Define new ceph_file_layout structure and rename old ceph_file_layout
to ceph_file_layout_legacy. This is preparation for adding namespace
to ceph_file_layout structure.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

All other filesystems do not add dirty pages to fscache. They all
disable fscache when inode is opened for write. Only ceph adds
dirty pages to fscache, but the code is buggy.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

If readpages fails, fscache needs to cleanup its internal state.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Signed-off-by: NYan, Zheng <zyan@redhat.com>

writepage() can be interrupted when it's called by direct memory
reclaimer (the direct memory relaimer is killed). To avoid lossing
data, we redirty the page.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

ceph_update_writeable_page() is used by ceph_write_begin(). It beaks
atomicity of write operation if it's interruptible.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

when ceph_update_writeable_page() return -EAGAIN, caller should
lock the page and call ceph_update_writeable_page() again.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Signed-off-by: NYan, Zheng <zyan@redhat.com>

Fault and page_mkwrite are supposed to be uninterruptable. But they
call ceph functions that are interruptible. So they should block
signals before calling functions that are interruptible
Signed-off-by: NYan, Zheng <zyan@redhat.com>

truncate_pagecache() may decrease inode's reference. This can cause
deadlock if inode's last reference is dropped and iput_final() wants
to evict the inode. (evict() calls inode_wait_for_writeback(), which
waits for ceph_writepages_start() to return).

The fix is use work thead to truncate dirty pages. Also add 'forced
umount' check to ceph_update_writeable_page(), which prevents new
pages getting dirty.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

If you specify ACK | ONDISK and set ->r_unsafe_callback, both
->r_callback and ->r_unsafe_callback(true) are called on ack.  This is
very confusing.  Redo this so that only one of them is called:

    ->r_unsafe_callback(true), on ack
    ->r_unsafe_callback(false), on commit

or

    ->r_callback, on ack|commit

Decode everything in decode_MOSDOpReply() to reduce clutter.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

finish_read(), its only user, uses it to get to hdr.data_len, which is
what ->r_result is set to on success.  This gains us the ability to
safely call callbacks from contexts other than reply, e.g. map check.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

The crux of this is getting rid of ceph_osdc_build_request(), so that
MOSDOp can be encoded not before but after calc_target() calculates the
actual target.  Encoding now happens within ceph_osdc_start_request().

Also nuked is the accompanying bunch of pointers into the encoded
buffer that was used to update fields on each send - instead, the
entire front is re-encoded.  If we want to support target->name_len !=
base->name_len in the future, there is no other way, because oid is
surrounded by other fields in the encoded buffer.

Encoding OSD ops and adding data items to the request message were
mixed together in osd_req_encode_op().  While we want to re-encode OSD
ops, we don't want to add duplicate data items to the message when
resending, so all call to ceph_osdc_msg_data_add() are factored out
into a new setup_request_data().
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Introduce ceph_osd_request_target, containing all mapping-related
fields of ceph_osd_request and calc_target() for calculating mappings
and populating it.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Currently ceph_object_id can hold object names of up to 100
(CEPH_MAX_OID_NAME_LEN) characters.  This is enough for all use cases,
expect one - long rbd image names:

- a format 1 header is named "<imgname>.rbd"
- an object that points to a format 2 header is named "rbd_id.<imgname>"

We operate on these potentially long-named objects during rbd map, and,
for format 1 images, during header refresh.  (A format 2 header name is
a small system-generated string.)

Lift this 100 character limit by making ceph_object_id be able to point
to an externally-allocated string.  Apart from being able to work with
almost arbitrarily-long named objects, this allows us to reduce the
size of ceph_object_id from >100 bytes to 64 bytes.
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

The size of ->r_request and ->r_reply messages depends on the size of
the object name (ceph_object_id), while the size of ceph_osd_request is
fixed.  Move message allocation into a separate function that would
have to be called after ceph_object_id and ceph_object_locator (which
is also going to become variable in size with RADOS namespaces) have
been filled in:

    req = ceph_osdc_alloc_request(...);
    <fill in req->r_base_oid>
    <fill in req->r_base_oloc>
    ceph_osdc_alloc_messages(req);
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Signed-off-by: NIlya Dryomov <idryomov@gmail.com>

Including blkdev_direct_IO and dax_do_io.  It has to be ki_pos to actually
work, so eliminate the superflous argument.
Signed-off-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NAl Viro <viro@zeniv.linux.org.uk>

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:

 - <foo> << (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - <foo> >> (PAGE_CACHE_SHIFT - PAGE_SHIFT) -> <foo>;

 - 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: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Acked-by: NMichal Hocko <mhocko@suse.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

If page->mapping is NULL, releasepage() callback does not get called.
Remove the unnecessary NULL check to make static code analysis tool
happy
Signed-off-by: NYan, Zheng <zyan@redhat.com>

ceph_empty_snapc->num_snaps == 0 at all times.  Passing such a snapc to
ceph_osdc_alloc_request() (possibly through ceph_osdc_new_request()) is
equivalent to passing NULL, as ceph_osdc_alloc_request() uses it only
for sizing the request message.

Further, in all four cases the subsequent ceph_osdc_build_request() is
passed NULL for snapc, meaning that 0 is encoded for seq and num_snaps
and making ceph_empty_snapc entirely useless.  The two cases where it
actually mattered were removed in commits 86056090 ("ceph: avoid
sending unnessesary FLUSHSNAP message") and 23078637 ("ceph: fix
queuing inode to mdsdir's snaprealm").
Signed-off-by: NIlya Dryomov <idryomov@gmail.com>
Reviewed-by: NYan, Zheng <zyan@redhat.com>

A negative value rc compared to the positive value ENOENT in the
finish_read() function.
Signed-off-by: NAnton Protopopov <a.s.protopopov@gmail.com>
Signed-off-by: NYan, Zheng <zyan@redhat.com>

This patch makes ceph_writepages_start() try using single OSD request
to write all dirty pages within a strip unit. When a nonconsecutive
dirty page is found, ceph_writepages_start() tries starting a new write
operation to existing OSD request. If it succeeds, it uses the new
operation to writeback the dirty page.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Add support for the format change of MClientReply/MclientCaps.
Also add code that denies access to inodes with pool_ns layouts.
Signed-off-by: NYan, Zheng <zyan@redhat.com>
Reviewed-by: NSage Weil <sage@redhat.com>

Cap message from MDS can update i_size. In that case, we don't
hold i_mutex. So it's unsafe to directly access inode->i_size
while holding i_mutex.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

The variant pagep will still get the invalid page point, although ceph
fails in function ceph_update_writeable_page.

To fix this issue, Assigne the page to pagep until there is no failure
in function ceph_update_writeable_page.
Signed-off-by: NMinfei Huang <mnfhuang@gmail.com>
Signed-off-by: NYan, Zheng <zyan@redhat.com>

ceph_update_writeable_page() unlocks the page on errors, so
page_mkwrite() should not unlock the page again.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

There are many places which use mapping_gfp_mask to restrict a more
generic gfp mask which would be used for allocations which are not
directly related to the page cache but they are performed in the same
context.

Let's introduce a helper function which makes the restriction explicit and
easier to track.  This patch doesn't introduce any functional changes.

[akpm@linux-foundation.org: coding-style fixes]
Signed-off-by: NMichal Hocko <mhocko@suse.com>
Suggested-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

With two exceptions (drm/qxl and drm/radeon) all vm_operations_struct
structs should be constant.
Signed-off-by: NKirill A. Shutemov <kirill.shutemov@linux.intel.com>
Reviewed-by: NOleg Nesterov <oleg@redhat.com>
Cc: "H. Peter Anvin" <hpa@zytor.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Ingo Molnar <mingo@elte.hu>
Cc: Minchan Kim <minchan@kernel.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

When readahead encounters file holes, osd reply returns error -ENOENT,
finish_read() skips adding pages to the the page cache. So readahead
does not work for file holes. The fix is adding zero pages to the
page cache when -ENOENT is returned.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

After forced umount, ceph_writepages_start() skips flushing dirty
pages. To make sure inode's reference count get dropped to zero,
we need to invalidate dirty pages.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

This patch makes try_get_cap_refs() and __do_request() check
if the file system was forced umount, and return -EIO if it was.
This patch also adds a helper function to drops dirty caps and
wakes up blocking operation.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Before a page get locked, someone else can write data to the page
and increase the i_size. So we should re-check the i_size after
pages are locked.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

GFP_NOFS memory allocation is required for page writeback path.
But there is no need to use GFP_NOFS in syscall path and readpage
path
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Signed-off-by: NYan, Zheng <zyan@redhat.com>

In most cases that snap context is needed, we are holding
reference of CEPH_CAP_FILE_WR. So we can set ceph inode's
i_head_snapc when getting the CEPH_CAP_FILE_WR reference,
and make codes get snap context from i_head_snapc. This makes
the code simpler.

Another benefit of this change is that we can handle snap
notification more elegantly. Especially when snap context
is updated while someone else is doing write. The old queue
cap_snap code may set cap_snap's context to ether the old
context or the new snap context, depending on if i_head_snapc
is set. The new queue capp_snap code always set cap_snap's
context to the old snap context.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Cached_context in ceph_snap_realm is directly accessed by
uninline_data() and get_pool_perm(). This is racy in theory.
both uninline_data() and get_pool_perm() do not modify existing
object, they only create new object. So we can pass the empty
snap context to them.  Unlike cached_context in ceph_snap_realm,
we do not need to protect the empty snap context.
Signed-off-by: NYan, Zheng <zyan@redhat.com>

Signed-off-by: NYan, Zheng <zyan@redhat.com>

Signed-off-by: NYan, Zheng <zyan@redhat.com>
Reviewed-by: NAlex Elder <elder@linaro.org>

For CEPH_OSD_CMPXATTR_MODE_U64, OSD expects the u64 to be encoded
as string in object's xattr.
Signed-off-by: NYan, Zheng <zyan@redhat.com>