So far fiemap used some rather convoluted logic to terminate the iteration and
calculate the number of extents to pass to fm_extent_count. Simplify this by:
* Get the whole number of extents that this file has and keep iterating until
we've printed all extents
* Always use a hard-coded batch of 32 extents so we don't have to worry about
any extra calculations
Signed-off-by: Nikolay Borisov <nborisov@xxxxxxxx>
---
io/fiemap.c | 37 +++++++++++++++++++++----------------
1 file changed, 21 insertions(+), 16 deletions(-)
diff --git a/io/fiemap.c b/io/fiemap.c
index 30c49112e089..ef54b265ab91 100644
--- a/io/fiemap.c
+++ b/io/fiemap.c
@@ -23,6 +23,8 @@
#include "init.h"
#include "io.h"
+#define EXTENT_BATCH 32
+
static cmdinfo_t fiemap_cmd;
static const __u64 blocksize = 512;
static int max_extents = 0;
@@ -95,7 +97,7 @@ print_verbose(
memset(lbuf, 0, sizeof(lbuf));
}
- if ((*cur_extent + 1) == max_extents)
+ if (*cur_extent == max_extents)
return;
snprintf(lbuf, sizeof(lbuf), "[%llu..%llu]:", lstart,
@@ -137,7 +139,7 @@ print_plain(
(*cur_extent)++;
}
- if ((*cur_extent + 1) == max_extents)
+ if (*cur_extent == max_extents)
return;
printf("\t%d: [%llu..%llu]: %llu..%llu", *cur_extent,
@@ -215,7 +217,7 @@ fiemap_f(
char **argv)
{
struct fiemap *fiemap;
- int num_extents = 32;
+ int num_extents;
int last = 0;
int lflag = 0;
int vflag = 0;
@@ -251,10 +253,15 @@ fiemap_f(
}
}
- if (max_extents)
- num_extents = min(num_extents, max_extents);
+ ret = get_extent_count(file->fd, last_logical, -1);
+ if (ret < 0) {
+ exitcode = 1;
+ return 0;
+ }
+ num_extents = ret;
+
map_size = sizeof(struct fiemap) +
- (num_extents * sizeof(struct fiemap_extent));
+ (EXTENT_BATCH * sizeof(struct fiemap_extent));
fiemap = malloc(map_size);
if (!fiemap) {
fprintf(stderr, _("%s: malloc of %d bytes failed.\n"),
@@ -265,16 +272,14 @@ fiemap_f(
printf("%s:\n", file->name);
- while (!last && ((cur_extent + 1) != max_extents)) {
- if (max_extents)
- num_extents = min(num_extents,
- max_extents - (cur_extent + 1));
+ while (!last && num_extents) {
+ /* Query a batch worth of extents */
memset(fiemap, 0, map_size);
fiemap->fm_flags = fiemap_flags;
fiemap->fm_start = last_logical;
fiemap->fm_length = -1LL;
- fiemap->fm_extent_count = num_extents;
+ fiemap->fm_extent_count = EXTENT_BATCH;
ret = ioctl(file->fd, FS_IOC_FIEMAP, (unsigned long)fiemap);
if (ret < 0) {
@@ -307,17 +312,17 @@ fiemap_f(
print_plain(extent, lflag, blocksize,
&cur_extent, &last_logical);
- if (extent->fe_flags & FIEMAP_EXTENT_LAST) {
+ if (extent->fe_flags & FIEMAP_EXTENT_LAST ||
+ cur_extent == max_extents) {
last = 1;
break;
}
-
- if ((cur_extent + 1) == max_extents)
- break;
}
+
+ num_extents -= fiemap->fm_mapped_extents;
}
- if ((cur_extent + 1) == max_extents)
+ if (cur_extent == max_extents)
goto out;
memset(&st, 0, sizeof(st));
--
2.7.4
--
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