Re: [PATCH 0/2] rsxx: Two important bug fixes for the rsxx blockdriver.

From: Jens Axboe
Date: Wed Oct 23 2013 - 07:25:48 EST


On Fri, Oct 18 2013, Philip J. Kelleher wrote:
> The incoming patches are for the rsxx driver (drivers/block/rsxx)
>
> Patch1:
> This patch fixes a bug in which discards were always
> calling pci_unmap_page. Discards should never call the
> pci_unmap_page function call because they are never mapped.
>
> This caused a race condition on PowerPC systems when issuing
> discards, writes, and reads all at the same time. The
> pci_map_page function would eventually map logical address
> 0 for a read or write. Discards are always assigned a DMA
> address of 0 because they are never mapped. So if
> pci_map_page mapped address 0 for a DMA and a discard was
> "unmapped" then the address would be freed and would cause
> an EEH event to occur when Hardware accesses the address.
>
> This was injected/uncovered in commit:
> b347f9cf0bc8d42ee95ba1d3837fd93045ab336b
>
> The pci_dma_mapping_error function declares -1 a DMA_ERROR
> not 0 like initially thought.
>
> This patch should fall on top of commit id:
> fc1967bb08a6184ed44ef990e1dd4389901b809c
>
>
> Patch2:
> This patch fixes a possible Kernel Panic on driver load if
> the configuration on the card is messed up or not yet set.
> The driver could possible give a 32 bit unsigned all Fs to
> the kernel as the device's block size.
>
> Now we only write the block size to the kernel if the
> configuration from the card is valid.

Applied both for 3.13. Please stop putting that ----- line at the end of
your patches. It goes into the git commit messages and just makes
everything look ugly, I have to fix those up manually.

--
Jens Axboe

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