9p: local: always return -1 on error in local_unlinkat_common

local_unlinkat_common() is supposed to always return -1 on error.
This is being done by jumps to the 'err_out' label, which is
a 'return

9p: local: always return -1 on error in local_unlinkat_common

local_unlinkat_common() is supposed to always return -1 on error.
This is being done by jumps to the 'err_out' label, which is
a 'return ret' call, and 'ret' is initialized with -1.

Unfortunately there is a condition in which the function will
return 0 on error: in a case where flags == AT_REMOVEDIR, 'ret'
will be 0 when reaching

map_dirfd = openat_dir(...)

And, if map_dirfd == -1 and errno != ENOENT, the existing 'err_out'
jump will execute 'return ret', when ret is still set to zero
at that point.

This patch fixes it by changing all 'err_out' labels by
'return -1' calls, ensuring that the function will always
return -1 on error conditions. 'ret' can be left unintialized
since it's now being used just to store the result of 'unlinkat'
calls.

CC: Greg Kurz <groug@kaod.org>
Signed-off-by: Daniel Henrique Barboza <danielhb413@gmail.com>
[groug: changed prefix in title to be "9p: local:"]
Signed-off-by: Greg Kurz <groug@kaod.org>

show more ...

9pfs: local: Fix possible memory leak in local_link()

There is a possible memory leak while local_link return -1 without free
odirpath and oname.

Reported-by: Euler Robot <euler.robot@huawei.com>
S

9pfs: local: Fix possible memory leak in local_link()

There is a possible memory leak while local_link return -1 without free
odirpath and oname.

Reported-by: Euler Robot <euler.robot@huawei.com>
Signed-off-by: Jaijun Chen <chenjiajun8@huawei.com>
Signed-off-by: Xiang Zheng <zhengxiang9@huawei.com>
Reviewed-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Signed-off-by: Greg Kurz <groug@kaod.org>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-error-2019-12-17-v2' into staging

Error reporting patches for 2019-12-17

# gpg: Signature made Wed 18 Dec 2019 07:45:24 GMT
# gpg:

Merge remote-tracking branch 'remotes/armbru/tags/pull-error-2019-12-17-v2' into staging

Error reporting patches for 2019-12-17

# gpg: Signature made Wed 18 Dec 2019 07:45:24 GMT
# gpg: using RSA key 354BC8B3D7EB2A6B68674E5F3870B400EB918653
# gpg: issuer "armbru@redhat.com"
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>" [full]
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>" [full]
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-error-2019-12-17-v2: (35 commits)
nbd: assert that Error** is not NULL in nbd_iter_channel_error
hw/vfio/ap: drop local_err from vfio_ap_realize
backends/cryptodev: drop local_err from cryptodev_backend_complete()
include/qom/object.h: rename Error ** parameter to more common errp
hw/usb: rename Error ** parameter to more common errp
hw/tpm: rename Error ** parameter to more common errp
hw/sd: drop extra whitespace in sdhci_sysbus_realize() header
hw/s390x: rename Error ** parameter to more common errp
monitor/qmp-cmds: rename Error ** parameter to more common errp
qga: rename Error ** parameter to more common errp
hw/i386/amd_iommu: rename Error ** parameter to more common errp
block/snapshot: rename Error ** parameter to more common errp
hw/core/qdev: cleanup Error ** variables
9pfs: make Error **errp const where it is appropriate
ppc: make Error **errp const where it is appropriate
Revert "ppc: well form kvmppc_hint_smt_possible error hint helper"
qdev-monitor: make Error **errp const where it is appropriate
vnc: drop Error pointer indirection in vnc_client_io_error
hmp: drop Error pointer indirection in hmp_handle_error
error: make Error **errp const where it is appropriate
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

9pfs: make Error **errp const where it is appropriate

Mostly, Error ** is for returning error from the function, so the
callee sets it. However error_append_security_model_hint and
error_append_sock

9pfs: make Error **errp const where it is appropriate

Mostly, Error ** is for returning error from the function, so the
callee sets it. However error_append_security_model_hint and
error_append_socket_sockfd_hint get already filled errp
parameter. They don't change the pointer itself, only change the
internal state of referenced Error object. So we can make it Error
*const * errp, to stress the behavior. It will also help coccinelle
script (in future) to distinguish such cases from common errp usage.

Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
Acked-by: Greg Kurz <groug@kaod.org>
Message-Id: <20191205174635.18758-9-vsementsov@virtuozzo.com>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
[Commit message replaced]
Signed-off-by: Markus Armbruster <armbru@redhat.com>

show more ...

Merge remote-tracking branch 'remotes/gkurz/tags/9p-next-2019-10-10' into staging

The most notable change is that we now detect cross-device setups in the
host since it may cause inode number collis

Merge remote-tracking branch 'remotes/gkurz/tags/9p-next-2019-10-10' into staging

The most notable change is that we now detect cross-device setups in the
host since it may cause inode number collision and mayhem in the guest.
A new fsdev property is added for the user to choose the appropriate
policy to handle that: either remap all inode numbers or fail I/Os to
another host device or just print out a warning (default behaviour).

This is also my last PR as _active_ maintainer of 9pfs.

# gpg: Signature made Thu 10 Oct 2019 12:14:07 BST
# gpg: using RSA key B4828BAF943140CEF2A3491071D4D5E5822F73D6
# gpg: Good signature from "Greg Kurz <groug@kaod.org>" [full]
# gpg: aka "Gregory Kurz <gregory.kurz@free.fr>" [full]
# gpg: aka "[jpeg image of size 3330]" [full]
# Primary key fingerprint: B482 8BAF 9431 40CE F2A3 4910 71D4 D5E5 822F 73D6

* remotes/gkurz/tags/9p-next-2019-10-10:
MAINTAINERS: Downgrade status of virtio-9p to "Odd Fixes"
9p: Use variable length suffixes for inode remapping
9p: stat_to_qid: implement slow path
9p: Added virtfs option 'multidevs=remap|forbid|warn'
9p: Treat multiple devices on one export as an error
fsdev: Add return value to fsdev_throttle_parse_opts()
9p: Simplify error path of v9fs_device_realize_common()
9p: unsigned type for type, version, path

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

9p: Added virtfs option 'multidevs=remap|forbid|warn'

'warn' (default): Only log an error message (once) on host if more than one
device is shared by same export, except of that just ignore this con

9p: Added virtfs option 'multidevs=remap|forbid|warn'

'warn' (default): Only log an error message (once) on host if more than one
device is shared by same export, except of that just ignore this config
error though. This is the default behaviour for not breaking existing
installations implying that they really know what they are doing.

'forbid': Like 'warn', but except of just logging an error this
also denies access of guest to additional devices.

'remap': Allows to share more than one device per export by remapping
inodes from host to guest appropriately. To support multiple devices on the
9p share, and avoid qid path collisions we take the device id as input to
generate a unique QID path. The lowest 48 bits of the path will be set
equal to the file inode, and the top bits will be uniquely assigned based
on the top 16 bits of the inode and the device id.

Signed-off-by: Antonios Motakis <antonios.motakis@huawei.com>
[CS: - Rebased to https://github.com/gkurz/qemu/commits/9p-next
(SHA1 7fc4c49e91).
- Added virtfs option 'multidevs', original patch simply did the inode
remapping without being asked.
- Updated hash calls to new xxhash API.
- Updated docs for new option 'multidevs'.
- Fixed v9fs_do_readdir() not having remapped inodes.
- Log error message when running out of prefixes in
qid_path_prefixmap().
- Fixed definition of QPATH_INO_MASK.
- Wrapped qpp_table initialization to dedicated qpp_table_init()
function.
- Dropped unnecessary parantheses in qpp_lookup_func().
- Dropped unnecessary g_malloc0() result checks. ]
Signed-off-by: Christian Schoenebeck <qemu_oss@crudebyte.com>
[groug: - Moved "multidevs" parsing to the local backend.
- Added hint to invalid multidevs option error.
- Turn "remap" into "x-remap". ]
Signed-off-by: Greg Kurz <groug@kaod.org>

show more ...

fsdev: Add return value to fsdev_throttle_parse_opts()

It is more convenient to use the return value of the function to notify
errors, rather than to be tied up setting up the &local_err boilerplate

fsdev: Add return value to fsdev_throttle_parse_opts()

It is more convenient to use the return value of the function to notify
errors, rather than to be tied up setting up the &local_err boilerplate.

Signed-off-by: Greg Kurz <groug@kaod.org>

show more ...

9p: Simplify error path of v9fs_device_realize_common()

Make v9fs_device_unrealize_common() idempotent and use it for rollback,
in order to reduce code duplication.

Signed-off-by: Greg Kurz <groug@

9p: Simplify error path of v9fs_device_realize_common()

Make v9fs_device_unrealize_common() idempotent and use it for rollback,
in order to reduce code duplication.

Signed-off-by: Greg Kurz <groug@kaod.org>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-error-2018-10-22' into staging

Error reporting patches for 2018-10-22

# gpg: Signature made Mon 22 Oct 2018 13:20:23 BST
# gpg:

Merge remote-tracking branch 'remotes/armbru/tags/pull-error-2018-10-22' into staging

Error reporting patches for 2018-10-22

# gpg: Signature made Mon 22 Oct 2018 13:20:23 BST
# gpg: using RSA key 3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-error-2018-10-22: (40 commits)
error: Drop bogus "use error_setg() instead" admonitions
vpc: Fail open on bad header checksum
block: Clean up bdrv_img_create()'s error reporting
vl: Simplify call of parse_name()
vl: Fix exit status for -drive format=help
blockdev: Convert drive_new() to Error
vl: Assert drive_new() does not fail in default_drive()
fsdev: Clean up error reporting in qemu_fsdev_add()
spice: Clean up error reporting in add_channel()
tpm: Clean up error reporting in tpm_init_tpmdev()
numa: Clean up error reporting in parse_numa()
vnc: Clean up error reporting in vnc_init_func()
ui: Convert vnc_display_init(), init_keyboard_layout() to Error
ui/keymaps: Fix handling of erroneous include files
vl: Clean up error reporting in device_init_func()
vl: Clean up error reporting in parse_fw_cfg()
vl: Clean up error reporting in mon_init_func()
vl: Clean up error reporting in machine_set_property()
vl: Clean up error reporting in chardev_init_func()
qom: Clean up error reporting in user_creatable_add_opts_foreach()
...

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

error: Fix use of error_prepend() with &error_fatal, &error_abort

From include/qapi/error.h:

* Pass an existing error to the caller with the message modified:
* error_propagate(errp, err);

error: Fix use of error_prepend() with &error_fatal, &error_abort

From include/qapi/error.h:

* Pass an existing error to the caller with the message modified:
* error_propagate(errp, err);
* error_prepend(errp, "Could not frobnicate '%s': ", name);

Fei Li pointed out that doing error_propagate() first doesn't work
well when @errp is &error_fatal or &error_abort: the error_prepend()
is never reached.

Since I doubt fixing the documentation will stop people from getting
it wrong, introduce error_propagate_prepend(), in the hope that it
lures people away from using its constituents in the wrong order.
Update the instructions in error.h accordingly.

Convert existing error_prepend() next to error_propagate to
error_propagate_prepend(). If any of these get reached with
&error_fatal or &error_abort, the error messages improve. I didn't
check whether that's the case anywhere.

Cc: Fei Li <fli@suse.com>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Message-Id: <20181017082702.5581-2-armbru@redhat.com>

show more ...

Merge remote-tracking branch 'remotes/gkurz/tags/for-upstream' into staging

The Darwin host support still needs some more work. It won't make it for
soft-freeze, but I'd like these preparatory patch

Merge remote-tracking branch 'remotes/gkurz/tags/for-upstream' into staging

The Darwin host support still needs some more work. It won't make it for
soft-freeze, but I'd like these preparatory patches to be merged anyway.

# gpg: Signature made Fri 29 Jun 2018 11:39:04 BST
# gpg: using RSA key 71D4D5E5822F73D6
# gpg: Good signature from "Greg Kurz <groug@kaod.org>"
# gpg: aka "Gregory Kurz <gregory.kurz@free.fr>"
# gpg: aka "[jpeg image of size 3330]"
# Primary key fingerprint: B482 8BAF 9431 40CE F2A3 4910 71D4 D5E5 822F 73D6

* remotes/gkurz/tags/for-upstream:
9p: darwin: Explicitly cast comparisons of mode_t with -1
cutils: Provide strchrnul

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

9p: darwin: Explicitly cast comparisons of mode_t with -1

Comparisons of mode_t with -1 require an explicit cast, since mode_t
is unsigned on Darwin.

Signed-off-by: Keno Fischer <keno@juliacomputin

9p: darwin: Explicitly cast comparisons of mode_t with -1

Comparisons of mode_t with -1 require an explicit cast, since mode_t
is unsigned on Darwin.

Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Signed-off-by: Greg Kurz <groug@kaod.org>

show more ...

cutils: Provide strchrnul

strchrnul is a GNU extension and thus unavailable on a number of targets.
In the review for a commit removing strchrnul from 9p, I was asked to
create a qemu_strchrnul help

cutils: Provide strchrnul

strchrnul is a GNU extension and thus unavailable on a number of targets.
In the review for a commit removing strchrnul from 9p, I was asked to
create a qemu_strchrnul helper to factor out this functionality.
Do so, and use it in a number of other places in the code base that inlined
the replacement pattern in a place where strchrnul could be used.

Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Acked-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Markus Armbruster <armbru@redhat.com>
Signed-off-by: Greg Kurz <groug@kaod.org>

show more ...

Merge remote-tracking branch 'remotes/gkurz/tags/for-upstream' into staging

Mostly bug fixes and code sanitization motivated by the upcoming
support for Darwin hosts. Thanks to Keno Fischer.

# gpg:

Merge remote-tracking branch 'remotes/gkurz/tags/for-upstream' into staging

Mostly bug fixes and code sanitization motivated by the upcoming
support for Darwin hosts. Thanks to Keno Fischer.

# gpg: Signature made Thu 07 Jun 2018 11:30:56 BST
# gpg: using RSA key 71D4D5E5822F73D6
# gpg: Good signature from "Greg Kurz <groug@kaod.org>"
# gpg: aka "Gregory Kurz <gregory.kurz@free.fr>"
# gpg: aka "[jpeg image of size 3330]"
# Primary key fingerprint: B482 8BAF 9431 40CE F2A3 4910 71D4 D5E5 822F 73D6

* remotes/gkurz/tags/for-upstream:
9p: xattr: Properly translate xattrcreate flags
9p: Properly check/translate flags in unlinkat
9p: local: Avoid warning if FS_IOC_GETVERSION is not defined
9p: xattr: Fix crashes due to free of uninitialized value
9p: Move a couple xattr functions to 9p-util
9p: local: Properly set errp in fstatfs error path
9p: proxy: Fix size passed to `connect`

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

9p: local: Avoid warning if FS_IOC_GETVERSION is not defined

Both `stbuf` and `local_ioc_getversion` where unused when
FS_IOC_GETVERSION was not defined, causing a compiler warning.

Reorganize the

9p: local: Avoid warning if FS_IOC_GETVERSION is not defined

Both `stbuf` and `local_ioc_getversion` where unused when
FS_IOC_GETVERSION was not defined, causing a compiler warning.

Reorganize the code to avoid this warning.

Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Signed-off-by: Greg Kurz <groug@kaod.org>

show more ...

9p: local: Properly set errp in fstatfs error path

In the review of

9p: Avoid warning if FS_IOC_GETVERSION is not defined

Grep Kurz noted this error path was failing to set errp.
Fix that.

Si

9p: local: Properly set errp in fstatfs error path

In the review of

9p: Avoid warning if FS_IOC_GETVERSION is not defined

Grep Kurz noted this error path was failing to set errp.
Fix that.

Signed-off-by: Keno Fischer <keno@juliacomputing.com>
[added local: to commit title, Greg Kurz]
Signed-off-by: Greg Kurz <groug@kaod.org>

show more ...

Merge remote-tracking branch 'remotes/armbru/tags/pull-misc-2018-02-07-v4' into staging

Miscellaneous patches for 2018-02-07

# gpg: Signature made Fri 09 Feb 2018 12:52:51 GMT
# gpg:

Merge remote-tracking branch 'remotes/armbru/tags/pull-misc-2018-02-07-v4' into staging

Miscellaneous patches for 2018-02-07

# gpg: Signature made Fri 09 Feb 2018 12:52:51 GMT
# gpg: using RSA key 3870B400EB918653
# gpg: Good signature from "Markus Armbruster <armbru@redhat.com>"
# gpg: aka "Markus Armbruster <armbru@pond.sub.org>"
# Primary key fingerprint: 354B C8B3 D7EB 2A6B 6867 4E5F 3870 B400 EB91 8653

* remotes/armbru/tags/pull-misc-2018-02-07-v4:
Move include qemu/option.h from qemu-common.h to actual users
Drop superfluous includes of qapi/qmp/qjson.h
Drop superfluous includes of qapi/qmp/dispatch.h
Include qapi/qmp/qnull.h exactly where needed
Include qapi/qmp/qnum.h exactly where needed
Include qapi/qmp/qbool.h exactly where needed
Include qapi/qmp/qstring.h exactly where needed
Include qapi/qmp/qdict.h exactly where needed
Include qapi/qmp/qlist.h exactly where needed
Include qapi/qmp/qobject.h exactly where needed
qdict qlist: Make most helper macros functions
Eliminate qapi/qmp/types.h
Typedef the subtypes of QObject in qemu/typedefs.h, too
Include qmp-commands.h exactly where needed
Drop superfluous includes of qapi/qmp/qerror.h
Include qapi/error.h exactly where needed
Drop superfluous includes of qapi-types.h and test-qapi-types.h
Clean up includes
Use #include "..." for our own headers, <...> for others
vnc: use stubs for CONFIG_VNC=n dummy functions

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

Move include qemu/option.h from qemu-common.h to actual users

qemu-common.h includes qemu/option.h, but most places that include the
former don't actually need the latter. Drop the include, and add

Move include qemu/option.h from qemu-common.h to actual users

qemu-common.h includes qemu/option.h, but most places that include the
former don't actually need the latter. Drop the include, and add it
to the places that actually need it.

While there, drop superfluous includes of both headers, and
separate #include from file comment with a blank line.

This cleanup makes the number of objects depending on qemu/option.h
drop from 4545 (out of 4743) to 284 in my "build everything" tree.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-20-armbru@redhat.com>
[Semantic conflict with commit bdd6a90a9e in block/nvme.c resolved]

show more ...

Include qapi/error.h exactly where needed

This cleanup makes the number of objects depending on qapi/error.h
drop from 1910 (out of 4743) to 1612 in my "build everything" tree.

While there, separat

Include qapi/error.h exactly where needed

This cleanup makes the number of objects depending on qapi/error.h
drop from 1910 (out of 4743) to 1612 in my "build everything" tree.

While there, separate #include from file comment with a blank line,
and drop a useless comment on why qemu/osdep.h is included first.

Reviewed-by: Eric Blake <eblake@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Message-Id: <20180201111846.21846-5-armbru@redhat.com>
[Semantic conflict with commit 34e304e975 resolved, OSX breakage fixed]

show more ...

Merge remote-tracking branch 'origin/master' into HEAD

Resolve conflicts around apb.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>

Merge remote-tracking branch 'remotes/gkurz/tags/for-upstream' into staging

- Aneesh no longer listed in MAINTAINERS,
- deprecation of the handle backend,
- improved error reporting, especially when

Merge remote-tracking branch 'remotes/gkurz/tags/for-upstream' into staging

- Aneesh no longer listed in MAINTAINERS,
- deprecation of the handle backend,
- improved error reporting, especially when the local backend fails to
open the VirtFS root,
- virtio-9p-test to behave more like a real virtio guest driver: set
DRIVER_OK when ready to use the device and process the used ring
for completed requests,
- cosmetic fixes (mostly coding style related).

# gpg: Signature made Mon 08 Jan 2018 10:19:18 GMT
# gpg: using RSA key 0x71D4D5E5822F73D6
# gpg: Good signature from "Greg Kurz <groug@kaod.org>"
# gpg: aka "Gregory Kurz <gregory.kurz@free.fr>"
# gpg: aka "[jpeg image of size 3330]"
# Primary key fingerprint: B482 8BAF 9431 40CE F2A3 4910 71D4 D5E5 822F 73D6

* remotes/gkurz/tags/for-upstream:
MAINTAINERS: Drop Aneesh as 9pfs maintainer
9pfs: deprecate handle backend
fsdev: improve error handling of backend init
fsdev: improve error handling of backend opts parsing
tests: virtio-9p: set DRIVER_OK before using the device
tests: virtio-9p: fix ISR dependence
9pfs: make pdu_marshal() and pdu_unmarshal() static functions
9pfs: fix error path in pdu_submit()
9pfs: fix type in *_parse_opts declarations
9pfs: handle: fix type definition
9pfs: fix some type definitions
fsdev: fix some type definitions
9pfs: fix XattrOperations typedef
virtio-9p: move unrealize/realize after virtio_9p_transport definition

Signed-off-by: Peter Maydell <peter.maydell@linaro.org>

show more ...

fsdev: improve error handling of backend init

This patch changes some error messages in the backend init code and
convert backends to propagate QEMU Error objects instead of calling
error_report().

fsdev: improve error handling of backend init

This patch changes some error messages in the backend init code and
convert backends to propagate QEMU Error objects instead of calling
error_report().

One notable improvement is that the local backend now provides a more
detailed error report when it fails to open the shared directory.

Signed-off-by: Greg Kurz <groug@kaod.org>

show more ...

fsdev: improve error handling of backend opts parsing

This patch changes some error messages in the backend opts parsing
code and convert backends to propagate QEMU Error objects instead
of calling

fsdev: improve error handling of backend opts parsing

This patch changes some error messages in the backend opts parsing
code and convert backends to propagate QEMU Error objects instead
of calling error_report().

Signed-off-by: Greg Kurz <groug@kaod.org>

show more ...

9pfs: fix type in *_parse_opts declarations

To comply with the QEMU coding style.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Eric Blake <eblake@redhat.com>

9pfs: local: clarify fchmodat_nofollow() implementation

Since fchmodat(2) on Linux doesn't support AT_SYMLINK_NOFOLLOW, we have to
implement it using workarounds. There are two different ways, depen

9pfs: local: clarify fchmodat_nofollow() implementation

Since fchmodat(2) on Linux doesn't support AT_SYMLINK_NOFOLLOW, we have to
implement it using workarounds. There are two different ways, depending on
whether the system supports O_PATH or not.

In the case O_PATH is supported, we rely on the behavhior of openat(2)
when passing O_NOFOLLOW | O_PATH and the file is a symbolic link. Even
if openat_file() already adds O_NOFOLLOW to the flags, this patch makes
it explicit that we need both creation flags to obtain the expected
behavior.

This is only cleanup, no functional change.

Signed-off-by: Greg Kurz <groug@kaod.org>
Reviewed-by: Philippe Mathieu-Daudé <f4bug@amsat.org>

show more ...