From 25e8700721a71128c9f6143dc2effcdbcee692fc Mon Sep 17 00:00:00 2001 From: Amar Tumballi Date: Thu, 16 Jun 2011 05:30:05 +0000 Subject: 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 Signed-off-by: Anand Avati BUG: 2258 (enhance gluster volume rebalance) URL: http://bugs.gluster.com/cgi-bin/bugzilla3/show_bug.cgi?id=2258 --- xlators/mgmt/glusterd/src/glusterd-rebalance.c | 76 ++++++++++++++++++++++++-- 1 file changed, 70 insertions(+), 6 deletions(-) (limited to 'xlators/mgmt') 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 +#include +#include #include #include @@ -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); -- cgit