btrfs-progs: Fix -Waddress-of-packed-member warning in btrfs_dev_stats_values callers

[BUG]
GCC 9.1.0 will report the following error when compiling btrfs-progs:

  In file included from print-tree.c:24:
  ctree.h: In function 'btrfs_dev_stats_values':
  ctree.h:2408:9: warning: taking address of packed member of 'struct btrfs_dev_stats_item' may result in an unaligned pointer value [-Waddress-of-packed-member]
   2408 |  return p->values;
        |         ^

[FIX]
Follow the kernel way of accessing dev stats by using
btrfs_dev_stats_value(eb, ptr, index).
So that we don't need to bother accessing the packed member.

This also unifies the helper function in kernel and btrfs-progs.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
master
Qu Wenruo 2019-06-17 15:59:34 +08:00 committed by David Sterba
parent 991ad9b004
commit 95ae4184ea
2 changed files with 19 additions and 15 deletions

13
ctree.h
View File

@ -2416,6 +2416,19 @@ static inline struct btrfs_disk_balance_args* btrfs_balance_item_sys(
return &p->sys;
}
static inline u64 btrfs_dev_stats_value(const struct extent_buffer *eb,
const struct btrfs_dev_stats_item *ptr,
int index)
{
u64 val;
read_extent_buffer(eb, &val,
offsetof(struct btrfs_dev_stats_item, values) +
((unsigned long)ptr) + (index * sizeof(u64)),
sizeof(val));
return val;
}
/*
* this returns the number of bytes used by the item on disk, minus the
* size of any extent headers. If a file is compressed on disk, this is

View File

@ -953,32 +953,23 @@ static void print_balance_item(struct extent_buffer *eb,
static void print_dev_stats(struct extent_buffer *eb,
struct btrfs_dev_stats_item *stats, u32 size)
{
struct btrfs_dev_stats_item *item;
const unsigned long offset = (unsigned long)stats;
u32 known = BTRFS_DEV_STAT_VALUES_MAX * sizeof(__le64);
int i;
item = (struct btrfs_dev_stats_item *)(eb->data + offset);
printf("\t\tdevice stats\n");
printf("\t\twrite_errs %llu read_errs %llu flush_errs %llu corruption_errs %llu generation %llu\n",
(unsigned long long)get_unaligned_le64(
&item->values[BTRFS_DEV_STAT_WRITE_ERRS]),
(unsigned long long)get_unaligned_le64(
&item->values[BTRFS_DEV_STAT_READ_ERRS]),
(unsigned long long)get_unaligned_le64(
&item->values[BTRFS_DEV_STAT_FLUSH_ERRS]),
(unsigned long long)get_unaligned_le64(
&item->values[BTRFS_DEV_STAT_CORRUPTION_ERRS]),
(unsigned long long)get_unaligned_le64(
&item->values[BTRFS_DEV_STAT_GENERATION_ERRS]));
btrfs_dev_stats_value(eb, stats, BTRFS_DEV_STAT_WRITE_ERRS),
btrfs_dev_stats_value(eb, stats, BTRFS_DEV_STAT_READ_ERRS),
btrfs_dev_stats_value(eb, stats, BTRFS_DEV_STAT_FLUSH_ERRS),
btrfs_dev_stats_value(eb, stats, BTRFS_DEV_STAT_CORRUPTION_ERRS),
btrfs_dev_stats_value(eb, stats, BTRFS_DEV_STAT_GENERATION_ERRS));
if (known < size) {
printf("\t\tunknown stats item bytes %u", size - known);
for (i = BTRFS_DEV_STAT_VALUES_MAX; i * sizeof(__le64) < size; i++) {
printf("\t\tunknown item %u offset %zu value %llu\n",
i, i * sizeof(__le64),
(unsigned long long)le64_to_cpu(&item->values[i]));
btrfs_dev_stats_value(eb, stats, i));
}
}
}