linux.git/fs/proc/inode.c, branch v5.3

fs/proc/inode.c: use typeof_member() macro

2019-07-17T02:23:21+00:00

Don't repeat function signatures twice.

This is a kind-of-precursor for "struct proc_ops".

Note:

	typeof(pde->proc_fops->...) ...;

can't be used because ->proc_fops is "const struct file_operations *".
"const" prevents assignment down the code and it can't be deleted in the
type system.

Link: http://lkml.kernel.org/r/20190529191110.GB5703@avx2
Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

procfs: switch to ->free_inode()

2019-05-02T02:43:25+00:00

Signed-off-by: Al Viro

proc: Add fs_context support to procfs

2019-02-28T08:29:28+00:00

Add fs_context support to procfs.

Signed-off-by: David Howells 
cc: Alexey Dobriyan 
Signed-off-by: Al Viro

procfs: Move proc_fill_super() to fs/proc/root.c

2019-02-28T08:29:27+00:00

Move proc_fill_super() to fs/proc/root.c as that's where the other
superblock stuff is.

Signed-off-by: David Howells 
Reviewed-by: Alexey Dobriyan 
cc: Alexey Dobriyan 
Signed-off-by: Al Viro

fs/proc/inode.c: delete unnecessary variable in proc_alloc_inode()

2019-01-04T21:13:45+00:00

Link: http://lkml.kernel.org/r/20181203164015.GA6904@avx2
Signed-off-by: Alexey Dobriyan 
Reviewed-by: Andrew Morton 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

mm: zero-seek shrinkers

2018-10-26T23:26:33+00:00

The page cache and most shrinkable slab caches hold data that has been
read from disk, but there are some caches that only cache CPU work, such
as the dentry and inode caches of procfs and sysfs, as well as the subset
of radix tree nodes that track non-resident page cache.

Currently, all these are shrunk at the same rate: using DEFAULT_SEEKS for
the shrinker's seeks setting tells the reclaim algorithm that for every
two page cache pages scanned it should scan one slab object.

This is a bogus setting.  A virtual inode that required no IO to create is
not twice as valuable as a page cache page; shadow cache entries with
eviction distances beyond the size of memory aren't either.

In most cases, the behavior in practice is still fine.  Such virtual
caches don't tend to grow and assert themselves aggressively, and usually
get picked up before they cause problems.  But there are scenarios where
that's not true.

Our database workloads suffer from two of those.  For one, their file
workingset is several times bigger than available memory, which has the
kernel aggressively create shadow page cache entries for the non-resident
parts of it.  The workingset code does tell the VM that most of these are
expendable, but the VM ends up balancing them 2:1 to cache pages as per
the seeks setting.  This is a huge waste of memory.

These workloads also deal with tens of thousands of open files and use
/proc for introspection, which ends up growing the proc_inode_cache to
absurdly large sizes - again at the cost of valuable cache space, which
isn't a reasonable trade-off, given that proc inodes can be re-created
without involving the disk.

This patch implements a "zero-seek" setting for shrinkers that results in
a target ratio of 0:1 between their objects and IO-backed caches.  This
allows such virtual caches to grow when memory is available (they do
cache/avoid CPU work after all), but effectively disables them as soon as
IO-backed objects are under pressure.

It then switches the shrinkers for procfs and sysfs metadata, as well as
excess page cache shadow nodes, to the new zero-seek setting.

Link: http://lkml.kernel.org/r/20181009184732.762-5-hannes@cmpxchg.org
Signed-off-by: Johannes Weiner 
Reported-by: Domas Mituzas 
Reviewed-by: Andrew Morton 
Reviewed-by: Rik van Riel 
Acked-by: Peter Zijlstra (Intel) 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

proc: fixup PDE allocation bloat

2018-08-22T17:52:45+00:00

24074a35c5c975 ("proc: Make inline name size calculation automatic")
started to put PDE allocations into kmalloc-256 which is unnecessary as
~40 character names are very rare.

Put allocation back into kmalloc-192 cache for 64-bit non-debug builds.

Put BUILD_BUG_ON to know when PDE size has gotten out of control.

[adobriyan@gmail.com: fix BUILD_BUG_ON breakage on powerpc64]
  Link: http://lkml.kernel.org/r/20180703191602.GA25521@avx2
Link: http://lkml.kernel.org/r/20180617215732.GA24688@avx2
Signed-off-by: Alexey Dobriyan 
Cc: David Howells 
Cc: Al Viro 
Cc: Stephen Rothwell 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

proc: Make inline name size calculation automatic

2018-06-15T04:48:57+00:00

Make calculation of the size of the inline name in struct proc_dir_entry
automatic, rather than having to manually encode the numbers and failing to
allow for lockdep.

Require a minimum inline name size of 33+1 to allow for names that look
like two hex numbers with a dash between.

Reported-by: Al Viro 
Signed-off-by: David Howells 
Signed-off-by: Al Viro

proc: move "struct proc_dir_entry" into kmem cache

2018-04-11T17:28:34+00:00

"struct proc_dir_entry" is variable sized because of 0-length trailing
array for name, however, because of SLAB padding allocations it is
possible to make "struct proc_dir_entry" fixed sized and allocate same
amount of memory.

It buys fine-grained debugging with poisoning and usercopy protection
which is not possible with kmalloc-* caches.

Currently, on 32-bit 91+ byte allocations go into kmalloc-128 and on
64-bit 147+ byte allocations go to kmalloc-192 anyway.

Additional memory is allocated only for 38/46+ byte long names which are
rare or may not even exist in the wild.

Link: http://lkml.kernel.org/r/20180223205504.GA17139@avx2
Signed-off-by: Alexey Dobriyan 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds

proc: account "struct pde_opener"

2018-04-11T17:28:33+00:00

The allocation is persistent in fact as any fool can open a file in
/proc and sit on it.

Link: http://lkml.kernel.org/r/20180214082409.GC17157@avx2
Signed-off-by: Alexey Dobriyan 
Cc: Al Viro 
Cc: Kees Cook 
Signed-off-by: Andrew Morton 
Signed-off-by: Linus Torvalds