src/e4compact: add sparse file optimization

[xfstests-dev.git] / src / e4compact.c

diff --git a/src/e4compact.c b/src/e4compact.c
index 314c329bb8ff24bd40fcd0ff0c2b8f17b3a01763..a0f216bb472a699a95984ab257b459b49d985fc5 100644 (file)
--- a/src/e4compact.c
+++ b/src/e4compact.c
@@ -16,6 +16,8 @@
 #include <ctype.h>
 #include <limits.h>
 #include <errno.h>
+#include <linux/fs.h>
+#include <linux/fiemap.h>
 #include <linux/types.h>
 #include <fcntl.h>
 #include <sys/ioctl.h>
@@ -40,6 +42,7 @@ struct move_extent {
 
 #define EXT4_IOC_MOVE_EXT      _IOWR('f', 15, struct move_extent)
 #endif
+#define EXTENT_MAX_COUNT        512
 
 struct donor_info
 {
@@ -50,11 +53,12 @@ struct donor_info
 
 static int ignore_error = 0;
 static int verbose = 0;
+static int do_sparse = 0;
 static unsigned blk_per_pg;
 static unsigned blk_sz;
 
-
-static int do_defrag_one(int fd, char *name,__u64 start, __u64 len, struct donor_info *donor)
+static int do_defrag_range(int fd, char *name,__u64 start, __u64 len,
+                          struct donor_info *donor)
 {
        int ret, retry;
        struct move_extent mv_ioc;
@@ -119,10 +123,64 @@ static int do_defrag_one(int fd, char *name,__u64 start, __u64 len, struct donor
        return ret;
 }
 
+static int do_defrag_sparse(int fd, char *name,__u64 start, __u64 len,
+                           struct donor_info *donor)
+{
+       int i, ret = 0;
+       struct fiemap   *fiemap_buf = NULL;
+       struct fiemap_extent    *ext_buf = NULL;
+
+       fiemap_buf = malloc(EXTENT_MAX_COUNT * sizeof(struct fiemap_extent)
+                           + sizeof(struct fiemap));
+       if (fiemap_buf == NULL) {
+               fprintf(stderr, "%s Can not allocate memory\n", __func__);
+               return -1;
+       }
+       ext_buf = fiemap_buf->fm_extents;
+       memset(fiemap_buf, 0, sizeof(struct fiemap));
+       fiemap_buf->fm_flags |= FIEMAP_FLAG_SYNC;
+       fiemap_buf->fm_extent_count = EXTENT_MAX_COUNT;
+
+       do {
+               __u64 next;
+
+               fiemap_buf->fm_start = start * blk_sz;
+               fiemap_buf->fm_length = len * blk_sz;
+               ret = ioctl(fd, FS_IOC_FIEMAP, fiemap_buf);
+               if (ret < 0 || fiemap_buf->fm_mapped_extents == 0) {
+                       fprintf(stderr, "%s Can get extent info for %s ret:%d mapped:%d",
+                               __func__, name, ret, fiemap_buf->fm_mapped_extents);
+                       goto out;
+               }
+               for (i = 0; i < fiemap_buf->fm_mapped_extents; i++) {
+                       ret = do_defrag_range(fd, name,
+                                             ext_buf[i].fe_logical / blk_sz,
+                                             ext_buf[i].fe_length / blk_sz,
+                                             donor);
+                       if (ret)
+                               goto out;
+               }
+               next = (ext_buf[fiemap_buf->fm_mapped_extents -1].fe_logical +
+                          ext_buf[fiemap_buf->fm_mapped_extents -1].fe_length) /
+                       blk_sz;
+               if (next <  start + len) {
+                       len -= next  - start;
+                       start = next;
+               } else
+                       break;
+
+       } while (fiemap_buf->fm_mapped_extents == EXTENT_MAX_COUNT &&
+                !(ext_buf[EXTENT_MAX_COUNT-1].fe_flags & FIEMAP_EXTENT_LAST));
+out:
+       free(fiemap_buf);
+       return ret;
+}
+
 void usage()
 {
        printf("Usage: -f donor_file [-o donor_offset] [-v] [-i]\n"
               "\t\t -v: verbose\n"
+              "\t\t -s: enable sparse file optimization\n"
               "\t\t -i: ignore errors\n");
 }
 
@@ -138,9 +196,10 @@ int main(int argc, char **argv)
        extern int optind;
        int c;
        char * donor_name = NULL;
+       __u64 eof_blk;
 
        donor.offset = 0;
-       while ((c = getopt(argc, argv, "f:o:iv")) != -1) {
+       while ((c = getopt(argc, argv, "f:o:isv")) != -1) {
                switch (c) {
                case 'o':
                        donor.offset = atol(optarg);
@@ -151,6 +210,9 @@ int main(int argc, char **argv)
                case 'v':
                        verbose = 1;
                        break;
+               case 's':
+                       do_sparse = 1;
+                       break;
                case 'f':
                        donor_name = (optarg);
                        break;
@@ -207,13 +269,17 @@ int main(int argc, char **argv)
                                break;
 
                }
-               if (st.st_size && st.st_blocks) {
-                       ret = do_defrag_one(fd, line, 0,
-                                           (st.st_size  + blk_sz-1)/ blk_sz,
-                                           &donor);
-                       if (ret && !ignore_error)
-                               break;
-               }
+               if (!(st.st_size && st.st_blocks))
+                       continue;
+
+               eof_blk = (st.st_size + blk_sz-1) / blk_sz;
+               if (do_sparse)
+                       ret = do_defrag_sparse(fd, line, 0, eof_blk, &donor);
+               else
+                       ret = do_defrag_range(fd, line, 0, eof_blk, &donor);
+               if (ret && !ignore_error)
+                       break;
+
        }
        free(line);
        return ret;