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btrfs: compression: inline alloc_workspace

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Replace indirect calls to alloc_workspace by switch and calls to the
specific callbacks. This is mainly to get rid of the indirection due to
spectre vulnerability mitigations.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
This commit is contained in:
David Sterba
2019-10-04 02:47:39 +02:00
parent 5907a9bb13
commit c778df1406
5 changed files with 18 additions and 8 deletions
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21
fs/btrfs/compression.c
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@@ -912,7 +912,6 @@ fail:
const struct btrfs_compress_op btrfs_heuristic_compress = {
.workspace_manager = &heuristic_wsm,
.alloc_workspace = alloc_heuristic_ws,
.free_workspace = free_heuristic_ws,
};
@@ -924,6 +923,22 @@ static const struct btrfs_compress_op * const btrfs_compress_op[] = {
&btrfs_zstd_compress,
};
static struct list_head *alloc_workspace(int type, unsigned int level)
{
switch (type) {
case BTRFS_COMPRESS_NONE: return alloc_heuristic_ws(level);
case BTRFS_COMPRESS_ZLIB: return zlib_alloc_workspace(level);
case BTRFS_COMPRESS_LZO: return lzo_alloc_workspace(level);
case BTRFS_COMPRESS_ZSTD: return zstd_alloc_workspace(level);
default:
/*
* This can't happen, the type is validated several times
* before we get here.
*/
BUG();
}
}
static void btrfs_init_workspace_manager(int type)
{
const struct btrfs_compress_op *ops = btrfs_compress_op[type];
@@ -941,7 +956,7 @@ static void btrfs_init_workspace_manager(int type)
* Preallocate one workspace for each compression type so we can
* guarantee forward progress in the worst case
*/
workspace = wsm->ops->alloc_workspace(0);
workspace = alloc_workspace(type, 0);
if (IS_ERR(workspace)) {
pr_warn(
"BTRFS: cannot preallocate compression workspace, will try later\n");
@@ -1020,7 +1035,7 @@ again:
* context of btrfs_compress_bio/btrfs_compress_pages
*/
nofs_flag = memalloc_nofs_save();
workspace = wsm->ops->alloc_workspace(level);
workspace = alloc_workspace(type, level);
memalloc_nofs_restore(nofs_flag);
if (IS_ERR(workspace)) {