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lightnvm: limit get chunk meta request size

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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: Matias Bjørling <mb@lightnvm.io>
Reviewed-by: Javier González <javier@cnexlabs.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
This commit is contained in:
Matias Bjørling 2018-07-13 10:48:41 +02:00 committed by Jens Axboe
parent 921aebfac0
commit 59a8f43b63
1 changed files with 8 additions and 2 deletions
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10
drivers/nvme/host/lightnvm.c
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@ -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);