qemu-e2k/block
Kevin Wolf 34fa110e42 file-posix: Fix write_zeroes with unmap on block devices
The BLKDISCARD ioctl doesn't guarantee that the discarded blocks read as
all-zero afterwards, so don't try to abuse it for zero writing. We try
to only use this if BLKDISCARDZEROES tells us that it is safe, but this
is unreliable on older kernels and a constant 0 in newer kernels. In
other words, this code path is never actually used with newer kernels,
so we don't even try to unmap while writing zeros.

This patch removes the abuse of discard for writing zeroes from
file-posix and instead adds a new function that uses interfaces that are
actually meant to deallocate and zero out at the same time. Only if
those fail, it falls back to zeroing out without unmap. We never fall
back to a discard operation any more that may or may not result in
zeros.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2018-07-30 15:35:37 +02:00
..
Makefile.objs block: Add blklogwrites 2018-07-05 10:29:19 +02:00
accounting.c block/accounting: introduce latency histogram 2018-03-19 14:58:37 -05:00
backup.c block: Fix typos in comments (found by codespell) 2018-07-23 16:50:43 +02:00
blkdebug.c qstring: Move qstring_from_substr()'s @end one to the right 2018-07-28 09:09:58 +02:00
blklogwrites.c block: Use BdrvChild to discard 2018-07-10 16:01:52 +02:00
blkreplay.c block: Use BdrvChild to discard 2018-07-10 16:01:52 +02:00
blkverify.c qstring: Move qstring_from_substr()'s @end one to the right 2018-07-28 09:09:58 +02:00
block-backend.c block: Use BdrvChild to discard 2018-07-10 16:01:52 +02:00
bochs.c block: Deprecate bdrv_set_read_only() and users 2017-11-17 13:35:59 +01:00
cloop.c block: Deprecate bdrv_set_read_only() and users 2017-11-17 13:35:59 +01:00
commit.c job: Add error message for failing jobs 2018-05-30 13:31:01 +02:00
copy-on-read.c block: Use BdrvChild to discard 2018-07-10 16:01:52 +02:00
create.c block/create: Mark blockdev-create stable 2018-05-30 13:31:18 +02:00
crypto.c block/crypto: Fix memory leak in create error path 2018-07-05 10:29:19 +02:00
crypto.h block/crypto: Simplify block_crypto_{open,create}_opts_init() 2018-06-29 14:20:56 +02:00
curl.c block: Fix typos in comments (found by codespell) 2018-07-23 16:50:43 +02:00
dirty-bitmap.c dirty-bitmap: fix double lock on bitmap enabling 2018-07-04 02:12:49 -04:00
dmg-bz2.c dmg: Move libbz2 code to dmg-bz2.so 2016-10-07 14:14:06 +02:00
dmg.c block: Deprecate bdrv_set_read_only() and users 2017-11-17 13:35:59 +01:00
dmg.h block: remove "qemu/osdep.h" from header file 2017-12-18 17:07:02 +03:00
file-posix.c file-posix: Fix write_zeroes with unmap on block devices 2018-07-30 15:35:37 +02:00
file-win32.c block: Prefix file driver trace points with "file_" 2018-07-10 16:01:51 +02:00
gluster.c block: Fix typos in comments (found by codespell) 2018-07-23 16:50:43 +02:00
io.c block: Use common write req handling in truncate 2018-07-10 16:46:22 +02:00
iscsi-opts.c Move include qemu/option.h from qemu-common.h to actual users 2018-02-09 13:52:16 +01:00
iscsi.c block: Add copy offloading trace points 2018-07-10 16:01:52 +02:00
linux-aio.c linux-aio: properly bubble up errors from initialization 2018-06-27 13:06:34 +01:00
mirror.c block: Use BdrvChild to discard 2018-07-10 16:01:52 +02:00
nbd-client.c nbd/client: Add x-dirty-bitmap to query bitmap from server 2018-07-02 15:27:38 -05:00
nbd-client.h nbd/client: Add x-dirty-bitmap to query bitmap from server 2018-07-02 15:27:38 -05:00
nbd.c qstring: Move qstring_from_substr()'s @end one to the right 2018-07-28 09:09:58 +02:00
nfs.c block: Convert .bdrv_truncate callback to coroutine_fn 2018-06-29 14:20:56 +02:00
null.c null: Switch to byte-based read/write 2018-05-15 16:11:41 +02:00
nvme.c qobject: Modify qobject_ref() to return obj 2018-05-04 08:27:53 +02:00
parallels.c parallels: Switch to byte-based calls 2018-06-29 14:20:56 +02:00
parallels.h Clean up includes 2018-02-09 05:05:11 +01:00
qapi.c qobject: Replace qobject_incref/QINCREF qobject_decref/QDECREF 2018-05-04 08:27:53 +02:00
qcow.c qcow: fix a reference leak 2018-07-30 15:35:37 +02:00
qcow2-bitmap.c qcow2: add overlap check for bitmap directory 2018-07-09 19:43:24 +02:00
qcow2-cache.c qcow2: Allow configuring the L2 slice size 2018-02-13 17:00:00 +01:00
qcow2-cluster.c qcow2: Free allocated clusters on write error 2018-06-29 14:20:56 +02:00
qcow2-refcount.c Block layer patches: 2018-07-10 17:28:29 +01:00
qcow2-snapshot.c block: use local path for local headers 2018-05-31 04:16:06 +03:00
qcow2.c qcow2: A grammar fix in conflicting cache sizing error message 2018-07-30 15:35:37 +02:00
qcow2.h qcow2: add overlap check for bitmap directory 2018-07-09 19:43:24 +02:00
qed-check.c block: convert bdrv_check callback to coroutine_fn 2018-03-09 15:17:47 +01:00
qed-cluster.c qed: protect table cache with CoMutex 2017-07-17 11:34:11 +08:00
qed-l2-cache.c qed: protect table cache with CoMutex 2017-07-17 11:34:11 +08:00
qed-table.c block: convert bdrv_check callback to coroutine_fn 2018-03-09 15:17:47 +01:00
qed.c block: Convert .bdrv_truncate callback to coroutine_fn 2018-06-29 14:20:56 +02:00
qed.h qed: protect table cache with CoMutex 2017-07-17 11:34:11 +08:00
quorum.c block: Add block-specific QDict header 2018-06-15 14:49:44 +02:00
raw-format.c Block layer patches: 2018-07-10 17:28:29 +01:00
rbd.c block: Convert .bdrv_truncate callback to coroutine_fn 2018-06-29 14:20:56 +02:00
replication.c replication: Switch to byte-based calls 2018-06-29 14:20:56 +02:00
sheepdog.c block: Convert .bdrv_truncate callback to coroutine_fn 2018-06-29 14:20:56 +02:00
snapshot.c block: Add block-specific QDict header 2018-06-15 14:49:44 +02:00
ssh.c block: Convert .bdrv_truncate callback to coroutine_fn 2018-06-29 14:20:56 +02:00
stream.c job: Add error message for failing jobs 2018-05-30 13:31:01 +02:00
throttle-groups.c throttle-groups: fix hang when group member leaves 2018-07-19 13:08:26 +01:00
throttle.c block: Use BdrvChild to discard 2018-07-10 16:01:52 +02:00
trace-events block: Add copy offloading trace points 2018-07-10 16:01:52 +02:00
vdi.c vdi: Use definitions from "qemu/units.h" 2018-07-02 14:45:23 +02:00
vhdx-endian.c block: use local path for local headers 2018-05-31 04:16:06 +03:00
vhdx-log.c block: use local path for local headers 2018-05-31 04:16:06 +03:00
vhdx.c block: Fix typos in comments (found by codespell) 2018-07-23 16:50:43 +02:00
vhdx.h block: vhdx - update PAYLOAD_BLOCK_UNMAPPED value to match 1.00 spec 2014-12-12 15:42:22 +00:00
vmdk.c vmdk: Fix possible segfault with non-VMDK backing 2018-07-09 19:43:24 +02:00
vpc.c block: Factor out qobject_input_visitor_new_flat_confused() 2018-06-15 14:49:44 +02:00
vvfat.c block/vvfat: Disable debug message by default 2018-07-23 16:50:43 +02:00
vxhs.c block: Add block-specific QDict header 2018-06-15 14:49:44 +02:00
win32-aio.c file-win32: Switch to byte-based callbacks 2018-05-15 16:11:41 +02:00
write-threshold.c Include less of the generated modular QAPI headers 2018-03-02 13:45:50 -06:00