seeing that "fast" symlinks still get allocation + copy, we might as
well simply switch them to pagecache-based variant of ->follow_link();
just need an appropriate ->readpage() for them...
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
After we moved inode_sync_wait() from end_writeback() it doesn't make sense
to call the function end_writeback() anymore. Rename it to clear_inode()
which well says what the function really does - set I_CLEAR flag.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Fengguang Wu <fengguang.wu@intel.com>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: (31 commits)
ocfs2: avoid unaligned access to dqc_bitmap
ocfs2: Use filemap_write_and_wait() instead of write_inode_now()
ocfs2: honor O_(D)SYNC flag in fallocate
ocfs2: Add a missing journal credit in ocfs2_link_credits() -v2
ocfs2: send correct UUID to cleancache initialization
ocfs2: Commit transactions in error cases -v2
ocfs2: make direntry invalid when deleting it
fs/ocfs2/dlm/dlmlock.c: free kmem_cache_zalloc'd data using kmem_cache_free
ocfs2: Avoid livelock in ocfs2_readpage()
ocfs2: serialize unaligned aio
ocfs2: Implement llseek()
ocfs2: Fix ocfs2_page_mkwrite()
ocfs2: Add comment about orphan scanning
ocfs2: Clean up messages in the fs
ocfs2/cluster: Cluster up now includes network connections too
ocfs2/cluster: Add new function o2net_fill_node_map()
ocfs2/cluster: Fix output in file elapsed_time_in_ms
ocfs2/dlm: dlmlock_remote() needs to account for remastery
ocfs2/dlm: Take inflight reference count for remotely mastered resources too
ocfs2/dlm: Cleanup dlm_wait_for_node_death() and dlm_wait_for_node_recovery()
...
Since ocfs2 has no ->write_inode method, there's no point in calling
write_inode_now() from ocfs2_cleanup_delete_inode(). Use
filemap_write_and_wait() instead. This helps us to cleanup inode writing
interfaces...
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Joel Becker <jlbec@evilplan.org>
Replace remaining direct i_nlink updates with a new set_nlink()
updater function.
Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
Tested-by: Toshiyuki Okajima <toshi.okajima@jp.fujitsu.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
ocfs2_iget is used to get/create inode. Only iget5_locked
will give us an inode = NULL. So move this check ahead of
ocfs2_read_locked_inode so that we don't need to check
inode before we read and unlock inode. This is also helpful
for trace event(see the next patch).
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
mlog_exit is used to record the exit status of a function.
But because it is added in so many functions, if we enable it,
the system logs get filled up quickly and cause too much I/O.
So actually no one can open it for a production system or even
for a test.
This patch just try to remove it or change it. So:
1. if all the error paths already use mlog_errno, it is just removed.
Otherwise, it will be replaced by mlog_errno.
2. if it is used to print some return value, it is replaced with
mlog(0,...).
mlog_exit_ptr is changed to mlog(0.
All those mlog(0,...) will be replaced with trace events later.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
ENTRY is used to record the entry of a function.
But because it is added in so many functions, if we enable it,
the system logs get filled up quickly and cause too much I/O.
So actually no one can open it for a production system or even
for a test.
So for mlog_entry_void, we just remove it.
for mlog_entry(...), we replace it with mlog(0,...), and they
will be replace by trace event later.
Signed-off-by: Tao Ma <boyu.mt@taobao.com>
Track negative dentries by recording the generation number of the parent
directory in d_fsdata. The generation number for the parent directory is
recorded in the inode_info, which increments every time the lock on the
directory is dropped.
If the generation number of the parent directory and the negative dentry
matches, there is no need to perform the revalidate, else a revalidate
is forced. This improves performance in situations where nodes look for
the same non-existent file multiple times.
Thanks Mark for explaining the DLM sequence.
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.de>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
For local mounts, ocfs2_read_locked_inode() calls ocfs2_read_blocks_sync() to
read the inode off the disk. The latter first checks to see if that block is
cached in the journal, and, if so, returns that block. That is ok.
But ocfs2_read_locked_inode() goes wrong when it tries to validate the checksum
of such blocks. Blocks that are cached in the journal may not have had their
checksum computed as yet. We should not validate the checksums of such blocks.
Fixes ossbz#1282
http://oss.oracle.com/bugzilla/show_bug.cgi?id=1282
Signed-off-by: Sunil Mushran <sunil.mushran@oracle.com>
Cc: stable@kernel.org
Singed-off-by: Tao Ma <tao.ma@oracle.com>
* 'upstream-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jlbec/ocfs2: (47 commits)
ocfs2: Silence a gcc warning.
ocfs2: Don't retry xattr set in case value extension fails.
ocfs2:dlm: avoid dlm->ast_lock lockres->spinlock dependency break
ocfs2: Reset xattr value size after xa_cleanup_value_truncate().
fs/ocfs2/dlm: Use kstrdup
fs/ocfs2/dlm: Drop memory allocation cast
Ocfs2: Optimize punching-hole code.
Ocfs2: Make ocfs2_find_cpos_for_left_leaf() public.
Ocfs2: Fix hole punching to correctly do CoW during cluster zeroing.
Ocfs2: Optimize ocfs2 truncate to use ocfs2_remove_btree_range() instead.
ocfs2: Block signals for mkdir/link/symlink/O_CREAT.
ocfs2: Wrap signal blocking in void functions.
ocfs2/dlm: Increase o2dlm lockres hash size
ocfs2: Make ocfs2_extend_trans() really extend.
ocfs2/trivial: Code cleanup for allocation reservation.
ocfs2: make ocfs2_adjust_resv_from_alloc simple.
ocfs2: Make nointr a default mount option
ocfs2/dlm: Make o2dlm domain join/leave messages KERN_NOTICE
o2net: log socket state changes
ocfs2: print node # when tcp fails
...
Truncate is just a special case of punching holes(from new i_size to
end), we therefore could take advantage of the existing
ocfs2_remove_btree_range() to reduce the comlexity and redundancy in
alloc.c. The goal here is to make truncate more generic and
straightforward.
Several functions only used by ocfs2_commit_truncate() will smiply be
removed.
ocfs2_remove_btree_range() was originally used by the hole punching
code, which didn't take refcount trees into account (definitely a bug).
We therefore need to change that func a bit to handle refcount trees.
It must take the refcount lock, calculate and reserve blocks for
refcount tree changes, and decrease refcounts at the end. We replace
ocfs2_lock_allocators() here by adding a new func
ocfs2_reserve_blocks_for_rec_trunc() which accepts some extra blocks to
reserve. This will not hurt any other code using
ocfs2_remove_btree_range() (such as dir truncate and hole punching).
I merged the following steps into one patch since they may be
logically doing one thing, though I know it looks a little bit fat
to review.
1). Remove redundant code used by ocfs2_commit_truncate(), since we're
moving to ocfs2_remove_btree_range anyway.
2). Add a new func ocfs2_reserve_blocks_for_rec_trunc() for purpose of
accepting some extra blocks to reserve.
3). Change ocfs2_prepare_refcount_change_for_del() a bit to fit our
needs. It's safe to do this since it's only being called by
truncate.
4). Change ocfs2_remove_btree_range() a bit to take refcount case into
account.
5). Finally, we change ocfs2_commit_truncate() to call
ocfs2_remove_btree_range() in a proper way.
The patch has been tested normally for sanity check, stress tests
with heavier workload will be expected.
Based on this patch, fixing the punching holes bug will be fairly easy.
Signed-off-by: Tristan Ye <tristan.ye@oracle.com>
Acked-by: Mark Fasheh <mfasheh@suse.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
ocfs2 sometimes needs to block signals around dlm operations, but it
currently does it with sigprocmask(). Even worse, it's checking the
error code of sigprocmask(). The in-kernel sigprocmask() can only error
if you get the SIG_* argument wrong. We don't.
Wrap the sigprocmask() calls with ocfs2_[un]block_signals(). These
functions are void, but they will BUG() if somehow sigprocmask() returns
an error.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Use the reservations system for unindexed dir tree allocations. We don't
bother with the indexed tree as reads from it are mostly random anyway.
Directory reservations are marked seperately, to allow the reservations code
a chance to optimize their window sizes. This patch allocates only 8 bits
for directory windows as they generally are not expected to grow as quickly
as file data. Future improvements to dir window sizing can trivially be
made.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
jbd[2]_journal_dirty_metadata() only returns 0. It's been returning 0
since before the kernel moved to git. There is no point in checking
this error.
ocfs2_journal_dirty() has been faithfully returning the status since the
beginning. All over ocfs2, we have blocks of code checking this can't
fail status. In the past few years, we've tried to avoid adding these
checks, because they are pointless. But anyone who looks at our code
assumes they are needed.
Finally, ocfs2_journal_dirty() is made a void function. All error
checking is removed from other files. We'll BUG_ON() the status of
jbd2_journal_dirty_metadata() just in case they change it someday. They
won't.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
gcc warns that a variable is uninitialized. It's actually handled, but
an early return fools gcc. Let's just initialize the variable to a
garbage value that will crash if the usage is ever broken.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
If "handle" is non null at the end of the function then we assume it's a
valid pointer and pass it to ocfs2_commit_trans();
Signed-off-by: Dan Carpenter <error27@gmail.com>
Cc: <stable@kernel.org>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Currently in the error path of ocfs2_symlink and ocfs2_mknod, we just call
iput with the inode we failed with, but the inode wipe code will complain
because we don't add the inode to orphan dir. One solution would be to lock
the orphan dir during the entire transaction, but that's too heavy for a
rare error path. Instead, we add a flag, OCFS2_INODE_SKIP_ORPHAN_DIR which
tells the inode wipe code that it won't find this inode in the orphan dir.
[ Merge fixes and comment style cleanups -Mark ]
Signed-off-by: Li Dongyang <lidongyang@novell.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files. percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.
percpu.h -> slab.h dependency is about to be removed. Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability. As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.
http://userweb.kernel.org/~tj/misc/slabh-sweep.py
The script does the followings.
* Scan files for gfp and slab usages and update includes such that
only the necessary includes are there. ie. if only gfp is used,
gfp.h, if slab is used, slab.h.
* When the script inserts a new include, it looks at the include
blocks and try to put the new include such that its order conforms
to its surrounding. It's put in the include block which contains
core kernel includes, in the same order that the rest are ordered -
alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
doesn't seem to be any matching order.
* If the script can't find a place to put a new include (mostly
because the file doesn't have fitting include block), it prints out
an error message indicating which .h file needs to be added to the
file.
The conversion was done in the following steps.
1. The initial automatic conversion of all .c files updated slightly
over 4000 files, deleting around 700 includes and adding ~480 gfp.h
and ~3000 slab.h inclusions. The script emitted errors for ~400
files.
2. Each error was manually checked. Some didn't need the inclusion,
some needed manual addition while adding it to implementation .h or
embedding .c file was more appropriate for others. This step added
inclusions to around 150 files.
3. The script was run again and the output was compared to the edits
from #2 to make sure no file was left behind.
4. Several build tests were done and a couple of problems were fixed.
e.g. lib/decompress_*.c used malloc/free() wrappers around slab
APIs requiring slab.h to be added manually.
5. The script was run on all .h files but without automatically
editing them as sprinkling gfp.h and slab.h inclusions around .h
files could easily lead to inclusion dependency hell. Most gfp.h
inclusion directives were ignored as stuff from gfp.h was usually
wildly available and often used in preprocessor macros. Each
slab.h inclusion directive was examined and added manually as
necessary.
6. percpu.h was updated not to include slab.h.
7. Build test were done on the following configurations and failures
were fixed. CONFIG_GCOV_KERNEL was turned off for all tests (as my
distributed build env didn't work with gcov compiles) and a few
more options had to be turned off depending on archs to make things
build (like ipr on powerpc/64 which failed due to missing writeq).
* x86 and x86_64 UP and SMP allmodconfig and a custom test config.
* powerpc and powerpc64 SMP allmodconfig
* sparc and sparc64 SMP allmodconfig
* ia64 SMP allmodconfig
* s390 SMP allmodconfig
* alpha SMP allmodconfig
* um on x86_64 SMP allmodconfig
8. percpu.h modifications were reverted so that it could be applied as
a separate patch and serve as bisection point.
Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.
Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
The rule is that all inodes in the orphan dir have ORPHANED_FL,
otherwise we treated it as an ERROR. This rule works well except
for some rare cases of reflink operation:
http://oss.oracle.com/bugzilla/show_bug.cgi?id=1215
The problem is caused by how reflink and our orphan_scan thread
interact.
* The orphan scan pulls the orphans into a queue first, then runs the
queue at a later time. We only hold the orphan_dir's lock
during scanning.
* Reflink create a oprhaned target in orphan_dir as its first step.
It removes the target and clears the flag as the final step.
These two steps take the orphan_dir's lock, but it is not held for
the duration.
Based on the above semantics, a reflink inode can be moved out of the
orphan dir and have its ORPHANED_FL cleared before the queue of orphans
is run. This leads to a ERROR in ocfs2_query_wipde_inode().
This patch teaches ocfs2_query_wipe_inode() to detect previously
orphaned reflink targets. If a reflink fails or a crash occurs during
the relfink operation, the inode will retain ORPHANED_FL and will be
properly wiped.
Signed-off-by: Tristan Ye <tristan.ye@oracle.com>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
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: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan 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: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Get rid of the drop 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_drop helper to __dquot_drop
and vfs_dq_drop to dquot_drop to have a consistent namespace.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Currently clear_inode calls vfs_dq_drop directly. This means
we tie the quota code into the VFS. Get rid of that and make the
filesystem responsible for the drop inside the ->clear_inode
superblock operation.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Get rid of the alloc_inode and free_inode dquot operations - they are
always called from the filesystem and if a filesystem really needs
their own (which none currently does) it can just call into it's
own routine directly.
Also get rid of the vfs_dq_alloc/vfs_dq_free wrappers and always
call the lowlevel dquot_alloc_inode / dqout_free_inode routines
directly, which now lose the number argument which is always 1.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Now with xattr refcount support, we need to check whether
we have xattr refcounted before we remove the refcount tree.
Now the mechanism is:
1) Check whether i_clusters == 0, if no, exit.
2) check whether we have i_xattr_loc in dinode. if yes, exit.
2) Check whether we have inline xattr stored outside, if yes, exit.
4) Remove the tree.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
The next step in divorcing metadata I/O management from struct inode is
to pass struct ocfs2_caching_info to the journal functions. Thus the
journal locks a metadata cache with the cache io_lock function. It also
can compare ci_last_trans and ci_created_trans directly.
This is a large patch because of all the places we change
ocfs2_journal_access..(handle, inode, ...) to
ocfs2_journal_access..(handle, INODE_CACHE(inode), ...).
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Similar ip_last_trans, ip_created_trans tracks the creation of a journal
managed inode. This specifically tracks what transaction created the
inode. This is so the code can know if the inode has ever been written
to disk.
This behavior is desirable for any journal managed object. We move it
to struct ocfs2_caching_info as ci_created_trans so that any object
using ocfs2_caching_info can rely on this behavior.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
We have the read side of metadata caching isolated to struct
ocfs2_caching_info, now we need the write side. This means the journal
functions. The journal only does a couple of things with struct inode.
This change moves the ip_last_trans field onto struct
ocfs2_caching_info as ci_last_trans. This field tells the journal
whether a pending journal flush is required.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
We are really passing the inode into the ocfs2_read/write_blocks()
functions to get at the metadata cache. This commit passes the cache
directly into the metadata block functions, divorcing them from the
inode.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
We don't really want to cart around too many new fields on the
ocfs2_caching_info structure. So let's wrap all our access of the
parent object in a set of operations. One pointer on caching_info, and
more flexibility to boot.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
We want to use the ocfs2_caching_info structure in places that are not
inodes. To do that, it can no longer rely on referencing the inode
directly.
This patch moves the flags to ocfs2_caching_info->ci_flags, stores
pointers to the parent's locks on the ocfs2_caching_info, and renames
the constants and flags to reflect its independant state.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Add lockdep support to OCFS2. The support also covers all of the cluster
locks except for open locks, journal locks, and local quotafile locks. These
are special because they are acquired for a node, not for a particular process
and lockdep cannot deal with such type of locking.
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Joel Becker <joel.becker@oracle.com>
For nfs exporting, ocfs2_get_dentry() returns the dentry for fh.
ocfs2_get_dentry() may read from disk when the inode is not in memory,
without any cross cluster lock. this leads to the file system loading a
stale inode.
This patch fixes above problem.
Solution is that in case of inode is not in memory, we get the cluster
lock(PR) of alloc inode where the inode in question is allocated from (this
causes node on which deletion is done sync the alloc inode) before reading
out the inode itsself. then we check the bitmap in the group (the inode in
question allcated from) to see if the bit is clear. if it's clear then it's
stale. if the bit is set, we then check generation as the existing code
does.
We have to read out the inode in question from disk first to know its alloc
slot and allot bit. And if its not stale we read it out using ocfs2_iget().
The second read should then be from cache.
And also we have to add a per superblock nfs_sync_lock to cover the lock for
alloc inode and that for inode in question. this is because ocfs2_get_dentry()
and ocfs2_delete_inode() lock on them in reverse order. nfs_sync_lock is locked
in EX mode in ocfs2_get_dentry() and in PR mode in ocfs2_delete_inode(). so
that mutliple ocfs2_delete_inode() can run concurrently in normal case.
[mfasheh@suse.com: build warning fixes and comment cleanups]
Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Acked-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
In ocfs2, the inode block search looks for the "emptiest" inode
group to allocate from. So if an inode alloc file has many equally
(or almost equally) empty groups, new inodes will tend to get
spread out amongst them, which in turn can put them all over the
disk. This is undesirable because directory operations on conceptually
"nearby" inodes force a large number of seeks.
So we add ip_last_used_group in core directory inodes which records
the last used allocation group. Another field named ip_last_used_slot
is also added in case inode stealing happens. When claiming new inode,
we passed in directory's inode so that the allocation can use this
information.
For more details, please see
http://oss.oracle.com/osswiki/OCFS2/DesignDocs/InodeAllocationStrategy.
Signed-off-by: Tao Ma <tao.ma@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Since we've now got a directory format capable of handling a large number of
entries, we can increase the maximum link count supported. This only gets
increased if the directory indexing feature is turned on.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Acked-by: Joel Becker <joel.becker@oracle.com>
This patch makes use of Ocfs2's flexible btree code to add an additional
tree to directory inodes. The new tree stores an array of small,
fixed-length records in each leaf block. Each record stores a hash value,
and pointer to a block in the traditional (unindexed) directory tree where a
dirent with the given name hash resides. Lookup exclusively uses this tree
to find dirents, thus providing us with constant time name lookups.
Some of the hashing code was copied from ext3. Unfortunately, it has lots of
unfixed checkpatch errors. I left that as-is so that tracking changes would
be easier.
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Acked-by: Joel Becker <joel.becker@oracle.com>
The per-metadata-type ocfs2_journal_access_*() functions hook up jbd2
commit triggers and allow us to compute metadata ecc right before the
buffers are written out. This commit provides ecc for inodes, extent
blocks, group descriptors, and quota blocks. It is not safe to use
extened attributes and metaecc at the same time yet.
The ocfs2_extent_tree and ocfs2_path abstractions in alloc.c both hide
the type of block at their root. Before, it didn't matter, but now the
root block must use the appropriate ocfs2_journal_access_*() function.
To keep this abstract, the structures now have a pointer to the matching
journal_access function and a wrapper call to call it.
A few places use naked ocfs2_write_block() calls instead of adding the
blocks to the journal. We make sure to calculate their checksum and ecc
before the write.
Since we pass around the journal_access functions. Let's typedef them
in ocfs2.h.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
Add block check calls to the read_block validate functions. This is the
almost all of the read-side checking of metaecc. xattr buckets are not checked
yet. Writes are also unchecked, and so a read-write mount will quickly fail.
Signed-off-by: Joel Becker <joel.becker@oracle.com>
Signed-off-by: Mark Fasheh <mfasheh@suse.com>
