An osd request defines information about where data to be read
should be placed as well as where data to write comes from.
Currently these are represented by common fields.

Keep information about data for writing separate from data to be
read by splitting these into data_in and data_out fields.

This is the key patch in this whole series, in that it actually
identifies which osd requests generate outgoing data and which
generate incoming data.  It's less obvious (currently) that an osd
CALL op generates both outgoing and incoming data; that's the focus
of some upcoming work.

This resolves:
    http://tracker.ceph.com/issues/4127Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

An osd request uses either pages or a bio list for its data.  Use a
union to record information about the two, and add a data type
tag to select between them.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Pull the fields in an osd request structure that define the data for
the request out into a separate structure.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

Currently ceph_osdc_new_request() assigns an osd request's
r_num_pages and r_alignment fields.  The only thing it does
after that is call ceph_osdc_build_request(), and that doesn't
need those fields to be assigned.

Move the assignment of those fields out of ceph_osdc_new_request()
and into its caller.  As a result, the page_align parameter is no
longer used, so get rid of it.

Note that in ceph_sync_write(), the value for req->r_num_pages had
already been calculated earlier (as num_pages, and fortunately
it was computed the same way).  So don't bother recomputing it,
but because it's not needed earlier, move that calculation after the
call to ceph_osdc_new_request().  Hold off making the assignment to
r_alignment, doing it instead r_pages and r_num_pages are
getting set.

Similarly, in start_read(), nr_pages already holds the number of
pages in the array (and is calculated the same way), so there's no
need to recompute it.  Move the assignment of the page alignment
down with the others there as well.

This and the next few patches are preparation work for:
    http://tracker.ceph.com/issues/4127Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

(This is being reposted.  The first one had a problem because it
erroneously added a similar change elsewhere; that change has been
dropped.)

The next patch in this series points out that the calculation for
the number of pages in an osd request is getting done twice.  It
is not obvious, but the result of both calculations is identical.
This patch simplifies one of them--as a separate step--to make
it clear that the transformation in the next patch is valid.

In ceph_sync_write() there is some magic that computes page_align
for an osd request.  But a little analysis shows it can be
simplified.

First, we have:
 	io_align = pos & ~PAGE_MASK;
which is used here:
	page_align = (pos - io_align + buf_align) & ~PAGE_MASK;

Note (pos - io_align) simply rounds "pos" down to the nearest multiple
of the page size.

We also have:
 	buf_align = (unsigned long)data & ~PAGE_MASK;

Adding buf_align to that rounded-down "pos" value will stay within
the same page; the result will just be offset by the page offset for
the "data" pointer.  The final mask therefore leaves just the value
of "buf_align".

One more simplification.  Note that the result of calc_pages_for()
is invariant of which page the offset starts in--the only thing that
matters is the offset within the starting page.  We will have
put the proper page offset to use into "page_align", so just use
that in calculating num_pages.

This resolves:
    http://tracker.ceph.com/issues/4166Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

make __ceph_do_pending_vmtruncate() acquire the i_mutex if the caller
does not hold the i_mutex, so ceph_aio_read() can call safely.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NGreg Farnum <greg@inktank.com>

ceph_aio_write() has an optimization that marks CEPH_CAP_FILE_WR
cap dirty before data is copied to page cache and inode size is
updated. The optimization avoids slow cap revocation caused by
balance_dirty_pages(), but introduces inode size update race. If
ceph_check_caps() flushes the dirty cap before the inode size is
updated, MDS can miss the new inode size. So just remove the
optimization.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NGreg Farnum <greg@inktank.com>

commit 22cddde1 breaks the atomicity of write operation, it also
introduces a deadlock between write and truncate.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: NGreg Farnum <greg@inktank.com>

Conflicts:
	fs/ceph/addr.c

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

The "num_reply" parameter to ceph_osdc_new_request() is never
used inside that function, so get rid of it.

Note that ceph_sync_write() passes 2 for that argument, while all
other callers pass 1.  It doesn't matter, but perhaps someone should
verify this doesn't indicate a problem.
Signed-off-by: NAlex Elder <elder@inktank.com>
Reviewed-by: NJosh Durgin <josh.durgin@inktank.com>

The mds now sends back a created inode if the create request
performed the create.  If the file already existed, no inode is
returned in the reply.  This allows ceph to set the created flag
in atomic_open so that permissions are properly checked in the case
that the file wasn't created by the create call to the mds.

To ensure compability with previous kernels, a feature for sending
back the inode in the create reply was added, so that the mds will
only send back the inode if the client indicates it supports the
feature.
Signed-off-by: NSam Lang <sam.lang@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

The error returned by ceph_mdsc_do_request includes errors sending the
request, errors on timeout, or any errors coming from the mds.  If
ceph_mdsc_do_request returns an error, the reply struct will most likely
be bogus.  We need to bail out and propogate the error instead of
overwriting it.
Signed-off-by: NSam Lang <sam.lang@inktank.com>
Reviewed-by: NSage Weil <sage@inktank.com>

But the kernel decided to call it "origin" instead.  Fix most of the
sites.
Acked-by: NHugh Dickins <hughd@google.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

ceph_aio_write() has an optimization that marks cap EPH_CAP_FILE_WR
dirty before data is copied to page cache and inode size is updated.
If ceph_check_caps() flushes the dirty cap before the inode size is
updated, MDS can miss the new inode size. The fix is move
ceph_{get,put}_cap_refs() into ceph_write_{begin,end}() and call
__ceph_mark_dirty_caps() after inode size is updated.
Signed-off-by: NYan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: NSage Weil <sage@inktank.com>

If we are creating an osd request and get an invalid layout, return
an EINVAL to the caller.  We switch up the return to have an error
code instead of NULL implying -ENOMEM.
Signed-off-by: NSage Weil <sage@inktank.com>
Reviewed-by: NAlex Elder <elder@inktank.com>

The initial ->atomic_open op was carried over from the old intent code,
which was incomplete and didn't really work.  Replace it with a fresh
method.  In particular:

 * always attempt to do an atomic open+lookup, both for the create case
   and for lookups of existing files.
 * fix symlink handling by returning 1 to the VFS so that we can follow
   the link to its destination. This fixes a longstanding ceph bug (#2392).
Signed-off-by: NSage Weil <sage@inktank.com>

Just pass struct file *.  Methods are happier that way...
There's no need to return struct file * from finish_open() now,
so let it return int.  Next: saner prototypes for parts in
namei.c
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Change of calling conventions:
old		new
NULL		1
file		0
ERR_PTR(-ve)	-ve

Caller *knows* that struct file *; no need to return it.
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

... and let finish_open() report having opened the file via that sucker.
Next step: don't modify od->filp at all.

[AV: FILE_CREATE was already used by cifs; Miklos' fix folded]
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

Add an ->atomic_open implementation which replaces the atomic lookup+open+create
operation implemented via ->lookup and ->create operations.
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
CC: Sage Weil <sage@newdream.net>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

What was the purpose of this?
Signed-off-by: NMiklos Szeredi <mszeredi@suse.cz>
CC: Sage Weil <sage@newdream.net>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

This was an ill-conceived feature that has been removed from Ceph.  Do
this gracefully:

 - reject attempts to specify a preferred_osd via the ioctl
 - stop exposing this information via virtual xattrs
 - always fill in -1 for requests, in case we talk to an older server
 - don't calculate preferred_osd placements/pgids
Reviewed-by: NAlex Elder <elder@inktank.com>
Signed-off-by: NSage Weil <sage@inktank.com>

Commit 06222e49 got the if wrong so that
it always evaluates as true.  This is semantically harmless, but makes
SEEK_CUR and SEEK_SET needlessly query the server.

Rewrite the if to explicitly enumerate the cases we DO need a valid i_size
to make this code less fragile.
Reported-by: NRoel Kluin <roel.kluin@gmail.com>
Signed-off-by: NSage Weil <sage@newdream.net>

We have been using i_lock to protect all kinds of data structures in the
ceph_inode_info struct, including lists of inodes that we need to iterate
over while avoiding races with inode destruction.  That requires grabbing
a reference to the inode with the list lock protected, but igrab() now
takes i_lock to check the inode flags.

Changing the list lock ordering would be a painful process.

However, using a ceph-specific i_ceph_lock in the ceph inode instead of
i_lock is a simple mechanical change and avoids the ordering constraints
imposed by igrab().
Reported-by: NAmon Ott <a.ott@m-privacy.de>
Signed-off-by: NSage Weil <sage@newdream.net>

d_parent is protected by d_lock: use it when looking up a dentry's parent
directory inode.  Also take a reference and drop it in the caller to avoid
a use-after-free.
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Reviewed-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

We weren't properly calling lookup_instantiate_filp when setting up the
lookup intent, which could lead to file leakage on errors.  So:

 - use separate helper for the hidden snapdir translation, immediately
   following the mds request
 - use ceph_finish_lookup for the final dentry/return value dance in the
   exit path
 - lookup_instantiate_filp on success
Reported-by: NAl Viro <viro@ZenIV.linux.org.uk>
Reviewed-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

We only need to put these on the directory unsafe list if they have
side effects that fsync(2) should flush out.
Reviewed-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

We were always getting NULL here because the intent file f_dentry is always
NULL at this point, which means we were always passing NULL to
ceph_mdsc_do_request.  In reality, this was fine, since this isn't
currently ever a write operation that needs to get strung on the dir's
unsafe list.

Use the dir explicitly, and only pass it if this open has side-effects that
a dir fsync should flush.
Reviewed-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

The generic_file_aio_write call may block on balance_dirty_pages while we
flush data to the OSDs.  If we hold a reference to the FILE_WR cap during
that interval revocation by the MDS (e.g., to do a stat(2)) may be very
slow.
Reviewed-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

This allows us to force IO through the sync path which you normally only
get when multiple clients are reading/writing to the same file or by
mounting with -o sync.  Among other things, this lets test programs verify
correctness with a single mount.
Reviewed-by: NYehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: NSage Weil <sage@newdream.net>

This converts everybody to handle SEEK_HOLE/SEEK_DATA properly.  In some cases
we just return -EINVAL, in others we do the normal generic thing, and in others
we're simply making sure that the properly due-dilligence is done.  For example
in NFS/CIFS we need to make sure the file size is update properly for the
SEEK_HOLE and SEEK_DATA case, but since it calls the generic llseek stuff itself
that is all we have to do.  Thanks,
Signed-off-by: NJosef Bacik <josef@redhat.com>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

->create() instances are much happier that way...
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

We were iterating across stripe boundaries properly, but not moving the
write buffer pointer forward.  This caused us to rewrite the same data
after the break.  Fix by adjusting the data pointer forward, and
recalculating the io and buffer alignment after the break.
Signed-off-by: NSage Weil <sage@newdream.net>

 dd if=/dev/urandom of=/mnt/fs_depot/dd10 bs=500 seek=8388 count=1
 dd if=/mnt/fs_depot/dd10 of=/root/dd10out bs=500 skip=8388 count=1
Reported-by: NHenry C Chang <henry.cy.chang@gmail.com>
Signed-off-by: NSage Weil <sage@newdream.net>

Getting ENOENT is equivalent to reading 0 bytes.  Make that correction
before setting up the hit_stripe and was_short flags.

Fixes the following case:
 dd if=/dev/zero of=/mnt/fs_depot/dd3 bs=1 seek=1048576 count=0
 dd if=/mnt/fs_depot/dd3 of=/root/ddout1 skip=8 bs=500 count=2 iflag=direct
Reported-by: NHenry C Chang <henry.cy.chang@gmail.com>
Signed-off-by: NSage Weil <sage@newdream.net>

If we get a short read from the OSD because the object is small, we need to
zero the remainder of the buffer.  For O_DIRECT reads, the attempted range
is not trimmed to i_size by the VFS, so we were actually looping
indefinitely.

Fix by trimming by i_size, and the unconditionally zeroing the trailing
range.
Reported-by: NJeff Wu <cpwu@tnsoft.com.cn>
Signed-off-by: NSage Weil <sage@newdream.net>

We should use ihold whenever we already have a stable inode ref, even
when we aren't holding i_lock.  This avoids adding new and unnecessary
locking dependencies.
Signed-off-by: NSage Weil <sage@newdream.net>

The __mark_dirty_inode helper now takes i_lock as of 250df6ed.  Fix the
one ceph callers that held i_lock (__ceph_mark_dirty_caps) to return the
flags value so that the callers can do it outside of i_lock.
Signed-off-by: NSage Weil <sage@newdream.net>

In sync_write_wait(), we assume that the newest request is at the
tail of unsafe write list. We should maintain the semantics here.
Signed-off-by: NHenry C Chang <henry_c_chang@tcloudcomputing.com>
Signed-off-by: NSage Weil <sage@newdream.net>

This fixes the list corruption warning like this:

------------[ cut here ]------------
WARNING: at lib/list_debug.c:30 __list_add+0x68/0x81()
Hardware name: X8DTU
list_add corruption. prev->next should be next (ffff880618931250), but was (null). (prev=ffff880c188b9130).
Modules linked in: nfsd lockd nfs_acl auth_rpcgss exportfs ceph libceph libcrc32c sunrpc ipv6 fuse igb i2c_i801 ioatdma i2c_core iTCO_wdt iTCO_vendor_support joydev dca serio_raw usb_storage [last unloaded: scsi_wait_scan]
Pid: 10977, comm: smbd Tainted: G        W  2.6.32.23-170.Elaster.xendom0.fc12.x86_64 #1
Call Trace:
[<ffffffff8105753c>] warn_slowpath_common+0x7c/0x94
[<ffffffff810575ab>] warn_slowpath_fmt+0x41/0x43
[<ffffffff812351a3>] __list_add+0x68/0x81
[<ffffffffa014799d>] ceph_aio_write+0x614/0x8a2 [ceph]
[<ffffffff8111d2a0>] do_sync_write+0xe8/0x125
[<ffffffff81075a1f>] ? autoremove_wake_function+0x0/0x39
[<ffffffff811f21ec>] ? selinux_file_permission+0x5c/0xb3
[<ffffffff811e8521>] ? security_file_permission+0x16/0x18
[<ffffffff8111d864>] vfs_write+0xae/0x10b
[<ffffffff8111d91b>] sys_pwrite64+0x5a/0x76
[<ffffffff81012d32>] system_call_fastpath+0x16/0x1b
---[ end trace 08573eb9f07ff6f4 ]---
Signed-off-by: NHenry C Chang <henry_c_chang@tcloudcomputing.com>
Signed-off-by: NSage Weil <sage@newdream.net>