Commit Graph

2 Commits

Author SHA1 Message Date
Alexey Dobriyan
99b7623380 proc 2/2: remove struct proc_dir_entry::owner
Setting ->owner as done currently (pde->owner = THIS_MODULE) is racy
as correctly noted at bug #12454. Someone can lookup entry with NULL
->owner, thus not pinning enything, and release it later resulting
in module refcount underflow.

We can keep ->owner and supply it at registration time like ->proc_fops
and ->data.

But this leaves ->owner as easy-manipulative field (just one C assignment)
and somebody will forget to unpin previous/pin current module when
switching ->owner. ->proc_fops is declared as "const" which should give
some thoughts.

->read_proc/->write_proc were just fixed to not require ->owner for
protection.

rmmod'ed directories will be empty and return "." and ".." -- no harm.
And directories with tricky enough readdir and lookup shouldn't be modular.
We definitely don't want such modular code.

Removing ->owner will also make PDE smaller.

So, let's nuke it.

Kudos to Jeff Layton for reminding about this, let's say, oversight.

http://bugzilla.kernel.org/show_bug.cgi?id=12454

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
2009-03-31 01:14:44 +04:00
Geert Uytterhoeven
f507cd2203 ps3/block: Replace mtd/ps3vram by block/ps3vram
Convert the PS3 Video RAM Storage Driver from an MTD driver to a plain block
device driver.

The ps3vram driver exposes unused video RAM on the PS3 as a block device
suitable for storage or swap.  Fast data transfer is achieved using a local
cache in system RAM and DMA transfers via the GPU.

The new driver is ca. 50% faster for reading, and ca. 10% for writing.

Signed-off-by: Geert Uytterhoeven <Geert.Uytterhoeven@sonycom.com>
Acked-by: Geoff Levand <geoffrey.levand@am.sony.com>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>
2009-03-13 16:07:19 +11:00