erofs: kill use_vmap module parameter
As Christoph said [1],
"vm_map_ram is supposed to generally behave better. So if
it doesn't please report that that to the arch maintainer
and linux-mm so that they can look into the issue. Having
user make choices of deep down kernel internals is just
a horrible interface.
Please talk to maintainers of other bits of the kernel
if you see issues and / or need enhancements. "
Let's redo the previous conclusion and kill the vmap
approach.
[1] https://lore.kernel.org/r/20190830165533.GA10909@infradead.org/
Reported-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: Gao Xiang <gaoxiang25@huawei.com>
Link: https://lore.kernel.org/r/20190904020912.63925-21-gaoxiang25@huawei.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
diff --git a/Documentation/filesystems/erofs.txt b/Documentation/filesystems/erofs.txt
index c3b5f60..b0c0853 100644
--- a/Documentation/filesystems/erofs.txt
+++ b/Documentation/filesystems/erofs.txt
@@ -67,10 +67,6 @@
It still does in-place I/O decompression
for the rest compressed physical clusters.
-Module parameters
-=================
-use_vmap=[0|1] Use vmap() instead of vm_map_ram() (default 0).
-
On-disk details
===============
diff --git a/fs/erofs/decompressor.c b/fs/erofs/decompressor.c
index 8ed3850..37177d4 100644
--- a/fs/erofs/decompressor.c
+++ b/fs/erofs/decompressor.c
@@ -28,10 +28,6 @@
char *name;
};
-static bool use_vmap;
-module_param(use_vmap, bool, 0444);
-MODULE_PARM_DESC(use_vmap, "Use vmap() instead of vm_map_ram() (default 0)");
-
static int z_erofs_lz4_prepare_destpages(struct z_erofs_decompress_req *rq,
struct list_head *pagepool)
{
@@ -221,32 +217,6 @@
}
}
-static void *erofs_vmap(struct page **pages, unsigned int count)
-{
- int i = 0;
-
- if (use_vmap)
- return vmap(pages, count, VM_MAP, PAGE_KERNEL);
-
- while (1) {
- void *addr = vm_map_ram(pages, count, -1, PAGE_KERNEL);
-
- /* retry two more times (totally 3 times) */
- if (addr || ++i >= 3)
- return addr;
- vm_unmap_aliases();
- }
- return NULL;
-}
-
-static void erofs_vunmap(const void *mem, unsigned int count)
-{
- if (!use_vmap)
- vm_unmap_ram(mem, count);
- else
- vunmap(mem);
-}
-
static int z_erofs_decompress_generic(struct z_erofs_decompress_req *rq,
struct list_head *pagepool)
{
@@ -255,7 +225,7 @@
const struct z_erofs_decompressor *alg = decompressors + rq->alg;
unsigned int dst_maptype;
void *dst;
- int ret;
+ int ret, i;
if (nrpages_out == 1 && !rq->inplace_io) {
DBG_BUGON(!*rq->out);
@@ -293,9 +263,19 @@
goto dstmap_out;
}
- dst = erofs_vmap(rq->out, nrpages_out);
+ i = 0;
+ while (1) {
+ dst = vm_map_ram(rq->out, nrpages_out, -1, PAGE_KERNEL);
+
+ /* retry two more times (totally 3 times) */
+ if (dst || ++i >= 3)
+ break;
+ vm_unmap_aliases();
+ }
+
if (!dst)
return -ENOMEM;
+
dst_maptype = 2;
dstmap_out:
@@ -304,7 +284,7 @@
if (!dst_maptype)
kunmap_atomic(dst);
else if (dst_maptype == 2)
- erofs_vunmap(dst, nrpages_out);
+ vm_unmap_ram(dst, nrpages_out);
return ret;
}