btrfs-progs: ioctl.h: copy commented version of scrub_progress structure

Copied from uapi/linux/btrfs.h, no-op change.

Signed-off-by: David Sterba <dsterba@suse.cz>

diff --git a/ioctl.h b/ioctl.h
index 758de2e..a1af035 100644 (file)
--- a/ioctl.h
+++ b/ioctl.h
@@ -84,23 +84,41 @@ struct btrfs_ioctl_vol_args_v2 {
        char name[BTRFS_SUBVOL_NAME_MAX + 1];
 };
 
-
+/*
+ * structure to report errors and progress to userspace, either as a
+ * result of a finished scrub, a canceled scrub or a progress inquiry
+ */
 struct btrfs_scrub_progress {
-       __u64 data_extents_scrubbed;
-       __u64 tree_extents_scrubbed;
-       __u64 data_bytes_scrubbed;
-       __u64 tree_bytes_scrubbed;
-       __u64 read_errors;
-       __u64 csum_errors;
-       __u64 verify_errors;
-       __u64 no_csum;
-       __u64 csum_discards;
-       __u64 super_errors;
-       __u64 malloc_errors;
-       __u64 uncorrectable_errors;
-       __u64 corrected_errors;
-       __u64 last_physical;
-       __u64 unverified_errors;
+       __u64 data_extents_scrubbed;    /* # of data extents scrubbed */
+       __u64 tree_extents_scrubbed;    /* # of tree extents scrubbed */
+       __u64 data_bytes_scrubbed;      /* # of data bytes scrubbed */
+       __u64 tree_bytes_scrubbed;      /* # of tree bytes scrubbed */
+       __u64 read_errors;              /* # of read errors encountered (EIO) */
+       __u64 csum_errors;              /* # of failed csum checks */
+       __u64 verify_errors;            /* # of occurences, where the metadata
+                                        * of a tree block did not match the
+                                        * expected values, like generation or
+                                        * logical */
+       __u64 no_csum;                  /* # of 4k data block for which no csum
+                                        * is present, probably the result of
+                                        * data written with nodatasum */
+       __u64 csum_discards;            /* # of csum for which no data was found
+                                        * in the extent tree. */
+       __u64 super_errors;             /* # of bad super blocks encountered */
+       __u64 malloc_errors;            /* # of internal kmalloc errors. These
+                                        * will likely cause an incomplete
+                                        * scrub */
+       __u64 uncorrectable_errors;     /* # of errors where either no intact
+                                        * copy was found or the writeback
+                                        * failed */
+       __u64 corrected_errors;         /* # of errors corrected */
+       __u64 last_physical;            /* last physical address scrubbed. In
+                                        * case a scrub was aborted, this can
+                                        * be used to restart the scrub */
+       __u64 unverified_errors;        /* # of occurences where a read for a
+                                        * full (64k) bio failed, but the re-
+                                        * check succeeded for each 4k piece.
+                                        * Intermittent error. */
 };
 
 #define BTRFS_SCRUB_READONLY   1