linux.git/fs/ufs, 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

kmemcg: account certain kmem allocations to memcg

2016-01-15T00:00:49+00:00

Mark those kmem allocations that are known to be easily triggered from
userspace as __GFP_ACCOUNT/SLAB_ACCOUNT, which makes them accounted to
memcg.  For the list, see below:

 - threadinfo
 - task_struct
 - task_delay_info
 - pid
 - cred
 - mm_struct
 - vm_area_struct and vm_region (nommu)
 - anon_vma and anon_vma_chain
 - signal_struct
 - sighand_struct
 - fs_struct
 - files_struct
 - fdtable and fdtable->full_fds_bits
 - dentry and external_name
 - inode for all filesystems. This is the most tedious part, because
   most filesystems overwrite the alloc_inode method.

The list is far from complete, so feel free to add more objects.
Nevertheless, it should be close to "account everything" approach and
keep most workloads within bounds.  Malevolent users will be able to
breach the limit, but this was possible even with the former "account
everything" approach (simply because it did not account everything in
fact).

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: Vladimir Davydov 
Acked-by: Johannes Weiner 
Acked-by: Michal Hocko 
Cc: Tejun Heo 
Cc: Greg Thelen 
Cc: Christoph Lameter 
Cc: Pekka Enberg 
Cc: David Rientjes 
Cc: Joonsoo Kim 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

don't put symlink bodies in pagecache into highmem

2015-12-09T03:41:36+00:00

kmap() in page_follow_link_light() needed to go - allowing to hold
an arbitrary number of kmaps for long is a great way to deadlocking
the system.

new helper (inode_nohighmem(inode)) needs to be used for pagecache
symlinks inodes; done for all in-tree cases.  page_follow_link_light()
instrumented to yell about anything missed.

Signed-off-by: Al Viro

ufs: get rid of ->setattr() for symlinks

2015-12-07T01:43:26+00:00

It was to needed for a couple of months in 2010, until UFS
quota support got dropped.  Since then it's equivalent to
simple_setattr() (i.e. the default) for everything except the
regular files.  And dropping it there allows to convert all
UFS symlinks to {page,simple}_symlink_inode_operations, getting
rid of fs/ufs/symlink.c completely.

Signed-off-by: Al Viro

fix ufs write vs readpage race when writing into a hole

2015-09-09T17:43:12+00:00

Followup to the UFS series - with the way we clear the new blocks (via
buffer cache, possibly on more than a page worth of file) we really
should not insert a reference to new block into inode block tree until
after we'd cleared it.

Signed-off-by: Al Viro 
Signed-off-by: Linus Torvalds

ufs_inode_get{frag,block}(): get rid of 'phys' argument

2015-07-06T21:40:05+00:00

Just pass NULL as locked_page in case of first block in the indirect
chain.  Old calling conventions aside, a reason for having 'phys'
was that ufs_inode_getfrag() used to be able to do _two_ allocations
- indirect block and extending/reallocating a tail.  We needed
locked_page for the latter (it's a data), but we also needed to
figure out that indirect block is metadata.  So we used to pass
non-NULL locked_page in all cases *and* used NULL phys as
indication of being asked to allocate an indirect.

With tail unpacking taken into a separate function we don't need
those convolutions anymore.

Signed-off-by: Al Viro

ufs_getfrag_block(): tidy up a bit

2015-07-06T21:40:04+00:00

Signed-off-by: Al Viro

ufs_inode_getblock(): failure to read an indirect block is -EIO

2015-07-06T21:40:03+00:00

... and not "write to beginning of the disk", TYVM...

Signed-off-by: Al Viro

ufs_getfrag_block(): turn following indirects into a loop

2015-07-06T21:40:02+00:00

Signed-off-by: Al Viro

ufs_inode_getfrag(): pass index instead of 'fragment'

2015-07-06T21:40:01+00:00

same story as with ufs_inode_getblock()

Signed-off-by: Al Viro