kernel/linux.git/drivers/md/linear.c, branch v2.6.28

md: linear: Fix a division by zero bug for very small arrays.

2008-11-06T08:41:24+00:00

We currently oops with a divide error on starting a linear software raid array consisting of at least two very small (< 500K) devices. The bug is caused by the calculation of the hash table size which tries to compute sector_div(sz, base) with "base" being zero due to the small size of the component devices of the array. Fix this by requiring the hash spacing to be at least one which implies that also "base" is non-zero. This bug has existed since about 2.6.14. Cc: stable@kernel.org Signed-off-by: Andre Noll Signed-off-by: NeilBrown

md: Remove unnecessary #includes, #defines, and function declarations.

2008-10-13T00:55:12+00:00

A lot of cruft has gathered over the years. Time to remove it. Signed-off-by: NeilBrown

md: Convert remaining 1k representations in linear.c to sectors.

2008-10-13T00:55:12+00:00

This patch renames hash_spacing and preshift to spacing and sector_shift respectively with the following change of semantics: Case 1: (sizeof(sector_t) <= sizeof(u32)). ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ In this case, we have sector_shift = preshift = 0 and spacing = 2 * hash_spacing. Hence, the index for the hash table which is computed by the new code in which_dev() as sector / spacing equals the old value which was (sector/2) / hash_spacing. Note also that the value of nb_zone stays the same because both sz and base double. Case 2: (sizeof(sector_t) > sizeof(u32)). ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ (aka the shifting dance case). Here we have sector_shift = preshift + 1 and spacing = 2 * hash_spacing during the computation of nb_zone and curr_sector, but spacing = hash_spacing in which_dev() because in the last hunk of the patch for linear.c we shift down conf->spacing (= 2 * hash_spacing) by one more bit than in the old code. Hence in the computation of nb_zone, sz and base have the same value as before, so nb_zone is not affected. Also curr_sector in the next hunk stays the same. In which_dev() the hash table index is computed as (sector >> sector_shift) / spacing In view of sector_shift = preshift + 1 and spacing = hash_spacing, this equals ((sector/2) >> preshift) / hash_spacing which is the value computed by the old code. Signed-off-by: Andre Noll Signed-off-by: NeilBrown

md: linear.c: Make two local variables sector-based.

2008-10-13T00:55:12+00:00

This is a preparation for representing also the remaining fields of struct linear_private_data as sectors. Signed-off-by: Andre Noll Signed-off-by: NeilBrown

md: linear: Represent dev_info->size and dev_info->offset in sectors.

2008-10-13T00:55:12+00:00

Rename them to num_sectors and start_sector which is more descriptive. Signed-off-by: Andre Noll Signed-off-by: NeilBrown

md: linear.c: Remove broken debug code.

2008-10-13T00:55:12+00:00

conf->smallest_size is undefined since day one of the git repo.. Signed-off-by: Andre Noll Signed-off-by: NeilBrown

md: linear.c: Remove pointless initialization of curr_offset.

2008-10-13T00:55:12+00:00

Signed-off-by: Andre Noll Signed-off-by: NeilBrown

md: linear.c: Fix typo in comment.

2008-10-13T00:55:12+00:00

Signed-off-by: Andre Noll Signed-off-by: NeilBrown

block: mark bio_split_pool static

2008-10-09T06:57:05+00:00

Since all bio_split calls refer the same single bio_split_pool, the bio_split function can use bio_split_pool directly instead of the mempool_t parameter; then the mempool_t parameter can be removed from bio_split param list, and bio_split_pool is only referred in fs/bio.c file, can be marked static. Signed-off-by: Denis ChengRq Signed-off-by: Jens Axboe

block: move stats from disk to part0

2008-10-09T06:56:08+00:00

Move stats related fields - stamp, in_flight, dkstats - from disk to part0 and unify stat handling such that... * part_stat_*() now updates part0 together if the specified partition is not part0. ie. part_stat_*() are now essentially all_stat_*(). * {disk|all}_stat_*() are gone. * part_round_stats() is updated similary. It handles part0 stats automatically and disk_round_stats() is killed. * part_{inc|dec}_in_fligh() is implemented which automatically updates part0 stats for parts other than part0. * disk_map_sector_rcu() is updated to return part0 if no part matches. Combined with the above changes, this makes NULL special case handling in callers unnecessary. * Separate stats show code paths for disk are collapsed into part stats show code paths. * Rename disk_stat_lock/unlock() to part_stat_lock/unlock() While at it, reposition stat handling macros a bit and add missing parentheses around macro parameters. Signed-off-by: Tejun Heo Signed-off-by: Jens Axboe