linux-toradex.git/drivers/mtd/mtd_blkdevs.c, branch v3.11

block_device_operations->release() should return void

2013-05-07T06:16:21+00:00

The value passed is 0 in all but "it can never happen" cases (and those
only in a couple of drivers) *and* it would've been lost on the way
out anyway, even if something tried to pass something meaningful.
Just don't bother.

Signed-off-by: Al Viro

mtd_blktrans_ops->release() should return void

2013-05-06T01:31:22+00:00

Both existing instances always return 0 and even if they didn't,
the value would be lost on the way out.  Just don't bother...

Signed-off-by: Al Viro

mtd: mtd_blkdevs: Replace request handler kthread with a workqueue

2012-11-21T15:02:23+00:00

By replacing a kthread with a workqueue, the code is now a bit clearer.
There's also a slight reduction of code size (numbers apply for x86):
Before:
   text	   data	    bss	    dec	    hex	filename
   3248	     36	      0	   3284	    cd4	drivers/mtd/mtd_blkdevs.o

After:
   text	   data	    bss	    dec	    hex	filename
   3150	     36	      0	   3186	    c72	drivers/mtd/mtd_blkdevs.o

Due to lack of real hardware, tests have been performed on an emulated
environment with mtdswap and mtdblock over nandsim devices.
Some real testing should be done, before merging this patch.

Signed-off-by: Ezequiel Garcia 
Signed-off-by: Artem Bityutskiy

mtd: mtd_blkdev: Use a different name for block_device_operations variable

2012-11-21T15:02:05+00:00

struct mtd_blktrans_ops is a type, and mtd_blktrans_ops is a variable.
To improve code clarity it's better to not use the same names,
so we just change the latter.

Signed-off-by: Ezequiel Garcia 
Signed-off-by: Artem Bityutskiy

mtd: mtdblock: call mtd_sync() only if opened for write

2012-03-26T23:11:11+00:00

Because it is useless to call it if the device is opened in R/O mode, and also
harmful: on CFI NOR flash it may block for long time waiting for erase
operations to complete is another partition with a R/W file-system on this
chip.

Artem Bityutskiy: write commit message, amend the patch to match the latest
tree (we use mtd_sync(), not mtd->sync() nowadays).

Signed-off-by: Alexander Stein 
Signed-off-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse

mtd: mtd_blkdevs: don't increase 'open' count on error path

2012-01-09T18:04:01+00:00

Some error paths in mtd_blkdevs were fixed in the following commit:

    commit 94735ec4044a6d318b83ad3c5794e931ed168d10
    mtd: mtd_blkdevs: fix error path in blktrans_open

But on these error paths, the block device's `dev->open' count is
already incremented before we check for errors. This meant that, while
the error path was handled correctly on the first time through
blktrans_open(), the device is erroneously considered already open on
the second time through.

This problem can be seen, for instance, when a UBI volume is
simultaneously mounted as a UBIFS partition and read through its
corresponding gluebi mtdblockX device. This results in blktrans_open()
passing its error checks (with `dev->open > 0') without actually having
a handle on the device. Here's a summarized log of the actions and
results with nandsim:

    # modprobe nandsim
    # modprobe mtdblock
    # modprobe gluebi
    # modprobe ubifs
    # ubiattach /dev/ubi_ctrl -m 0
    ...
    # ubimkvol /dev/ubi0 -N test -s 16MiB
    ...
    # mount -t ubifs ubi0:test /mnt
    # ls /dev/mtdblock*
    /dev/mtdblock0  /dev/mtdblock1
    # cat /dev/mtdblock1 > /dev/null
    cat: can't open '/dev/mtdblock4': Device or resource busy
    # cat /dev/mtdblock1 > /dev/null

    CPU 0 Unable to handle kernel paging request at virtual address
    fffffff0, epc == 8031536c, ra == 8031f280
    Oops[#1]:
    ...
    Call Trace:
    [<8031536c>] ubi_leb_read+0x14/0x164
    [<8031f280>] gluebi_read+0xf0/0x148
    [<802edba8>] mtdblock_readsect+0x64/0x198
    [<802ecfe4>] mtd_blktrans_thread+0x330/0x3f4
    [<8005be98>] kthread+0x88/0x90
    [<8000bc04>] kernel_thread_helper+0x10/0x18

Cc: stable@kernel.org [3.0+]
Signed-off-by: Brian Norris 
Signed-off-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse

mtd: mark block device queue as non-rotational

2011-10-14T08:22:48+00:00

This is similar to what the nbd driver does, among others.

Signed-off-by: Dan McGee 
Signed-off-by: Artem Bityutskiy

mtd: mtd_blkdevs: fix error path in blktrans_open

2011-05-25T00:53:45+00:00

The 'blktrans_open()' does not handle possible '__get_mtd_device()' failures
because it does not check the error code. Moreover, the 'dev->tr->open()'
failures are not handled correctly because in this case the function just
goes ahead and gets the mtd device, then returns an error. But Instead, it
should _not_ try to get the mtd device, then it should put back the module
and the kref.

This patch fixes the issue. Note, I only compile-tested it. This patch was
inspired by a bug report about a similar issue in 2.6.34 kernels
sent by Mike Turner  to the MTD mailing list:

http://lists.infradead.org/pipermail/linux-mtd/2011-April/034980.html

Signed-off-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse

Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6 into for-linus-1

2011-03-25T15:41:20+00:00

* 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6: (9356 commits)
  [media] rc: update for bitop name changes
  fs: simplify iget & friends
  fs: pull inode->i_lock up out of writeback_single_inode
  fs: rename inode_lock to inode_hash_lock
  fs: move i_wb_list out from under inode_lock
  fs: move i_sb_list out from under inode_lock
  fs: remove inode_lock from iput_final and prune_icache
  fs: Lock the inode LRU list separately
  fs: factor inode disposal
  fs: protect inode->i_state with inode->i_lock
  lib, arch: add filter argument to show_mem and fix private implementations
  SLUB: Write to per cpu data when allocating it
  slub: Fix debugobjects with lockless fastpath
  autofs4: Do not potentially dereference NULL pointer returned by fget() in autofs_dev_ioctl_setpipefd()
  autofs4 - remove autofs4_lock
  autofs4 - fix d_manage() return on rcu-walk
  autofs4 - fix autofs4_expire_indirect() traversal
  autofs4 - fix dentry leak in autofs4_expire_direct()
  autofs4 - reinstate last used update on access
  vfs - check non-mountpoint dentry might block in __follow_mount_rcu()
  ...

NOTE!

This merge commit was created to fix compilation error. The block
tree was merged upstream and removed the 'elv_queue_empty()'
function which the new 'mtdswap' driver is using. So a simple
merge of the mtd tree with upstream does not compile. And the
mtd tree has already be published, so re-basing it is not an option.

To fix this unfortunate situation, I had to merge upstream into the
mtd-2.6.git tree without committing, put the fixup patch on top of
this, and then commit this. The result is that we do not have commits
which do not compile.

In other words, this merge commit "merges" 3 things: the MTD tree, the
upstream tree, and the fixup patch.

mtd_blkdevs: Set the maximum discards size

2011-03-11T14:22:46+00:00

Set max_discard_sectors to UINT_MAX.

Signed-off-by: Jarkko Lavinen 
Tested-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse