

+8 −2
Original line number Diff line number Diff line
@@ -583,7 +583,13 @@ static int nvme_nvm_get_chk_meta(struct nvm_dev *ndev, 
	struct ppa_addr ppa;

	size_t left = nchks * sizeof(struct nvme_nvm_chk_meta);

	size_t log_pos, offset, len;

	int ret, i;

	int ret, i, max_len;



	/*

	 * limit requests to maximum 256K to avoid issuing arbitrary large

	 * requests when the device does not specific a maximum transfer size.

	 */

	max_len = min_t(unsigned int, ctrl->max_hw_sectors << 9, 256 * 1024);



	/* Normalize lba address space to obtain log offset */

	ppa.ppa = slba;
@@ -596,7 +602,7 @@ static int nvme_nvm_get_chk_meta(struct nvm_dev *ndev, 
	offset = log_pos * sizeof(struct nvme_nvm_chk_meta);



	while (left) {

		len = min_t(unsigned int, left, ctrl->max_hw_sectors << 9);

		len = min_t(unsigned int, left, max_len);



		ret = nvme_get_log_ext(ctrl, ns, NVME_NVM_LOG_REPORT_CHUNK,

				dev_meta, len, offset);