Add SEEK_DATA/SEEK_HOLE to lseek()/llseek()

The approach taken was the rework zfs_holey() as little as
possible and then just wrap the code as needed to ensure
correct locking and error handling.

Tested with xfstests 285 and 286.  All tests pass except for
7-9 of 285 which try to reserve blocks first via fallocate(2)
and fail because fallocate(2) is not yet supported.

Note that the filp->f_lock spinlock did not exist prior to
Linux 2.6.30, but we avoid the need for autotools check by
virtue of the fact that SEEK_DATA/SEEK_HOLE support was not
added until Linux 3.1.

An autoconf check was added for lseek_execute() which is
currently a private function but the expectation is that it
will be exported perhaps as early as Linux 3.11.

Reviewed-by: Richard Laager <rlaager@wiktel.com>
Signed-off-by: Richard Yao <ryao@gentoo.org>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #1384
This commit is contained in:
Li Dongyang
2013-06-13 13:51:09 -04:00
committed by Brian Behlendorf
parent cf91b2b6b2
commit 802e7b5feb
6 changed files with 97 additions and 11 deletions
+1
View File
@@ -38,6 +38,7 @@ extern "C" {
extern int zfs_open(struct inode *ip, int mode, int flag, cred_t *cr);
extern int zfs_close(struct inode *ip, int flag, cred_t *cr);
extern int zfs_holey(struct inode *ip, int cmd, loff_t *off);
extern int zfs_read(struct inode *ip, uio_t *uio, int ioflag, cred_t *cr);
extern int zfs_write(struct inode *ip, uio_t *uio, int ioflag, cred_t *cr);
extern int zfs_access(struct inode *ip, int mode, int flag, cred_t *cr);