Hi Jaegeuk, On 2017/7/27 5:44, Jaegeuk Kim wrote: > Change log from v1: > - add /sys/fs/f2fs/dev/features > > This patch exposes what features are supported by current f2fs build to sysfs > entry via: > > /sys/fs/f2fs/features/> /sys/fs/f2fs/dev/features > > Signed-off-by: Jaegeuk Kim <jaegeuk@xxxxxxxxxx> > --- > fs/f2fs/sysfs.c | 138 +++++++++++++++++++++++++++++++++++++++++++++----------- > 1 file changed, 112 insertions(+), 26 deletions(-) > > diff --git a/fs/f2fs/sysfs.c b/fs/f2fs/sysfs.c > index 5a78b9af92ef..83ab0dd73b2c 100644 > --- a/fs/f2fs/sysfs.c > +++ b/fs/f2fs/sysfs.c > @@ -18,7 +18,6 @@ > #include "gc.h" > > static struct proc_dir_entry *f2fs_proc_root; > -static struct kset *f2fs_kset; > > /* Sysfs support for f2fs */ > enum { > @@ -41,6 +40,7 @@ struct f2fs_attr { > const char *, size_t); > int struct_type; > int offset; > + int id; > }; > > static unsigned char *__struct_ptr(struct f2fs_sb_info *sbi, int struct_type) > @@ -76,6 +76,28 @@ static ssize_t lifetime_write_kbytes_show(struct f2fs_attr *a, > BD_PART_WRITTEN(sbi))); > } > > +static ssize_t features_show(struct f2fs_attr *a, > + struct f2fs_sb_info *sbi, char *buf) > +{ > + struct super_block *sb = sbi->sb; > + int len = 0; > + > + if (!sb->s_bdev->bd_part) > + return snprintf(buf, PAGE_SIZE, "0\n"); > + > + if (f2fs_sb_has_crypto(sb)) > + len += snprintf(buf, PAGE_SIZE - len, "%s\n", "encryption"); How about printing as below: len += snprintf(buf, PAGE_SIZE - len, "%s\n", "encryption "); It avoids unneeded ',' in the beginning of output string: cat /sys/fs/f2fs/zram0/features , extra_attr, projquota, inode_checksum > + if (f2fs_sb_mounted_blkzoned(sb)) > + len += snprintf(buf, PAGE_SIZE - len, "%s\n", ", blkzoned"); len += snprintf(buf, PAGE_SIZE - len, "%s\n", "blkzoned "); > + if (f2fs_sb_has_extra_attr(sb)) > + len += snprintf(buf, PAGE_SIZE - len, "%s\n", ", extra_attr"); ditto > + if (f2fs_sb_has_project_quota(sb)) > + len += snprintf(buf, PAGE_SIZE - len, "%s\n", ", projquota"); ditto > + if (f2fs_sb_has_inode_chksum(sb)) > + len += snprintf(buf, PAGE_SIZE - len, "%s\n", ", inode_checksum"); ditto > + return len; > +} > + > static ssize_t f2fs_sbi_show(struct f2fs_attr *a, > struct f2fs_sb_info *sbi, char *buf) > { > @@ -155,6 +177,24 @@ static void f2fs_sb_release(struct kobject *kobj) > complete(&sbi->s_kobj_unregister); > } > > +enum feat_id { > + FEAT_CRYPTO = 0, > + FEAT_BLKZONED, > + FEAT_ATOMIC_WRITE, Adds below missing macro: FEAT_EXTRA_ATTR, FEAT_PROJECT_QUOTA, FEAT_INODE_CHECKSUM, > +}; > + > +static ssize_t f2fs_feature_show(struct f2fs_attr *a, > + struct f2fs_sb_info *sbi, char *buf) > +{ > + switch (a->id) { > + case FEAT_CRYPTO: > + case FEAT_BLKZONED: > + case FEAT_ATOMIC_WRITE: case FEAT_EXTRA_ATTR: case FEAT_PROJECT_QUOTA: case FEAT_INODE_CHECKSUM: > + return snprintf(buf, PAGE_SIZE, "supported\n"); > + } > + return 0; > +} > + > #define F2FS_ATTR_OFFSET(_struct_type, _name, _mode, _show, _store, _offset) \ > static struct f2fs_attr f2fs_attr_##_name = { \ > .attr = {.name = __stringify(_name), .mode = _mode }, \ > @@ -172,6 +212,13 @@ static struct f2fs_attr f2fs_attr_##_name = { \ > #define F2FS_GENERAL_RO_ATTR(name) \ > static struct f2fs_attr f2fs_attr_##name = __ATTR(name, 0444, name##_show, NULL) > > +#define F2FS_FEATURE_RO_ATTR(_name, _id) \ > +static struct f2fs_attr f2fs_attr_##_name = { \ > + .attr = {.name = __stringify(_name), .mode = 0444 }, \ > + .show = f2fs_feature_show, \ > + .id = _id, \ > +} > + > F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_min_sleep_time, min_sleep_time); > F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_max_sleep_time, max_sleep_time); > F2FS_RW_ATTR(GC_THREAD, f2fs_gc_kthread, gc_no_gc_sleep_time, no_gc_sleep_time); > @@ -196,6 +243,15 @@ 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); > #endif > F2FS_GENERAL_RO_ATTR(lifetime_write_kbytes); > +F2FS_GENERAL_RO_ATTR(features); > + > +#ifdef CONFIG_F2FS_FS_ENCRYPTION > +F2FS_FEATURE_RO_ATTR(encryption, FEAT_CRYPTO); > +#endif > +#ifdef CONFIG_BLK_DEV_ZONED > +F2FS_FEATURE_RO_ATTR(block_zoned, FEAT_BLKZONED); > +#endif > +F2FS_FEATURE_RO_ATTR(atomic_write, FEAT_ATOMIC_WRITE); F2FS_FEATURE_RO_ATTR(extra_attr, FEAT_EXTRA_ATTR); F2FS_FEATURE_RO_ATTR(project_quota, FEAT_PROJECT_QUOTA); F2FS_FEATURE_RO_ATTR(inode_checksum, FEAT_INODE_CHECKSUM); > > #define ATTR_LIST(name) (&f2fs_attr_##name.attr) > static struct attribute *f2fs_attrs[] = { > @@ -222,21 +278,50 @@ static struct attribute *f2fs_attrs[] = { > ATTR_LIST(inject_type), > #endif > ATTR_LIST(lifetime_write_kbytes), > + ATTR_LIST(features), > ATTR_LIST(reserved_blocks), > NULL, > }; > > +static struct attribute *f2fs_feat_attrs[] = { > +#ifdef CONFIG_F2FS_FS_ENCRYPTION > + ATTR_LIST(encryption), > +#endif > +#ifdef CONFIG_BLK_DEV_ZONED > + ATTR_LIST(block_zoned), > +#endif > + ATTR_LIST(atomic_write), ATTR_LIST(extra_attr), ATTR_LIST(project_quota), ATTR_LIST(inode_checksum), Thanks, > + NULL, > +}; > + > static const struct sysfs_ops f2fs_attr_ops = { > .show = f2fs_attr_show, > .store = f2fs_attr_store, > }; > > -static struct kobj_type f2fs_ktype = { > +static struct kobj_type f2fs_sb_ktype = { > .default_attrs = f2fs_attrs, > .sysfs_ops = &f2fs_attr_ops, > .release = f2fs_sb_release, > }; > > +static struct kobj_type f2fs_ktype = { > + .sysfs_ops = &f2fs_attr_ops, > +}; > + > +static struct kset f2fs_kset = { > + .kobj = {.ktype = &f2fs_ktype}, > +}; > + > +static struct kobj_type f2fs_feat_ktype = { > + .default_attrs = f2fs_feat_attrs, > + .sysfs_ops = &f2fs_attr_ops, > +}; > + > +static struct kobject f2fs_feat = { > + .kset = &f2fs_kset, > +}; > + > static int segment_info_seq_show(struct seq_file *seq, void *offset) > { > struct super_block *sb = seq->private; > @@ -306,18 +391,29 @@ F2FS_PROC_FILE_DEF(segment_bits); > > int __init f2fs_init_sysfs(void) > { > - f2fs_proc_root = proc_mkdir("fs/f2fs", NULL); > + int ret; > > - f2fs_kset = kset_create_and_add("f2fs", NULL, fs_kobj); > - if (!f2fs_kset) > - return -ENOMEM; > - return 0; > + kobject_set_name(&f2fs_kset.kobj, "f2fs"); > + f2fs_kset.kobj.parent = fs_kobj; > + ret = kset_register(&f2fs_kset); > + if (ret) > + return ret; > + > + ret = kobject_init_and_add(&f2fs_feat, &f2fs_feat_ktype, > + NULL, "features"); > + if (ret) > + kset_unregister(&f2fs_kset); > + else > + f2fs_proc_root = proc_mkdir("fs/f2fs", NULL); > + return ret; > } > > void f2fs_exit_sysfs(void) > { > - kset_unregister(f2fs_kset); > + kobject_put(&f2fs_feat); > + kset_unregister(&f2fs_kset); > remove_proc_entry("fs/f2fs", NULL); > + f2fs_proc_root = NULL; > } > > int f2fs_register_sysfs(struct f2fs_sb_info *sbi) > @@ -325,6 +421,13 @@ int f2fs_register_sysfs(struct f2fs_sb_info *sbi) > struct super_block *sb = sbi->sb; > int err; > > + sbi->s_kobj.kset = &f2fs_kset; > + init_completion(&sbi->s_kobj_unregister); > + err = kobject_init_and_add(&sbi->s_kobj, &f2fs_sb_ktype, NULL, > + "%s", sb->s_id); > + if (err) > + return err; > + > if (f2fs_proc_root) > sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root); > > @@ -334,32 +437,15 @@ int f2fs_register_sysfs(struct f2fs_sb_info *sbi) > proc_create_data("segment_bits", S_IRUGO, sbi->s_proc, > &f2fs_seq_segment_bits_fops, sb); > } > - > - sbi->s_kobj.kset = f2fs_kset; > - init_completion(&sbi->s_kobj_unregister); > - err = kobject_init_and_add(&sbi->s_kobj, &f2fs_ktype, NULL, > - "%s", sb->s_id); > - if (err) > - goto err_out; > return 0; > -err_out: > - if (sbi->s_proc) { > - remove_proc_entry("segment_info", sbi->s_proc); > - remove_proc_entry("segment_bits", sbi->s_proc); > - remove_proc_entry(sb->s_id, f2fs_proc_root); > - } > - return err; > } > > void f2fs_unregister_sysfs(struct f2fs_sb_info *sbi) > { > - kobject_del(&sbi->s_kobj); > - kobject_put(&sbi->s_kobj); > - wait_for_completion(&sbi->s_kobj_unregister); > - > if (sbi->s_proc) { > remove_proc_entry("segment_info", sbi->s_proc); > remove_proc_entry("segment_bits", sbi->s_proc); > remove_proc_entry(sbi->sb->s_id, f2fs_proc_root); > } > + kobject_del(&sbi->s_kobj); > } >