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authorDarrick J. Wong <darrick.wong@oracle.com>2017-04-30 07:36:53 +0300
committerTheodore Ts'o <tytso@mit.edu>2017-04-30 07:36:53 +0300
commit0c9ec4beecac94cb450c8abb2ac8b7e8a79240ea (patch)
tree95dec5ec2bd1b53c425c29bc98e7506e41e4747e /fs/ext4/ioctl.c
parentd0649f0416feb616d34d15e541716cb8a555e899 (diff)
downloadlinux-0c9ec4beecac94cb450c8abb2ac8b7e8a79240ea.tar.xz
ext4: support GETFSMAP ioctls
Support the GETFSMAP ioctls so that we can use the xfs free space management tools to probe ext4 as well. Note that this is a partial implementation -- we only report fixed-location metadata and free space; everything else is reported as "unknown". Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com> Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Diffstat (limited to 'fs/ext4/ioctl.c')
-rw-r--r--fs/ext4/ioctl.c90
1 files changed, 90 insertions, 0 deletions
diff --git a/fs/ext4/ioctl.c b/fs/ext4/ioctl.c
index a4273ddb9922..dfcb815275f1 100644
--- a/fs/ext4/ioctl.c
+++ b/fs/ext4/ioctl.c
@@ -19,6 +19,9 @@
#include <linux/delay.h>
#include "ext4_jbd2.h"
#include "ext4.h"
+#include <linux/fsmap.h>
+#include "fsmap.h"
+#include <trace/events/ext4.h>
/**
* Swap memory between @a and @b for @len bytes.
@@ -489,6 +492,90 @@ int ext4_shutdown(struct super_block *sb, unsigned long arg)
return 0;
}
+struct getfsmap_info {
+ struct super_block *gi_sb;
+ struct fsmap_head __user *gi_data;
+ unsigned int gi_idx;
+ __u32 gi_last_flags;
+};
+
+static int ext4_getfsmap_format(struct ext4_fsmap *xfm, void *priv)
+{
+ struct getfsmap_info *info = priv;
+ struct fsmap fm;
+
+ trace_ext4_getfsmap_mapping(info->gi_sb, xfm);
+
+ info->gi_last_flags = xfm->fmr_flags;
+ ext4_fsmap_from_internal(info->gi_sb, &fm, xfm);
+ if (copy_to_user(&info->gi_data->fmh_recs[info->gi_idx++], &fm,
+ sizeof(struct fsmap)))
+ return -EFAULT;
+
+ return 0;
+}
+
+static int ext4_ioc_getfsmap(struct super_block *sb,
+ struct fsmap_head __user *arg)
+{
+ struct getfsmap_info info = {0};
+ struct ext4_fsmap_head xhead = {0};
+ struct fsmap_head head;
+ bool aborted = false;
+ int error;
+
+ if (copy_from_user(&head, arg, sizeof(struct fsmap_head)))
+ return -EFAULT;
+ if (memchr_inv(head.fmh_reserved, 0, sizeof(head.fmh_reserved)) ||
+ memchr_inv(head.fmh_keys[0].fmr_reserved, 0,
+ sizeof(head.fmh_keys[0].fmr_reserved)) ||
+ memchr_inv(head.fmh_keys[1].fmr_reserved, 0,
+ sizeof(head.fmh_keys[1].fmr_reserved)))
+ return -EINVAL;
+ /*
+ * ext4 doesn't report file extents at all, so the only valid
+ * file offsets are the magic ones (all zeroes or all ones).
+ */
+ if (head.fmh_keys[0].fmr_offset ||
+ (head.fmh_keys[1].fmr_offset != 0 &&
+ head.fmh_keys[1].fmr_offset != -1ULL))
+ return -EINVAL;
+
+ xhead.fmh_iflags = head.fmh_iflags;
+ xhead.fmh_count = head.fmh_count;
+ ext4_fsmap_to_internal(sb, &xhead.fmh_keys[0], &head.fmh_keys[0]);
+ ext4_fsmap_to_internal(sb, &xhead.fmh_keys[1], &head.fmh_keys[1]);
+
+ trace_ext4_getfsmap_low_key(sb, &xhead.fmh_keys[0]);
+ trace_ext4_getfsmap_high_key(sb, &xhead.fmh_keys[1]);
+
+ info.gi_sb = sb;
+ info.gi_data = arg;
+ error = ext4_getfsmap(sb, &xhead, ext4_getfsmap_format, &info);
+ if (error == EXT4_QUERY_RANGE_ABORT) {
+ error = 0;
+ aborted = true;
+ } else if (error)
+ return error;
+
+ /* If we didn't abort, set the "last" flag in the last fmx */
+ if (!aborted && info.gi_idx) {
+ info.gi_last_flags |= FMR_OF_LAST;
+ if (copy_to_user(&info.gi_data->fmh_recs[info.gi_idx - 1].fmr_flags,
+ &info.gi_last_flags,
+ sizeof(info.gi_last_flags)))
+ return -EFAULT;
+ }
+
+ /* copy back header */
+ head.fmh_entries = xhead.fmh_entries;
+ head.fmh_oflags = xhead.fmh_oflags;
+ if (copy_to_user(arg, &head, sizeof(struct fsmap_head)))
+ return -EFAULT;
+
+ return 0;
+}
+
long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
{
struct inode *inode = file_inode(filp);
@@ -499,6 +586,8 @@ long ext4_ioctl(struct file *filp, unsigned int cmd, unsigned long arg)
ext4_debug("cmd = %u, arg = %lu\n", cmd, arg);
switch (cmd) {
+ case FS_IOC_GETFSMAP:
+ return ext4_ioc_getfsmap(sb, (void __user *)arg);
case EXT4_IOC_GETFLAGS:
ext4_get_inode_flags(ei);
flags = ei->i_flags & EXT4_FL_USER_VISIBLE;
@@ -1009,6 +1098,7 @@ long ext4_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
case EXT4_IOC_GET_ENCRYPTION_PWSALT:
case EXT4_IOC_GET_ENCRYPTION_POLICY:
case EXT4_IOC_SHUTDOWN:
+ case FS_IOC_GETFSMAP:
break;
default:
return -ENOIOCTLCMD;