Re: [PATCH 2/2] f2fs: expose extension_list sysfs entry

From: Chao Yu
Date: Mon Feb 26 2018 - 03:33:52 EST


Hi Jaegeuk,

On 2018/2/25 17:29, Jaegeuk Kim wrote:
> On 02/11, Chao Yu wrote:
>> From: Chao Yu <yuchao0@xxxxxxxxxx>
>>
>> This patch adds a sysfs entry 'extension_list' to support lookup/
>> add/delete item in extension list.
>
> Hi Chao,
>
> We need Doc change as well.

Oh, right, let me add it.

Thanks,

>
> Thanks,
>
>>
>> Lookup:
>> cat /sys/fs/f2fs/<device>/extentsion_list
>>
>> Add:
>> echo 'extension' > /sys/fs/f2fs/<device>/extentsion_list
>>
>> Delete:
>> echo '!extension' > /sys/fs/f2fs/<device>/extentsion_list
>>
>> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
>> ---
>> fs/f2fs/f2fs.h | 4 +++-
>> fs/f2fs/file.c | 4 ++--
>> fs/f2fs/namei.c | 42 +++++++++++++++++++++++++++++++++++++++---
>> fs/f2fs/super.c | 2 +-
>> fs/f2fs/sysfs.c | 40 ++++++++++++++++++++++++++++++++++++++++
>> include/linux/f2fs_fs.h | 3 ++-
>> 6 files changed, 87 insertions(+), 8 deletions(-)
>>
>> diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
>> index 0332c44a1d93..030436be2a35 100644
>> --- a/fs/f2fs/f2fs.h
>> +++ b/fs/f2fs/f2fs.h
>> @@ -1048,7 +1048,7 @@ struct f2fs_sb_info {
>> struct super_block *sb; /* pointer to VFS super block */
>> struct proc_dir_entry *s_proc; /* proc entry */
>> struct f2fs_super_block *raw_super; /* raw super block pointer */
>> - struct mutex sb_lock; /* lock for raw super block */
>> + struct rw_semaphore sb_lock; /* lock for raw super block */
>> int valid_super_block; /* valid super block no */
>> unsigned long s_flag; /* flags for sbi */
>>
>> @@ -2612,6 +2612,8 @@ void handle_failed_inode(struct inode *inode);
>> /*
>> * namei.c
>> */
>> +int update_extension_list(struct f2fs_sb_info *sbi, const char *name,
>> + bool set);
>> struct dentry *f2fs_get_parent(struct dentry *child);
>>
>> /*
>> diff --git a/fs/f2fs/file.c b/fs/f2fs/file.c
>> index f26a0bd17469..f64bcd0a7f73 100644
>> --- a/fs/f2fs/file.c
>> +++ b/fs/f2fs/file.c
>> @@ -1969,7 +1969,7 @@ static int f2fs_ioc_get_encryption_pwsalt(struct file *filp, unsigned long arg)
>> if (err)
>> return err;
>>
>> - mutex_lock(&sbi->sb_lock);
>> + down_write(&sbi->sb_lock);
>>
>> if (uuid_is_nonzero(sbi->raw_super->encrypt_pw_salt))
>> goto got_it;
>> @@ -1988,7 +1988,7 @@ static int f2fs_ioc_get_encryption_pwsalt(struct file *filp, unsigned long arg)
>> 16))
>> err = -EFAULT;
>> out_err:
>> - mutex_unlock(&sbi->sb_lock);
>> + up_write(&sbi->sb_lock);
>> mnt_drop_write_file(filp);
>> return err;
>> }
>> diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
>> index c4c94c7e9f4f..fa8e5c06ba39 100644
>> --- a/fs/f2fs/namei.c
>> +++ b/fs/f2fs/namei.c
>> @@ -171,16 +171,52 @@ static int is_multimedia_file(const unsigned char *s, const char *sub)
>> static inline void set_cold_files(struct f2fs_sb_info *sbi, struct inode *inode,
>> const unsigned char *name)
>> {
>> - int i;
>> - __u8 (*extlist)[8] = sbi->raw_super->extension_list;
>> + __u8 (*extlist)[F2FS_EXTENSION_LEN] = sbi->raw_super->extension_list;
>> + int i, count;
>> +
>> + down_read(&sbi->sb_lock);
>> +
>> + count = le32_to_cpu(sbi->raw_super->extension_count);
>>
>> - int count = le32_to_cpu(sbi->raw_super->extension_count);
>> for (i = 0; i < count; i++) {
>> if (is_multimedia_file(name, extlist[i])) {
>> file_set_cold(inode);
>> break;
>> }
>> }
>> +
>> + up_read(&sbi->sb_lock);
>> +}
>> +
>> +int update_extension_list(struct f2fs_sb_info *sbi, const char *name, bool set)
>> +{
>> + __u8 (*extlist)[F2FS_EXTENSION_LEN] = sbi->raw_super->extension_list;
>> + int count = le32_to_cpu(sbi->raw_super->extension_count);
>> + int i;
>> +
>> + for (i = 0; i < count; i++) {
>> + if (strcmp(name, extlist[i]))
>> + continue;
>> +
>> + if (set)
>> + return -EINVAL;
>> +
>> + memcpy(extlist[i], extlist[i + 1],
>> + F2FS_EXTENSION_LEN * (count - i - 1));
>> + memset(extlist[count - 1], 0, F2FS_EXTENSION_LEN);
>> + sbi->raw_super->extension_count = cpu_to_le32(count - 1);
>> + return 0;
>> + }
>> +
>> + if (!set)
>> + return -EINVAL;
>> +
>> + if (count == F2FS_MAX_EXTENSION)
>> + return -EINVAL;
>> +
>> + strncpy(extlist[count], name, strlen(name));
>> + sbi->raw_super->extension_count = cpu_to_le32(count + 1);
>> + return 0;
>> }
>>
>> static int f2fs_create(struct inode *dir, struct dentry *dentry, umode_t mode,
>> diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
>> index 1b49ad477dd9..9b17355434f6 100644
>> --- a/fs/f2fs/super.c
>> +++ b/fs/f2fs/super.c
>> @@ -2233,7 +2233,7 @@ static void init_sb_info(struct f2fs_sb_info *sbi)
>> sbi->dirty_device = 0;
>> spin_lock_init(&sbi->dev_lock);
>>
>> - mutex_init(&sbi->sb_lock);
>> + init_rwsem(&sbi->sb_lock);
>> }
>>
>> static int init_percpu_info(struct f2fs_sb_info *sbi)
>> diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c
>> index 374ee5c82f94..d27b28e602a6 100644
>> --- a/fs/f2fs/sysfs.c
>> +++ b/fs/f2fs/sysfs.c
>> @@ -136,6 +136,18 @@ static ssize_t f2fs_sbi_show(struct f2fs_attr *a,
>> if (!ptr)
>> return -EINVAL;
>>
>> + if (!strcmp(a->attr.name, "extension_list")) {
>> + __u8 (*extlist)[F2FS_EXTENSION_LEN] =
>> + sbi->raw_super->extension_list;
>> + int count = le32_to_cpu(sbi->raw_super->extension_count);
>> + int len = 0, i;
>> +
>> + for (i = 0; i < count; i++)
>> + len += snprintf(buf + len, PAGE_SIZE - len, "%s\n",
>> + extlist[i]);
>> + return len;
>> + }
>> +
>> ui = (unsigned int *)(ptr + a->offset);
>>
>> return snprintf(buf, PAGE_SIZE, "%u\n", *ui);
>> @@ -154,6 +166,32 @@ static ssize_t f2fs_sbi_store(struct f2fs_attr *a,
>> if (!ptr)
>> return -EINVAL;
>>
>> + if (!strcmp(a->attr.name, "extension_list")) {
>> + const char *name = strim((char *)buf);
>> + bool set = true;
>> +
>> + if (name[0] == '!') {
>> + name++;
>> + set = false;
>> + }
>> +
>> + if (strlen(name) >= F2FS_EXTENSION_LEN)
>> + return -EINVAL;
>> +
>> + down_write(&sbi->sb_lock);
>> +
>> + ret = update_extension_list(sbi, name, set);
>> + if (ret)
>> + goto out;
>> +
>> + ret = f2fs_commit_super(sbi, false);
>> + if (ret)
>> + update_extension_list(sbi, name, !set);
>> +out:
>> + up_write(&sbi->sb_lock);
>> + return ret ? ret : count;
>> + }
>> +
>> ui = (unsigned int *)(ptr + a->offset);
>>
>> ret = kstrtoul(skip_spaces(buf), 0, &t);
>> @@ -307,6 +345,7 @@ F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, idle_interval, interval_time[REQ_TIME]);
>> F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, iostat_enable, iostat_enable);
>> F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, readdir_ra, readdir_ra);
>> F2FS_RW_ATTR(F2FS_SBI, f2fs_sb_info, gc_pin_file_thresh, gc_pin_file_threshold);
>> +F2FS_RW_ATTR(F2FS_SBI, f2fs_super_block, extension_list, extension_list);
>> #ifdef CONFIG_F2FS_FAULT_INJECTION
>> F2FS_RW_ATTR(FAULT_INFO_RATE, f2fs_fault_info, inject_rate, inject_rate);
>> F2FS_RW_ATTR(FAULT_INFO_TYPE, f2fs_fault_info, inject_type, inject_type);
>> @@ -357,6 +396,7 @@ static struct attribute *f2fs_attrs[] = {
>> ATTR_LIST(iostat_enable),
>> ATTR_LIST(readdir_ra),
>> ATTR_LIST(gc_pin_file_thresh),
>> + ATTR_LIST(extension_list),
>> #ifdef CONFIG_F2FS_FAULT_INJECTION
>> ATTR_LIST(inject_rate),
>> ATTR_LIST(inject_type),
>> diff --git a/include/linux/f2fs_fs.h b/include/linux/f2fs_fs.h
>> index f7f09907e69d..3d03f51282ac 100644
>> --- a/include/linux/f2fs_fs.h
>> +++ b/include/linux/f2fs_fs.h
>> @@ -21,6 +21,7 @@
>> #define F2FS_BLKSIZE 4096 /* support only 4KB block */
>> #define F2FS_BLKSIZE_BITS 12 /* bits for F2FS_BLKSIZE */
>> #define F2FS_MAX_EXTENSION 64 /* # of extension entries */
>> +#define F2FS_EXTENSION_LEN 8 /* max size of extension */
>> #define F2FS_BLK_ALIGN(x) (((x) + F2FS_BLKSIZE - 1) >> F2FS_BLKSIZE_BITS)
>>
>> #define NULL_ADDR ((block_t)0) /* used as block_t addresses */
>> @@ -102,7 +103,7 @@ struct f2fs_super_block {
>> __u8 uuid[16]; /* 128-bit uuid for volume */
>> __le16 volume_name[MAX_VOLUME_NAME]; /* volume name */
>> __le32 extension_count; /* # of extensions below */
>> - __u8 extension_list[F2FS_MAX_EXTENSION][8]; /* extension array */
>> + __u8 extension_list[F2FS_MAX_EXTENSION][F2FS_EXTENSION_LEN];/* extension array */
>> __le32 cp_payload;
>> __u8 version[VERSION_LEN]; /* the kernel version */
>> __u8 init_version[VERSION_LEN]; /* the initial kernel version */
>> --
>> 2.14.1.145.gb3622a4ee
>
> .
>