linux-stable.git/fs/ceph/file.c, branch linux-3.13.y

ceph: use fscache as a local presisent cache

2013-09-06T16:50:11+00:00

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 
Signed-off-by: Sage Weil

ceph: allow sync_read/write return partial successed size of read/write.

2013-08-27T19:28:46+00:00

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

ceph: fix bugs about handling short-read for sync read mode.

2013-08-27T19:28:45+00:00

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 
Signed-off-by: Jianpeng Ma

ceph: fix fallocate division

2013-08-27T19:26:29+00:00

We need to use do_div to divide by a 64-bit value.

Signed-off-by: Sage Weil 
Reviewed-by: Josh Durgin

ceph: punch hole support

2013-08-15T18:12:17+00:00

This patch implements fallocate and punch hole support for Ceph kernel client.

Signed-off-by: Li Wang 
Signed-off-by: Yunchuan Wen

ceph: introduce i_truncate_mutex

2013-08-15T18:12:06+00:00

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 
Signed-off-by: Yan, Zheng

Merge remote-tracking branch 'linus/master' into testing

2013-08-15T18:11:45+00:00

ceph: replace hold_mutex flag with goto

2013-08-10T00:55:48+00:00

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 
Reviewed-by: Jianpeng Ma

ceph: Move the place for EOLDSNAPC handle in ceph_aio_write to easily understand

2013-08-10T00:55:43+00:00

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 
Reviewed-by: Sage Weil

ceph: Don't use ceph-sync-mode for synchronous-fs.

2013-08-10T00:55:18+00:00

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 
Reviewed-by: Sage Weil