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| author |  Dave Chinner <dchinner@redhat.com>
| 2012-10-09 14:50:52 +1100 |
|---|---|---|
| committer |  Ben Myers <bpm@sgi.com>
| 2012-11-02 15:42:35 -0500 |
| commit | 1375cb65e87b327a8dd4f920c3e3d837fb40e9c2 (patch) | |
| tree | 65864cb563db56e2bb8fe2e63f2c21d4e61a01c4 /fs/xfs/xfs_fsops.c | |
| parent | xfs: move allocation stack switch up to xfs_bmapi_allocate (diff) | |
| download | linux-1375cb65e87b327a8dd4f920c3e3d837fb40e9c2.tar.gz linux-1375cb65e87b327a8dd4f920c3e3d837fb40e9c2.tar.bz2 linux-1375cb65e87b327a8dd4f920c3e3d837fb40e9c2.zip | |
xfs: growfs: don't read garbage for new secondary superblocks
When updating new secondary superblocks in a growfs operation, the
superblock buffer is read from the newly grown region of the
underlying device. This is not guaranteed to be zero, so violates
the underlying assumption that the unused parts of superblocks are
zero filled. Get a new buffer for these secondary superblocks to
ensure that the unused regions are zero filled correctly.
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Signed-off-by: Ben Myers <bpm@sgi.com>
Diffstat (limited to 'fs/xfs/xfs_fsops.c')
| -rw-r--r-- | fs/xfs/xfs_fsops.c | 21 |
1 files changed, 19 insertions, 2 deletions
diff --git a/fs/xfs/xfs_fsops.c b/fs/xfs/xfs_fsops.c index c25b094efbf7..4beaede43277 100644 --- a/fs/xfs/xfs_fsops.c +++ b/fs/xfs/xfs_fsops.c @@ -399,9 +399,26 @@ xfs_growfs_data_private( /* update secondary superblocks. */ for (agno = 1; agno < nagcount; agno++) { - error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, + error = 0; + /* + * new secondary superblocks need to be zeroed, not read from + * disk as the contents of the new area we are growing into is + * completely unknown. + */ + if (agno < oagcount) { + error = xfs_trans_read_buf(mp, NULL, mp->m_ddev_targp, XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)), XFS_FSS_TO_BB(mp, 1), 0, &bp); + } else { + bp = xfs_trans_get_buf(NULL, mp->m_ddev_targp, + XFS_AGB_TO_DADDR(mp, agno, XFS_SB_BLOCK(mp)), + XFS_FSS_TO_BB(mp, 1), 0); + if (bp) + xfs_buf_zero(bp, 0, BBTOB(bp->b_length)); + else + error = ENOMEM; + } + if (error) { xfs_warn(mp, "error %d reading secondary superblock for ag %d", @@ -423,7 +440,7 @@ xfs_growfs_data_private( break; /* no point in continuing */ } } - return 0; + return error; error0: xfs_trans_cancel(tp, XFS_TRANS_ABORT); |