block: Take graph lock for most of .bdrv_open

Most implementations of .bdrv_open first open their file child (which is
an operation that internally takes the write lock and therefore we
shouldn't ho

block: Take graph lock for most of .bdrv_open

Most implementations of .bdrv_open first open their file child (which is
an operation that internally takes the write lock and therefore we
shouldn't hold the graph lock while calling it), and afterwards many
operations that require holding the graph lock, e.g. for accessing
bs->file.

This changes block drivers that follow this pattern to take the graph
lock after opening the child node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-24-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Take graph lock for most of .bdrv_open

Most implementations of .bdrv_open first open their file child (which is
an operation that internally takes the write lock and therefore we
shouldn't ho

block: Take graph lock for most of .bdrv_open

Most implementations of .bdrv_open first open their file child (which is
an operation that internally takes the write lock and therefore we
shouldn't hold the graph lock while calling it), and afterwards many
operations that require holding the graph lock, e.g. for accessing
bs->file.

This changes block drivers that follow this pattern to take the graph
lock after opening the child node.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-ID: <20231027155333.420094-24-kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block/throttle-groups: Use ThrottleDirection instread of bool is_write

'bool is_write' style is obsolete from throttle framework, adapt
block throttle groups to the new style:
- use ThrottleDirectio

block/throttle-groups: Use ThrottleDirection instread of bool is_write

'bool is_write' style is obsolete from throttle framework, adapt
block throttle groups to the new style:
- use ThrottleDirection instead of 'bool is_write'. Ex,
schedule_next_request(ThrottleGroupMember *tgm, bool is_write)
-> schedule_next_request(ThrottleGroupMember *tgm, ThrottleDirection direction)

- use THROTTLE_MAX instead of hard code. Ex, ThrottleGroupMember *tokens[2]
-> ThrottleGroupMember *tokens[THROTTLE_MAX]

- use ThrottleDirection instead of hard code on iteration. Ex, (i = 0; i < 2; i++)
-> for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++)

Use a simple python script to test the new style:
#!/usr/bin/python3
import subprocess
import random
import time

commands = ['virsh blkdeviotune jammy vda --write-bytes-sec ', \
'virsh blkdeviotune jammy vda --write-iops-sec ', \
'virsh blkdeviotune jammy vda --read-bytes-sec ', \
'virsh blkdeviotune jammy vda --read-iops-sec ']

for loop in range(1, 1000):
time.sleep(random.randrange(3, 5))
command = commands[random.randrange(0, 3)] + str(random.randrange(0, 1000000))
subprocess.run(command, shell=True, check=True)

This works fine.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Message-Id: <20230728022006.1098509-10-pizhenwei@bytedance.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>

show more ...

block/throttle-groups: Use ThrottleDirection instread of bool is_write

'bool is_write' style is obsolete from throttle framework, adapt
block throttle groups to the new style:
- use ThrottleDirectio

block/throttle-groups: Use ThrottleDirection instread of bool is_write

'bool is_write' style is obsolete from throttle framework, adapt
block throttle groups to the new style:
- use ThrottleDirection instead of 'bool is_write'. Ex,
schedule_next_request(ThrottleGroupMember *tgm, bool is_write)
-> schedule_next_request(ThrottleGroupMember *tgm, ThrottleDirection direction)

- use THROTTLE_MAX instead of hard code. Ex, ThrottleGroupMember *tokens[2]
-> ThrottleGroupMember *tokens[THROTTLE_MAX]

- use ThrottleDirection instead of hard code on iteration. Ex, (i = 0; i < 2; i++)
-> for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++)

Use a simple python script to test the new style:
#!/usr/bin/python3
import subprocess
import random
import time

commands = ['virsh blkdeviotune jammy vda --write-bytes-sec ', \
'virsh blkdeviotune jammy vda --write-iops-sec ', \
'virsh blkdeviotune jammy vda --read-bytes-sec ', \
'virsh blkdeviotune jammy vda --read-iops-sec ']

for loop in range(1, 1000):
time.sleep(random.randrange(3, 5))
command = commands[random.randrange(0, 3)] + str(random.randrange(0, 1000000))
subprocess.run(command, shell=True, check=True)

This works fine.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Message-Id: <20230728022006.1098509-10-pizhenwei@bytedance.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>

show more ...

block/throttle-groups: Use ThrottleDirection instread of bool is_write

'bool is_write' style is obsolete from throttle framework, adapt
block throttle groups to the new style:
- use ThrottleDirectio

block/throttle-groups: Use ThrottleDirection instread of bool is_write

'bool is_write' style is obsolete from throttle framework, adapt
block throttle groups to the new style:
- use ThrottleDirection instead of 'bool is_write'. Ex,
schedule_next_request(ThrottleGroupMember *tgm, bool is_write)
-> schedule_next_request(ThrottleGroupMember *tgm, ThrottleDirection direction)

- use THROTTLE_MAX instead of hard code. Ex, ThrottleGroupMember *tokens[2]
-> ThrottleGroupMember *tokens[THROTTLE_MAX]

- use ThrottleDirection instead of hard code on iteration. Ex, (i = 0; i < 2; i++)
-> for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++)

Use a simple python script to test the new style:
#!/usr/bin/python3
import subprocess
import random
import time

commands = ['virsh blkdeviotune jammy vda --write-bytes-sec ', \
'virsh blkdeviotune jammy vda --write-iops-sec ', \
'virsh blkdeviotune jammy vda --read-bytes-sec ', \
'virsh blkdeviotune jammy vda --read-iops-sec ']

for loop in range(1, 1000):
time.sleep(random.randrange(3, 5))
command = commands[random.randrange(0, 3)] + str(random.randrange(0, 1000000))
subprocess.run(command, shell=True, check=True)

This works fine.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Message-Id: <20230728022006.1098509-10-pizhenwei@bytedance.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>

show more ...

block/throttle-groups: Use ThrottleDirection instread of bool is_write

'bool is_write' style is obsolete from throttle framework, adapt
block throttle groups to the new style:
- use ThrottleDirectio

block/throttle-groups: Use ThrottleDirection instread of bool is_write

'bool is_write' style is obsolete from throttle framework, adapt
block throttle groups to the new style:
- use ThrottleDirection instead of 'bool is_write'. Ex,
schedule_next_request(ThrottleGroupMember *tgm, bool is_write)
-> schedule_next_request(ThrottleGroupMember *tgm, ThrottleDirection direction)

- use THROTTLE_MAX instead of hard code. Ex, ThrottleGroupMember *tokens[2]
-> ThrottleGroupMember *tokens[THROTTLE_MAX]

- use ThrottleDirection instead of hard code on iteration. Ex, (i = 0; i < 2; i++)
-> for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++)

Use a simple python script to test the new style:
#!/usr/bin/python3
import subprocess
import random
import time

commands = ['virsh blkdeviotune jammy vda --write-bytes-sec ', \
'virsh blkdeviotune jammy vda --write-iops-sec ', \
'virsh blkdeviotune jammy vda --read-bytes-sec ', \
'virsh blkdeviotune jammy vda --read-iops-sec ']

for loop in range(1, 1000):
time.sleep(random.randrange(3, 5))
command = commands[random.randrange(0, 3)] + str(random.randrange(0, 1000000))
subprocess.run(command, shell=True, check=True)

This works fine.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Message-Id: <20230728022006.1098509-10-pizhenwei@bytedance.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>

show more ...

block/throttle-groups: Use ThrottleDirection instread of bool is_write

'bool is_write' style is obsolete from throttle framework, adapt
block throttle groups to the new style:
- use ThrottleDirectio

block/throttle-groups: Use ThrottleDirection instread of bool is_write

'bool is_write' style is obsolete from throttle framework, adapt
block throttle groups to the new style:
- use ThrottleDirection instead of 'bool is_write'. Ex,
schedule_next_request(ThrottleGroupMember *tgm, bool is_write)
-> schedule_next_request(ThrottleGroupMember *tgm, ThrottleDirection direction)

- use THROTTLE_MAX instead of hard code. Ex, ThrottleGroupMember *tokens[2]
-> ThrottleGroupMember *tokens[THROTTLE_MAX]

- use ThrottleDirection instead of hard code on iteration. Ex, (i = 0; i < 2; i++)
-> for (dir = THROTTLE_READ; dir < THROTTLE_MAX; dir++)

Use a simple python script to test the new style:
#!/usr/bin/python3
import subprocess
import random
import time

commands = ['virsh blkdeviotune jammy vda --write-bytes-sec ', \
'virsh blkdeviotune jammy vda --write-iops-sec ', \
'virsh blkdeviotune jammy vda --read-bytes-sec ', \
'virsh blkdeviotune jammy vda --read-iops-sec ']

for loop in range(1, 1000):
time.sleep(random.randrange(3, 5))
command = commands[random.randrange(0, 3)] + str(random.randrange(0, 1000000))
subprocess.run(command, shell=True, check=True)

This works fine.

Signed-off-by: zhenwei pi <pizhenwei@bytedance.com>
Message-Id: <20230728022006.1098509-10-pizhenwei@bytedance.com>
Reviewed-by: Hanna Czenczek <hreitz@redhat.com>
Signed-off-by: Hanna Czenczek <hreitz@redhat.com>

show more ...

block: Mark bdrv_co_refresh_total_sectors() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_refresh_total_sectors() need to hold a reader lock for the

block: Mark bdrv_co_refresh_total_sectors() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_refresh_total_sectors() need to hold a reader lock for the
graph.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-24-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark public read/write functions GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pread*/pwrite*() need to hold a reader lock for the graph.

For some places

block: Mark public read/write functions GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pread*/pwrite*() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-12-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark bdrv_co_pwrite_zeroes() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pwrite_zeroes() need to hold a reader lock for the graph.

For some

block: Mark bdrv_co_pwrite_zeroes() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pwrite_zeroes() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-10-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark bdrv_co_pdiscard() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pdiscard() need to hold a reader lock for the graph.

For some places, w

block: Mark bdrv_co_pdiscard() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pdiscard() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-9-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark bdrv_co_flush() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_flush() need to hold a reader lock for the graph.

For some places, we know

block: Mark bdrv_co_flush() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_flush() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-8-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark bdrv_co_refresh_total_sectors() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_refresh_total_sectors() need to hold a reader lock for the

block: Mark bdrv_co_refresh_total_sectors() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_refresh_total_sectors() need to hold a reader lock for the
graph.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-24-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark public read/write functions GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pread*/pwrite*() need to hold a reader lock for the graph.

For some places

block: Mark public read/write functions GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pread*/pwrite*() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-12-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark bdrv_co_pwrite_zeroes() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pwrite_zeroes() need to hold a reader lock for the graph.

For some

block: Mark bdrv_co_pwrite_zeroes() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pwrite_zeroes() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-10-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark bdrv_co_pdiscard() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pdiscard() need to hold a reader lock for the graph.

For some places, w

block: Mark bdrv_co_pdiscard() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pdiscard() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-9-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark bdrv_co_flush() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_flush() need to hold a reader lock for the graph.

For some places, we know

block: Mark bdrv_co_flush() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_flush() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-8-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark bdrv_co_refresh_total_sectors() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_refresh_total_sectors() need to hold a reader lock for the

block: Mark bdrv_co_refresh_total_sectors() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_refresh_total_sectors() need to hold a reader lock for the
graph.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-24-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark public read/write functions GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pread*/pwrite*() need to hold a reader lock for the graph.

For some places

block: Mark public read/write functions GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pread*/pwrite*() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-12-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark bdrv_co_pwrite_zeroes() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pwrite_zeroes() need to hold a reader lock for the graph.

For some

block: Mark bdrv_co_pwrite_zeroes() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pwrite_zeroes() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-10-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark bdrv_co_pdiscard() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pdiscard() need to hold a reader lock for the graph.

For some places, w

block: Mark bdrv_co_pdiscard() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_pdiscard() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-9-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Mark bdrv_co_flush() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_flush() need to hold a reader lock for the graph.

For some places, we know

block: Mark bdrv_co_flush() and callers GRAPH_RDLOCK

This adds GRAPH_RDLOCK annotations to declare that callers of
bdrv_co_flush() need to hold a reader lock for the graph.

For some places, we know that they will hold the lock, but we don't have
the GRAPH_RDLOCK annotations yet. In this case, add assume_graph_lock()
with a FIXME comment. These places will be removed once everything is
properly annotated.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230203152202.49054-8-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed

BlockDriver->bdrv_getlength is categorized as IO callback, and it
currently doesn't run in a coroutine. We should let it take a graph

block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed

BlockDriver->bdrv_getlength is categorized as IO callback, and it
currently doesn't run in a coroutine. We should let it take a graph
rdlock since the callback traverses the block nodes graph, which however
is only possible in a coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

Because now this function creates a new coroutine and polls, we need to
take the AioContext lock where it is missing, for the only reason that
internally co_wrapper calls AIO_WAIT_WHILE and it expects to release the
AioContext lock.

This is especially messy when a co_wrapper creates a coroutine and polls
in bdrv_open_driver, because this function has so many callers in so
many context that it can easily lead to deadlocks. Therefore the new
rule for bdrv_open_driver is that the caller must always hold the
AioContext lock of the given bs (except if it is a coroutine), because
the function calls bdrv_refresh_total_sectors() which is now a
co_wrapper.

Once the rwlock is ultimated and placed in every place it needs to be,
we will poll using AIO_WAIT_WHILE_UNLOCKED and remove the AioContext
lock.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-7-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed

BlockDriver->bdrv_getlength is categorized as IO callback, and it
currently doesn't run in a coroutine. We should let it take a graph

block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed

BlockDriver->bdrv_getlength is categorized as IO callback, and it
currently doesn't run in a coroutine. We should let it take a graph
rdlock since the callback traverses the block nodes graph, which however
is only possible in a coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

Because now this function creates a new coroutine and polls, we need to
take the AioContext lock where it is missing, for the only reason that
internally co_wrapper calls AIO_WAIT_WHILE and it expects to release the
AioContext lock.

This is especially messy when a co_wrapper creates a coroutine and polls
in bdrv_open_driver, because this function has so many callers in so
many context that it can easily lead to deadlocks. Therefore the new
rule for bdrv_open_driver is that the caller must always hold the
AioContext lock of the given bs (except if it is a coroutine), because
the function calls bdrv_refresh_total_sectors() which is now a
co_wrapper.

Once the rwlock is ultimated and placed in every place it needs to be,
we will poll using AIO_WAIT_WHILE_UNLOCKED and remove the AioContext
lock.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-7-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...

block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed

BlockDriver->bdrv_getlength is categorized as IO callback, and it
currently doesn't run in a coroutine. We should let it take a graph

block: Convert bdrv_refresh_total_sectors() to co_wrapper_mixed

BlockDriver->bdrv_getlength is categorized as IO callback, and it
currently doesn't run in a coroutine. We should let it take a graph
rdlock since the callback traverses the block nodes graph, which however
is only possible in a coroutine.

Therefore turn it into a co_wrapper to move the actual function into a
coroutine where the lock can be taken.

Because now this function creates a new coroutine and polls, we need to
take the AioContext lock where it is missing, for the only reason that
internally co_wrapper calls AIO_WAIT_WHILE and it expects to release the
AioContext lock.

This is especially messy when a co_wrapper creates a coroutine and polls
in bdrv_open_driver, because this function has so many callers in so
many context that it can easily lead to deadlocks. Therefore the new
rule for bdrv_open_driver is that the caller must always hold the
AioContext lock of the given bs (except if it is a coroutine), because
the function calls bdrv_refresh_total_sectors() which is now a
co_wrapper.

Once the rwlock is ultimated and placed in every place it needs to be,
we will poll using AIO_WAIT_WHILE_UNLOCKED and remove the AioContext
lock.

Signed-off-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20230113204212.359076-7-kwolf@redhat.com>
Reviewed-by: Emanuele Giuseppe Esposito <eesposit@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>

show more ...