[PATCH 1/3] mkfs.f2fs: fix wrong documentation

[PATCH 1/3] mkfs.f2fs: fix wrong documentation

[Jaegeuk Kim]

The -s should be the number of segments per a section.

Reported-by: Marc Lehmann <schmorp@schmorp.de>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 man/mkfs.f2fs.8 | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/man/mkfs.f2fs.8 b/man/mkfs.f2fs.8
index f386ac6..48654aa 100644
--- a/man/mkfs.f2fs.8
+++ b/man/mkfs.f2fs.8
@@ -21,7 +21,7 @@ mkfs.f2fs \- create an F2FS file system
 ]
 [
 .B \-s
-.I log-based-#-of-segments-per-section
+.I #-of-segments-per-section
 ]
 [
 .B \-z
@@ -60,10 +60,10 @@ Specify the volume label to the partition mounted as F2FS.
 Specify the percentage over the volume size for overprovision area. This area
 is hidden to users, and utilized by F2FS cleaner. The default percentage is 5%.
 .TP
-.BI \-s " log-based-#-of-segments-per-section"
-Specify the log-based number of segments per section. A section consists of
+.BI \-s " #-of-segments-per-section"
+Specify the number of segments per section. A section consists of
 multiple consecutive segments, and is the unit of garbage collection.
-The default number is 0, which means one segment is assigned to a section.
+The default number is 1, which means one segment is assigned to a section.
 .TP
 .BI \-z " #-of-sections-per-zone"
 Specify the number of sections per zone. A zone consists of multiple sections.
-- 
2.1.1


------------------------------------------------------------------------------

[PATCH 2/3] mkfs.f2fs: set overprovision size more precisely

[Jaegeuk Kim]

This patch introduces to set the default overprovision space according to the
partition size in order to provide more space.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 lib/libf2fs.c           |  4 ++--
 mkfs/f2fs_format.c      | 40 ++++++++++++++++++++++++++++++++++++++++
 mkfs/f2fs_format_main.c |  5 -----
 3 files changed, 42 insertions(+), 7 deletions(-)

diff --git a/lib/libf2fs.c b/lib/libf2fs.c
index 7fd2550..e8f4d47 100644
--- a/lib/libf2fs.c
+++ b/lib/libf2fs.c
@@ -353,8 +353,8 @@ void f2fs_init_configuration(struct f2fs_configuration *c)
 	c->blks_per_seg = DEFAULT_BLOCKS_PER_SEGMENT;
 
 	/* calculated by overprovision ratio */
-	c->reserved_segments = 48;
-	c->overprovision = 5;
+	c->reserved_segments = 0;
+	c->overprovision = 0;
 	c->segs_per_sec = 1;
 	c->secs_per_zone = 1;
 	c->segs_per_zone = 1;
diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
index f879bca..21e74fe 100644
--- a/mkfs/f2fs_format.c
+++ b/mkfs/f2fs_format.c
@@ -155,6 +155,33 @@ static void configure_extension_list(void)
 	free(config.extension_list);
 }
 
+static u_int32_t get_best_overprovision(void)
+{
+	u_int32_t reserved, ovp, candidate, end, diff, space;
+	u_int32_t max_ovp = 0, max_space = 0;
+
+	if (get_sb(segment_count_main) < 256) {
+		candidate = 10;
+		end = 95;
+		diff = 5;
+	} else {
+		candidate = 1;
+		end = 10;
+		diff = 1;
+	}
+
+	for (; candidate <= end; candidate += diff) {
+		reserved = 2 * (100 / candidate + 1) + 6;
+		ovp = (get_sb(segment_count_main) - reserved) * candidate / 100;
+		space = get_sb(segment_count_main) - reserved - ovp;
+		if (max_space < space) {
+			max_space = space;
+			max_ovp = candidate;
+		}
+	}
+	return max_ovp;
+}
+
 static int f2fs_prepare_super_block(void)
 {
 	u_int32_t blk_size_bytes;
@@ -310,6 +337,14 @@ static int f2fs_prepare_super_block(void)
 
 	set_sb(segment_count_main, get_sb(section_count) * config.segs_per_sec);
 
+	/* Let's determine the best reserved and overprovisioned space */
+	if (config.overprovision == 0)
+		config.overprovision = get_best_overprovision();
+
+	config.reserved_segments =
+			(2 * (100 / config.overprovision + 1) + 6)
+			* config.segs_per_sec;
+
 	if ((get_sb(segment_count_main) - 2) <
 					config.reserved_segments) {
 		MSG(1, "\tError: Device size is not sufficient for F2FS volume,\
@@ -497,6 +532,11 @@ static int f2fs_write_check_point_pack(void)
 	set_cp(overprov_segment_count, get_cp(overprov_segment_count) +
 			get_cp(rsvd_segment_count));
 
+	MSG(0, "Info: Overprovision ratio = %u%%\n", config.overprovision);
+	MSG(0, "Info: Overprovision segments = %u (GC reserved = %u)\n",
+					get_cp(overprov_segment_count),
+					config.reserved_segments);
+
 	/* main segments - reserved segments - (node + data segments) */
 	set_cp(free_segment_count, get_sb(segment_count_main) - 6);
 	set_cp(user_block_count, ((get_cp(free_segment_count) + 6 -
diff --git a/mkfs/f2fs_format_main.c b/mkfs/f2fs_format_main.c
index 5a9e7e2..fc612d8 100644
--- a/mkfs/f2fs_format_main.c
+++ b/mkfs/f2fs_format_main.c
@@ -56,7 +56,6 @@ static void f2fs_show_info()
 
 	if (config.vol_label)
 		MSG(0, "Info: Label = %s\n", config.vol_label);
-	MSG(0, "Info: Overprovision ratio = %u%%\n", config.overprovision);
 	MSG(0, "Info: Segments per section = %d\n", config.segs_per_sec);
 	MSG(0, "Info: Sections per zone = %d\n", config.secs_per_zone);
 	MSG(0, "Info: Trim is %s\n", config.trim ? "enabled": "disabled");
@@ -134,10 +133,6 @@ static void f2fs_parse_options(int argc, char *argv[])
 				config.total_sectors,
 				config.total_sectors * 512);
 	}
-
-	config.reserved_segments  =
-			(2 * (100 / config.overprovision + 1) + 6)
-			* config.segs_per_sec;
 	config.segs_per_zone = config.segs_per_sec * config.secs_per_zone;
 }
 
-- 
2.1.1


------------------------------------------------------------------------------

[PATCH 3/3] mkfs.f2fs: don't need to limit MIN_VOLUME SIZE

[Jaegeuk Kim]

The minimum volume size is determined while preparing superblock.

Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
---
 include/f2fs_fs.h | 1 -
 lib/libf2fs.c     | 7 -------
 2 files changed, 8 deletions(-)

diff --git a/include/f2fs_fs.h b/include/f2fs_fs.h
index 59cc0d1..38a774c 100644
--- a/include/f2fs_fs.h
+++ b/include/f2fs_fs.h
@@ -209,7 +209,6 @@ static inline uint64_t bswap_64(uint64_t val)
 #define CHECKSUM_OFFSET		4092
 
 /* for mkfs */
-#define F2FS_MIN_VOLUME_SIZE	104857600
 #define	F2FS_NUMBER_OF_CHECKPOINT_PACK	2
 #define	DEFAULT_SECTOR_SIZE		512
 #define	DEFAULT_SECTORS_PER_BLOCK	8
diff --git a/lib/libf2fs.c b/lib/libf2fs.c
index e8f4d47..83d1296 100644
--- a/lib/libf2fs.c
+++ b/lib/libf2fs.c
@@ -499,13 +499,6 @@ int f2fs_get_device_info(struct f2fs_configuration *c)
 	MSG(0, "Info: sector size = %u\n", c->sector_size);
 	MSG(0, "Info: total sectors = %"PRIu64" (%"PRIu64" MB)\n",
 				c->total_sectors, c->total_sectors >> 11);
-	if (c->total_sectors <
-			(F2FS_MIN_VOLUME_SIZE / c->sector_size)) {
-		MSG(0, "Error: Min volume size supported is %d\n",
-				F2FS_MIN_VOLUME_SIZE);
-		return -1;
-	}
-
 	return 0;
 }
 
-- 
2.1.1


------------------------------------------------------------------------------