From: Gao Xiang <hsiang...@aol.com> Previously, nlink of directories is treated as 1 for simplicity.
Since st_nlink for dirs is actualy not well defined, nlink=1 seems to pacify `find' (even without -noleaf option) and other utilities. AFAICT, isofs, romfs and cramfs always set it to 1, Overlayfs sets it to 1 conditionally, btrfs[1], ceph[2] and FUSE client historically set it to 1. The convention under unix is that it's # of subdirs including "." and "..". This patch tries to follow such convention if possible to optimize `find' performance since it's not quite hard for local fs. [1] https://lore.kernel.org/r/20100124003336.GP23006@think [2] https://lore.kernel.org/r/20180521092729.17470-1-lhenriq...@suse.com Signed-off-by: Gao Xiang <hsiang...@aol.com> --- lib/inode.c | 33 +++++++++++++++++++++++++++++---- 1 file changed, 29 insertions(+), 4 deletions(-) diff --git a/lib/inode.c b/lib/inode.c index 618eb284550f..357ac480154a 100644 --- a/lib/inode.c +++ b/lib/inode.c @@ -25,7 +25,7 @@ struct erofs_sb_info sbi; #define S_SHIFT 12 -static unsigned char erofs_type_by_mode[S_IFMT >> S_SHIFT] = { +static unsigned char erofs_ftype_by_mode[S_IFMT >> S_SHIFT] = { [S_IFREG >> S_SHIFT] = EROFS_FT_REG_FILE, [S_IFDIR >> S_SHIFT] = EROFS_FT_DIR, [S_IFCHR >> S_SHIFT] = EROFS_FT_CHRDEV, @@ -35,6 +35,11 @@ static unsigned char erofs_type_by_mode[S_IFMT >> S_SHIFT] = { [S_IFLNK >> S_SHIFT] = EROFS_FT_SYMLINK, }; +static unsigned char erofs_mode_to_ftype(umode_t mode) +{ + return erofs_ftype_by_mode[(mode & S_IFMT) >> S_SHIFT]; +} + #define NR_INODE_HASHTABLE 16384 struct list_head inode_hashtable[NR_INODE_HASHTABLE]; @@ -156,7 +161,7 @@ static int __allocate_inode_bh_data(struct erofs_inode *inode, int erofs_prepare_dir_file(struct erofs_inode *dir) { struct erofs_dentry *d; - unsigned int d_size; + unsigned int d_size, i_nlink; int ret; /* dot is pointed to the current dir inode */ @@ -169,16 +174,28 @@ int erofs_prepare_dir_file(struct erofs_inode *dir) d->inode = erofs_igrab(dir->i_parent); d->type = EROFS_FT_DIR; - /* let's calculate dir size */ + /* let's calculate dir size and update i_nlink */ d_size = 0; + i_nlink = 0; list_for_each_entry(d, &dir->i_subdirs, d_child) { int len = strlen(d->name) + sizeof(struct erofs_dirent); if (d_size % EROFS_BLKSIZ + len > EROFS_BLKSIZ) d_size = round_up(d_size, EROFS_BLKSIZ); d_size += len; + + i_nlink += (d->type == EROFS_FT_DIR); } dir->i_size = d_size; + /* + * if there're too many subdirs as compact form, set nlink=1 + * rather than upgrade to use extented form instead. + */ + if (i_nlink > USHRT_MAX && + dir->inode_isize == sizeof(struct erofs_inode_compact)) + dir->i_nlink = 1; + else + dir->i_nlink = i_nlink; /* no compression for all dirs */ dir->datalayout = EROFS_INODE_FLAT_INLINE; @@ -957,6 +974,10 @@ struct erofs_inode *erofs_mkfs_build_tree(struct erofs_inode *dir) ret = PTR_ERR(d); goto err_closedir; } + + /* to count i_nlink for directories */ + d->type = (dp->d_type == DT_DIR ? + EROFS_FT_DIR : EROFS_FT_UNKNOWN); } if (errno) { @@ -978,6 +999,7 @@ struct erofs_inode *erofs_mkfs_build_tree(struct erofs_inode *dir) list_for_each_entry(d, &dir->i_subdirs, d_child) { char buf[PATH_MAX]; + unsigned char ftype; if (is_dot_dotdot(d->name)) { erofs_d_invalidate(d); @@ -1000,7 +1022,10 @@ fail: goto err; } - d->type = erofs_type_by_mode[d->inode->i_mode >> S_SHIFT]; + ftype = erofs_mode_to_ftype(d->inode->i_mode); + DBG_BUGON(d->type != EROFS_FT_UNKNOWN && d->type != ftype); + d->type = ftype; + erofs_d_invalidate(d); erofs_info("add file %s/%s (nid %llu, type %d)", dir->i_srcpath, d->name, (unsigned long long)d->nid, -- 2.24.0
