znode_t::z_{unlinked,zn_prefetch} are not boolean

[kusumi]

Motivation and Context

Description

Several boolean-like members in znode_t (incore structure) are
of uint8_t. Change assignments to use 1/0. Majority of them are
already 1/0 with some exceptions fixed in this commit.

How Has This Been Tested?

Types of changes

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Performance enhancement (non-breaking change which improves efficiency)
• Code cleanup (non-breaking change which makes code smaller or more readable)
• Breaking change (fix or feature that would cause existing functionality to change)
• Documentation (a change to man pages or other documentation)

Checklist:

• My code follows the ZFS on Linux code style requirements.
• I have updated the documentation accordingly.
• I have read the contributing document.
• I have added tests to cover my changes.
• All new and existing tests passed.
• All commit messages are properly formatted and contain Signed-off-by.

[behlendorf]

It looks like it would be worthwhile to convert all of these uint8_t's to boolean_t's and to co-locate them. That should save a full uint64_t per znode_t which does add up! What do you think of something like this?

diff --git a/include/sys/zfs_znode.h b/include/sys/zfs_znode.h
index d4a3ea7..ef53684 100644
--- a/include/sys/zfs_znode.h
+++ b/include/sys/zfs_znode.h
@@ -192,10 +192,14 @@ typedef struct znode {
        krwlock_t       z_name_lock;    /* "master" lock for dirent locks */
        zfs_dirlock_t   *z_dirlocks;    /* directory entry lock list */
        rangelock_t     z_rangelock;    /* file range locks */
-       uint8_t         z_unlinked;     /* file has been unlinked */
-       uint8_t         z_atime_dirty;  /* atime needs to be synced */
-       uint8_t         z_zn_prefetch;  /* Prefetch znodes? */
-       uint8_t         z_moved;        /* Has this znode been moved? */
+       boolean_t       z_unlinked;     /* file has been unlinked */
+       boolean_t       z_atime_dirty;  /* atime needs to be synced */
+       boolean_t       z_zn_prefetch;  /* Prefetch znodes? */
+       boolean_t       z_moved;        /* Has this znode been moved? */
+       boolean_t       z_is_sa;        /* are we native sa? */
+       boolean_t       z_is_mapped;    /* are we mmap'ed */
+       boolean_t       z_is_ctldir;    /* are we .zfs entry */
+       boolean_t       z_is_stale;     /* are we stale due to rollback? */
        uint_t          z_blksz;        /* block size in bytes */
        uint_t          z_seq;          /* modification sequence number */
        uint64_t        z_mapcnt;       /* number of pages mapped to file */
@@ -212,10 +216,6 @@ typedef struct znode {
        uint64_t        z_projid;       /* project ID */
        list_node_t     z_link_node;    /* all znodes in fs link */
        sa_handle_t     *z_sa_hdl;      /* handle to sa data */
-       boolean_t       z_is_sa;        /* are we native sa? */
-       boolean_t       z_is_mapped;    /* are we mmap'ed */
-       boolean_t       z_is_ctldir;    /* are we .zfs entry */
-       boolean_t       z_is_stale;     /* are we stale due to rollback? */
        struct inode    z_inode;        /* generic vfs inode */
 } znode_t;
 

[kusumi]

Updated.
I also prefer this way, if we want to change znode_t (increases diff vs other zfs) for non-functional stuff.

[codecov]

Codecov Report

Merging #9092 into master will decrease coverage by 12.51%.
The diff coverage is n/a.

@@             Coverage Diff             @@
##           master    #9092       +/-   ##
===========================================
- Coverage   79.32%   66.81%   -12.52%     
===========================================
  Files         400      326       -74     
  Lines      121640   104364    -17276     
===========================================
- Hits        96493    69729    -26764     
- Misses      25147    34635     +9488

Flag	Coverage Δ
#kernel	?
#user	66.81% <ø> (-0.74%)	⬇️

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