4 ms·

So, because it supports more than one KBI it is a derived work, whereas if it had one static KBI to only work on one specific version it would not be derived?

• jepler 11y ago
  Not necessarily. But let's look at one specific instance of adapting to a different "KBI", as you call it. I picked HAVE_VFS_ITERATE, just because it sounded interesting. What's the story? Well, in May 2013, Al Viro committed code to Linux to add several new "KBIs", dir_emit and related functions (in include/linux/fs.h, which does not have a license block): commit 5f99f4e79abc64ed9d93a4b0158b21c64ff7f478 Author: Al Viro <viro@zeniv.linux.org.uk> AuthorDate: Wed May 15 20:23:06 2013 -0400 Commit: Al Viro <viro@zeniv.linux.org.uk> CommitDate: Sat Jun 29 12:46:48 2013 +0400 [readdir] switch dcache_readdir() users to ->iterate() new helpers - dir_emit_dot(file, ctx, dentry), dir_emit_dotdot(file, ctx), dir_emit_dots(file, ctx). Signed-off-by: Al Viro <viro@zeniv.linux.org.uk> ... +static inline bool dir_emit(struct dir_context *ctx, + const char *name, int namelen, + u64 ino, unsigned type) +{ + return ctx->actor(ctx, name, namelen, ctx->pos, ino, type) == 0; +} +static inline bool dir_emit_dot(struct file *file, struct dir_context *ctx) +{ + return ctx->actor(ctx, ".", 1, ctx->pos, + file->f_path.dentry->d_inode->i_ino, DT_DIR) == 0; +} +static inline bool dir_emit_dotdot(struct file *file, struct dir_context *ctx) +{ + return ctx->actor(ctx, "..", 2, ctx->pos, + parent_ino(file->f_path.dentry), DT_DIR) == 0; +} +static inline bool dir_emit_dots(struct file *file, struct dir_context *ctx) +{ + if (ctx->pos == 0) { + if (!dir_emit_dot(file, ctx)) + return false; + ctx->pos = 1; + } + if (ctx->pos == 1) { + if (!dir_emit_dotdot(file, ctx)) + return false; + ctx->pos = 2; + } + return true; +} Soon after, this was added in zfsonlinux/zfs.git in include/sys/zpl.h (which has a CDDL license block), gated by HAVE_VFS_ITERATE: commit 0f37d0c8bed442dd0d2c1b1dddd68653fa6eec66 Author: Richard Yao <ryao@gentoo.org> AuthorDate: Wed Aug 7 08:53:45 2013 -0400 Commit: Brian Behlendorf <behlendorf1@llnl.gov> CommitDate: Thu Aug 15 16:19:07 2013 -0700 Linux 3.11 compat: fops->iterate() ... Compatibility with older kernels was accomplished by adding versions of the trivial dir_emit* helper functions. ... +static inline bool +dir_emit(struct dir_context *ctx, const char *name, int namelen, + uint64_t ino, unsigned type) +{ + return ctx->actor(ctx->dirent, name, namelen, ctx->pos, ino, type) == 0; +} + +static inline bool +dir_emit_dot(struct file *file, struct dir_context *ctx) +{ + return ctx->actor(ctx->dirent, ".", 1, ctx->pos, + file->f_path.dentry->d_inode->i_ino, DT_DIR) == 0; +} + +static inline bool +dir_emit_dotdot(struct file *file, struct dir_context *ctx) +{ + return ctx->actor(ctx->dirent, "..", 2, ctx->pos, + parent_ino(file->f_path.dentry), DT_DIR) == 0; +} + +static inline bool +dir_emit_dots(struct file *file, struct dir_context *ctx) +{ + if (ctx->pos == 0) { + if (!dir_emit_dot(file, ctx)) + return false; + ctx->pos = 1; + } + if (ctx->pos == 1) { + if (!dir_emit_dotdot(file, ctx)) + return false; + ctx->pos = 2; + } + return true; +} Except that Richard Yao took care to say he felt the copying was "trivial", I don't think this example inspires much confidence that zfs.ko is not a derived work of some GPL software.