[PATCH 05/11] f2fs: add mount option to select fault injection ratio

[Jaegeuk Kim]

This patch adds a mount option to select fault ratio.

Signed-off-by: Jaegeuk Kim <jaeg...@kernel.org>
---
 fs/f2fs/Kconfig |  8 ++++++++
 fs/f2fs/f2fs.h  |  1 +
 fs/f2fs/super.c | 16 ++++++++++++++++
 3 files changed, 25 insertions(+)

diff --git a/fs/f2fs/Kconfig b/fs/f2fs/Kconfig
index 1f8982a..378c221 100644
--- a/fs/f2fs/Kconfig
+++ b/fs/f2fs/Kconfig
@@ -94,3 +94,11 @@ config F2FS_IO_TRACE
          information and block IO patterns in the filesystem level.
 
          If unsure, say N.
+
+config F2FS_FAULT_INJECTION
+       bool "F2FS fault injection facility"
+       depends on F2FS_FS
+       help
+         Test F2FS to inject faults such as ENOMEM, ENOSPC, and so on.
+
+         If unsure, say N.
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 364d5fd..0684d3e 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -56,6 +56,7 @@
 #define F2FS_MOUNT_EXTENT_CACHE                0x00002000
 #define F2FS_MOUNT_FORCE_FG_GC         0x00004000
 #define F2FS_MOUNT_DATA_FLUSH          0x00008000
+#define F2FS_MOUNT_FAULT_INJECTION     0x00010000
 
 #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 90d4b86..b27febd 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -39,6 +39,10 @@ static struct proc_dir_entry *f2fs_proc_root;
 static struct kmem_cache *f2fs_inode_cachep;
 static struct kset *f2fs_kset;
 
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+u32 f2fs_fault_rate = 0;
+#endif
+
 /* f2fs-wide shrinker description */
 static struct shrinker f2fs_shrinker_info = {
        .scan_objects = f2fs_shrink_scan,
@@ -68,6 +72,7 @@ enum {
        Opt_noextent_cache,
        Opt_noinline_data,
        Opt_data_flush,
+       Opt_fault_injection,
        Opt_err,
 };
 
@@ -93,6 +98,7 @@ static match_table_t f2fs_tokens = {
        {Opt_noextent_cache, "noextent_cache"},
        {Opt_noinline_data, "noinline_data"},
        {Opt_data_flush, "data_flush"},
+       {Opt_fault_injection, "fault_injection=%u"},
        {Opt_err, NULL},
 };
 
@@ -433,6 +439,16 @@ static int parse_options(struct super_block *sb, char 
*options)
                case Opt_data_flush:
                        set_opt(sbi, DATA_FLUSH);
                        break;
+               case Opt_fault_injection:
+                       if (args->from && match_int(args, &arg))
+                               return -EINVAL;
+#ifdef CONFIG_F2FS_FAULT_INJECTION
+                       f2fs_fault_rate = arg;
+#else
+                       f2fs_msg(sb, KERN_INFO,
+                               "FAULT_INJECTION was not selected");
+#endif
+                       break;
                default:
                        f2fs_msg(sb, KERN_ERR,
                                "Unrecognized mount option \"%s\" or missing 
value",
-- 
2.6.3