Include linux/fs.h to avoid the following build failure on uclibc or
musl raised since version 6.0.0:
../block/export/fuse.c: In function 'fuse_lseek':
../block/export/fuse.c:641:19: error: 'SEEK_HOLE' undeclared (first use in this function)
641 | if (whence != SEEK_HOLE && whence != SEEK_DATA) {
| ^~~~~~~~~
../block/export/fuse.c:641:19: note: each undeclared identifier is reported only once for each function it appears in
../block/export/fuse.c:641:42: error: 'SEEK_DATA' undeclared (first use in this function); did you mean 'SEEK_SET'?
641 | if (whence != SEEK_HOLE && whence != SEEK_DATA) {
| ^~~~~~~~~
| SEEK_SET
Fixes:
- http://autobuild.buildroot.org/results/33c90ebf04997f4d3557cfa66abc9cf9a3076137
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Message-Id: <20210827220301.272887-1-fontaine.fabrice@gmail.com>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Fix the following build failure on musl raised since version 6.0.0 and
4ca37a96a7
because musl does not define FALLOC_FL_ZERO_RANGE:
../block/export/fuse.c: In function 'fuse_fallocate':
../block/export/fuse.c:563:23: error: 'FALLOC_FL_ZERO_RANGE' undeclared (first use in this function)
563 | } else if (mode & FALLOC_FL_ZERO_RANGE) {
| ^~~~~~~~~~~~~~~~~~~~
Fixes:
- http://autobuild.buildroot.org/results/b96e3d364fd1f8bbfb18904a742e73327d308f64
Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Message-Id: <20210809095101.1101336-1-fontaine.fabrice@gmail.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Reviewed-by: Denis V. Lunev <den@openvz.org>
Signed-off-by: Hanna Reitz <hreitz@redhat.com>
Allow changing the file mode, UID, and GID through SETATTR.
Without allow_other, UID and GID are not allowed to be changed, because
it would not make sense. Also, changing group or others' permissions
is not allowed either.
For read-only exports, +w cannot be set.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210625142317.271673-5-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
In order to support changing other attributes than the file size in
fuse_setattr(), we have to give each its own independent branch. This
also applies to the only attribute we do support right now.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20210625142317.271673-4-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Without the allow_other mount option, no user (not even root) but the
one who started qemu/the storage daemon can access the export. Allow
users to configure the export such that such accesses are possible.
While allow_other is probably what users want, we cannot make it an
unconditional default, because passing it is only possible (for non-root
users) if the global fuse.conf configuration file allows it. Thus, the
default is an 'auto' mode, in which we first try with allow_other, and
then fall back to without.
FuseExport.allow_other reports whether allow_other was actually used as
a mount option or not. Currently, this information is not used, but a
future patch will let this field decide whether e.g. an export's UID and
GID can be changed through chmod.
One notable thing about 'auto' mode is that libfuse may print error
messages directly to stderr, and so may fusermount (which it executes).
Our export code cannot really filter or hide them. Therefore, if 'auto'
fails its first attempt and has to fall back, fusermount will print an
error message that mounting with allow_other failed.
This behavior necessitates a change to iotest 308, namely we need to
filter out this error message (because if the first attempt at mounting
with allow_other succeeds, there will be no such message).
Furthermore, common.rc's _make_test_img should use allow-other=off for
FUSE exports, because iotests generally do not need to access images
from other users, so allow-other=on or allow-other=auto have no
advantage. OTOH, allow-other=on will not work on systems where
user_allow_other is disabled, and with allow-other=auto, we get said
error message that we would need to filter out again. Just disabling
allow-other is simplest.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210625142317.271673-3-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
We do not do any permission checks in fuse_open(), so let the kernel do
them. We already let fuse_getattr() report the proper UNIX permissions,
so this should work the way we want.
This causes a change in 308's reference output, because now opening a
non-writable export with O_RDWR fails already, instead of only actually
attempting to write to it. (That is an improvement.)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20210625142317.271673-2-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This is a relatively new feature in libfuse (available since 3.8.0,
which was released in November 2019), so we have to add a dedicated
check whether it is available before making use of it.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20201027190600.192171-7-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This allows allocating areas after the (old) EOF as part of a growing
resize, writing zeroes, and discarding.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20201027190600.192171-6-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
These will behave more like normal files in that writes beyond the EOF
will automatically grow the export size.
As an optimization, keep the RESIZE permission for growable exports so
we do not have to take it for every post-EOF write. (This permission is
not released when the export is destroyed, because at that point the
BlockBackend is destroyed altogether anyway.)
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20201027190600.192171-5-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
This makes the export actually useful instead of only producing errors
whenever it is accessed.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20201027190600.192171-4-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
block-export-add type=fuse allows mounting block graph nodes via FUSE on
some existing regular file. That file should then appears like a raw
disk image, and accesses to it result in accesses to the exported BDS.
Right now, we only implement the necessary block export functions to set
it up and shut it down. We do not implement any access functions, so
accessing the mount point only results in errors. This will be
addressed by a followup patch.
We keep a hash table of exported mount points, because we want to be
able to detect when users try to use a mount point twice. This is
because we invoke stat() to check whether the given mount point is a
regular file, but if that file is served by ourselves (because it is
already used as a mount point), then this stat() would have to be served
by ourselves, too, which is impossible to do while we (as the caller)
are waiting for it to settle. Therefore, keep track of mount point
paths to at least catch the most obvious instances of that problem.
Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-Id: <20201027190600.192171-3-mreitz@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
