Linux 4.11 compat: iops.getattr and friends

In torvalds/linux@a528d35, there are changes to the getattr family of functions,
struct kstat, and the interface of inode_operations .getattr.

The inode_operations .getattr and simple_getattr() interface changed to:

int (*getattr) (const struct path *, struct dentry *, struct kstat *,
    u32 request_mask, unsigned int query_flags)

The request_mask argument indicates which field(s) the caller intends to use.
Fields the caller has not specified via request_mask may be set in the returned
struct anyway, but their values may be approximate.

The query_flags argument indicates whether the filesystem must update
the attributes from the backing store.

Currently both fields are ignored.  It is possible that getattr-related
functions within zfs could be optimized based on the request_mask.

struct kstat includes new fields:
u32               result_mask;  /* What fields the user got */
u64               attributes;   /* See STATX_ATTR_* flags */
struct timespec   btime;        /* File creation time */

Fields attribute and btime are cleared; the result_mask reflects this.  These
appear to be optional based on simple_getattr() and vfs_getattr() within the
kernel, which take the same approach.

Reviewed-by: Chunwei Chen <david.chen@osnexus.com>
Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Olaf Faaland <faaland1@llnl.gov>
Closes #5875
This commit is contained in:
Olaf Faaland
2017-03-20 17:51:16 -07:00
committed by Brian Behlendorf
parent f974e41426
commit a3478c0747
5 changed files with 138 additions and 19 deletions
+43
View File
@@ -454,4 +454,47 @@ setattr_prepare(struct dentry *dentry, struct iattr *ia)
}
#endif
/*
* 4.11 API change
* These macros are defined by kernel 4.11. We define them so that the same
* code builds under kernels < 4.11 and >= 4.11. The macros are set to 0 so
* that it will create obvious failures if they are accidentally used when built
* against a kernel >= 4.11.
*/
#ifndef STATX_BASIC_STATS
#define STATX_BASIC_STATS 0
#endif
#ifndef AT_STATX_SYNC_AS_STAT
#define AT_STATX_SYNC_AS_STAT 0
#endif
/*
* 4.11 API change
* 4.11 takes struct path *, < 4.11 takes vfsmount *
*/
#ifdef HAVE_VFSMOUNT_IOPS_GETATTR
#define ZPL_GETATTR_WRAPPER(func) \
static int \
func(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) \
{ \
struct path path = { .mnt = mnt, .dentry = dentry }; \
return func##_impl(&path, stat, STATX_BASIC_STATS, \
AT_STATX_SYNC_AS_STAT); \
}
#elif defined(HAVE_PATH_IOPS_GETATTR)
#define ZPL_GETATTR_WRAPPER(func) \
static int \
func(const struct path *path, struct kstat *stat, u32 request_mask, \
unsigned int query_flags) \
{ \
return (func##_impl(path, stat, request_mask, query_flags)); \
}
#else
#error
#endif
#endif /* _ZFS_VFS_H */