File newdf-rework-calculations.patch of Package btrfsprogs
From: David Sterba <dsterba@suse.cz>
Date: Thu, 26 Jun 2014 15:42:24 +0200
Subject: [PATCH] newdf rework calculations
Fix negative numbers in estimated free space.
Signed-off-by: David Sterba <dsterba@suse.cz>
---
cmds-fi-disk_usage.c | 150 ++++++++++++++++++++++++++++++++++-----------------
1 file changed, 102 insertions(+), 48 deletions(-)
diff --git a/cmds-fi-disk_usage.c b/cmds-fi-disk_usage.c
index b30bd308df55..25d9d0061407 100644
--- a/cmds-fi-disk_usage.c
+++ b/cmds-fi-disk_usage.c
@@ -306,6 +306,7 @@ static void get_raid56_used(int fd, struct chunk_info *chunks, int chunkcount,
}
}
+#define MIN_UNALOCATED_THRESH (16 * 1024 * 1024)
static int print_filesystem_usage_overall(int fd, struct chunk_info *chunkinfo,
int chunkcount, struct device_info *devinfo, int devcount,
char *path, int mode)
@@ -313,16 +314,34 @@ static int print_filesystem_usage_overall(int fd, struct chunk_info *chunkinfo,
struct btrfs_ioctl_space_args *sargs = 0;
int i;
int ret = 0;
- int e, width;
- u64 total_disk; /* filesystem size == sum of
- device sizes */
- u64 total_chunks; /* sum of chunks sizes on disk(s) */
- u64 total_used; /* logical space used */
- u64 total_free; /* logical space un-used */
- double K;
- u64 raid5_used, raid6_used;
- u64 global_reserve;
- u64 global_reserve_used;
+ int width = 10; /* default 10 for human units */
+ /*
+ * r_* prefix is for raw data
+ * l_* is for logical
+ */
+ u64 r_total_size = 0; /* filesystem size, sum of device sizes */
+ u64 r_total_chunks = 0; /* sum of chunks sizes on disk(s) */
+ u64 r_total_used = 0;
+ u64 r_total_unused = 0;
+ u64 r_data_used = 0;
+ u64 r_data_chunks = 0;
+ u64 l_data_chunks = 0;
+ u64 r_metadata_used = 0;
+ u64 r_metadata_chunks = 0;
+ u64 l_metadata_chunks = 0;
+ u64 r_system_used = 0;
+ u64 r_system_chunks = 0;
+ double data_ratio;
+ double metadata_ratio;
+ /* logical */
+ u64 raid5_used = 0;
+ u64 raid6_used = 0;
+ u64 l_global_reserve = 0;
+ u64 l_global_reserve_used = 0;
+ /* logical */
+ u64 free_estimated = 0;
+ u64 free_min = 0;
+ int max_data_ratio = 1;
sargs = load_space_info(fd, path);
if (!sargs) {
@@ -330,27 +349,19 @@ static int print_filesystem_usage_overall(int fd, struct chunk_info *chunkinfo,
goto exit;
}
- total_disk = disk_size(path);
- e = errno;
- if (total_disk == 0) {
+ r_total_size = disk_size(path);
+ if (r_total_size == 0) {
fprintf(stderr,
"ERROR: couldn't get space info on '%s' - %s\n",
- path, strerror(e));
+ path, strerror(errno));
ret = 1;
goto exit;
}
get_raid56_used(fd, chunkinfo, chunkcount, &raid5_used, &raid6_used);
- total_chunks = 0;
- total_used = 0;
- total_free = 0;
- global_reserve = 0;
- global_reserve_used = 0;
-
for (i = 0; i < sargs->total_spaces; i++) {
- float ratio = 1;
- u64 allocated;
+ int ratio = 1;
u64 flags = sargs->spaces[i].flags;
/*
@@ -372,52 +383,95 @@ static int print_filesystem_usage_overall(int fd, struct chunk_info *chunkinfo,
else
ratio = 1;
- if (flags & BTRFS_SPACE_INFO_GLOBAL_RSV) {
- global_reserve = sargs->spaces[i].total_bytes;
- global_reserve_used = sargs->spaces[i].used_bytes;
+ if (!ratio) {
+ printf("WARNING: RAID56 detected, not implemented\n");
}
- allocated = sargs->spaces[i].total_bytes * ratio;
+ if (ratio > max_data_ratio)
+ max_data_ratio = ratio;
- total_chunks += allocated;
- total_used += sargs->spaces[i].used_bytes;
- total_free += (sargs->spaces[i].total_bytes -
- sargs->spaces[i].used_bytes);
+ if (flags & BTRFS_SPACE_INFO_GLOBAL_RSV) {
+ l_global_reserve = sargs->spaces[i].total_bytes;
+ l_global_reserve_used = sargs->spaces[i].used_bytes;
+ }
+ if ((flags & (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA))
+ == (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA)) {
+ printf("WARNING: MIXED blockgroups not handled\n");
+ }
+ if (flags & BTRFS_BLOCK_GROUP_DATA) {
+ r_data_used += sargs->spaces[i].used_bytes * ratio;
+ r_data_chunks += sargs->spaces[i].total_bytes * ratio;
+ l_data_chunks += sargs->spaces[i].total_bytes;
+ }
+ if (flags & BTRFS_BLOCK_GROUP_METADATA) {
+ r_metadata_used += sargs->spaces[i].used_bytes * ratio;
+ r_metadata_chunks += sargs->spaces[i].total_bytes * ratio;
+ l_metadata_chunks += sargs->spaces[i].total_bytes;
+ }
+ if (flags & BTRFS_BLOCK_GROUP_SYSTEM) {
+ r_system_used += sargs->spaces[i].used_bytes * ratio;
+ r_system_chunks += sargs->spaces[i].total_bytes * ratio;
+ }
}
+ r_total_chunks = r_data_chunks + r_metadata_chunks + r_system_chunks;
+ r_total_used = r_data_used + r_metadata_used + r_system_used;
+ r_total_unused = r_total_size - r_total_chunks;
+
+ /* Raw / Logical = raid factor, >= 1 */
+ data_ratio = (double)r_data_chunks / l_data_chunks;
+ metadata_ratio = (double)r_metadata_chunks / l_metadata_chunks;
+
+#if 0
/* add the raid5/6 allocated space */
total_chunks += raid5_used + raid6_used;
+#endif
- K = ((double)total_used + (double)total_free) / (double)total_chunks;
+ /*
+ * We're able to fill at least DATA for the unused space
+ *
+ * With mixed raid levels, this gives a rough estimate but more
+ * accurate than just counting the logical free space
+ * (l_data_chunks - l_data_used)
+ *
+ * In non-mixed case there's no difference.
+ */
+ free_estimated = (r_data_chunks - r_data_used) / data_ratio;
+ free_min = free_estimated;
+
+ /* Chop unallocatable space */
+ /* FIXME: must be applied per device */
+ if (r_total_unused >= MIN_UNALOCATED_THRESH) {
+ free_estimated += r_total_unused / data_ratio;
+ /* Match the calculation of 'df', use the highest raid ratio */
+ free_min += r_total_unused / max_data_ratio;
+ }
- if (mode == UNITS_HUMAN)
- width = 10;
- else
+ if (mode != UNITS_HUMAN)
width = 18;
printf("Overall:\n");
printf(" Device size:\t\t%*s\n", width,
- pretty_size_mode(total_disk, mode));
+ pretty_size_mode(r_total_size, mode));
printf(" Device allocated:\t\t%*s\n", width,
- pretty_size_mode(total_chunks, mode));
+ pretty_size_mode(r_total_chunks, mode));
printf(" Device unallocated:\t\t%*s\n", width,
- pretty_size_mode(total_disk - total_chunks, mode));
+ pretty_size_mode(r_total_unused, mode));
printf(" Used:\t\t\t%*s\n", width,
- pretty_size_mode(total_used, mode));
- printf(" Free (Estimated):\t\t%*s\t(",
+ pretty_size_mode(r_total_used, mode));
+ printf(" Free (estimated):\t\t%*s\t(",
width,
- pretty_size_mode((u64)(K * total_disk - total_used), mode));
- printf("Max: %s, ",
- pretty_size_mode(total_disk - total_chunks + total_free, mode));
- printf("min: %s)\n",
- pretty_size_mode((total_disk-total_chunks) / 2 + total_free, mode));
- printf(" Data to device ratio:\t%*.0f %%\n",
- width - 2, K * 100);
+ pretty_size_mode(free_estimated, mode));
+ printf("min: %s)\n", pretty_size_mode(free_min, mode));
+ printf(" Data ratio:\t\t\t%*.2f\n",
+ width, data_ratio);
+ printf(" Metadata ratio:\t\t%*.2f\n",
+ width, metadata_ratio);
printf(" Global reserve:\t\t%*s\t(used: %s)\n", width,
- pretty_size_mode(global_reserve, mode),
- pretty_size_mode(global_reserve_used, mode));
+ pretty_size_mode(l_global_reserve, mode),
+ pretty_size_mode(l_global_reserve_used, mode));
exit:
--
2.1.1
