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author | Carlos Maiolino <cmaiolino@redhat.com> | 2012-09-20 13:32:36 (GMT) |
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committer | Ben Myers <bpm@sgi.com> | 2012-09-26 20:42:42 (GMT) |
commit | 8aea3ff411b2ce8fe7b46644298ed243a920eb24 (patch) | |
tree | 19a8f40bf1f8b8f48d1d77d29fb87020d8c17f81 /fs/xfs/xfs_alloc_btree.h | |
parent | c3a58fecdd1934a8538ada9073107625f5151687 (diff) | |
download | linux-fsl-qoriq-8aea3ff411b2ce8fe7b46644298ed243a920eb24.tar.xz |
xfs: Fix m_agirotor reset during AG selection
xfs_ialloc_next_ag() currently resets m_agirotor when it is equal to
m_maxagi:
if (++mp->m_agirotor == mp->m_maxagi)
mp->m_agirotor = 0;
But, if for some reason mp->m_maxagi changes to a lower value than
current m_agirotor, this condition will never be true, causing
m_agirotor to exceed the maximum allowed value (m_maxagi).
This implies mainly during lookups for xfs_perag structs in its radix
tree, since the agno value used for the lookup is based on m_agirotor.
An out-of-range m_agirotor may cause a lookup failure which in case will
return NULL.
As an example, the value of m_maxagi is decreased during
inode64->inode32 remount process, case where I've found this problem.
Signed-off-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Mark Tinguely <tinguely@sgi.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
Diffstat (limited to 'fs/xfs/xfs_alloc_btree.h')
0 files changed, 0 insertions, 0 deletions