Pull vfs updates from Al Viro:
"The first vfs pile, with deep apologies for being very late in this
window.
Assorted cleanups and fixes, plus a large preparatory part of iov_iter
work. There's a lot more of that, but it'll probably go into the next
merge window - it *does* shape up nicely, removes a lot of
boilerplate, gets rid of locking inconsistencie between aio_write and
splice_write and I hope to get Kent's direct-io rewrite merged into
the same queue, but some of the stuff after this point is having
(mostly trivial) conflicts with the things already merged into
mainline and with some I want more testing.
This one passes LTP and xfstests without regressions, in addition to
usual beating. BTW, readahead02 in ltp syscalls testsuite has started
giving failures since "mm/readahead.c: fix readahead failure for
memoryless NUMA nodes and limit readahead pages" - might be a false
positive, might be a real regression..."
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (63 commits)
missing bits of "splice: fix racy pipe->buffers uses"
cifs: fix the race in cifs_writev()
ceph_sync_{,direct_}write: fix an oops on ceph_osdc_new_request() failure
kill generic_file_buffered_write()
ocfs2_file_aio_write(): switch to generic_perform_write()
ceph_aio_write(): switch to generic_perform_write()
xfs_file_buffered_aio_write(): switch to generic_perform_write()
export generic_perform_write(), start getting rid of generic_file_buffer_write()
generic_file_direct_write(): get rid of ppos argument
btrfs_file_aio_write(): get rid of ppos
kill the 5th argument of generic_file_buffered_write()
kill the 4th argument of __generic_file_aio_write()
lustre: don't open-code kernel_recvmsg()
ocfs2: don't open-code kernel_recvmsg()
drbd: don't open-code kernel_recvmsg()
constify blk_rq_map_user_iov() and friends
lustre: switch to kernel_sendmsg()
ocfs2: don't open-code kernel_sendmsg()
take iov_iter stuff to mm/iov_iter.c
process_vm_access: tidy up a bit
...
ceph_atomic_open() calls ceph_open() after receiving the MDS reply.
ceph_open() grabs an extra open file reference. (The open request
already holds an open file reference)
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Synchronize object->store_limit[_l] with new inode->i_size after file writing.
Tested-by: Milosz Tanski <milosz@adfin.com>
Signed-off-by: Yunchuan Wen <yunchuanwen@ubuntukylin.com>
Signed-off-by: Min Chen <minchen@ubuntukylin.com>
Signed-off-by: Li Wang <liwang@ubuntukylin.com>
The fsync(dirfd) only covers namespace operations, not inode updates.
We do not need to cover setattr variants or O_TRUNC.
Reported-by: Al Viro <viro@xeniv.linux.org.uk>
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Yan, Zheng <zheng.z.yan@intel.com>
Use min_t(size_t, ...) instead of plain min(), which does strict type
checking, to avoid compile warning on i386.
Cc: Jianpeng Ma <majianpeng@gmail.com>
Signed-off-by: Ilya Dryomov <ilya.dryomov@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
For readv/preadv sync-operatoin, ceph only do the first iov.
Now implement this.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Reviewed-by: Yan, Zheng <zheng.z.yan@intel.com>
For writev/pwritev sync-operatoin, ceph only do the first iov.
I divided the write-sync-operation into two functions. One for
direct-write, other for none-direct-sync-write. This is because for
none-direct-sync-write we can merge iovs to one. But for direct-write,
we can't merge iovs.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Reviewed-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Sage Weil <sage@inktank.com>
Adding support for fscache to the Ceph filesystem. This would bring it to on
par with some of the other network filesystems in Linux (like NFS, AFS, etc...)
In order to mount the filesystem with fscache the 'fsc' mount option must be
passed.
Signed-off-by: Milosz Tanski <milosz@adfin.com>
Signed-off-by: Sage Weil <sage@inktank.com>
For sync_read/write, it may do multi stripe operations.If one of those
met erro, we return the former successed size rather than a error value.
There is a exception for write-operation met -EOLDSNAPC.If this occur,we
retry the whole write again.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
cephfs . show_layout
>layyout.data_pool: 0
>layout.object_size: 4194304
>layout.stripe_unit: 4194304
>layout.stripe_count: 1
TestA:
>dd if=/dev/urandom of=test bs=1M count=2 oflag=direct
>dd if=/dev/urandom of=test bs=1M count=2 seek=4 oflag=direct
>dd if=test of=/dev/null bs=6M count=1 iflag=direct
The messages from func striped_read are:
ceph: file.c:350 : striped_read 0~6291456 (read 0) got 2097152 HITSTRIPE SHORT
ceph: file.c:350 : striped_read 2097152~4194304 (read 2097152) got 0 HITSTRIPE SHORT
ceph: file.c:381 : zero tail 4194304
ceph: file.c:390 : striped_read returns 6291456
The hole of file is from 2M--4M.But actualy it zero the last 4M include
the last 2M area which isn't a hole.
Using this patch, the messages are:
ceph: file.c:350 : striped_read 0~6291456 (read 0) got 2097152 HITSTRIPE SHORT
ceph: file.c:358 : zero gap 2097152 to 4194304
ceph: file.c:350 : striped_read 4194304~2097152 (read 4194304) got 2097152
ceph: file.c:384 : striped_read returns 6291456
TestB:
>echo majianpeng > test
>dd if=test of=/dev/null bs=2M count=1 iflag=direct
The messages are:
ceph: file.c:350 : striped_read 0~6291456 (read 0) got 11 HITSTRIPE SHORT
ceph: file.c:350 : striped_read 11~6291445 (read 11) got 0 HITSTRIPE SHORT
ceph: file.c:390 : striped_read returns 11
For this case,it did once more striped_read.It's no meaningless.
Using this patch, the message are:
ceph: file.c:350 : striped_read 0~6291456 (read 0) got 11 HITSTRIPE SHORT
ceph: file.c:384 : striped_read returns 11
Big thanks to Yan Zheng for the patch.
Reviewed-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
This patch implements fallocate and punch hole support for Ceph kernel client.
Signed-off-by: Li Wang <liwang@ubuntukylin.com>
Signed-off-by: Yunchuan Wen <yunchuanwen@ubuntukylin.com>
I encountered below deadlock when running fsstress
wmtruncate work truncate MDS
--------------- ------------------ --------------------------
lock i_mutex
<- truncate file
lock i_mutex (blocked)
<- revoking Fcb (filelock to MIX)
send request ->
handle request (xlock filelock)
At the initial time, there are some dirty pages in the page cache.
When the kclient receives the truncate message, it reduces inode size
and creates some 'out of i_size' dirty pages. wmtruncate work can't
truncate these dirty pages because it's blocked by the i_mutex. Later
when the kclient receives the cap message that revokes Fcb caps, It
can't flush all dirty pages because writepages() only flushes dirty
pages within the inode size.
When the MDS handles the 'truncate' request from kclient, it waits
for the filelock to become stable. But the filelock is stuck in
unstable state because it can't finish revoking kclient's Fcb caps.
The truncate pagecache locking has already caused lots of trouble
for use. I think it's time simplify it by introducing a new mutex.
We use the new mutex to prevent concurrent truncate_inode_pages().
There is no need to worry about race between buffered write and
truncate_inode_pages(), because our "get caps" mechanism prevents
them from concurrent execution.
Reviewed-by: Sage Weil <sage@inktank.com>
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
All of the early exit paths need to drop the mutex; it is only the normal
path through the function that does not. Skip the unlock in that case
with a goto out_unlocked.
Signed-off-by: Sage Weil <sage@inktank.com>
Reviewed-by: Jianpeng Ma <majianpeng@gmail.com>
Only for ceph_sync_write, the osd can return EOLDSNAPC.so move the
related codes after the call ceph_sync_write.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Sending reads and writes through the sync read/write paths bypasses the
page cache, which is not expected or generally a good idea. Removing
the write check is safe as there is a conditional vfs_fsync_range() later
in ceph_aio_write that already checks for the same flag (via
IS_SYNC(inode)).
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Reviewed-by: Sage Weil <sage@inktank.com>
We pass in a u64 value for "len" and then immediately truncate away the
upper 32 bits.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Reviewed-by: Alex Elder <alex.elder@linaro.org>
Pull Ceph updates from Sage Weil:
"There is some follow-on RBD cleanup after the last window's code drop,
a series from Yan fixing multi-mds behavior in cephfs, and then a
sprinkling of bug fixes all around. Some warnings, sleeping while
atomic, a null dereference, and cleanups"
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client: (36 commits)
libceph: fix invalid unsigned->signed conversion for timespec encoding
libceph: call r_unsafe_callback when unsafe reply is received
ceph: fix race between cap issue and revoke
ceph: fix cap revoke race
ceph: fix pending vmtruncate race
ceph: avoid accessing invalid memory
libceph: Fix NULL pointer dereference in auth client code
ceph: Reconstruct the func ceph_reserve_caps.
ceph: Free mdsc if alloc mdsc->mdsmap failed.
ceph: remove sb_start/end_write in ceph_aio_write.
ceph: avoid meaningless calling ceph_caps_revoking if sync_mode == WB_SYNC_ALL.
ceph: fix sleeping function called from invalid context.
ceph: move inode to proper flushing list when auth MDS changes
rbd: fix a couple warnings
ceph: clear migrate seq when MDS restarts
ceph: check migrate seq before changing auth cap
ceph: fix race between page writeback and truncate
ceph: reset iov_len when discarding cap release messages
ceph: fix cap release race
libceph: fix truncate size calculation
...
The locking order for pending vmtruncate is wrong, it can lead to
following race:
write wmtruncate work
------------------------ ----------------------
lock i_mutex
check i_truncate_pending check i_truncate_pending
truncate_inode_pages() lock i_mutex (blocked)
copy data to page cache
unlock i_mutex
truncate_inode_pages()
The fix is take i_mutex before calling __ceph_do_pending_vmtruncate()
Fixes: http://tracker.ceph.com/issues/5453
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
Either in vfs_write or io_submit,it call file_start/end_write.
The different between file_start/end_write and sb_start/end_write is
file_ only handle regular file.But i think in ceph_aio_write,it only
for regular file.
Signed-off-by: Jianpeng Ma <majianpeng@gmail.com>
Acked-by: Yan, Zheng <zheng.z.yan@intel.com>
For those file systems(btrfs/ext4/ocfs2/tmpfs) that support
SEEK_DATA/SEEK_HOLE functions, we end up handling the similar
matter in lseek_execute() to update the current file offset
to the desired offset if it is valid, ceph also does the
simliar things at ceph_llseek().
To reduce the duplications, this patch make lseek_execute()
public accessible so that we can call it directly from the
underlying file systems.
Thanks Dave Chinner for this suggestion.
[AV: call it vfs_setpos(), don't bring the removed 'inode' argument back]
v2->v1:
- Add kernel-doc comments for lseek_execute()
- Call lseek_execute() in ceph->llseek()
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Cc: Dave Chinner <dchinner@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Andi Kleen <andi@firstfloor.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Chris Mason <chris.mason@fusionio.com>
Cc: Josef Bacik <jbacik@fusionio.com>
Cc: Ben Myers <bpm@sgi.com>
Cc: Ted Tso <tytso@mit.edu>
Cc: Hugh Dickins <hughd@google.com>
Cc: Mark Fasheh <mfasheh@suse.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Sage Weil <sage@inktank.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
In the incremental move toward supporting distinct data items in an
osd request some of the functions had "write_request" parameters to
indicate, basically, whether the data belonged to in_data or the
out_data. Now that we maintain the data fields in the op structure
there is no need to indicate the direction, so get rid of the
"write_request" parameters.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Fix printk format warnings by using %zd for 'ssize_t' variables:
fs/ceph/file.c:751:2: warning: format '%ld' expects argument of type 'long int', but argument 11 has type 'ssize_t' [-Wformat]
fs/ceph/file.c:762:2: warning: format '%ld' expects argument of type 'long int', but argument 11 has type 'ssize_t' [-Wformat]
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: ceph-devel@vger.kernel.org
Signed-off-by: Sage Weil <sage@inktank.com>
copy write checks in __generic_file_aio_write to ceph_aio_write.
To make these checks cover sync write path.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Alex Elder <elder@inktank.com>
There is deadlock as illustrated bellow. The fix is taking i_mutex
before getting Fw cap reference.
write truncate MDS
--------------------- -------------------- --------------
get Fw cap
lock i_mutex
lock i_mutex (blocked)
request setattr.size ->
<- revoke Fw cap
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Reviewed-by: Sage Weil <sage@inktank.com>
An osd request currently has two callbacks. They inform the
initiator of the request when we've received confirmation for the
target osd that a request was received, and when the osd indicates
all changes described by the request are durable.
The only time the second callback is used is in the ceph file system
for a synchronous write. There's a race that makes some handling of
this case unsafe. This patch addresses this problem. The error
handling for this callback is also kind of gross, and this patch
changes that as well.
In ceph_sync_write(), if a safe callback is requested we want to add
the request on the ceph inode's unsafe items list. Because items on
this list must have their tid set (by ceph_osd_start_request()), the
request added *after* the call to that function returns. The
problem with this is that there's a race between starting the
request and adding it to the unsafe items list; the request may
already be complete before ceph_sync_write() even begins to put it
on the list.
To address this, we change the way the "safe" callback is used.
Rather than just calling it when the request is "safe", we use it to
notify the initiator the bounds (start and end) of the period during
which the request is *unsafe*. So the initiator gets notified just
before the request gets sent to the osd (when it is "unsafe"), and
again when it's known the results are durable (it's no longer
unsafe). The first call will get made in __send_request(), just
before the request message gets sent to the messenger for the first
time. That function is only called by __send_queued(), which is
always called with the osd client's request mutex held.
We then have this callback function insert the request on the ceph
inode's unsafe list when we're told the request is unsafe. This
will avoid the race because this call will be made under protection
of the osd client's request mutex. It also nicely groups the setup
and cleanup of the state associated with managing unsafe requests.
The name of the "safe" callback field is changed to "unsafe" to
better reflect its new purpose. It has a Boolean "unsafe" parameter
to indicate whether the request is becoming unsafe or is now safe.
Because the "msg" parameter wasn't used, we drop that.
This resolves the original problem reportedin:
http://tracker.ceph.com/issues/4706
Reported-by: Yan, Zheng <zheng.z.yan@intel.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Sage Weil <sage@inktank.com>
In ceph_sync_write(), if a safe callback is supplied with a request,
and an error is returned by ceph_osdc_wait_request(), a block of
code is executed to remove the request from the unsafe writes list
and drop references to capabilities acquired just prior to a call to
ceph_osdc_wait_request().
The only function used for this callback is sync_write_commit(),
and it does *exactly* what that block of error handling code does.
Now in ceph_osdc_wait_request(), if an error occurs (due to an
interupt during a wait_for_completion_interruptible() call),
complete_request() gets called, and that calls the request's
safe_callback method if it's defined.
So this means that this cleanup activity gets called twice in this
case, which is erroneous (and in fact leads to a crash).
Fix this by just letting the osd client handle the cleanup in
the event of an interrupt.
This resolves one problem mentioned in:
http://tracker.ceph.com/issues/4706
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yan, Zheng <zheng.z.yan@intel.com>
This ends up being a rather large patch but what it's doing is
somewhat straightforward.
Basically, this is replacing two calls with one. The first of the
two calls is initializing a struct ceph_osd_data with data (either a
page array, a page list, or a bio list); the second is setting an
osd request op so it associates that data with one of the op's
parameters. In place of those two will be a single function that
initializes the op directly.
That means we sort of fan out a set of the needed functions:
- extent ops with pages data
- extent ops with pagelist data
- extent ops with bio list data
and
- class ops with page data for receiving a response
We also have define another one, but it's only used internally:
- class ops with pagelist data for request parameters
Note that we *still* haven't gotten rid of the osd request's
r_data_in and r_data_out fields. All the osd ops refer to them for
their data. For now, these data fields are pointers assigned to the
appropriate r_data_* field when these new functions are called.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
An extent type osd operation currently implies that there will
be corresponding data supplied in the data portion of the request
(for write) or response (for read) message. Similarly, an osd class
method operation implies a data item will be supplied to receive
the response data from the operation.
Add a ceph_osd_data pointer to each of those structures, and assign
it to point to eithre the incoming or the outgoing data structure in
the osd message. The data is not always available when an op is
initially set up, so add two new functions to allow setting them
after the op has been initialized.
Begin to make use of the data item pointer available in the osd
operation rather than the request data in or out structure in
places where it's convenient. Add some assertions to verify
pointers are always set the way they're expected to be.
This is a sort of stepping stone toward really moving the data
into the osd request ops, to allow for some validation before
making that jump.
This is the first in a series of patches that resolve:
http://tracker.ceph.com/issues/4657
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
An osd request keeps a pointer to the osd operations (ops) array
that it builds in its request message.
In order to allow each op in the array to have its own distinct
data, we will need to keep track of each op's data, and that
information does not go over the wire.
As long as we're tracking the data we might as well just track the
entire (source) op definition for each of the ops. And if we're
doing that, we'll have no more need to keep a pointer to the
wire-encoded version.
This patch makes the array of source ops be kept with the osd
request structure, and uses that instead of the version encoded in
the message in places where that was previously used. The array
will be embedded in the request structure, and the maximum number of
ops we ever actually use is currently 2. So reduce CEPH_OSD_MAX_OP
to 2 to reduce the size of the structure.
The result of doing this sort of ripples back up, and as a result
various function parameters and local variables become unnecessary.
Make r_num_ops be unsigned, and move the definition of struct
ceph_osd_req_op earlier to ensure it's defined where needed.
It does not yet add per-op data, that's coming soon.
This resolves:
http://tracker.ceph.com/issues/4656
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Define and use functions that encapsulate the initializion of a
ceph_osd_data structure.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Defer building the osd request until just before submitting it in
all callers except ceph_writepages_start(). (That caller will be
handed in the next patch.)
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This patch moves the call to ceph_osdc_build_request() out of
ceph_osdc_new_request() and into its caller.
This is in order to defer formatting osd operation information into
the request message until just before request is started.
The only unusual (ab)user of ceph_osdc_build_request() is
ceph_writepages_start(), where the final length of write request may
change (downward) based on the current inode size or the oldest
snapshot context with dirty data for the inode.
The remaining callers don't change anything in the request after has
been built.
This means the ops array is now supplied by the caller. It also
means there is no need to pass the mtime to ceph_osdc_new_request()
(it gets provided to ceph_osdc_build_request()). And rather than
passing a do_sync flag, have the number of ops in the ops array
supplied imply adding a second STARTSYNC operation after the READ or
WRITE requested.
This and some of the patches that follow are related to having the
messenger (only) be responsible for filling the content of the
message header, as described here:
http://tracker.ceph.com/issues/4589
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
We should advance the user data pointer by _len_ instead of _written_.
_len_ is the data length written in each iteration while _written_ is the
accumulated data length we have writtent out.
Signed-off-by: Henry C Chang <henry.cy.chang@gmail.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
Tested-by: Sage Weil <sage@inktank.com>
Record the byte count for an osd request rather than the page count.
The number of pages can always be derived from the byte count (and
alignment/offset) but the reverse is not true.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
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/4127
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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/4127
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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/4166
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh 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: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Greg 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: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
commit 22cddde104 breaks the atomicity of write operation, it also
introduces a deadlock between write and truncate.
Signed-off-by: Yan, Zheng <zheng.z.yan@intel.com>
Reviewed-by: Greg Farnum <greg@inktank.com>
Conflicts:
fs/ceph/addr.c
