According to 'man 2 close' errors returned by close() should only be used
for either diagnostic purposes or for catching data loss due to a previous
write error, as an error result of close() usually indicates a deferred
error of a previous write operation.
Therefore not decrementing 'total_open_fd' on a close() error is wrong
and would yield in a higher open file descriptor count than actually the
case, leading to 9p server reclaiming open file descriptors too soon.
Based-on: <20250312152933.383967-7-groug@kaod.org>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <E1tvEyJ-004dMa-So@kylie.crudebyte.com>
Enhance the `use-after-unlink` test with a new check for the
case where the client wants to alter the size of an unlinked
file for which it still has an active fid.
Suggested-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <20250312152933.383967-7-groug@kaod.org>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Add and implement functions to 9pfs test client for sending a 9p2000.L
'Tsetattr' request and receiving its 'Rsetattr' response counterpart.
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Signed-off-by: Greg Kurz <groug@kaod.org>
Message-Id: <20250312152933.383967-6-groug@kaod.org>
Add an futimens operation to the fs driver and use if when a fid has
a valid file descriptor. This is required to support more cases where
the client wants to do an action on an unlinked file which it still
has an open file decriptor for.
Only 9P2000.L was considered.
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <20250312152933.383967-5-groug@kaod.org>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Add an ftruncate operation to the fs driver and use if when a fid has
a valid file descriptor. This is required to support more cases where
the client wants to do an action on an unlinked file which it still
has an open file decriptor for.
Only 9P2000.L was considered.
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <20250312152933.383967-4-groug@kaod.org>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
v9fs_getattr() currently peeks into V9fsFidOpenState to know if a fid
has a valid file descriptor or directory stream. Even though the fields
are accessible, this is an implementation detail of the local backend
that should not be manipulated directly by the server code.
Abstract that with a new has_valid_file_handle() backend operation.
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <20250312152933.383967-3-groug@kaod.org>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Factor out duplicated code to a single helper. More users to come.
Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Message-Id: <20250312152933.383967-2-groug@kaod.org>
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
This patch fixes two different bugs in v9fs_reclaim_fd():
1. Reduce latency:
This function calls v9fs_co_close() and v9fs_co_closedir() in a loop. Each
one of the calls adds two thread hops (between main thread and a fs driver
background thread). Each thread hop adds latency, which sums up in
function's loop to a significant duration.
Reduce overall latency by open coding what v9fs_co_close() and
v9fs_co_closedir() do, executing those and the loop itself altogether in
only one background thread block, hence reducing the total amount of
thread hops to only two.
2. Fix file descriptor leak:
The existing code called v9fs_co_close() and v9fs_co_closedir() to close
file descriptors. Both functions check right at the beginning if the 9p
request was cancelled:
if (v9fs_request_cancelled(pdu)) {
return -EINTR;
}
So if client sent a 'Tflush' message, v9fs_co_close() / v9fs_co_closedir()
returned without having closed the file descriptor and v9fs_reclaim_fd()
subsequently freed the FID without its file descriptor being closed, hence
leaking those file descriptors.
This 2nd bug is fixed by this patch as well by open coding v9fs_co_close()
and v9fs_co_closedir() inside of v9fs_reclaim_fd() and not performing the
v9fs_request_cancelled(pdu) check there.
Fixes: 7a46274529 ('hw/9pfs: Add file descriptor reclaim support')
Fixes: bccacf6c79 ('hw/9pfs: Implement TFLUSH operation')
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <5747469d3f039c53147e850b456943a1d4b5485c.1741339452.git.qemu_oss@crudebyte.com>
Even though this function is serialized to be always called from main
thread, v9fs_reclaim_fd() is dispatching the coroutine to a worker thread
in between via its v9fs_co_*() calls, hence leading to the situation where
v9fs_reclaim_fd() is effectively executed multiple times simultaniously,
which renders its LRU algorithm useless and causes high latency.
Fix this by adding a simple boolean variable to ensure this function is
only called once at a time. No synchronization needed for this boolean
variable as this function is only entered and returned on main thread.
Fixes: 7a46274529 ('hw/9pfs: Add file descriptor reclaim support')
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Greg Kurz <groug@kaod.org>
Message-Id: <5c622067efd66dd4ee5eca740dcf263f41db20b2.1741339452.git.qemu_oss@crudebyte.com>
Block devices that don't support discard have a discard_granularity of
0. Currently, this results in a division by zero when we try to make
sure that it's a multiple of request_alignment. Only try to update
bs->bl.pdiscard_alignment when we got a non-zero discard_granularity
from sysfs.
Fixes: f605796aae ('file-posix: probe discard alignment on Linux block devices')
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Stefan Hajnoczi <stefanha@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-ID: <20250429155654.102735-1-kwolf@redhat.com>
Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
This variable is no longer used outside tcg-target.c.inc.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
All integer opcodes are now converted to TCGOutOp.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Merge into INDEX_op_{ld,st,ld2,st2}, where "2" indicates that two
inputs or outputs are required. This simplifies the processing of
i64/i128 depending on host word size.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
The i386 backend can now check TCGOP_FLAGS to select
the correct set of constraints.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This will enable removing INDEX_op_qemu_st8_*_i32,
by exposing the operand size to constraint selection.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split these functions out from tcg_out_op.
Define outop_goto_ptr generically.
Call tcg_out_goto_ptr from tcg_reg_alloc_op.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Split these functions out from tcg_out_op.
Call it directly from tcg_gen_code.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Most tcg backends already have a function for this;
the rest can split one out from tcg_out_op.
Call it directly from tcg_gen_code.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
All uses have been replaced by add/sub carry opcodes.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Pass the sparc COND_* value not the tcg TCG_COND_* value.
This makes the usage within add2/sub2 clearer.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
We were using S32 | U32 for add2/sub2. But the ALGFI and SLGFI
insns that implement this both have uint32_t immediates.
This makes the composite range balanced and
enables use of -0xffffffff ... -0x80000001.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Do not clobber flags if they're live. Required in order
to perform register allocation on add/sub carry opcodes.
LA and AGHI are the same size, so use LA unconditionally.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Tested-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Use this in gen_addc and gen_rsubc, both of which need
add with carry-in and carry-out.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Use this in do_add, do_sub, and do_ds, all of which need
add with carry-in and carry-out.
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Create a function for performing an add with carry-in
and producing carry out. The carry-out result is boolean.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Using addci with two zeros as input in order to capture the value
of the carry-in bit is common. Special case this with sbb+neg so
that we do not have to load 0 into a register first.
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
