在 2020/11/25 23:55, Eric Sandeen 写道:
On 11/25/20 12:50 AM, Qinglang Miao wrote:
krealloc() may fail to expand the memory space.
Even with __GFP_NOFAIL?
* ``GFP_KERNEL | __GFP_NOFAIL`` - overrides the default allocator behavior
and all allocation requests will loop endlessly until they succeed.
This might be really dangerous especially for larger orders.
Add sanity checks to it,
and WARN() if that really happened.
As aside, there is no WARN added in this patch for a memory failure.
Fixes: 771915c4f688 ("xfs: remove kmem_realloc()")
Reported-by: Hulk Robot <hulkci@xxxxxxxxxx>
Signed-off-by: Qinglang Miao <miaoqinglang@xxxxxxxxxx>
---
fs/xfs/xfs_mount.c | 6 +++++-
1 file changed, 5 insertions(+), 1 deletion(-)
diff --git a/fs/xfs/xfs_mount.c b/fs/xfs/xfs_mount.c
index 150ee5cb8..c07f48c32 100644
--- a/fs/xfs/xfs_mount.c
+++ b/fs/xfs/xfs_mount.c
@@ -80,9 +80,13 @@ xfs_uuid_mount(
}
if (hole < 0) {
- xfs_uuid_table = krealloc(xfs_uuid_table,
+ uuid_t *if_xfs_uuid_table;
+ if_xfs_uuid_table = krealloc(xfs_uuid_table,
(xfs_uuid_table_size + 1) * sizeof(*xfs_uuid_table),
GFP_KERNEL | __GFP_NOFAIL);
+ if (!if_xfs_uuid_table)
+ goto out_duplicate;
And this would emit "Filesystem has duplicate UUID" which is not correct.
But anyway, the __GFP_NOFAIL in the call makes this all moot AFAICT.
-Eric
Hi Eric,
Sorry for neglecting __GFP_NOFAIL symbol, and I would add a WARN in
memory failure next time.
Thanks for your advice！
+ xfs_uuid_table = if_xfs_uuid_table;
hole = xfs_uuid_table_size++;
}
xfs_uuid_table[hole] = *uuid;
.
