Allow finer grained control over the file data cache, by allowing the
user to select a particular range of data to invalidate.
This is not the same as punching a hole. Instead, dirty data will get
flushed to disk, and any clean cached data gets thrown out of the
page cache for that range.
Signed-off-by: Trond Myklebust <Trond.Myklebust@xxxxxxxxxx>
---
fs/nfs/ioctl.c | 43 +++++++++++++++++++++++++++++++++++++++++++
fs/nfs/ioctl.h | 4 ++++
2 files changed, 47 insertions(+)
diff --git a/fs/nfs/ioctl.c b/fs/nfs/ioctl.c
index 9da5f7d..e19fa9e 100644
--- a/fs/nfs/ioctl.c
+++ b/fs/nfs/ioctl.c
@@ -55,6 +55,47 @@ out:
return ret;
}
+static bool nfs_cachectl_get_range(struct nfs_cachectl __user *argp,
+ loff_t *start, loff_t *len)
+{
+ u64 tmp;
+
+ if (get_user(tmp, &argp->start))
+ return false;
+ *start = tmp;
+ if (get_user(tmp, &argp->len))
+ return false;
+ *len = tmp;
+ return true;
+}
+
+static long nfs_ioctl_revalidate_range(struct file *filp,
+ struct nfs_cachectl __user *argp)
+{
+ loff_t start, len, end;
+ pgoff_t pgstart, pgend;
+
+ if (!nfs_cachectl_get_range(argp, &start, &len))
+ return -EFAULT;
+ end = -1;
+ if (len < 0) {
+ end = start - 1;
+ start += len;
+ } else if (len > 0)
+ end = start + len - 1;
+ if (start < 0)
+ return -EINVAL;
+
+ if (!S_ISREG(filp->f_path.dentry->d_inode->i_mode))
+ return -EINVAL;
+
+ vfs_fsync_range(filp, start, end, 1);
+
+ pgstart = start >> PAGE_CACHE_SHIFT;
+ pgend = end >> PAGE_CACHE_SHIFT;
+ return invalidate_inode_pages2_range(filp->f_mapping, pgstart, pgend);
+}
+
static long nfs_ioctl_cachectl(struct file *filp, struct nfs_cachectl __user *argp)
{
u64 cmd;
@@ -70,6 +111,8 @@ static long nfs_ioctl_cachectl(struct file *filp, struct nfs_cachectl __user *ar
return nfs_ioctl_cache_revalidate(filp, true, false);
case NFS_CACHECTL_REVALIDATE_DATA:
return nfs_ioctl_cache_revalidate(filp, false, true);
+ case NFS_CACHECTL_REVALIDATE_RANGE:
+ return nfs_ioctl_revalidate_range(filp, argp);
}
return -EINVAL;
}
diff --git a/fs/nfs/ioctl.h b/fs/nfs/ioctl.h
index cf79f0d..6cf8337 100644
--- a/fs/nfs/ioctl.h
+++ b/fs/nfs/ioctl.h
@@ -27,9 +27,13 @@
#define NFS_CACHECTL_REVALIDATE_ALL 1
#define NFS_CACHECTL_REVALIDATE_METADATA 2
#define NFS_CACHECTL_REVALIDATE_DATA 3
+#define NFS_CACHECTL_REVALIDATE_RANGE 4
struct nfs_cachectl {
u64 cmd;
+
+ u64 start;
+ u64 len;
};
#define NFS_IOC_CACHECTL _IOW('N', 1, struct nfs_cachectl)
--
1.7.11.7
--
To unsubscribe from this list: send the line "unsubscribe linux-nfs" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
