Messages in this thread | | | Date | Thu, 3 Jun 2021 17:40:48 -0700 | From | Eric Biggers <> | Subject | Re: [f2fs-dev] [PATCH] f2fs: clean up /sys/fs/f2fs/<disk>/features |
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On Thu, Jun 03, 2021 at 03:08:34PM -0700, Jaegeuk Kim wrote: > Let's create /sys/fs/f2fs/<disk>/feature_list/ to meet sysfs rule. > > Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org> > --- > Documentation/ABI/testing/sysfs-fs-f2fs | 18 ++- > fs/f2fs/f2fs.h | 3 + > fs/f2fs/sysfs.c | 152 +++++++++++++++++++++++- > 3 files changed, 168 insertions(+), 5 deletions(-) > > diff --git a/Documentation/ABI/testing/sysfs-fs-f2fs b/Documentation/ABI/testing/sysfs-fs-f2fs > index 5088281e312e..43b2cde80b70 100644 > --- a/Documentation/ABI/testing/sysfs-fs-f2fs > +++ b/Documentation/ABI/testing/sysfs-fs-f2fs > @@ -203,7 +203,23 @@ Description: Shows total written kbytes issued to disk. > What: /sys/fs/f2fs/<disk>/features > Date: July 2017 > Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> > -Description: Shows all enabled features in current device. > +Description: <deprecated: should use /sys/fs/f2fs/<disk>/feature_list/ > + Shows all enabled features in current device. > + Supported features: > + encryption, blkzoned, extra_attr, projquota, inode_checksum, > + flexible_inline_xattr, quota_ino, inode_crtime, lost_found, > + verity, sb_checksum, casefold, readonly, compression, > + encrypted_casefold, pin_file.
Isn't pin_file a feature of the implementation, not of a particular filesystem instance? I.e. something that should go in /sys/fs/f2fs/features/, not here.
Likewise for encrypted_casefold, as it is implied by encryption && casefold.
> + > +What: /sys/fs/f2fs/<disk>/feature_list/ > +Date: June 2021 > +Contact: "Jaegeuk Kim" <jaegeuk@kernel.org> > +Description: Expand /sys/fs/f2fs/<disk>/features to meet sysfs rule. > + Supported features: > + encryption, block_zoned, extra_attr, projquota, inode_checksum, > + flexible_inline_xattr, quota_ino, inode_crtime, lost_found, > + verity, sb_checksum, casefold, readonly, compression, > + encrypted_casefold, pin_file.
Is it intentional that the file has "blkzoned" but the directory has "blk_zoned"?
Also, your code has another difference -- "project_quota" is used instead of "projquota". But that's not mentioned above.
And encrypted_casefold and pin_file don't seem appropriate to include here, as mentioned above.
> @@ -1665,6 +1665,9 @@ struct f2fs_sb_info { > struct kobject s_stat_kobj; /* /sys/fs/f2fs/<devname>/stat */ > struct completion s_stat_kobj_unregister; > > + struct kobject s_disk_feat_kobj; /* /sys/fs/f2fs/<devname>/feature_list */ > + struct completion s_disk_feat_kobj_unregister;
This is for a particular filesystem instance, not a disk per se. (A f2fs filesystem can use multiple disks.) So having "disk" in the name doesn't make sense.
Please use more logical names like s_feature_list_kobj, f2fs_sb_feature_list_ktype, f2fs_sb_feat_attrs, etc.
> static ssize_t f2fs_feature_show(struct f2fs_attr *a, > struct f2fs_sb_info *sbi, char *buf) > { > + unsigned long feat_supp = 0; > + > switch (a->id) { > case FEAT_CRYPTO: > + feat_supp |= f2fs_sb_has_encrypt(sbi) ? > + (1 << FEAT_CRYPTO) : 0; > + fallthrough; > case FEAT_BLKZONED: > - case FEAT_ATOMIC_WRITE: > + feat_supp |= f2fs_sb_has_blkzoned(sbi) ? > + (1 << FEAT_BLKZONED) : 0; > + fallthrough; > case FEAT_EXTRA_ATTR: > + feat_supp |= f2fs_sb_has_extra_attr(sbi) ? > + (1 << FEAT_EXTRA_ATTR) : 0; > + fallthrough; > case FEAT_PROJECT_QUOTA: > + feat_supp |= f2fs_sb_has_project_quota(sbi) ? > + (1 << FEAT_PROJECT_QUOTA) : 0; > + fallthrough; > case FEAT_INODE_CHECKSUM: > + feat_supp |= f2fs_sb_has_inode_chksum(sbi) ? > + (1 << FEAT_INODE_CHECKSUM) : 0; > + fallthrough; > case FEAT_FLEXIBLE_INLINE_XATTR: > + feat_supp |= f2fs_sb_has_flexible_inline_xattr(sbi) ? > + (1 << FEAT_FLEXIBLE_INLINE_XATTR) : 0; > + fallthrough; > case FEAT_QUOTA_INO: > + feat_supp |= f2fs_sb_has_quota_ino(sbi) ? > + (1 << FEAT_QUOTA_INO) : 0; > + fallthrough; > case FEAT_INODE_CRTIME: > + feat_supp |= f2fs_sb_has_inode_crtime(sbi) ? > + (1 << FEAT_INODE_CRTIME) : 0; > + fallthrough; > case FEAT_LOST_FOUND: > + feat_supp |= f2fs_sb_has_lost_found(sbi) ? > + (1 << FEAT_LOST_FOUND) : 0; > + fallthrough; > case FEAT_VERITY: > + feat_supp |= f2fs_sb_has_verity(sbi) ? > + (1 << FEAT_VERITY) : 0; > + fallthrough; > case FEAT_SB_CHECKSUM: > + feat_supp |= f2fs_sb_has_sb_chksum(sbi) ? > + (1 << FEAT_SB_CHECKSUM) : 0; > + fallthrough; > case FEAT_CASEFOLD: > + feat_supp |= f2fs_sb_has_casefold(sbi) ? > + (1 << FEAT_CASEFOLD) : 0; > + fallthrough; > case FEAT_COMPRESSION: > + feat_supp |= f2fs_sb_has_compression(sbi) ? > + (1 << FEAT_COMPRESSION) : 0; > + fallthrough; > case FEAT_RO: > - case FEAT_TEST_DUMMY_ENCRYPTION_V2: > + feat_supp |= f2fs_sb_has_readonly(sbi) ? > + (1 << FEAT_RO) : 0; > + fallthrough; > case FEAT_ENCRYPTED_CASEFOLD: > - return sprintf(buf, "supported\n"); > + feat_supp |= (f2fs_sb_has_casefold(sbi) && > + f2fs_sb_has_encrypt(sbi)) ? > + (1 << FEAT_ENCRYPTED_CASEFOLD) : 0; > + fallthrough; > + case FEAT_PIN_FILE: > + feat_supp |= (1 << FEAT_PIN_FILE); > + fallthrough; > + case FEAT_TEST_DUMMY_ENCRYPTION_V2: > + case FEAT_ATOMIC_WRITE: > + if (!a->offset || feat_supp & (1 << a->id)) > + return sprintf(buf, "supported\n"); > } > - return 0; > + return sprintf(buf, "not supported\n"); > }
This function doesn't make much sense.
Part of the problem is that the same function is handling both /sys/fs/f2fs/features/ and /sys/fs/f2fs/$s_id/feature_list/.
All the former needs is to print "supported", since unsupported is indicated by the file not being there at all. So it should simply have its own ->show function separate from the one for feature_list/.
And the feature_list/ ones could just store the F2FS_FEATURE_* bit in f2fs_attr::id and check for it using F2FS_HAS_FEATURE(). That would be much simpler -- no need for the feat_id enum or the long switch statement.
Also for feature_list/ it might be better to use "unsupported" than "not supported", so that \<supported\> doesn't match...
> static struct f2fs_attr f2fs_attr_##_name = { \ > .attr = {.name = __stringify(_name), .mode = 0444 }, \ > .show = f2fs_feature_show, \ > + .offset = 0, \ > .id = _id, \ > }
There's no need to use the .offset argument if features/ and $s_id/feature_list/ just used different ->show functions.
> +#define F2FS_DISK_FEATURE_RO_ATTR(_name, _id) \
F2FS_SB_FEATURE_ATTR would be a much better name, since these pertain to a filesystem instance (not necessarily a disk), and all the feature attributes are read-only.
> static int __maybe_unused segment_info_seq_show(struct seq_file *seq, > void *offset) > { > @@ -1149,6 +1279,15 @@ int f2fs_register_sysfs(struct f2fs_sb_info *sbi) > if (err) > goto put_stat_kobj; > > + sbi->s_disk_feat_kobj.kset = &f2fs_kset; > + init_completion(&sbi->s_disk_feat_kobj_unregister); > + err = kobject_init_and_add(&sbi->s_disk_feat_kobj, > + &f2fs_disk_feat_ktype, > + &sbi->s_kobj, "feature_list"); > + if (err) > + goto put_stat_kobj; > + > + > if (f2fs_proc_root) > sbi->s_proc = proc_mkdir(sb->s_id, f2fs_proc_root); > > @@ -1166,6 +1305,8 @@ int f2fs_register_sysfs(struct f2fs_sb_info *sbi) > put_stat_kobj: > kobject_put(&sbi->s_stat_kobj); > wait_for_completion(&sbi->s_stat_kobj_unregister); > + kobject_put(&sbi->s_disk_feat_kobj); > + wait_for_completion(&sbi->s_disk_feat_kobj_unregister);
It seems this should go to its own label.
Also, please note that it's very easy to get confused between /sys/fs/f2fs/features/, /sys/fs/f2fs/$s_id/features, and /sys/fs/f2fs/$s_id/feature_list/. Adding some comments could clarify things a lot.
- Eric
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