linux.git/fs/logfs/dev_mtd.c, branch v4.6

mm, fs: get rid of PAGE_CACHE_* and page_cache_{get,release} macros

2016-04-04T17:41:08+00:00

PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} macros were introduced *long* time
ago with promise that one day it will be possible to implement page
cache with bigger chunks than PAGE_SIZE.

This promise never materialized.  And unlikely will.

We have many places where PAGE_CACHE_SIZE assumed to be equal to
PAGE_SIZE.  And it's constant source of confusion on whether
PAGE_CACHE_* or PAGE_* constant should be used in a particular case,
especially on the border between fs and mm.

Global switching to PAGE_CACHE_SIZE != PAGE_SIZE would cause to much
breakage to be doable.

Let's stop pretending that pages in page cache are special.  They are
not.

The changes are pretty straight-forward:

 -  << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ;

 -  >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> ;

 - PAGE_CACHE_{SIZE,SHIFT,MASK,ALIGN} -> PAGE_{SIZE,SHIFT,MASK,ALIGN};

 - page_cache_get() -> get_page();

 - page_cache_release() -> put_page();

This patch contains automated changes generated with coccinelle using
script below.  For some reason, coccinelle doesn't patch header files.
I've called spatch for them manually.

The only adjustment after coccinelle is revert of changes to
PAGE_CAHCE_ALIGN definition: we are going to drop it later.

There are few places in the code where coccinelle didn't reach.  I'll
fix them manually in a separate patch.  Comments and documentation also
will be addressed with the separate patch.

virtual patch

@@
expression E;
@@
- E << (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
expression E;
@@
- E >> (PAGE_CACHE_SHIFT - PAGE_SHIFT)
+ E

@@
@@
- PAGE_CACHE_SHIFT
+ PAGE_SHIFT

@@
@@
- PAGE_CACHE_SIZE
+ PAGE_SIZE

@@
@@
- PAGE_CACHE_MASK
+ PAGE_MASK

@@
expression E;
@@
- PAGE_CACHE_ALIGN(E)
+ PAGE_ALIGN(E)

@@
expression E;
@@
- page_cache_get(E)
+ get_page(E)

@@
expression E;
@@
- page_cache_release(E)
+ put_page(E)

Signed-off-by: Kirill A. Shutemov 
Acked-by: Michal Hocko 
Signed-off-by: Linus Torvalds

mtd: fix merge conflict resolution breakage

2012-02-01T19:10:24+00:00

This patch fixes merge conflict resolution breakage introduced by merge
d3712b9dfcf4 ("Merge tag 'for-linus' of git://github.com/prasad-joshi/logfs_upstream").

The commit changed 'mtd_can_have_bb()' function and made it always
return zero, which is incorrect.  Instead, we need it to return whether
the underlying flash device can have bad eraseblocks or not.  UBI needs
this information because it affects how it handles the underlying flash.
E.g., if the underlying flash is NOR, it cannot have bad blocks and any
write or erase error is fatal, and all we can do is to switch to R/O
mode.  We do not need to reserve a pool of good eraseblocks for bad
eraseblocks handling, and so on.

This patch also removes 'mtd_can_have_bb()' invocations from Logfs to
ensure correct Logfs behavior.

I've tested that with this patch UBI works on top of NOR and NAND
flashes emulated by mtdram and nandsim correspondingly.

This patch is based on patch from Linus Torvalds.

Signed-off-by: Artem Bityutskiy 
Acked-by: Jörn Engel 
Acked-by: Prasad Joshi 
Acked-by: Brian Norris 
Signed-off-by: Linus Torvalds

logfs: do not use 'mtd->block_isbad' directly

2012-01-09T18:26:25+00:00

Instead, use the new 'mtd_can_have_bb()' helper.

Cc: Jörn Engel 
Signed-off-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse

mtd: do not use mtd->sync directly

2012-01-09T18:26:21+00:00

This patch teaches 'mtd_sync()' to do nothing when the MTD driver does
not have the '->sync()' method, which allows us to remove all direct
'mtd->sync' accesses.

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

mtd: introduce mtd_block_isbad interface

2012-01-09T18:25:47+00:00

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

mtd: introduce mtd_sync interface

2012-01-09T18:25:35+00:00

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

mtd: introduce mtd_write interface

2012-01-09T18:25:20+00:00

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

mtd: introduce mtd_read interface

2012-01-09T18:25:19+00:00

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

mtd: introduce mtd_erase interface

2012-01-09T18:25:11+00:00

This patch is part of a patch-set which changes the MTD interface
from 'mtd->func()' form to 'mtd_func()' form. We need this because
we want to add common code to to all drivers in the mtd core level,
which is impossible with the current interface when MTD clients
call driver functions like 'read()' or 'write()' directly.

At this point we just introduce a new inline wrapper function, but
later some of them are expected to gain more code. E.g., the input
parameters check should be moved to the wrappers rather than be
duplicated at many drivers.

This particular patch introduced the 'mtd_erase()' interface. The
following patches add all the other interfaces one by one.

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

logfs: rename functions starting with mtd_

2012-01-09T18:24:54+00:00

We are going to re-work the MTD interface and change 'mtd->write()' to
'mtd_write()', 'mtd->read()' to 'mtd_read()' and so forth for all functions
in the 'struct mtd_info' structure.

However, logfs has its own 'mtd_read()', 'mtd_write()', etc functions
which collide with our changes. This patch renames these logfs functions
to 'logfs_mtd_read()', 'logfs_mtd_write()', etc.

Additionally, to make the 'fs/logfs/dev_mtd.c' file look consistent, rename
similarly all the other functions starting with 'mtd_'.

Cc: Jörn Engel 
Signed-off-by: Artem Bityutskiy 
Signed-off-by: David Woodhouse