Multiblock allocator calls BUG_ON in many case if the free and used
blocks count obtained looking at the bitmap is different from what
the allocator internally accounted for. Use ext4_error in such case
and don't panic the system.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
struct ext4_allocation_context is rather large, and this bloats
the stack of many functions which use it. Allocating it from
a named slab cache will alleviate this.
For example, with this change (on top of the noinline patch sent earlier):
-ext4_mb_new_blocks 200
+ext4_mb_new_blocks 40
-ext4_mb_free_blocks 344
+ext4_mb_free_blocks 168
-ext4_mb_release_inode_pa 216
+ext4_mb_release_inode_pa 40
-ext4_mb_release_group_pa 192
+ext4_mb_release_group_pa 24
Most of these stack-allocated structs are actually used only for
mballoc history; and in those cases often a smaller struct would do.
So changing that may be another way around it, at least for those
functions, if preferred. For now, in those cases where the ac
is only for history, an allocation failure simply skips the history
recording, and does not cause any other failures.
Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Repoted by Adrian Bunk <bunk@kernel.org>:
The Coverity checker spotted the following NULL dereference:
static int ext4_mb_mark_diskspace_used
{
...
if (!bitmap_bh)
goto out_err;
...
out_err:
sb->s_dirt = 1;
put_bh(bitmap_bh);
...
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Mingming Cao <cmm@us.ibm.com>
Aneesh Kumar K.V
Eric Sandeen
Alex Tomas