With this ioctl the segment usage information in the SUFILE can be
updated from userspace.
This is useful, because it allows the userspace GC to modify and update
segment usage entries for specific segments, which enables it to avoid
unnecessary write operations.
If a segment needs to be cleaned, but there is no or very little free
space to be gained, the cleaning operation basically degrades to
needless expensive copying of data. In the end the only thing that
changes is the location of the data and a timestamp in the segment usage
info. With this ioctl the GC can skip the copying and update the segment
usage entries directly instead.
Signed-off-by: Andreas Rohner <andreas.rohner@xxxxxxx>
---
fs/nilfs2/ioctl.c | 50 +++++++++++++++++++++++++++++++++++++++++++++++
include/linux/nilfs2_fs.h | 2 ++
2 files changed, 52 insertions(+)
diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c
index b44bdb2..c6a3faf 100644
--- a/fs/nilfs2/ioctl.c
+++ b/fs/nilfs2/ioctl.c
@@ -273,6 +273,13 @@ nilfs_ioctl_do_get_suinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
return ret;
}
+static ssize_t
+nilfs_ioctl_do_set_suinfo(struct the_nilfs *nilfs, __u64 *posp, int flags,
+ void *buf, size_t size, size_t nmembs)
+{
+ return nilfs_sufile_set_suinfo(nilfs->ns_sufile, buf, size, nmembs);
+}
+
static int nilfs_ioctl_get_sustat(struct inode *inode, struct file *filp,
unsigned int cmd, void __user *argp)
{
@@ -767,6 +774,44 @@ out:
return ret;
}
+static int nilfs_ioctl_set_info(struct inode *inode, struct file *filp,
+ unsigned int cmd, void __user *argp,
+ size_t membsz,
+ ssize_t (*dofunc)(struct the_nilfs *,
+ __u64 *, int,
+ void *, size_t, size_t))
+{
+ struct the_nilfs *nilfs = inode->i_sb->s_fs_info;
+ struct nilfs_transaction_info ti;
+ struct nilfs_argv argv;
+ int ret;
+
+ if (!capable(CAP_SYS_ADMIN))
+ return -EPERM;
+
+ ret = mnt_want_write_file(filp);
+ if (ret)
+ return ret;
+
+ ret = -EFAULT;
+ if (copy_from_user(&argv, argp, sizeof(argv)))
+ goto out;
+
+ if (argv.v_size < membsz)
+ return -EINVAL;
+
+ nilfs_transaction_begin(inode->i_sb, &ti, 0);
+ ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd), dofunc);
+ if (unlikely(ret < 0))
+ nilfs_transaction_abort(inode->i_sb);
+ else
+ nilfs_transaction_commit(inode->i_sb); /* never fails */
+
+out:
+ mnt_drop_write_file(filp);
+ return ret;
+}
+
static int nilfs_ioctl_get_info(struct inode *inode, struct file *filp,
unsigned int cmd, void __user *argp,
size_t membsz,
@@ -820,6 +865,10 @@ long nilfs_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
return nilfs_ioctl_get_info(inode, filp, cmd, argp,
sizeof(struct nilfs_suinfo),
nilfs_ioctl_do_get_suinfo);
+ case NILFS_IOCTL_SET_SUINFO:
+ return nilfs_ioctl_set_info(inode, filp, cmd, argp,
+ sizeof(struct nilfs_suinfo_update),
+ nilfs_ioctl_do_set_suinfo);
case NILFS_IOCTL_GET_SUSTAT:
return nilfs_ioctl_get_sustat(inode, filp, cmd, argp);
case NILFS_IOCTL_GET_VINFO:
@@ -859,6 +908,7 @@ long nilfs_compat_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
case NILFS_IOCTL_GET_CPINFO:
case NILFS_IOCTL_GET_CPSTAT:
case NILFS_IOCTL_GET_SUINFO:
+ case NILFS_IOCTL_SET_SUINFO:
case NILFS_IOCTL_GET_SUSTAT:
case NILFS_IOCTL_GET_VINFO:
case NILFS_IOCTL_GET_BDESCS:
diff --git a/include/linux/nilfs2_fs.h b/include/linux/nilfs2_fs.h
index 2ee1594..528e2c5 100644
--- a/include/linux/nilfs2_fs.h
+++ b/include/linux/nilfs2_fs.h
@@ -902,5 +902,7 @@ struct nilfs_bdesc {
_IOW(NILFS_IOCTL_IDENT, 0x8B, __u64)
#define NILFS_IOCTL_SET_ALLOC_RANGE \
_IOW(NILFS_IOCTL_IDENT, 0x8C, __u64[2])
+#define NILFS_IOCTL_SET_SUINFO \
+ _IOW(NILFS_IOCTL_IDENT, 0x8D, struct nilfs_argv)
#endif /* _LINUX_NILFS_FS_H */
--
1.8.5.3
--
To unsubscribe from this list: send the line "unsubscribe linux-nilfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
