btrfs filesystem show: skip duplicate fsids

If a given filesystem is mounted more than once, btrfs fi show will
print dups.  This adds a quick and dirty hash table of fsids it
has already printed and makes sure we don't print any fsid more than
once.

Signed-off-by: Chris Mason <chris.mason@fusionio.com>
This commit is contained in:
Chris Mason 2013-11-18 14:18:08 -05:00
parent e9ac73b441
commit 5aff090a39
1 changed files with 79 additions and 0 deletions

View File

@ -38,6 +38,74 @@
#include "commands.h"
#include "list_sort.h"
/*
* for btrfs fi show, we maintain a hash of fsids we've already printed.
* This way we don't print dups if a given FS is mounted more than once.
*/
#define SEEN_FSID_HASH_SIZE 256
struct seen_fsid {
u8 fsid[BTRFS_FSID_SIZE];
struct seen_fsid *next;
};
static struct seen_fsid *seen_fsid_hash[SEEN_FSID_HASH_SIZE] = {NULL,};
static int add_seen_fsid(u8 *fsid)
{
u8 hash = fsid[0];
int slot = hash % SEEN_FSID_HASH_SIZE;
struct seen_fsid *seen = seen_fsid_hash[slot];
struct seen_fsid *alloc;
if (!seen)
goto insert;
while (1) {
if (memcmp(seen->fsid, fsid, BTRFS_FSID_SIZE) == 0)
return -EEXIST;
if (!seen->next)
break;
seen = seen->next;
}
insert:
alloc = malloc(sizeof(*alloc));
if (!alloc)
return -ENOMEM;
alloc->next = NULL;
memcpy(alloc->fsid, fsid, BTRFS_FSID_SIZE);
if (seen)
seen->next = alloc;
else
seen_fsid_hash[slot] = alloc;
return 0;
}
static void free_seen_fsid(void)
{
int slot;
struct seen_fsid *seen;
struct seen_fsid *next;
for (slot = 0; slot < SEEN_FSID_HASH_SIZE; slot++) {
seen = seen_fsid_hash[slot];
while (seen) {
next = seen->next;
free(seen);
seen = next;
}
seen_fsid_hash[slot] = NULL;
}
}
static const char * const filesystem_cmd_group_usage[] = {
"btrfs filesystem [<group>] <command> [<args>]",
NULL
@ -224,6 +292,9 @@ static void print_one_uuid(struct btrfs_fs_devices *fs_devices)
u64 devs_found = 0;
u64 total;
if (add_seen_fsid(fs_devices->fsid))
return;
uuid_unparse(fs_devices->fsid, uuidbuf);
device = list_entry(fs_devices->devices.next, struct btrfs_device,
dev_list);
@ -274,6 +345,13 @@ static int print_one_fs(struct btrfs_ioctl_fs_info_args *fs_info,
int i;
char uuidbuf[37];
struct btrfs_ioctl_dev_info_args *tmp_dev_info;
int ret;
ret = add_seen_fsid(fs_info->fsid);
if (ret == -EEXIST)
return 0;
else if (ret)
return ret;
uuid_unparse(fs_info->fsid, uuidbuf);
printf("Label: %s uuid: %s\n",
@ -478,6 +556,7 @@ devs_only:
out:
printf("%s\n", BTRFS_BUILD_VERSION);
free_seen_fsid();
return 0;
}