Proposed way to do exclusive open:
0. First of all, we have to perform most of the work in kernel space;
1. Client exclusively opens the file with IT_RELEASE_OPEN.
1.1 exclusive open means the open will fail if the file is being opened by somebody else;
2. the MDT will handle IT_RELEASE as follows:
2.1 Revoke OPEN_LOCK on this file, just request EX mode of MDS_INODELOCK_OPEN lock and
release it;
2.2 Acquire a rwsem, say open_rwsem, with write mode before trying to the file; for the
normal open, it should acquire read mode of open_rwsem;
2.3 Check if the file is already being opened by others, if not return with -EBUSY;
2.4 Check if the file can be released;
2.5 Set a special flag in struct mdt_file_data to mark this open is exclusive;
2.5 Release open rwsem.
>From now on, if the file is opened by others, it will mark mdt_file_data that the
exclusive open is broken.
3. Client: if IT_RELEASE_OPEN is finished successfully, and do followings:
3.1 Acquire full PW or EX extent lock to flush dirty cache;
3.2 Pack the handle of layout lock, data version and other attars;
3.3 Close the file with IT_RELEASE_CLOSE.
4. Back to MDT to handle IT_RELEASE CLOSE:
4.1 Grab the open_rwsem
4.2 Check if the exclusive open has ever been broken, in that case, the RELEASE process
will fail;
4.3 Verify the data version matches archive;
4.4 Grab EX layout lock
4.5 Swap the layout
4.6 Release EX layout lock
4.7 Close the exclusive open
Basically we avoid granting EX layout lock back to client and introduce exclusive open so
that we know it if the file has ever being accessed. I hope this can simplify things
a little bit. Also, exclusive open can be used to implement file lease.
In this patch, a framework of lease is implemented. However,
only exclusive lease is supported right now.
To apply a lease, MDS_OPEN_LEASE must be set to open the file, EX
mode open lock is returned to the client side to hold a lease. From
that time on, if this file is opened again by other processes, the
open lock will be revoked so the client who holds the lease will
know the lease is already broken by checking that open lock.
To release a lease, normal close is used. The client will revoke the
open lock before sending CLOSE request.
Lease can be applied in two ways. ll_lease_open()/close() can be
called directly if the lease holder is in kernel space; or if the
lease holder lives in user space, it has to open the file first and
then use ioctl() with command LL_IOC_SET_LEASE to apply a lease. The
lease holder has to poll the lease status itself.
Intel-bug-id: https://jira.hpdd.intel.com/browse/LU-2919
Lustre-change: http://review.whamcloud.com/6730
Signed-off-by: Jinshan Xiong <jinshan.xiong@intel.com>
Signed-off-by: John L. Hammond <john.hammond@intel.com>
Reviewed-by: Andreas Dilger <andreas.dilger@intel.com>
Reviewed-by: Oleg Drokin <oleg.drokin@intel.com>
Signed-off-by: Peng Tao <bergwolf@gmail.com>
Signed-off-by: Andreas Dilger <andreas.dilger@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
This patch takes up the task mentioned in the TODO file of dwc2 to
cleanup the microframe scheduler code. The while(!done) loops have been
replaced with appropriate for loops and unnecessary variables
like done and ret have been removed.
Signed-off-by: Himangi Saraogi <himangi774@gmail.com>
Acked-by: Paul Zimmerman <paulz@synopsys.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix the following type of checkpatch warning to comply with coding
style:
WARNING: suspect code indent for conditional statements
Also join a debug string split across lines, as it was on the same lines
as the other changes anyway. And reformat some comments in the kernel
coding style for the same reason.
Signed-off-by: Kristina Martsenko <kristina.martsenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove an unnecessary semicolon and remove a space before another one to
comply with coding style.
Fix the following type of checkpatch warning:
WARNING: space prohibited before semicolon
Signed-off-by: Kristina Martsenko <kristina.martsenko@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix the following types of checkpatch errors to comply with coding
style:
ERROR: space required after that close brace '}'
ERROR: space required before the open brace '{'
Also change "if (x == 0)" into "if (!x)" on one line, to avoid
introducing new checkpatch issues.
Signed-off-by: Kristina Martsenko <kristina.martsenko@gmail.com>
Reviewed-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix the following types of checkpatch errors and warnings to comply with
coding style:
ERROR: space required before the open parenthesis '('
ERROR: space prohibited after that open parenthesis '('
ERROR: space prohibited before that close parenthesis ')'
WARNING: space prohibited between function name and open parenthesis '('
Signed-off-by: Kristina Martsenko <kristina.martsenko@gmail.com>
Reviewed-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fix the following types of checkpatch errors and warnings in
pack_generic.c to comply with coding style:
ERROR: space required before the open parenthesis '('
ERROR: space prohibited before that close parenthesis ')'
WARNING: space prohibited between function name and open parenthesis '('
Signed-off-by: Kristina Martsenko <kristina.martsenko@gmail.com>
Reviewed-by: Sarah Sharp <sarah.a.sharp@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixed a coding style issue - removed a blank before a tab.
Signed-off-by: Joachim Adolf Schuetz <jas@catbull.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove unnecessary variable ioctl from get_bypass_info().
As a consequence, this patch removes an assignment to ioctl in an if condition,
reported by checkpatch.pl.
Signed-off-by: Rupert Muchembled <rupert@rmuch.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Remove unnecessary variable ioctl from do_cmd().
As a consequence, this patch removes an assignment to ioctl in an if condition,
reported by checkpatch.pl.
Signed-off-by: Rupert Muchembled <rupert@rmuch.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Move structures to vnt_private and convert to pointers in
device_init_registers.
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Since typedef enum __device_init_type is only ever called
in one state.
Remove the typedef from main_usb.c:device_init_registers and
replace with macro values. The other values may be needed later.
Apply cold value to sInitCmd.byInitClass.
Remove if braces and correct formatting within.
Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
The lock sequence of dcon_blank_fb(fb_info->lock ---> console_lock) is against
with the one of console_callback(console_lock ---> fb_info->lock), it'll
lead to a potential dead lock, so reorder the lock sequence of dcon_blank_fb
to avoid the potential dead lock.
Signed-off-by: Gu Zheng <guz.fnst@cn.fujitsu.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Get rid of the needless __GFP_ZERO flag for kzalloc() at oz_elt_stream_create().
Signed-off-by: Jie Liu <jeff.liu@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixed the following coding style issues:
Lines 84-91,99-106,275,514: Replaced spaces at the start of the lines
with tabs.
Lines 205,271: Inserted spaces after the commas.
Lines 275,1060,1065: Indented the code with tabs instead of spaces.
Line 275: Inserted spaces around '=' and '<', also moved the trailing
statement on the next line.
Line 512: Removed space between function name and open parenthesis.
Line 839: Removed space after '&'.
Line 853: Removed space after '&'.
Signed-off-by: Aldo Iljazi <mail@aldo.io>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Fixed the following styling issues:
Line 30:
Removed space before open square bracket '['
Lines 31 to 155:
Moved the commas that were in the start of the lines, to the end of the lines.
Inserted spaces after the commas.
Inserted a one tab indentation to each line.
Signed-off-by: Aldo Iljazi <mail@aldo.io>
Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If SERIAL_PORT_DFNS isn't present by platform, it need be defined to
"nothing", like the 8250 serial driver does it.
All related macros also need be removed: IRQF_SHARED is defined in
"linux/interrupt.h", others will be defined when related architecture
has SERIAL_PORT_DFNS.
Or it will cause issue (for arc, with allmodconfig):
CC [M] drivers/staging/speakup/serialio.o
drivers/staging/speakup/serialio.c:12:2: error: initializer element is not constant
SERIAL_PORT_DFNS
^
drivers/staging/speakup/serialio.c:12:2: error: (near initialization for 'rs_table[0].baud_base')
drivers/staging/speakup/serialio.c:12:2: error: initializer element is not constant
drivers/staging/speakup/serialio.c:12:2: error: (near initialization for 'rs_table[1].baud_base')
drivers/staging/speakup/serialio.c:12:2: error: initializer element is not constant
drivers/staging/speakup/serialio.c:12:2: error: (near initialization for 'rs_table[2].baud_base')
drivers/staging/speakup/serialio.c:12:2: error: initializer element is not constant
drivers/staging/speakup/serialio.c:12:2: error: (near initialization for 'rs_table[3].baud_base')
Signed-off-by: Chen Gang <gang.chen@asianux.com>
Acked-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
If a comedi device is automatically detached by `comedi_auto_unconfig()`
any data buffers associated with subdevices that support asynchronous
commands will be freed. If the buffer is mmapped at the time, bad
things are likely to happen! Prevent this by moving some of the buffer
details from `struct comedi_async` into a new, dynamically allocated,
and kref-counted `struct comedi_buf_map`. This holds a list of pages, a
reference count, and enough information to free the pages. The new
member `buf_map` of `struct comedi_async` points to a `struct
comedi_buf_map` when the buffer size is non-zero.
Provide a new helper function `comedi_buf_is_mapped()` to check whether
an a buffer is mmapped. If it is mmapped, the buffer is not allowed to
be resized and the device is not allowed to be manually detached by the
`COMEDI_DEVCONFIG` ioctl. Provide helper functions
`comedi_buf_map_get()` and `comedi_buf_map_put()` to manipulate the
reference count of the `struct comedi_buf_map`, which will be freed
along with its contents via the 'release' callback of the `kref_put()`
call. The reference count is manipulated by the vma operations and the
mmap file operation.
Now, when the comedi device is automatically detached, the buffer will
be effectively freed by calling `comedi_buf_alloc()` with a new buffer
size of 0. That calls local function `__comedi_buf_free()` which calls
`comedi_buf_map_put()` on the `buf_map` member to free it. It won't
actually be freed until the final 'put'.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
`comedi_read_subdevice()` and `comedi_write_subdevice()` respectively
determine the read and write subdevice to use for a comedi device,
depending on a minor device number passed in. The comedi device has a
main "board" minor device number and may also have dynamically assigned,
subdevice-specific minor device numbers, in a range of numbers shared by
all comedi devices. If the minor device number is within the range of
subdevice-specific minor device numbers, both functions call
`comedi_subdevice_from_minor()` to determine what subdevice is
associated with the minor device number (if any) and then check the
subdevice belongs to the comedi device. Since the subdevice might
belong to a different comedi device, the check is not protected against
the subdevice being freed. Perform the check in
`comedi_subdevice_from_minor()` instead, where it is protected against
the subdevice being freed. Make it return `NULL` if the subdevice does
not belong to the device.
Signed-off-by: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
