linux/drivers/md, branch v3.2.18

MD: Add del_timer_sync to mddev_suspend (fix nasty panic)

2012-05-20T21:56:50Z

commit 0d9f4f135eb6dea06bdcb7065b1e4ff78274a5e9 upstream. Use del_timer_sync to remove timer before mddev_suspend finishes. We don't want a timer going off after an mddev_suspend is called. This is especially true with device-mapper, since it can call the destructor function immediately following a suspend. This results in the removal (kfree) of the structures upon which the timer depends - resulting in a very ugly panic. Therefore, we add a del_timer_sync to mddev_suspend to prevent this. Signed-off-by: NeilBrown Signed-off-by: Ben Hutchings

dm mpath: check if scsi_dh module already loaded before trying to load

2012-05-20T21:56:42Z

commit 510193a2d3d2e03ae53b95c0ae4f33cdff02cbf8 upstream. If the requested scsi_dh module is already loaded then skip request_module(). Multipath table loads can hang in an unnecessary __request_module. Reported-by: Ben Marzinski Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon Signed-off-by: Ben Hutchings

md: fix possible corruption of array metadata on shutdown.

2012-05-11T12:13:59Z

commit 30b8aa9172dfeaac6d77897c67ee9f9fc574cdbb upstream. commit c744a65c1e2d59acc54333ce8 md: don't set md arrays to readonly on shutdown. removed the possibility of a 'BUG' when data is written to an array that has just been switched to read-only, but also introduced the possibility that the array metadata could be corrupted. If, when md_notify_reboot gets the mddev lock, the array is in a state where it is assembled but hasn't been started (as can happen if the personality module is not available, or in other unusual situations), then incorrect metadata will be written out making it impossible to re-assemble the array. So only call __md_stop_writes() if the array has actually been activated. This patch is needed for any stable kernel which has had the above commit applied. Reported-by: Christoph Nelles Signed-off-by: NeilBrown Signed-off-by: Ben Hutchings

md/bitmap: prevent bitmap_daemon_work running while initialising bitmap

2012-04-22T22:30:58Z

commit afbaa90b80b1ec66e5137cc3824746bfdf559b18 upstream. If a bitmap is added while the array is active, it is possible for bitmap_daemon_work to run while the bitmap is being initialised. This is particularly a problem if bitmap_daemon_work sees bitmap->filemap as non-NULL before it has been filled in properly. So hold bitmap_info.mutex while filling in ->filemap to prevent problems. This patch is suitable for any -stable kernel, though it might not apply cleanly before about 3.1. Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman

dm thin: fix stacked bi_next usage

2012-04-02T16:53:06Z

commit 6f94a4c45a6f744383f9f695dde019998db3df55 upstream. Avoid using the bi_next field for the holder of a cell when deferring bios because a stacked device below might change it. Store the holder in a new field in struct cell instead. When a cell is created, the bio that triggered creation (the holder) was added to the same bio list as subsequent bios. In some cases we pass this holder bio directly to devices underneath. If those devices use the bi_next field there will be trouble... This also simplifies some code that had to work out which bio was the holder. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon Signed-off-by: Greg Kroah-Hartman

dm persistent data: fix btree rebalancing after remove

2012-04-02T16:53:05Z

commit b0988900bae9ecf968a8a8d086a9eec671a9517a upstream. When we remove an entry from a node we sometimes rebalance with it's two neighbours. This wasn't being done correctly; in some cases entries have to move all the way from the right neighbour to the left neighbour, or vice versa. This patch pretty much re-writes the balancing code to fix it. This code is barely used currently; only when you delete a thin device, and then only if you have hundreds of them in the same pool. Once we have discard support, which removes mappings, this will be used much more heavily. Signed-off-by: Joe Thornber Signed-off-by: Mike Snitzer Signed-off-by: Alasdair G Kergon Signed-off-by: Greg Kroah-Hartman

dm exception store: fix init error path

2012-04-02T16:53:05Z

commit aadbe266f2f89ccc68b52f4effc7b3a8b29521ef upstream. Call the correct exit function on failure in dm_exception_store_init. Signed-off-by: Andrei Warkentin Acked-by: Mike Snitzer Signed-off-by: Alasdair G Kergon Signed-off-by: Greg Kroah-Hartman

dm crypt: add missing error handling

2012-04-02T16:53:05Z

commit 72c6e7afc43e19f68a31dea204fc366624d6eee9 upstream. Always set io->error to -EIO when an error is detected in dm-crypt. There were cases where an error code would be set only if we finish processing the last sector. If there were other encryption operations in flight, the error would be ignored and bio would be returned with success as if no error happened. This bug is present in kcryptd_crypt_write_convert, kcryptd_crypt_read_convert and kcryptd_async_done. Signed-off-by: Mikulas Patocka Reviewed-by: Milan Broz Signed-off-by: Alasdair G Kergon Signed-off-by: Greg Kroah-Hartman

dm crypt: fix mempool deadlock

2012-04-02T16:53:05Z

commit aeb2deae2660a1773c83d3c6e9e6575daa3855d6 upstream. This patch fixes a possible deadlock in dm-crypt's mempool use. Currently, dm-crypt reserves a mempool of MIN_BIO_PAGES reserved pages. It allocates first MIN_BIO_PAGES with non-failing allocation (the allocation cannot fail and waits until the mempool is refilled). Further pages are allocated with different gfp flags that allow failing. Because allocations may be done in parallel, this code can deadlock. Example: There are two processes, each tries to allocate MIN_BIO_PAGES and the processes run simultaneously. It may end up in a situation where each process allocates (MIN_BIO_PAGES / 2) pages. The mempool is exhausted. Each process waits for more pages to be freed to the mempool, which never happens. To avoid this deadlock scenario, this patch changes the code so that only the first page is allocated with non-failing gfp mask. Allocation of further pages may fail. Signed-off-by: Mikulas Patocka Signed-off-by: Milan Broz Signed-off-by: Alasdair G Kergon Signed-off-by: Greg Kroah-Hartman

md: fix clearing of the 'changed' flags for the bad blocks list.

2012-04-02T16:52:46Z

commit d0962936bff659d20522555b517582a2715fd23f upstream. In super_1_sync (the first hunk) we need to clear 'changed' before checking read_seqretry(), otherwise we might race with other code adding a bad block and so won't retry later. In md_update_sb (the second hunk), in the case where there is no metadata (neither persistent nor external), we treat any bad blocks as an error. However we need to clear the 'changed' flag before calling md_ack_all_badblocks, else it won't do anything. This patch is suitable for -stable release 3.0 and later. Signed-off-by: NeilBrown Signed-off-by: Greg Kroah-Hartman