Re: [added to the 4.1 stable tree] xfs: Don't wrap growfs AGFL indexes

On 06/03/2016 07:05 PM, Dave Chinner wrote:

On Fri, Jun 03, 2016 at 05:35:03PM -0400, Sasha Levin wrote:

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From: Dave Chinner <redacted>

This patch has been added to the 4.1 stable tree. If you have any
objections, please let us know.

This should not go to the 4.1 tree. Check the stable notification
information, please:

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[ Upstream commit ad747e3b299671e1a53db74963cc6c5f6cdb9f6d ]

....

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cc: <redacted> # 4.4-4.5

It says 4.4 and 4.5 only.

That's correct, but the commit that this patch fixes was:

commit 96f859d52bcb1c6ea6f3388d39862bf7143e2f30
Author: Darrick J. Wong [off-list ref]
Date:   Mon Jan 4 16:13:21 2016 +1100

    libxfs: pack the agfl header structure so XFS_AGFL_SIZE is correct

    Because struct xfs_agfl is 36 bytes long and has a 64-bit integer
    inside it, gcc will quietly round the structure size up to the nearest
    64 bits -- in this case, 40 bytes.  This results in the XFS_AGFL_SIZE
    macro returning incorrect results for v5 filesystems on 64-bit
    machines (118 items instead of 119).  As a result, a 32-bit xfs_repair
    will see garbage in AGFL item 119 and complain.

    Therefore, tell gcc not to pad the structure so that the AGFL size
    calculation is correct.

    cc: [off-list ref] # 3.10 - 4.4
    Signed-off-by: Darrick J. Wong [off-list ref]
    Reviewed-by: Dave Chinner [off-list ref]
    Signed-off-by: Dave Chinner [off-list ref]

Which, as you see, was marked for and backported to -stable versions
prior to 4.4, which is why I've preferred to queue this commit even though
it's not supposed to go in and see if anyone objects.


Thanks,
Sasha