On 1/11/18 2:05 PM, Darrick J. Wong wrote:
> On Thu, Jan 11, 2018 at 01:37:37PM -0600, Eric Sandeen wrote:
>> Subject: libxfs: add function to free all bufferse in bcache
>
> s/bufferse/buffers/
That's just my flair ;)
>> libxfs_bcache_purge simply moves all "free" buffers
>> onto the xfs_buf_freelist mru list; add a new function to
>> actually free them when we tear everything down, so leak
>> checkers don't go nuts about lots of unfreed xfs_bufs
>> at exit.
>>
>> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxx>
>> Signed-off-by: Eric Sandeen <sandeen@xxxxxxxxxxx>
>> ---
>> libxfs/init.c | 2 ++
>> libxfs/libxfs_io.h | 1 +
>> libxfs/rdwr.c | 16 ++++++++++++++++
>> 3 files changed, 19 insertions(+)
>>
>> diff --git a/libxfs/init.c b/libxfs/init.c
>> index 7bde8b7..aea308b 100644
>> --- a/libxfs/init.c
>> +++ b/libxfs/init.c
>> @@ -889,6 +889,8 @@ void
>> libxfs_destroy(void)
>> {
>> manage_zones(1);
>> + libxfs_bcache_purge();
>> + libxfs_bcache_free();
>> cache_destroy(libxfs_bcache);
>> }
>>
>> diff --git a/libxfs/libxfs_io.h b/libxfs/libxfs_io.h
>> index 2fce04d..81d2804 100644
>> --- a/libxfs/libxfs_io.h
>> +++ b/libxfs/libxfs_io.h
>> @@ -191,6 +191,7 @@ extern void libxfs_readbuf_verify(struct xfs_buf *bp,
>> const struct xfs_buf_ops *ops);
>> extern xfs_buf_t *libxfs_getsb(struct xfs_mount *, int);
>> extern void libxfs_bcache_purge(void);
>> +extern void libxfs_bcache_free(void);
>> extern void libxfs_bcache_flush(void);
>> extern void libxfs_purgebuf(xfs_buf_t *);
>> extern int libxfs_bcache_overflowed(void);
>> diff --git a/libxfs/rdwr.c b/libxfs/rdwr.c
>> index c5ffd4d..1dcabdd 100644
>> --- a/libxfs/rdwr.c
>> +++ b/libxfs/rdwr.c
>> @@ -1278,6 +1278,22 @@ libxfs_bulkrelse(
>> }
>>
>> /*
>> + * Free everything from the xfs_buf_freelist MRU, used at final teardown
>> + */
>> +void
>> +libxfs_bcache_free(void)
>> +{
>> + struct list_head *cm_list;
>> + xfs_buf_t *bp, *next;
>> +
>> + cm_list = &xfs_buf_freelist.cm_list;
>> + list_for_each_entry_safe(bp, next, cm_list, b_node.cn_mru) {
>> + free(bp->b_addr);
>
> Hm, do we need to free bp->b_maps here? Just looking at
> __libxfs_getbufr (aka the other function that can tear down a
> bp->b_addr).
Oh yeah, probably so.
>> + free(bp);
>
> kmem_zone_free, since we got the bp from kmem_zone_alloc.
Well remember I faked up the zone allocation count for buffers in and out of
cache. If I zone_free here, count ll go way negative (but nobody will check at
that point). I'm not sure if this is all too strange to live...?
> Do we need to reinit xfs_buf_freelist.cm_list, since ->next now points
> to freed list items?
Probably so. Nobody uses it at this point anyway but still, best to leave it
in a sane state I guess.
-Eric
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