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authorAmar Tumballi <amar@gluster.com>2011-06-16 05:30:05 +0000
committerAnand Avati <avati@gluster.com>2011-06-16 22:02:06 -0700
commit25e8700721a71128c9f6143dc2effcdbcee692fc (patch)
treebf944a10012e100210df9fdd23867edff84b1529
parente3a061d6fa5f436fe37493b7257860014ae75950 (diff)
gluster rebalance: handle the migration of files with 'holes'.
treat a block (512bytes) of '0' as hole too (something like 'rsync') Signed-off-by: Amar Tumballi <amar@gluster.com> Signed-off-by: Anand Avati <avati@gluster.com> BUG: 2258 (enhance gluster volume rebalance) URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2258
-rw-r--r--xlators/mgmt/glusterd/src/glusterd-rebalance.c76
1 files changed, 70 insertions, 6 deletions
diff --git a/xlators/mgmt/glusterd/src/glusterd-rebalance.c b/xlators/mgmt/glusterd/src/glusterd-rebalance.c
index 3aba3b99076..0a072e7741a 100644
--- a/xlators/mgmt/glusterd/src/glusterd-rebalance.c
+++ b/xlators/mgmt/glusterd/src/glusterd-rebalance.c
@@ -23,6 +23,8 @@
#endif
#include <inttypes.h>
+#include <sys/types.h>
+#include <unistd.h>
#include <sys/resource.h>
#include <sys/statvfs.h>
@@ -45,6 +47,55 @@
#define GF_DISK_SECTOR_SIZE 512
+static int
+write_with_holes (int fd, const char *buf, int size, off_t offset)
+{
+ int ret = -1;
+ int start_idx = 0;
+ int tmp_offset = 0;
+ int write_needed = 0;
+
+ for (start_idx = 0; (start_idx + GF_DISK_SECTOR_SIZE) <= size;
+ start_idx += GF_DISK_SECTOR_SIZE) {
+ /* Check if a block has full '0's. assume as hole if true */
+ if (mem_0filled (buf + start_idx, GF_DISK_SECTOR_SIZE) == 0) {
+ write_needed = 1;
+ continue;
+ }
+
+ if (write_needed) {
+ ret = write (fd, buf + tmp_offset,
+ (start_idx - tmp_offset));
+ if (ret < 0)
+ goto out;
+
+ write_needed = 0;
+ }
+ tmp_offset = start_idx + GF_DISK_SECTOR_SIZE;
+
+ ret = lseek (fd, (offset + tmp_offset), SEEK_SET);
+ if (ret < 0)
+ goto out;
+ }
+
+ if ((start_idx < size) || write_needed) {
+ /* This means, last chunk is not yet written.. write it */
+ ret = write (fd, buf + tmp_offset, (size - tmp_offset));
+ if (ret < 0)
+ goto out;
+ }
+
+ /* do it regardless of all the above cases as we had to 'write' the
+ given number of bytes */
+ ret = ftruncate (fd, offset + size);
+ if (ret)
+ goto out;
+
+ ret = 0;
+out:
+ return ret;
+
+}
int
gf_glusterd_rebalance_move_data (glusterd_volinfo_t *volinfo, const char *dir)
{
@@ -60,8 +111,10 @@ gf_glusterd_rebalance_move_data (glusterd_volinfo_t *volinfo, const char *dir)
char tmp_filename[PATH_MAX] = {0,};
char value[16] = {0,};
char linkinfo[PATH_MAX] = {0,};
- struct statvfs src_statfs = {0,};
- struct statvfs dst_statfs = {0,};
+ struct statvfs src_statfs = {0,};
+ struct statvfs dst_statfs = {0,};
+ int file_has_holes = 0;
+ off_t offset = 0;
if (!volinfo->defrag)
goto out;
@@ -152,15 +205,26 @@ gf_glusterd_rebalance_move_data (glusterd_volinfo_t *volinfo, const char *dir)
continue;
}
+ /* Try to preserve 'holes' while migrating data */
+ if (stbuf.st_size > (stbuf.st_blocks * GF_DISK_SECTOR_SIZE))
+ file_has_holes = 1;
+
+ offset = 0;
while (1) {
- ret = read (src_fd, defrag->databuf, 131072);
+ ret = read (src_fd, defrag->databuf, 128 * GF_UNIT_KB);
if (!ret || (ret < 0)) {
break;
}
- ret = write (dst_fd, defrag->databuf, ret);
- if (ret < 0) {
+
+ if (!file_has_holes)
+ ret = write (dst_fd, defrag->databuf, ret);
+ else
+ ret = write_with_holes (dst_fd, defrag->databuf,
+ ret, offset);
+ if (ret < 0)
break;
- }
+
+ offset += ret;
}
ret = stat (full_path, &new_stbuf);