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nvme-pci: fix host memory buffer allocation fallback 

nvme_alloc_host_mem currently contains two loops that are interwinded,
and the outer retry loop turns out to be broken.  Fix this by untangling
the two.

Based on a report an initial patch from Akinobu Mita.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reported-by: Akinobu Mita <akinobu.mita@gmail.com>
Tested-by: Akinobu Mita <akinobu.mita@gmail.com>
Reviewed-by: Keith Busch <keith.busch@intel.com>
Cc: stable@vger.kernel.org
This commit is contained in:
Christoph Hellwig 2017-09-11 12:08:43 -04:00
parent 608cc4b14a
commit 92dc689563
1 changed files with 30 additions and 18 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

48
drivers/nvme/host/pci.c
View File

@ -1612,18 +1612,16 @@ static void nvme_free_host_mem(struct nvme_dev *dev)
dev->host_mem_descs = NULL;
}
static int nvme_alloc_host_mem(struct nvme_dev *dev, u64 min, u64 preferred)
static int __nvme_alloc_host_mem(struct nvme_dev *dev, u64 preferred,
u32 chunk_size)
{
struct nvme_host_mem_buf_desc *descs;
u32 chunk_size, max_entries, len;
u32 max_entries, len;
dma_addr_t descs_dma;
int i = 0;
void **bufs;
u64 size = 0, tmp;
/* start big and work our way down */
chunk_size = min(preferred, (u64)PAGE_SIZE << MAX_ORDER);
retry:
tmp = (preferred + chunk_size - 1);
do_div(tmp, chunk_size);
max_entries = tmp;
@ -1650,15 +1648,9 @@ static int nvme_alloc_host_mem(struct nvme_dev *dev, u64 min, u64 preferred)
i++;
}
if (!size || (min && size < min)) {
dev_warn(dev->ctrl.device,
"failed to allocate host memory buffer.\n");
if (!size)
goto out_free_bufs;
}
dev_info(dev->ctrl.device,
"allocated %lld MiB host memory buffer.\n",
size >> ilog2(SZ_1M));
dev->nr_host_mem_descs = i;
dev->host_mem_size = size;
dev->host_mem_descs = descs;
@ -1679,15 +1671,28 @@ static int nvme_alloc_host_mem(struct nvme_dev *dev, u64 min, u64 preferred)
dma_free_coherent(dev->dev, max_entries * sizeof(*descs), descs,
descs_dma);
out:
/* try a smaller chunk size if we failed early */
if (chunk_size >= PAGE_SIZE * 2 && (i == 0 || size < min)) {
chunk_size /= 2;
goto retry;
}
dev->host_mem_descs = NULL;
return -ENOMEM;
}
static int nvme_alloc_host_mem(struct nvme_dev *dev, u64 min, u64 preferred)
{
u32 chunk_size;
/* start big and work our way down */
for (chunk_size = min_t(u64, preferred, PAGE_SIZE << MAX_ORDER);
chunk_size >= PAGE_SIZE * 2;
chunk_size /= 2) {
if (!__nvme_alloc_host_mem(dev, preferred, chunk_size)) {
if (!min || dev->host_mem_size >= min)
return 0;
nvme_free_host_mem(dev);
}
}
return -ENOMEM;
}
static void nvme_setup_host_mem(struct nvme_dev *dev)
{
u64 max = (u64)max_host_mem_size_mb * SZ_1M;
@ -1715,10 +1720,17 @@ static void nvme_setup_host_mem(struct nvme_dev *dev)
}
if (!dev->host_mem_descs) {
if (nvme_alloc_host_mem(dev, min, preferred))
if (nvme_alloc_host_mem(dev, min, preferred)) {
dev_warn(dev->ctrl.device,
"failed to allocate host memory buffer.\n");
return;
}
dev_info(dev->ctrl.device,
"allocated %lld MiB host memory buffer.\n",
dev->host_mem_size >> ilog2(SZ_1M));
}
if (nvme_set_host_mem(dev, enable_bits))
nvme_free_host_mem(dev);
}