Capped at 15 because of currently used encoding, which is also a reasonable
limit because highest levels shine only on blocks much bigger than btrfs'
128KB.
Memory is allocated for the biggest supported level rather than for
what is actually used.
Signed-off-by: Adam Borowski <kilob...@angband.pl>
---
fs/btrfs/compression.c | 21 +++++++++++++++------
fs/btrfs/props.c | 2 +-
fs/btrfs/super.c | 3 ++-
fs/btrfs/zstd.c | 24 +++++++++++++++++++-----
4 files changed, 37 insertions(+), 13 deletions(-)
diff --git a/fs/btrfs/compression.c b/fs/btrfs/compression.c
index 71782ec976c7..2d4337756fef 100644
--- a/fs/btrfs/compression.c
+++ b/fs/btrfs/compression.c
@@ -1091,13 +1091,22 @@ int btrfs_compress_heuristic(struct inode *inode, u64
start, u64 end)
unsigned int btrfs_compress_str2level(const char *str)
{
- if (strncmp(str, "zlib", 4) != 0)
+ long level;
+ int max;
+
+ if (strncmp(str, "zlib", 4) == 0)
+ max = 9;
+ else if (strncmp(str, "zstd", 4) == 0)
+ max = 15; // encoded on 4 bits, real max is 22
+ else
return 0;
- if ('1' <= str[4] && str[4] <= '9' )
- return str[4] - '0';
- if (str[4] == ':' && '1' <= str[5] && str[5] <= '9')
- return str[5] - '0';
+ str += 4;
+ if (*str == ':')
+ str++;
- return 0;
+ if (kstrtoul(str, 10, &level))
+ return 0;
+
+ return (level > max) ? 0 : level;
}
diff --git a/fs/btrfs/props.c b/fs/btrfs/props.c
index f6a05f836629..2e35aa2b2d79 100644
--- a/fs/btrfs/props.c
+++ b/fs/btrfs/props.c
@@ -414,7 +414,7 @@ static int prop_compression_apply(struct inode *inode,
type = BTRFS_COMPRESS_LZO;
else if (!strncmp("zlib", value, 4))
type = BTRFS_COMPRESS_ZLIB;
- else if (!strncmp("zstd", value, len))
+ else if (!strncmp("zstd", value, 4))
type = BTRFS_COMPRESS_ZSTD;
else
return -EINVAL;
diff --git a/fs/btrfs/super.c b/fs/btrfs/super.c
index 537e04120457..f9d4522336db 100644
--- a/fs/btrfs/super.c
+++ b/fs/btrfs/super.c
@@ -515,9 +515,10 @@ int btrfs_parse_options(struct btrfs_fs_info *info, char
*options,
btrfs_clear_opt(info->mount_opt, NODATASUM);
btrfs_set_fs_incompat(info, COMPRESS_LZO);
no_compress = 0;
- } else if (strcmp(args[0].from, "zstd") == 0) {
+ } else if (strncmp(args[0].from, "zstd", 4) == 0) {
compress_type = "zstd";
info->compress_type = BTRFS_COMPRESS_ZSTD;
+ info->compress_level =
btrfs_compress_str2level(args[0].from);
btrfs_set_opt(info->mount_opt, COMPRESS);
btrfs_clear_opt(info->mount_opt, NODATACOW);
btrfs_clear_opt(info->mount_opt, NODATASUM);
diff --git a/fs/btrfs/zstd.c b/fs/btrfs/zstd.c
index 607ce47b483a..99e11cb2d60e 100644
--- a/fs/btrfs/zstd.c
+++ b/fs/btrfs/zstd.c
@@ -26,11 +26,14 @@
#define ZSTD_BTRFS_MAX_WINDOWLOG 17
#define ZSTD_BTRFS_MAX_INPUT (1 << ZSTD_BTRFS_MAX_WINDOWLOG)
#define ZSTD_BTRFS_DEFAULT_LEVEL 3
+// Max supported by the algorithm is 22, but gains for small blocks (128KB)
+// are limited, thus we cap at 15.
+#define ZSTD_BTRFS_MAX_LEVEL 15
-static ZSTD_parameters zstd_get_btrfs_parameters(size_t src_len)
+static ZSTD_parameters zstd_get_btrfs_parameters(size_t src_len, int level)
{
- ZSTD_parameters params = ZSTD_getParams(ZSTD_BTRFS_DEFAULT_LEVEL,
- src_len, 0);
+ ZSTD_parameters params = ZSTD_getParams(level, src_len, 0);
+ BUG_ON(level > ZSTD_maxCLevel());
if (params.cParams.windowLog > ZSTD_BTRFS_MAX_WINDOWLOG)
params.cParams.windowLog = ZSTD_BTRFS_MAX_WINDOWLOG;
@@ -43,6 +46,7 @@ struct workspace {
size_t size;
char *buf;
struct list_head list;
+ int level;
};
static void zstd_free_workspace(struct list_head *ws)
@@ -57,7 +61,8 @@ static void zstd_free_workspace(struct list_head *ws)
static struct list_head *zstd_alloc_workspace(void)
{
ZSTD_parameters params =
- zstd_get_btrfs_parameters(ZSTD_BTRFS_MAX_INPUT);
+ zstd_get_btrfs_parameters(ZSTD_BTRFS_MAX_INPUT,
+ ZSTD_BTRFS_MAX_LEVEL);
struct workspace *workspace;
workspace = kzalloc(sizeof(*workspace), GFP_KERNEL);
@@ -101,7 +106,7 @@ static int zstd_compress_pages(struct list_head *ws,
unsigned long len = *total_out;
const unsigned long nr_dest_pages = *out_pages;
unsigned long max_out = nr_dest_pages * PAGE_SIZE;
- ZSTD_parameters params = zstd_get_btrfs_parameters(len);
+ ZSTD_parameters params = zstd_get_btrfs_parameters(len,
workspace->level);
*out_pages = 0;
*total_out = 0;
@@ -423,10 +428,19 @@ static int zstd_decompress(struct list_head *ws, unsigned
char *data_in,
return ret;
}
+static void zstd_set_level(struct list_head *ws, unsigned int type)
+{
+ struct workspace *workspace = list_entry(ws, struct workspace, list);
+ unsigned level = (type & 0xF0) >> 4;
+
+ workspace->level = level > 0 ? level : ZSTD_BTRFS_DEFAULT_LEVEL;
+}
+
const struct btrfs_compress_op btrfs_zstd_compress = {
.alloc_workspace = zstd_alloc_workspace,
.free_workspace = zstd_free_workspace,
.compress_pages = zstd_compress_pages,
.decompress_bio = zstd_decompress_bio,
.decompress = zstd_decompress,
+ .set_level = zstd_set_level,
};
--
2.14.1
--
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