This just moves code around for the most part. It was pulled out as
a separate patch to avoid cluttering up some upcoming patches which
are more substantive. The point is basically to group everything
related to initializing the snapshot context together.
The only functional change is that rbd_header_from_disk() now
ensures the (in-core) header it is passed is zero-filled. This
allows a simpler error handling path in rbd_header_from_disk().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Fix a few spots in rbd_header_from_disk() to use sizeof (object)
rather than sizeof (type). Use a local variable to record sizes
to shorten some lines and improve readability.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Fix a number of spots where a pointer value that is known to
have become invalid but was not reset to null.
Also, toss in a change so we use sizeof (object) rather than
sizeof (type).
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The snap_names_len field of an rbd_image_header structure is defined
with type size_t. That field is used as both the source and target
of 64-bit byte-order swapping operations though, so it's best to
define it with type u64 instead.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The purpose of __rbd_init_snaps_header() is to compare a new
snapshot context with an rbd device's list of existing snapshots.
It updates the list by adding any new snapshots or removing any
that are not present in the new snapshot context.
The code as written is a little confusing, because it traverses both
the existing snapshot list and the set of snapshots in the snapshot
context in reverse. This was done based on an assumption about
snapshots that is not true--namely that a duplicate snapshot name
could cause an error in intepreting things if they were not
processed in ascending order.
These precautions are not necessary, because:
- all snapshots are uniquely identified by their snapshot id
- a new snapshot cannot be created if the rbd device has another
snapshot with the same name
(It is furthermore not currently possible to rename a snapshot.)
This patch re-implements __rbd_init_snaps_header() so it passes
through both the existing snapshot list and the entries in the
snapshot context in forward order. It still does the same thing
as before, but I find the logic considerably easier to understand.
By going forward through the names in the snapshot context, there
is no longer a need for the rbd_prev_snap_name() helper function.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
If a read-only rbd device is opened for writing in rbd_open(), it
returns without dropping the just-acquired device reference.
Fix this by moving the read-only check before getting the reference.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Create a simple helper that handles the common case of calling
__rbd_refresh_header() while holding the ctl_mutex.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Add a new parameter to __rbd_refresh_header() through which the
version of the header object is passed back to the caller. In most
cases this isn't needed. The main motivation is to normalize
(almost) all calls to __rbd_refresh_header() so they are all
wrapped immediately by mutex_lock()/mutex_unlock().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This fixes a few issues in rbd_header_from_disk():
- There is a check intended to catch overflow, but it's wrong in
two ways.
- First, the type we don't want to overflow is size_t, not
unsigned int, and there is now a SIZE_MAX we can use for
use with that type.
- Second, we're allocating the snapshot ids and snapshot
image sizes separately (each has type u64; on disk they
grouped together as a rbd_image_header_ondisk structure).
So we can use the size of u64 in this overflow check.
- If there are no snapshots, then there should be no snapshot
names. Enforce this, and issue a warning if we encounter a
header with no snapshots but a non-zero snap_names_len.
- When saving the snapshot names into the header, be more direct
in defining the offset in the on-disk structure from which
they're being copied by using "snap_count" rather than "i"
in the array index.
- If an error occurs, the "snapc" and "snap_names" fields are
freed at the end of the function. Make those fields be null
pointers after they're freed, to be explicit that they are
no longer valid.
- Finally, move the definition of the local variable "i" to the
innermost scope in which it's needed.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
All of the callers of rbd_req_sync_op() except one pass a non-null
"ops" pointer. The only one that does not is rbd_req_sync_read(),
which passes CEPH_OSD_OP_READ as its "opcode" and, CEPH_OSD_FLAG_READ
for "flags".
By allocating the ops array in rbd_req_sync_read() and moving the
special case code for the null ops pointer into it, it becomes
clear that much of that code is not even necessary.
In addition, the "opcode" argument to rbd_req_sync_op() is never
actually used, so get rid of that.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
rbd_header_add_snap() passes the address of a version variable to
rbd_req_sync_exec(), but it ignores the result. Just pass a null
pointer instead.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Either rbd_create_rw_ops() will succeed, or it will fail because a
memory allocation failed. Have it just return a valid pointer or
null rather than stuffing a pointer into a provided address and
returning an errno.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
It's not obvious whether the snapshot pointer whose address is
provided to __rbd_add_snap_dev() will be assigned by that function.
Change it to return the snapshot, or a pointer-coded errno in the
event of a failure.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
rbd_req_sync_unwatch() only ever uses rbd_dev->header_name as the
value of its "object_name" parameter, and that value is available
within the function already. So get rid of the parameter.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
rbd_req_sync_notify_ack() only ever uses rbd_dev->header_name as the
value of its "object_name" parameter, and that value is available
within the function already. So get rid of the parameter.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
rbd_req_sync_notify() only ever uses rbd_dev->header_name as the
value of its "object_name" parameter, and that value is available
within the function already. So get rid of the parameter.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
rbd_req_sync_watch() is only called in one place, and in that place
it passes rbd_dev->header_name as the value of the "object_name"
parameter. This value is available within the function already.
Having the extra parameter leaves the impression the object name
could take on different values, but it does not.
So get rid of the parameter. We can always add it back again if
we find we want to watch some other object in the future.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Both rbd_register_snap_dev() and __rbd_remove_snap_dev() have
rbd_dev parameters that are unused. Remove them.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The function rbd_header_from_disk() is only called in one spot, and
it passes GFP_KERNEL as its value for the gfp_flags parameter.
Just drop that parameter and substitute GFP_KERNEL everywhere within
that function it had been used. (If we find we need the parameter
again in the future it's easy enough to add back again.)
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The "snapc" parameter to in rbd_req_sync_read() is not used, so
get rid of it.
Reported-by: Josh Durgin <josh.durgin@inktank.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The "id" field of an rbd device structure represents the unique
client-local device id mapped to the underlying rbd image. Each rbd
image will have another id--the image id--and each snapshot has its
own id as well. The simple name "id" no longer conveys the
information one might like to have.
Rename the device "id" field in struct rbd_dev to be "dev_id" to
make it a little more obvious what we're dealing with without having
to think more about context.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
If an rbd image header is read and it doesn't begin with the
expected magic information, a warning is displayed. This is
a fairly simple test, but it could be extended at some point.
Fix the comparison so it actually looks at the "text" field
rather than the front of the structure.
In any case, encapsulate the validity test in its own function.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There was a dout() call in rbd_do_request() that was reporting
the reporting the offset as the length and vice versa. While
fixing that I did a quick scan of other dout() calls and fixed
a couple of other minor things.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
This just replaces a while loop with list_for_each_entry_safe()
in __rbd_remove_all_snaps().
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
In commit c666601a there was inadvertently added an extra
initialization of rbd_dev->header_rwsem. This gets rid of the
duplicate.
Reported-by: Guangliang Zhao <gzhao@suse.com>
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
The snap_seq field in an rbd_image_header structure held the value
from the rbd image header when it was last refreshed. We now
maintain this value in the snapc->seq field. So get rid of the
other one.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
In rbd_header_add_snap() there is code to set snapc->seq to the
just-added snapshot id. This is the only remnant left of the
use of that field for recording which snapshot an rbd_dev was
associated with. That functionality is no longer supported,
so get rid of that final bit of code.
Doing so means we never actually set snapc->seq any more. On the
server, the snapshot context's sequence value represents the highest
snapshot id ever issued for a particular rbd image. So we'll make
it have that meaning here as well. To do so, set this value
whenever the rbd header is (re-)read. That way it will always be
consistent with the rest of the snapshot context we maintain.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
In rbd_header_set_snap(), there is logic to make the snap context's
seq field get set to a particular snapshot id, or 0 if there is no
snapshot for the rbd image.
This seems to be an artifact of how the current snapshot id for an
rbd_dev was recorded before the rbd_dev->snap_id field began to be
used for that purpose.
There's no need to update the value of snapc->seq here any more, so
stop doing it. Tidy up a few local variables in that function
while we're at it.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
In what appears to be an artifact of a different way of encoding
whether an rbd image maps a snapshot, __rbd_refresh_header() has
code that arranges to update the seq value in an rbd image's
snapshot context to point to the first entry in its snapshot
array if that's where it was pointing initially.
We now use rbd_dev->snap_id to record the snapshot id--using the
special value CEPH_NOSNAP to indicate the rbd_dev is not mapping a
snapshot at all.
There is therefore no need to check for this case, nor to update the
seq value, in __rbd_refresh_header(). Just preserve the seq value
that rbd_read_header() provides (which, at the moment, is nothing).
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Previously the original header version was sent. Now, we update it
when the header changes.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@inktank.com>
This prevents a race between requests with a given snap context and
header updates that free it. The osd client was already expecting the
snap context to be reference counted, since it get()s it in
ceph_osdc_build_request and put()s it when the request completes.
Also remove the second down_read()/up_read() on header_rwsem in
rbd_do_request, which wasn't actually preventing this race or
protecting any other data.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@inktank.com>
If an image was mapped to a snapshot, the size of the head version
would be shown. Protect capacity with header_rwsem, since it may
change.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Snapshots cannot be resized, and the new capacity of head should not
be reflected by the snapshot.
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
When a snapshot is deleted, the OSD will return ENOENT when reading
from it. This is normally interpreted as a hole by rbd, which will
return zeroes. To minimize the time in which this can happen, stop
requests early when we are notified that our snapshot no longer
exists.
[elder@inktank.com: updated __rbd_init_snaps_header() logic]
Signed-off-by: Josh Durgin <josh.durgin@inktank.com>
Reviewed-by: Alex Elder <elder@inktank.com>
Several functions include a num_reply parameter, but it is never
used. Just get rid of it everywhere--it seems to be something
that never got fully implemented.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Use the name "ceph_opts" consistently (rather than just "opt") for
pointers to a ceph_options structure.
Change the few spots that don't use "rbd_opts" for a rbd_options
pointer to match the rest.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Rename variables named "obj" which represent object names so they're
consistently named "object_name".
Rename the "cls" and "method" parameters in rbd_req_sync_exec()
to be "class_name" and "method_name", and make similar changes
to the names of local variables in that function representing
the lengths of those names.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
An rbd image is not a single object, but a logical construct made up
of an aggregation of objects.
Rename some fields in struct rbd_dev, in hopes of reinforcing this.
obj --> image_name
obj_len --> image_name_len
obj_md_name --> header_name
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Most variables that represent a struct rbd_device are named
"rbd_dev", but in some cases "dev" is used instead. Change all the
"dev" references so they use "rbd_dev" consistently, to make it
clear from the name that we're working with an RBD device (as
opposed to, for example, a struct device). Similarly, change the
name of the "dev" field in struct rbd_notify_info to be "rbd_dev".
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is no need to impose a small limit the length of the snapshot
name recorded for an rbd image in a struct rbd_dev. Remove the
limitation by allocating space for the snapshot name dynamically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is no need to impose a small limit the length of the rbd image
name recorded in a struct rbd_dev. Remove the limitation by
allocating space for the image name dynamically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is no need to impose a small limit the length of the header
name recorded for an rbd image in a struct rbd_dev. Remove the
limitation by allocating space for the header name dynamically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is no need to impose a small limit the length of the object
prefix recorded for an rbd image in a struct rbd_image_header.
Remove the limitation by allocating space for the object prefix
dynamically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
There is no need to impose a small limit the length of the pool name
recorded for an rbd image in a struct rbd_device. Remove the
limitation by allocating space for the pool name ynamically.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Add an entry under /sys/bus/rbd/devices/<N>/ named "pool_id" that
provides the id for the pool the rbd image is assocatied with. This
is in addition to the pool name already provided.
Rename the "poolid" field in struct rbd_device to be "pool_id".
Update the documentation to reflect the addition of this new entry.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Each rbd image has a name that forms the basis of all data objects
backing the device. Old (format 1) images refer to this name as the
"block name," while new (format 2) images use the term "object
prefix" for this.
Change the field name in the in-core rbd image header structure to
reflect the more modern usage. We intentionally keep the the name
"block_name" in the on-disk definition for format 1 image headers.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Define a new function dup_token(), to be used during argument
parsing for making dynamically-allocated copies of tokens being
parsed.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
In rbd_req_sync_notify_ack(), a local variable was needlessly being
used to hold a null pointer. Just pass NULL instead.
Signed-off-by: Alex Elder <elder@inktank.com>
Reviewed-by: Yehuda Sadeh <yehuda@inktank.com>
Reviewed-by: Josh Durgin <josh.durgin@inktank.com>
Sparse complains about this because:
drivers/block/rbd.c:996:20: warning: cast to restricted __le32
drivers/block/rbd.c:996:20: warning: cast from restricted __le16
These are set in osd_req_encode_op() and they are le16.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Alex Elder <elder@inktank.com>
This function rereads the entire header and handles any changes in
it, not just changes in snapshots.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Snapshot sizes should be the same type as regular image sizes. This
only affects their displayed size in sysfs, not the reported size of
an actual block device sizes.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
The snapid parameters passed to rbd_do_op() and rbd_req_sync_op()
are now always either a valid snapid or an explicit CEPH_NOSNAP.
[elder@dreamhost.com: Rephrased the description]
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
When a device was open at a snapshot, and snapshots were deleted or
added, data from the wrong snapshot could be read. Instead of
assuming the snap context is constant, store the actual snap id when
the device is initialized, and rely on the OSDs to signal an error
if we try reading from a snapshot that was deleted.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
This is updated whenever a snapshot is added or deleted, and the
snapc pointer is changed with every refresh of the header.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
ondisk->snap_count is read from disk via rbd_req_sync_read() and thus
needs validation. Otherwise, a bogus `snap_count' could overflow the
kmalloc() size, leading to memory corruption.
Also use `u32' consistently for `snap_count'.
[elder@dreamhost.com: changed to use UINT_MAX rather than ULONG_MAX]
Signed-off-by: Xi Wang <xi.wang@gmail.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
We should use the gfp_flags that the caller specified instead of
GFP_KERNEL here.
There is only one caller and it uses GFP_KERNEL, so this change is
just a cleanup and doesn't change how the code works.
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
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: Alex Elder <elder@inktank.com>
Signed-off-by: Sage Weil <sage@inktank.com>
A recent change made changes to the rbd_client_list be protected by
a spinlock. Unfortunately in rbd_put_client(), the lock is taken
before possibly dropping the last reference to an rbd_client, and on
the last reference that eventually calls flush_workqueue() which can
sleep.
The problem was flagged by a debug spinlock warning:
BUG: spinlock wrong CPU on CPU#3, rbd/27814
The solution is to move the spinlock acquisition and release inside
rbd_client_release(), which is the spot where it's really needed for
protecting the removal of the rbd_client from the client list.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Reviewed-by: Sage Weil <sage@newdream.net>
A new temporary header is allocated each time the header changes, but
only the changed properties are copied over. We don't need a new
semaphore for each header update.
This addresses http://tracker.newdream.net/issues/2174
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
Reviewed-by: Alex Elder <elder@dreamhost.com>
Currently an rbd device's id is released when it is removed, but it
is done before the code is run to clean up sysfs-related files (such
as /sys/bus/rbd/devices/1).
It's possible that an rbd is still in use after the rbd_remove()
call has been made. It's essentially the same as an active inode
that stays around after it has been removed--until its final close
operation. This means that the id shows up as free for reuse at a
time it should not be.
The effect of this was seen by Jens Rehpoehler, who:
- had a filesystem mounted on an rbd device
- unmapped that filesystem (without unmounting)
- found that the mount still worked properly
- but hit a panic when he attempted to re-map a new rbd device
This re-map attempt found the previously-unmapped id available.
The subsequent attempt to reuse it was met with a panic while
attempting to (re-)install the sysfs entry for the new mapped
device.
Fix this by holding off "putting" the rbd id, until the rbd_device
release function is called--when the last reference is finally
dropped.
Note: This fixes: http://tracker.newdream.net/issues/1907
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Here is another set of small code tidy-ups:
- Define SECTOR_SHIFT and SECTOR_SIZE, and use these symbolic
names throughout. Tell the blk_queue system our physical
block size, in the (unlikely) event we want to use something
other than the default.
- Delete the definition of struct rbd_info, which is never used.
- Move the definition of dev_to_rbd() down in its source file,
just above where it gets first used, and change its name to
dev_to_rbd_dev().
- Replace an open-coded operation in rbd_dev_release() to use
dev_to_rbd_dev() instead.
- Calculate the segment size for a given rbd_device just once in
rbd_init_disk().
- Use the '%zd' conversion specifier in rbd_snap_size_show(),
since the value formatted is a size_t.
- Switch to the '%llu' conversion specifier in rbd_snap_id_show().
since the value formatted is unsigned.
Signed-off-by: Alex Elder <elder@dreamhost.com>
A few blocks of code are rearranged a bit here:
- In rbd_header_from_disk():
- Don't bother computing snap_count until we're sure the
on-disk header starts with a good signature.
- Move a few independent lines of code so they are *after* a
check for a failed memory allocation.
- Get rid of unnecessary local variable "ret".
- Make a few other changes in rbd_read_header(), similar to the
above--just moving things around a bit while preserving the
functionality.
- In rbd_rq_fn(), just assign rq in the while loop's controlling
expression rather than duplicating it before and at the end of
the loop body. This allows the use of "continue" rather than
"goto next" in a number of spots.
- Rearrange the logic in snap_by_name(). End result is the same.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Once rbd_bus_type is registered, it allows an "add" operation via
the /sys/bus/rbd/add bus attribute, and adding a new rbd device that
way establishes a connection between the device and rbd_root_dev.
But rbd_root_dev is not registered until after the rbd_bus_type
registration is complete. This could (in principle anyway) result
in an invalid state.
Since rbd_root_dev has no tie to rbd_bus_type we can reorder these
two initializations and never be faced with this scenario.
In addition, unregister the device in the event the bus registration
fails at module init time.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
The mon_addrs buffer in rbd_add is used to hold a copy of the
monitor IP addresses supplied via /sys/bus/rbd/add. That is
passed to rbd_get_client(), which never modifies it (nor do
any of the functions it gets passed to thereafter)--the mon_addr
parameter to rbd_get_client() is a pointer to constant data, so it
can't be modifed. Furthermore, rbd_get_client() has the length of
the mon_addrs buffer and that is used to ensure nothing goes beyond
its end.
Based on all this, there is no reason that a buffer needs to
be used to hold a copy of the mon_addrs provided via
/sys/bus/rbd/add. Instead, the location within that passed-in
buffer can be provided, along with the length of the "token"
therein which represents the monitor IP's.
A small change to rbd_add_parse_args() allows the address within the
buffer to be passed back, and the length is already returned. This
now means that, at least from the perspective of this interface,
there is no such thing as a list of monitor addresses that is too
long.
Signed-off-by: Alex Elder <elder@dreamhost.com>
The argument parsing routine already computes the size of the
mon_addrs buffer it extracts from the "command." Pass it to the
caller so it can use it to provide the length to rbd_get_client().
Signed-off-by: Alex Elder <elder@dreamhost.com>
This is a bit gratuitous, but there are a few things that can be
verified at build time rather than run time, so do that.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Make use of a few simple helper routines to parse the arguments
rather than sscanf(). This will treat both missing and too-long
arguments as invalid input (rather than silently truncating the
input in the too-long case). In time this can also be used by
rbd_add() to use the passed-in buffer in place, rather than copying
its contents into new buffers.
It appears to me that the sscanf() previously used would not
correctly handle a supplied snapshot--the two final "%s" conversion
specifications were not separated by a space, and I'm not sure
how sscanf() handles that situation. It may not be well-defined.
So that may be a bug this change fixes (but I didn't verify that).
The sizes of the mon_addrs and options buffers are now passed to
rbd_add_parse_args(), so they can be supplied to copy_token().
Signed-off-by: Alex Elder <elder@dreamhost.com>
Move the code that parses the arguments provided to rbd_add() (which
are supplied via /sys/bus/rbd/add) into a separate function.
Also rename the "mon_dev_name" variable in rbd_add() to be
"mon_addrs". The variable represents a list of one or more
comma-separated monitor IP addresses, each with an optional port
number. I think "mon_addrs" captures that notion a little better.
Signed-off-by: Alex Elder <elder@dreamhost.com>
If a couple pointers are initialized to NULL then a single
"out_nomem" label can be used for all of the memory allocation
failure cases in rbd_add().
Also, get rid of the "irc" local variable there. There is no
real need for "rc" to be type ssize_t, and it can be used in
the spot "irc" was.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
The length of the string containing the monitor address
specification(s) will never exceed the length of the string passed
in to rbd_add(). The same holds true for the ceph + rbd options
string. So reduce the amount of memory allocated for these to
that length rather than the maximum (1024 bytes).
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Since rbd_get_client() currently returns an error code. It assigns
the rbd_client field of the rbd_device structure it is passed if
successful. Instead, have it return the created rbd_client
structure and return a pointer-coded error if there is an error.
This makes the assignment of the client pointer more obvious at the
call site.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Here are a few very simple cleanups:
- Add a "RBD_" prefix to the two driver name string definitions.
- Move the definition of struct rbd_request below struct rbd_req_coll
to avoid the need for an empty declaration of the latter.
- Move and group the definitions of rbd_root_dev_release() and
rbd_root_dev, as well as rbd_bus_type and rbd_bus_attrs[],
close to the top of the file. Arrange the latter so
rbd_bus_type.bus_attrs can be initialized statically.
- Get rid of an unnecessary local variable in rbd_open().
- Rework some hokey logic in rbd_bus_add_dev(), so the value of
"ret" at the end is either 0 or -ENOENT to avoid the need for
the code duplication that was there.
- Rename a goto target in rbd_add().
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
The spinlock used to protect rbd_client_list is named "node_lock".
Rename it to "rbd_client_list_lock" to make it more obvious what
it's for.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Since rbd_client_create() is only called in one place, move the
acquisition of the mutex around that call inside that function.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Since rbd_get_client() is only called in one place, move the
acquisition of the mutex around that call inside that function.
Furthermore, within rbd_get_client(), it appears the mutex only
needs to be held while calling rbd_client_create(). (Moving
the lock inside that function will wait for the next patch.)
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
In rbd_get_client(), if a client is reused, a number of things
get done while still holding the list lock unnecessarily.
This just moves a few things that need no lock protection outside
the lock.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
It used to be that selecting a new unique identifier for an added
rbd device required searching all existing ones to find the highest
id is used. A recent change made that unnecessary, but made it
so that id's used were monotonically non-decreasing. It's a bit
more pleasant to have smaller rbd id's though, and this change
makes ids get allocated as they were before--each new id is one more
than the maximum currently in use.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
The only time entries are added to or removed from the global
rbd_dev_list is exactly when a "put" or "get" operation is being
performed on a rbd_dev's id. So just move the list management code
into get/put routines.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
The rbd_dev_list is just a simple list of all the current
rbd_devices. Using the ctl_mutex as a concurrency guard is
overkill. Instead, use a spinlock for that specific purpose.
This also reduces the window that the ctl_mutex needs to be held in
rbd_add().
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
In order to select a new unique identifier for an added rbd device,
the list of all existing ones is searched and a value one greater
than the highest id is used.
The list search can be avoided by using an atomic variable that
keeps track of the current highest id. Using a get/put model for
id's we can limit the boundless growth of id numbers a bit by
arranging to reuse the current highest id once it gets released.
Add these calls to "put" the id when an rbd is getting removed.
Note that this changes the pattern of device id's used--new values
will never be below the highest one seen so far (even if there
exists an unused lower one). I assert this is OK because the key
property of an rbd id is its uniqueness, not its magnitude.
Regardless, a follow-on patch will restore the old way of doing
things, I just think this commit just makes the incremental change
to atomics a little easier to understand.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Move the loop that finds a new unique rbd id to use into
its own helper function.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
There's already a constant for this anyway.
Since rbd_header_set_snap() is only used to set the rbd device
snap_name field, just do that within that function rather than
having it take the snap_name as an argument.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
v2: Changed interface rbd_header_set_snap() so it explicitly updates
the snap_name in the rbd_device. Also added a BUILD_BUG_ON()
to verify the size of the snap_name field is sufficient for
SNAP_HEAD_NAME.
The rbd_device structure maintains a duplicate copy of the
ceph_client pointer maintained in its rbd_client structure. There
appears to be no good reason for this, and its presence presents a
risk of them getting out of synch or otherwise misused. So kill it
off, and use the rbd_client copy only.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
ceph_parse_options() takes the address of a pointer as an argument
and uses it to return the address of an allocated structure if
successful. With this interface is not evident at call sites that
the pointer is always initialized. Change the interface to return
the address instead (or a pointer-coded error code) to make the
validity of the returned pointer obvious.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
Some minor cleanups in "drivers/block/rbd.c:
- Use the more meaningful "RBD_MAX_OBJ_NAME_LEN" in place if "96"
in the definition of RBD_MAX_MD_NAME_LEN.
- Use DEFINE_SPINLOCK() to define and initialize node_lock.
- Drop a needless (char *) cast in parse_rbd_opts_token().
- Make a few minor formatting changes.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
* 'for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/sage/ceph-client:
rbd: fix safety of rbd_put_client()
rbd: fix a memory leak in rbd_get_client()
ceph: create a new session lock to avoid lock inversion
ceph: fix length validation in parse_reply_info()
ceph: initialize client debugfs outside of monc->mutex
ceph: change "ceph.layout" xattr to be "ceph.file.layout"
The rbd_client structure uses a kref to arrange for cleaning up and
freeing an instance when its last reference is dropped. The cleanup
routine is rbd_client_release(), and one of the things it does is
delete the rbd_client from rbd_client_list. It acquires node_lock
to do so, but the way it is done is still not safe.
The problem is that when attempting to reuse an existing rbd_client,
the structure found might already be in the process of getting
destroyed and cleaned up.
Here's the scenario, with "CLIENT" representing an existing
rbd_client that's involved in the race:
Thread on CPU A | Thread on CPU B
--------------- | ---------------
rbd_put_client(CLIENT) | rbd_get_client()
kref_put() | (acquires node_lock)
kref->refcount becomes 0 | __rbd_client_find() returns CLIENT
calls rbd_client_release() | kref_get(&CLIENT->kref);
| (releases node_lock)
(acquires node_lock) |
deletes CLIENT from list | ...and starts using CLIENT...
(releases node_lock) |
and frees CLIENT | <-- but CLIENT gets freed here
Fix this by having rbd_put_client() acquire node_lock. The result
could still be improved, but at least it avoids this problem.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
If an existing rbd client is found to be suitable for use in
rbd_get_client(), the rbd_options structure is not being
freed as it should. Fix that.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
New rbd device structures get initialized in rbd_add(). Many of
the fields rely on being initially zero-filled. However we lockdep
was noticing that the rw_semaphore embedded in the header field
was not getting properly initialized. Fix that.
Signed-off-by: Alex Elder <elder@dreamhost.com>
Signed-off-by: Sage Weil <sage@newdream.net>
This doesn't interact with resizing well, since it doesn't set the
size of the device to the size at the snapshot. It's also an expensive
operation to be synchronous. Rollback can still be done with the
userspace rbd tool.
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
* 'for-linus' of git://ceph.newdream.net/git/ceph-client:
libceph: fix double-free of page vector
ceph: fix 32-bit ino numbers
libceph: force resend of osd requests if we skip an osdmap
ceph: use kernel DNS resolver
ceph: fix ceph_monc_init memory leak
ceph: let the set_layout ioctl set single traits
Revert "ceph: don't truncate dirty pages in invalidate work thread"
ceph: replace leading spaces with tabs
libceph: warn on msg allocation failures
libceph: don't complain on msgpool alloc failures
libceph: always preallocate mon connection
libceph: create messenger with client
ceph: document ioctls
ceph: implement (optional) max read size
ceph: rename rsize -> rasize
ceph: make readpages fully async
This simplifies the init/shutdown paths, and makes client->msgr available
during the rest of the setup process.
Signed-off-by: Sage Weil <sage@newdream.net>
This is a resend from the original, changing the title from PATCH to
RFC(since this is a review for commit, and I should have put that the first go around).
and also removing some of the commit's with ia64 and bash since it is significant.
let me know if I might have missed anything etc..
Signed-off-by: Justin P. Mattock <justinmattock@gmail.com>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>
This improves performance since more requests can be merged.
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Josh Durgin <josh.durgin@dreamhost.com>
We were missing this cleanup, so when a device was released
the osd didn't clean up its watchers list, so following notifications
could be slow as osd needed to timeout on the client.
Signed-off-by: Yehuda Sadeh <yehuda@hq.newdream.net>
