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Johannes Thumshirn
3b4f6966d7
[ Upstream commit7ce3e61071] We have two reports of failed memory allocation in btrfs' code which is calling into report zones. Both of these reports have the following signature coming from __vmalloc_area_node(): kworker/u17:5: vmalloc error: size 0, failed to allocate pages, mode:0x10dc2(GFP_KERNEL|__GFP_HIGHMEM|__GFP_NORETRY|__GFP_ZERO), nodemask=(null),cpuset=/,mems_allowed=0 Further debugging showed these where allocations of one sector (512 bytes) and at least one of the reporter's systems where low on memory, so going through the overhead of allocating a vm area failed. Switching the allocation from __vmalloc() to kvzalloc() avoids the overhead of vmalloc() on small allocations and succeeds. Note: the buffer is already freed using kvfree() so there's no need to adjust the free path. Cc: Qu Wenru <wqu@suse.com> Cc: Naohiro Aota <naohiro.aota@wdc.com> Link: https://github.com/kdave/btrfs-progs/issues/779 Link: https://github.com/kdave/btrfs-progs/issues/915 Fixes:23a50861ad("scsi: sd_zbc: Cleanup sd_zbc_alloc_report_buffer()") Signed-off-by: Johannes Thumshirn <johannes.thumshirn@wdc.com> Link: https://lore.kernel.org/r/20241030110253.11718-1-jth@kernel.org Reviewed-by: Damien Le Moal <dlemoal@kernel.org> Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com> Signed-off-by: Sasha Levin <sashal@kernel.org>