diff --git a/drivers/staging/erofs/Kconfig b/drivers/staging/erofs/Kconfig
index 1a5ec1bb5cda67e743ff2d8cb9de20261ada9fc6..edda055b3c64e294adc8a20d00f9008a0afe56ce 100644
--- a/drivers/staging/erofs/Kconfig
+++ b/drivers/staging/erofs/Kconfig
@@ -71,3 +71,9 @@ config EROFS_FS_USE_VM_MAP_RAM
If you don't know what these are, say N.
+config EROFS_FAULT_INJECTION
+ bool "EROFS fault injection facility"
+ depends on EROFS_FS
+ help
+ Test EROFS to inject faults such as ENOMEM, EIO, and so on.
+ If unsure, say N.
diff --git a/drivers/staging/erofs/inode.c b/drivers/staging/erofs/inode.c
index c01181153d90b4f94de7b48b276b46eb5d3fb38a..a6d3e129708ee028d1a7beec01da803c5306ce6a 100644
--- a/drivers/staging/erofs/inode.c
+++ b/drivers/staging/erofs/inode.c
@@ -113,6 +113,7 @@ static int read_inode(struct inode *inode, void *data)
static int fill_inline_data(struct inode *inode, void *data, unsigned m_pofs)
{
struct erofs_vnode *vi = EROFS_V(inode);
+ struct erofs_sb_info *sbi = EROFS_I_SB(inode);
int mode = vi->data_mapping_mode;
DBG_BUGON(mode >= EROFS_INODE_LAYOUT_MAX);
@@ -123,7 +124,7 @@ static int fill_inline_data(struct inode *inode, void *data, unsigned m_pofs)
/* fast symlink (following ext4) */
if (S_ISLNK(inode->i_mode) && inode->i_size < PAGE_SIZE) {
- char *lnk = kmalloc(inode->i_size + 1, GFP_KERNEL);
+ char *lnk = erofs_kmalloc(sbi, inode->i_size + 1, GFP_KERNEL);
if (unlikely(lnk == NULL))
return -ENOMEM;
diff --git a/drivers/staging/erofs/internal.h b/drivers/staging/erofs/internal.h
index 5862705c5caea480c23588591d8f31d5c22035fe..ca224866282f712e3504fb3691c1d3353e1a5923 100644
--- a/drivers/staging/erofs/internal.h
+++ b/drivers/staging/erofs/internal.h
@@ -42,6 +42,22 @@
#define DBG_BUGON(...) ((void)0)
#endif
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+enum {
+ FAULT_KMALLOC,
+ FAULT_MAX,
+};
+
+extern char *erofs_fault_name[FAULT_MAX];
+#define IS_FAULT_SET(fi, type) ((fi)->inject_type & (1 << (type)))
+
+struct erofs_fault_info {
+ atomic_t inject_ops;
+ unsigned int inject_rate;
+ unsigned int inject_type;
+};
+#endif
+
/* EROFS_SUPER_MAGIC_V1 to represent the whole file system */
#define EROFS_SUPER_MAGIC EROFS_SUPER_MAGIC_V1
@@ -70,14 +86,55 @@ struct erofs_sb_info {
char *dev_name;
unsigned int mount_opt;
+
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+ struct erofs_fault_info fault_info; /* For fault injection */
+#endif
};
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+#define erofs_show_injection_info(type) \
+ infoln("inject %s in %s of %pS", erofs_fault_name[type], \
+ __func__, __builtin_return_address(0))
+
+static inline bool time_to_inject(struct erofs_sb_info *sbi, int type)
+{
+ struct erofs_fault_info *ffi = &sbi->fault_info;
+
+ if (!ffi->inject_rate)
+ return false;
+
+ if (!IS_FAULT_SET(ffi, type))
+ return false;
+
+ atomic_inc(&ffi->inject_ops);
+ if (atomic_read(&ffi->inject_ops) >= ffi->inject_rate) {
+ atomic_set(&ffi->inject_ops, 0);
+ return true;
+ }
+ return false;
+}
+#endif
+
+static inline void *erofs_kmalloc(struct erofs_sb_info *sbi,
+ size_t size, gfp_t flags)
+{
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+ if (time_to_inject(sbi, FAULT_KMALLOC)) {
+ erofs_show_injection_info(FAULT_KMALLOC);
+ return NULL;
+ }
+#endif
+ return kmalloc(size, flags);
+}
+
#define EROFS_SB(sb) ((struct erofs_sb_info *)(sb)->s_fs_info)
#define EROFS_I_SB(inode) ((struct erofs_sb_info *)(inode)->i_sb->s_fs_info)
/* Mount flags set via mount options or defaults */
#define EROFS_MOUNT_XATTR_USER 0x00000010
#define EROFS_MOUNT_POSIX_ACL 0x00000020
+#define EROFS_MOUNT_FAULT_INJECTION 0x00000040
#define clear_opt(sbi, option) ((sbi)->mount_opt &= ~EROFS_MOUNT_##option)
#define set_opt(sbi, option) ((sbi)->mount_opt |= EROFS_MOUNT_##option)
diff --git a/drivers/staging/erofs/super.c b/drivers/staging/erofs/super.c
index 4a8a2664c80b289c289a589fef9e4266be5ec4f2..701425fed049b7cd82ce707f49e639c7aa17d971 100644
--- a/drivers/staging/erofs/super.c
+++ b/drivers/staging/erofs/super.c
@@ -129,6 +129,26 @@ out:
return ret;
}
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+char *erofs_fault_name[FAULT_MAX] = {
+ [FAULT_KMALLOC] = "kmalloc",
+};
+
+static void erofs_build_fault_attr(struct erofs_sb_info *sbi,
+ unsigned int rate)
+{
+ struct erofs_fault_info *ffi = &sbi->fault_info;
+
+ if (rate) {
+ atomic_set(&ffi->inject_ops, 0);
+ ffi->inject_rate = rate;
+ ffi->inject_type = (1 << FAULT_MAX) - 1;
+ } else {
+ memset(ffi, 0, sizeof(struct erofs_fault_info));
+ }
+}
+#endif
+
static void default_options(struct erofs_sb_info *sbi)
{
#ifdef CONFIG_EROFS_FS_XATTR
@@ -145,6 +165,7 @@ enum {
Opt_nouser_xattr,
Opt_acl,
Opt_noacl,
+ Opt_fault_injection,
Opt_err
};
@@ -153,6 +174,7 @@ static match_table_t erofs_tokens = {
{Opt_nouser_xattr, "nouser_xattr"},
{Opt_acl, "acl"},
{Opt_noacl, "noacl"},
+ {Opt_fault_injection, "fault_injection=%u"},
{Opt_err, NULL}
};
@@ -160,6 +182,7 @@ static int parse_options(struct super_block *sb, char *options)
{
substring_t args[MAX_OPT_ARGS];
char *p;
+ int arg = 0;
if (!options)
return 0;
@@ -204,6 +227,16 @@ static int parse_options(struct super_block *sb, char *options)
infoln("noacl options not supported");
break;
#endif
+ case Opt_fault_injection:
+ if (args->from && match_int(args, &arg))
+ return -EINVAL;
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+ erofs_build_fault_attr(EROFS_SB(sb), arg);
+ set_opt(EROFS_SB(sb), FAULT_INJECTION);
+#else
+ infoln("FAULT_INJECTION was not selected");
+#endif
+ break;
default:
errln("Unrecognized mount option \"%s\" "
"or missing value", p);
@@ -452,6 +485,11 @@ static int erofs_show_options(struct seq_file *seq, struct dentry *root)
seq_puts(seq, ",acl");
else
seq_puts(seq, ",noacl");
+#endif
+#ifdef CONFIG_EROFS_FAULT_INJECTION
+ if (test_opt(sbi, FAULT_INJECTION))
+ seq_printf(seq, ",fault_injection=%u",
+ sbi->fault_info.inject_rate);
#endif
return 0;
}