btrfs-progs: per-thread, per-call pretty buffer

We don't need callers to manage string storage for each pretty_sizes()
call.  We can use a macro to have per-thread and per-call static storage
so that pretty_sizes() can be used as many times as needed in printf()
arguments without requiring a bunch of supporting variables.

This lets us have a natural interface at the cost of requiring __thread
and TLS from gcc and a small amount of static storage.  This seems
better than the current code or doing something with illegible format
specifier macros.

Signed-off-by: Zach Brown <zab@redhat.com>
Acked-by: Wang Shilong <wangs.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@fusionio.com>

diff --git a/btrfs-calc-size.c b/btrfs-calc-size.c
index c4adfb0..5aa0b70 100644 (file)
--- a/btrfs-calc-size.c
+++ b/btrfs-calc-size.c
@@ -162,18 +162,11 @@ out_print:
                       stat.total_inline, stat.total_nodes, stat.total_leaves,
                       level + 1);
        } else {
-               char *total_size;
-               char *inline_size;
-
-               total_size = pretty_sizes(stat.total_bytes);
-               inline_size = pretty_sizes(stat.total_inline);
-
                printf("\t%s total size, %s inline data, %Lu nodes, "
                       "%Lu leaves, %d levels\n",
-                      total_size, inline_size, stat.total_nodes,
-                      stat.total_leaves, level + 1);
-               free(total_size);
-               free(inline_size);
+                      pretty_size(stat.total_bytes),
+                      pretty_size(stat.total_inline),
+                      stat.total_nodes, stat.total_leaves, level + 1);
        }
 out:
        btrfs_free_path(path);

diff --git a/btrfs-fragments.c b/btrfs-fragments.c
index a012fe1..7ec77e7 100644 (file)
--- a/btrfs-fragments.c
+++ b/btrfs-fragments.c
@@ -87,7 +87,7 @@ print_bg(FILE *html, char *name, u64 start, u64 len, u64 used, u64 flags,
 
        fprintf(html, "<p>%s chunk starts at %lld, size is %s, %.2f%% used, "
                      "%.2f%% fragmented</p>\n", chunk_type(flags), start,
-                     pretty_sizes(len), 100.0 * used / len, 100.0 * frag);
+                     pretty_size(len), 100.0 * used / len, 100.0 * frag);
        fprintf(html, "<img src=\"%s\" border=\"1\" />\n", name);
 }
 

diff --git a/cmds-filesystem.c b/cmds-filesystem.c
index f41a72a..222e458 100644 (file)
--- a/cmds-filesystem.c
+++ b/cmds-filesystem.c
@@ -111,8 +111,6 @@ static int cmd_df(int argc, char **argv)
 
        for (i = 0; i < sargs->total_spaces; i++) {
                char description[80];
-               char *total_bytes;
-               char *used_bytes;
                int written = 0;
                u64 flags = sargs->spaces[i].flags;
 
@@ -155,10 +153,9 @@ static int cmd_df(int argc, char **argv)
                        written += 7;
                }
 
-               total_bytes = pretty_sizes(sargs->spaces[i].total_bytes);
-               used_bytes = pretty_sizes(sargs->spaces[i].used_bytes);
-               printf("%s: total=%s, used=%s\n", description, total_bytes,
-                      used_bytes);
+               printf("%s: total=%s, used=%s\n", description,
+                       pretty_size(sargs->spaces[i].total_bytes),
+                       pretty_size(sargs->spaces[i].used_bytes));
        }
        close(fd);
        free(sargs);
@@ -192,7 +189,6 @@ static void print_one_uuid(struct btrfs_fs_devices *fs_devices)
        char uuidbuf[37];
        struct list_head *cur;
        struct btrfs_device *device;
-       char *super_bytes_used;
        u64 devs_found = 0;
        u64 total;
 
@@ -204,25 +200,20 @@ static void print_one_uuid(struct btrfs_fs_devices *fs_devices)
        else
                printf("Label: none ");
 
-       super_bytes_used = pretty_sizes(device->super_bytes_used);
 
        total = device->total_devs;
        printf(" uuid: %s\n\tTotal devices %llu FS bytes used %s\n", uuidbuf,
-              (unsigned long long)total, super_bytes_used);
-
-       free(super_bytes_used);
+              (unsigned long long)total,
+              pretty_size(device->super_bytes_used));
 
        list_for_each(cur, &fs_devices->devices) {
-               char *total_bytes;
-               char *bytes_used;
                device = list_entry(cur, struct btrfs_device, dev_list);
-               total_bytes = pretty_sizes(device->total_bytes);
-               bytes_used = pretty_sizes(device->bytes_used);
+
                printf("\tdevid %4llu size %s used %s path %s\n",
                       (unsigned long long)device->devid,
-                      total_bytes, bytes_used, device->name);
-               free(total_bytes);
-               free(bytes_used);
+                      pretty_size(device->total_bytes),
+                      pretty_size(device->bytes_used), device->name);
+
                devs_found++;
        }
        if (devs_found < total) {

diff --git a/cmds-scrub.c b/cmds-scrub.c
index 95dfee3..bf50650 100644 (file)
--- a/cmds-scrub.c
+++ b/cmds-scrub.c
@@ -139,7 +139,6 @@ static void print_scrub_summary(struct btrfs_scrub_progress *p)
 {
        u64 err_cnt;
        u64 err_cnt2;
-       char *bytes;
 
        err_cnt = p->read_errors +
                        p->csum_errors +
@@ -151,10 +150,11 @@ static void print_scrub_summary(struct btrfs_scrub_progress *p)
        if (p->malloc_errors)
                printf("*** WARNING: memory allocation failed while scrubbing. "
                       "results may be inaccurate\n");
-       bytes = pretty_sizes(p->data_bytes_scrubbed + p->tree_bytes_scrubbed);
-       printf("\ttotal bytes scrubbed: %s with %llu errors\n", bytes,
+
+       printf("\ttotal bytes scrubbed: %s with %llu errors\n",
+               pretty_size(p->data_bytes_scrubbed + p->tree_bytes_scrubbed),
                max(err_cnt, err_cnt2));
-       free(bytes);
+
        if (err_cnt || err_cnt2) {
                printf("\terror details:");
                PRINT_SCRUB_ERROR(p->read_errors, "read");

diff --git a/mkfs.c b/mkfs.c
index 95fceb3..ade85c7 100644 (file)
--- a/mkfs.c
+++ b/mkfs.c
@@ -1356,7 +1356,6 @@ int main(int ac, char **av)
        u64 num_of_meta_chunks = 0;
        u64 size_of_data = 0;
        u64 source_dir_size = 0;
-       char *pretty_buf;
        struct btrfs_super_block *super;
        u64 flags;
        int dev_cnt = 0;
@@ -1629,8 +1628,7 @@ raid_groups:
        printf("fs created label %s on %s\n\tnodesize %u leafsize %u "
            "sectorsize %u size %s\n",
            label, first_file, nodesize, leafsize, sectorsize,
-           pretty_buf = pretty_sizes(btrfs_super_total_bytes(root->fs_info->super_copy)));
-       free(pretty_buf);
+           pretty_size(btrfs_super_total_bytes(root->fs_info->super_copy)));
 
        printf("%s\n", BTRFS_BUILD_VERSION);
        btrfs_commit_transaction(trans, root);

diff --git a/utils.c b/utils.c
index 1eeda0f..ced85aa 100644 (file)
--- a/utils.c
+++ b/utils.c
@@ -1152,13 +1152,14 @@ out:
 }
 
 static char *size_strs[] = { "", "KB", "MB", "GB", "TB",
-                           "PB", "EB", "ZB", "YB"};
-char *pretty_sizes(u64 size)
+                           "PB", "EB"};
+void pretty_size_snprintf(u64 size, char *str, size_t str_bytes)
 {
        int num_divs = 0;
-        int pretty_len = 16;
        float fraction;
-       char *pretty;
+
+       if (str_bytes == 0)
+               return;
 
        if( size < 1024 ){
                fraction = size;
@@ -1172,13 +1173,13 @@ char *pretty_sizes(u64 size)
                        num_divs ++;
                }
 
-               if (num_divs >= ARRAY_SIZE(size_strs))
-                       return NULL;
+               if (num_divs >= ARRAY_SIZE(size_strs)) {
+                       str[0] = '\0';
+                       return;
+               }
                fraction = (float)last_size / 1024;
        }
-       pretty = malloc(pretty_len);
-       snprintf(pretty, pretty_len, "%.2f%s", fraction, size_strs[num_divs]);
-       return pretty;
+       snprintf(str, str_bytes, "%.2f%s", fraction, size_strs[num_divs]);
 }
 
 /*

diff --git a/utils.h b/utils.h
index 3c17e14..36fb591 100644 (file)
--- a/utils.h
+++ b/utils.h
@@ -44,7 +44,15 @@ int check_mounted_where(int fd, const char *file, char *where, int size,
                        struct btrfs_fs_devices **fs_devices_mnt);
 int btrfs_device_already_in_root(struct btrfs_root *root, int fd,
                                 int super_offset);
-char *pretty_sizes(u64 size);
+
+void pretty_size_snprintf(u64 size, char *str, size_t str_bytes);
+#define pretty_size(size)                                              \
+       ({                                                              \
+               static __thread char _str[24];                          \
+               pretty_size_snprintf((size), _str, sizeof(_str));       \
+               _str;                                                   \
+       })
+
 int get_mountpt(char *dev, char *mntpt, size_t size);
 int btrfs_scan_block_devices(int run_ioctl);
 u64 parse_size(char *s);