linux.git/fs/nilfs2/bmap.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

nilfs2: add bmap function to seek a valid key

2015-04-17T13:04:03+00:00

Add a new bmap function, nilfs_bmap_seek_key(), which seeks a valid
entry and returns its key starting from a given key.  This function
can be used to skip hole blocks efficiently.

Signed-off-by: Ryusuke Konishi 
Cc: Dan Carpenter 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

nilfs2: unify type of key arguments in bmap interface

2015-04-17T13:04:03+00:00

The type of key arguments in block mapping interface varies depending
on function.  For instance, nilfs_bmap_lookup_at_level() takes "__u64"
for its key argument whereas nilfs_bmap_lookup() takes "unsigned
long".

This fits them to "__u64" to eliminate the variation.

Signed-off-by: Ryusuke Konishi 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

nilfs2: get rid of NILFS_I_NILFS

2011-05-10T13:21:56+00:00

This replaces all references of NILFS_I_NILFS(inode)->ns_bdev with
inode->i_sb->s_bdev and unfolds remaining uses of NILFS_I_NILFS inline
function.

Before 2.6.37, referring to a nilfs object from inodes needed a
conditional judgement, and NILFS_I_NILFS was helpful to simplify it.
But now we can simply do it by going through a super block instance
like inode->i_sb->s_fs_info.

Signed-off-by: Ryusuke Konishi

nilfs2: get rid of nilfs_sb_info structure

2011-03-09T02:54:26+00:00

This directly uses sb->s_fs_info to keep a nilfs filesystem object and
fully removes the intermediate nilfs_sb_info structure.  With this
change, the hierarchy of on-memory structures of nilfs will be
simplified as follows:

Before:
  super_block
       -> nilfs_sb_info
             -> the_nilfs
                   -> cptree --+-> nilfs_root (current file system)
                               +-> nilfs_root (snapshot A)
                               +-> nilfs_root (snapshot B)
                               :
             -> nilfs_sc_info (log writer structure)
After:
  super_block
       -> the_nilfs
             -> cptree --+-> nilfs_root (current file system)
                         +-> nilfs_root (snapshot A)
                         +-> nilfs_root (snapshot B)
                         :
             -> nilfs_sc_info (log writer structure)

The reason why we didn't design so from the beginning is because the
initial shape also differed from the above.  The early hierachy was
composed of "per-mount-point" super_block -> nilfs_sb_info pairs and a
shared nilfs object.  On the kernel 2.6.37, it was changed to the
current shape in order to unify super block instances into one per
device, and this cleanup became applicable as the result.

Signed-off-by: Ryusuke Konishi

nilfs2: record used amount of each checkpoint in checkpoint list

2011-03-08T05:58:31+00:00

This records the number of used blocks per checkpoint in each
checkpoint entry of cpfile.  Even though userland tools can get the
block count via nilfs_get_cpinfo ioctl, it was not updated by the
nilfs2 kernel code.  This fixes the issue and makes it available for
userland tools to calculate used amount per checkpoint.

Signed-off-by: Ryusuke Konishi 
Cc: Jiro SEKIBA

nilfs2: unfold nilfs_dat_inode function

2011-01-10T05:38:39+00:00

nilfs_dat_inode function was a wrapper to switch between normal dat
inode and gcdat, a clone of the dat inode for garbage collection.

This function got obsolete when the gcdat inode was removed, and now
we can access the dat inode directly from a nilfs object.  So, we will
unfold the wrapper and remove it.

Signed-off-by: Ryusuke Konishi

nilfs2: call nilfs_error inside bmap routines

2011-01-10T05:05:45+00:00

Some functions using nilfs bmap routines can wrongly return invalid
argument error (i.e. -EINVAL) that bmap returns as an internal code
for btree corruption.

This fixes the issue by catching and converting the internal EINVAL to
EIO and calling nilfs_error function inside bmap routines.

Signed-off-by: Ryusuke Konishi

nilfs2: get rid of GCDAT inode

2010-10-23T00:24:38+00:00

This applies prepared rollback function and redirect function of
metadata file to DAT file, and eliminates GCDAT inode.

Signed-off-by: Ryusuke Konishi

nilfs2: add routines to save and restore bmap state

2010-10-23T00:24:37+00:00

This adds routines to save and restore the state of bmap structure.
The bmap state is stored in a given nilfs_bmap_store object.

These routines will be used to roll back the state of dat inode
without using gcdat inode.

Signed-off-by: Ryusuke Konishi