All places outside of core VFS that checked ->read and ->write for being NULL or
called the methods directly are gone now, so NULL {read,write} with non-NULL
{read,write}_iter will do the right thing in all cases.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Add a new mount option which enables a new "lazytime" mode.  This mode
causes atime, mtime, and ctime updates to only be made to the
in-memory version of the inode.  The on-disk times will only get
updated when (a) if the inode needs to be updated for some non-time
related change, (b) if userspace calls fsync(), syncfs() or sync(), or
(c) just before an undeleted inode is evicted from memory.

This is OK according to POSIX because there are no guarantees after a
crash unless userspace explicitly requests via a fsync(2) call.

For workloads which feature a large number of random write to a
preallocated file, the lazytime mount option significantly reduces
writes to the inode table.  The repeated 4k writes to a single block
will result in undesirable stress on flash devices and SMR disk
drives.  Even on conventional HDD's, the repeated writes to the inode
table block will trigger Adjacent Track Interference (ATI) remediation
latencies, which very negatively impact long tail latencies --- which
is a very big deal for web serving tiers (for example).

Google-Bug-Id: 18297052
Signed-off-by: NTheodore Ts'o <tytso@mit.edu>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

iter_file_splice_write() - a ->splice_write() instance that gathers the
pipe buffers, builds a bio_vec-based iov_iter covering those and feeds
it to ->write_iter().  A bunch of simple cases coverted to that...

[AV: fixed the braino spotted by Cyrill]
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Copy the scheme I introduced to btrfs many years ago to only use the
xattr handler for ACLs, but pass plain attrs straight through.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDave Kleikamp <dave.kleikamp@oracle.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Removed vmtruncate
Signed-off-by: NMarco Stornelli <marco.stornelli@gmail.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Cc: Dave Kleikamp <shaggy@kernel.org>
Signed-off-by: NEric W. Biederman <ebiederm@xmission.com>

Replace the ->check_acl method with a ->get_acl method that simply reads an
ACL from disk after having a cache miss.  This means we can replace the ACL
checking boilerplate code with a single implementation in namei.c.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Btrfs needs to be able to control how filemap_write_and_wait_range() is called
in fsync to make it less of a painful operation, so push down taking i_mutex and
the calling of filemap_write_and_wait() down into the ->fsync() handlers.  Some
file systems can drop taking the i_mutex altogether it seems, like ext3 and
ocfs2.  For correctness sake I just pushed everything down in all cases to make
sure that we keep the current behavior the same for everybody, and then each
individual fs maintainer can make up their mind about what to do from there.
Thanks,
Acked-by: NJan Kara <jack@suse.cz>
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Let filesystems handle waiting for direct I/O requests themselves instead
of doing it beforehand.  This means filesystem-specific locks to prevent
new dio referenes from appearing can be held.  This is important to allow
generalizing i_dio_count to non-DIO_LOCKING filesystems.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Resizing the file system can result in an in-memory inode being remapped
to a different aggregate group (AG). A cached AG number can cause
problems when trying to free or allocate inodes. Instead, save the IAG's
agstart address and calculate the agno when we need it.
Signed-off-by: NDave Kleikamp <dave.kleikamp@oracle.com>

Replace inode_setattr with opencoded variants of it in all callers.  This
moves the remaining call to vmtruncate into the filesystem methods where it
can be replaced with the proper truncate sequence.

In a few cases it was obvious that we would never end up calling vmtruncate
so it was left out in the opencoded variant:

 spufs: explicitly checks for ATTR_SIZE earlier
 btrfs,hugetlbfs,logfs,dlmfs: explicitly clears ATTR_SIZE earlier
 ufs: contains an opencoded simple_seattr + truncate that sets the filesize just above

In addition to that ncpfs called inode_setattr with handcrafted iattrs,
which allowed to trim down the opencoded variant.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Quota must being initialized if size or uid/git changes requested.
But initialization performed in two different places:
in case of i_size file system is responsible for dquot init
, but in case of uid/gid init will be called internally in
dquot_transfer().
This ambiguity makes code harder to understand.
Let's move this logic to one common helper function.
Signed-off-by: NDmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: NJan Kara <jack@suse.cz>

Get rid of the initialize dquot operation - it is now always called from
the filesystem and if a filesystem really needs it's own (which none
currently does) it can just call into it's own routine directly.

Rename the now static low-level dquot_initialize helper to __dquot_initialize
and vfs_dq_init to dquot_initialize to have a consistent namespace.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>

Currently various places in the VFS call vfs_dq_init directly.  This means
we tie the quota code into the VFS.  Get rid of that and make the
filesystem responsible for the initialization.   For most metadata operations
this is a straight forward move into the methods, but for truncate and
open it's a bit more complicated.

For truncate we currently only call vfs_dq_init for the sys_truncate case
because open already takes care of it for ftruncate and open(O_TRUNC) - the
new code causes an additional vfs_dq_init for those which is harmless.

For open the initialization is moved from do_filp_open into the open method,
which means it happens slightly earlier now, and only for regular files.
The latter is fine because we don't need to initialize it for operations
on special files, and we already do it as part of the namespace operations
for directories.

Add a dquot_file_open helper that filesystems that support generic quotas
can use to fill in ->open.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>

Get rid of the transfer dquot operation - it is now always called from
the filesystem and if a filesystem really needs it's own (which none
currently does) it can just call into it's own routine directly.

Rename the now static low-level dquot_transfer helper to __dquot_transfer
and vfs_dq_transfer to dquot_transfer to have a consistent namespace,
and make the new dquot_transfer return a normal negative errno value
which all callers expect.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>

Currently notify_change calls vfs_dq_transfer directly.  This means
we tie the quota code into the VFS.  Get rid of that and make the
filesystem responsible for the transfer.  Most filesystems already
do this, only ufs and udf need the code added, and for jfs it needs to
be enabled unconditionally instead of only when ACLs are enabled.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NJan Kara <jack@suse.cz>

This avoids an indirect call in the VFS for each path component lookup.

Well, at least as long as you own the directory in question, and the ACL
check is unnecessary.
Reviewed-by: NJames Morris <jmorris@namei.org>
Acked-by: NSerge Hallyn <serue@us.ibm.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

The ioctls were already compatible except for the actual values so this
was fairly easy to do.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>

Convert jfs_ioctl over to not use the BKL. The only potential race
I could see was with two ioctls in parallel changing the flags
and losing the updates. Use the i_mutex to protect against this.
Signed-off-by: NAndi Kleen <ak@suse.de>
Signed-off-by: NDave Kleikamp <shaggy@linux.vnet.ibm.com>

They can use generic_file_splice_read() instead. Since sys_sendfile() now
prefers that, there should be no change in behaviour.
Signed-off-by: NJens Axboe <jens.axboe@oracle.com>

Many struct inode_operations in the kernel can be "const".  Marking them const
moves these to the .rodata section, which avoids false sharing with potential
dirty data.  In addition it'll catch accidental writes at compile time to
these shared resources.
Signed-off-by: NArjan van de Ven <arjan@linux.intel.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

This allows the splice() and tee() syscalls to be used with JFS.
Signed-off-by: NDaniel Drake <ddrake@brontes3d.com>
Signed-off-by: NDave Kleikamp <shaggy@austin.ibm.com>

Removed trailing spaces & tabs, and spaces preceding tabs.
Also a couple very minor comment cleanups.
Signed-off-by: NDave Kleikamp <shaggy@austin.ibm.com>
(cherry picked from f74156539964d7b3d5164fdf8848e6a682f75b97 commit)

This patch cleans up generic_file_*_read/write() interfaces.  Christoph
Hellwig gave me the idea for this clean ups.

In a nutshell, all filesystems should set .aio_read/.aio_write methods and use
do_sync_read/ do_sync_write() as their .read/.write methods.  This allows us
to cleanup all variants of generic_file_* routines.

Final available interfaces:

generic_file_aio_read() - read handler
generic_file_aio_write() - write handler
generic_file_aio_write_nolock() - no lock write handler

__generic_file_aio_write_nolock() - internal worker routine
Signed-off-by: NBadari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This patch removes readv() and writev() methods and replaces them with
aio_read()/aio_write() methods.
Signed-off-by: NBadari Pulavarty <pbadari@us.ibm.com>
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

This is a conversion to make the various file_operations structs in fs/
const.  Basically a regexp job, with a few manual fixups

The goal is both to increase correctness (harder to accidentally write to
shared datastructures) and reducing the false sharing of cachelines with
things that get dirty in .data (while .rodata is nicely read only and thus
cache clean)
Signed-off-by: NArjan van de Ven <arjan@infradead.org>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>

ext2 inode attributes with relevance for jfs:

'a' 	EXT2_APPEND_FL       -> append only
'i' 	EXT2_IMMUTABLE_FL    -> immutable file
's' 	EXT2_SECRM_FL	     -> zero file
'u' 	EXT2_UNRM_FL	     -> allow for unrm
'A' 	EXT2_NOATIME_FL      -> no access time
'D' 	EXT2_DIRSYNC_FL      -> dirsync
'S' 	EXT2_SYNC_FL	     -> sync

overview of jfs flags (partially for OS/2)

value	   (OS/2)	Linux	ext2 attrs
------------------------------------------------
0x00010000 IFJOURNAL	-
0x00020000 ISPARSE  	used
0x00040000 INLINEEA 	used
0x00080000 -	    	-	JFS_NOATIME_FL

0x00100000 -	    	-	JFS_DIRSYNC_FL
0x00200000 -	    	-	JFS_SYNC_FL
0x00400000 -	    	-	JFS_SECRM_FL
0x00800000 ISWAPFILE	-	JFS_UNRM_FL

0x01000000 -	    	-	JFS_APPEND_FL
0x02000000 IREADONLY	-	JFS_IMMUTABLE_FL
0x04000000 IHIDDEN  	-	-
0x08000000 ISYSTEM  	-	-

0x10000000 -	    	-
0x20000000 IDIRECTORY	used
0x40000000 IARCHIVE 	-
0x80000000 INEWNAME 	-

the implementation is straight forward, except
for the fact that the attributes have to be mapped
to match with the ext2 ones to avoid a separate
tool for manipulating them (this could be avoided
when using a separate flag field in the on-disk
representation, but the overhead is minimal)

a special jfs_ioctl is added to allow for the new
JFS_IOC_GETFLAGS and JFS_IOC_SETFLAGS calls.

a helper function jfs_set_inode_flags() to transfer
the flags from the on-disk version to the inode

minor changes to allow flag inheritance on inode
creation, as well as a cleanup of the on-disk
flags (including the new ones)

beforementioned helper to map between ext2 and jfs
versions of the new flags ...

the JFS_SECRM_FL and JFS_UNRM_FL are not done yet
and I'm not 100% sure they are worth the effort,
the rest seems to work out of the box ...
Signed-off-by: NHerbert Poetzl <herbert@13thfloor.at>
Signed-off-by: NDave Kleikamp <shaggy@austin.ibm.com>

Signed-off-by: NDave Kleikamp <shaggy@austin.ibm.com>

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!