2015-02-05 09:56:41

by Chao Yu

[permalink] [raw]
Subject: [PATCH v3 07/10] f2fs: add a mount option for rb-tree extent cache

This patch adds a mount option 'extent_cache' in f2fs.

It is try to use a rb-tree based extent cache to cache more mapping information
with less memory if this option is set, otherwise we will use the original one
extent info cache.

Suggested-by: Changman Lee <[email protected]>
Signed-off-by: Chao Yu <[email protected]>
---
Documentation/filesystems/f2fs.txt | 4 ++++
fs/f2fs/f2fs.h | 1 +
fs/f2fs/super.c | 7 +++++++
3 files changed, 12 insertions(+)

diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt
index 6758aa3..d105c5b 100644
--- a/Documentation/filesystems/f2fs.txt
+++ b/Documentation/filesystems/f2fs.txt
@@ -140,6 +140,10 @@ nobarrier This option can be used if underlying storage guarantees
fastboot This option is used when a system wants to reduce mount
time as much as possible, even though normal performance
can be sacrificed.
+extent_cache Enable an extent cache based on rb-tree, it can cache
+ as many as extent which map between contiguous logical
+ address and physical address per inode, resulting in
+ increasing the cache hit ratio.

================================================================================
DEBUGFS ENTRIES
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index e184847..507e604 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -50,6 +50,7 @@
#define F2FS_MOUNT_FLUSH_MERGE 0x00000400
#define F2FS_MOUNT_NOBARRIER 0x00000800
#define F2FS_MOUNT_FASTBOOT 0x00001000
+#define F2FS_MOUNT_EXTENT_CACHE 0x00002000

#define clear_opt(sbi, option) (sbi->mount_opt.opt &= ~F2FS_MOUNT_##option)
#define set_opt(sbi, option) (sbi->mount_opt.opt |= F2FS_MOUNT_##option)
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index 8557582..07a5564 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -57,6 +57,7 @@ enum {
Opt_flush_merge,
Opt_nobarrier,
Opt_fastboot,
+ Opt_extent_cache,
Opt_err,
};

@@ -78,6 +79,7 @@ static match_table_t f2fs_tokens = {
{Opt_flush_merge, "flush_merge"},
{Opt_nobarrier, "nobarrier"},
{Opt_fastboot, "fastboot"},
+ {Opt_extent_cache, "extent_cache"},
{Opt_err, NULL},
};

@@ -365,6 +367,9 @@ static int parse_options(struct super_block *sb, char *options)
case Opt_fastboot:
set_opt(sbi, FASTBOOT);
break;
+ case Opt_extent_cache:
+ set_opt(sbi, EXTENT_CACHE);
+ break;
default:
f2fs_msg(sb, KERN_ERR,
"Unrecognized mount option \"%s\" or missing value",
@@ -597,6 +602,8 @@ static int f2fs_show_options(struct seq_file *seq, struct dentry *root)
seq_puts(seq, ",nobarrier");
if (test_opt(sbi, FASTBOOT))
seq_puts(seq, ",fastboot");
+ if (test_opt(sbi, EXTENT_CACHE))
+ seq_puts(seq, ",extent_cache");
seq_printf(seq, ",active_logs=%u", sbi->active_logs);

return 0;
--
2.2.1