When 2c74c2cb4b added support for
the 'readonly' flag against 9p filesystems, it also made QEMU
add the O_NOATIME flag as a side-effect.
The O_NOATIME flag, however, may only be set by the file owner,
or a user with CAP_FOWNER capability. QEMU cannot assume that
this is the case for filesytems exported to QEMU.
eg, run QEMU as non-root, and attempt to pass the host OS
filesystem through to the guest OS with readonly enable.
The result is that the guest OS cannot open any files at
all.
If O_NOATIME is really required, it should be optionally
enabled via a separate QEMU command line flag.
* hw/9pfs/virtio-9p.c: Remove O_NOATIME
Acked-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Move p9 marshaling/unmarshaling code to a separate file so that
proxy filesytem driver can use these calls. Also made marshaling
code generic to accept "struct iovec" instead of V9fsPDU.
Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Kernel internal values can change, add protocol values for these constant and
use them.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
The v9fs_read() and v9fs_write() functions rely on iovec[] manipulation
code should be replaced with QEMUIOVector to avoid duplicating code.
In the future it may be possible to make the code even more concise by
using QEMUIOVector consistently across virtio and 9pfs.
The "v" format specifier for pdu_marshal() and pdu_unmarshal() is
dropped since it does not actually pack/unpack anything. The specifier
was also not implemented to update the offset variable and could only be
used at the end of a format string, another sign that this shouldn't
really be a format specifier. Instead, see the new
v9fs_init_qiov_from_pdu() function.
This change avoids a possible iovec[] buffer overflow when indirect
vrings are used since the number of vectors is now limited by the
underlying VirtQueueElement and cannot be out-of-bounds.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Double semicolons should be single.
Signed-off-by: Dong Xu Wang <wdongxu@linux.vnet.ibm.com>
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
As per the 9p rfc, during TVERSION its necessary to clean all the active
fids, so that we start the session from a clean state. Its also needed in
scenarios where the guest is booting off 9p, and boot fails, and client
restarts, without any knowledge of the past, it will issue a TVERSION again
so this ensures that we always start from a clean state.
Signed-off-by: Deepak C Shetty <deepakcs@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Now when you try to migrate with VirtFS export path mounted, you get a proper QMP error:
(qemu) migrate tcp:localhost:4444
Migration is disabled when VirtFS export path '/tmp/' is mounted in the guest using mount_tag 'v_tmp'
(qemu)
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
AT_REMOVEDIR is not defined on all systems. Pass the raw flags from the
9p protocol, which are always there.
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Anthony Liguori <aliguori@us.ibm.com>
Markus Armbruster <armbru@redhat.com> sent fixes for va_list vararg
issues in v9fs_string_alloc_printf(). It turns out the function
duplicates g_vasprintf() and can therefore be eliminated entirely.
Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
To implement synthetic file system in Qemu we may not really
require file descriptor and Dir *. Make generic code use
V9fsFidOpenState instead.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
A new fsdev parameter "readonly" is introduced to control accessing 9p export.
"readonly" can be used to specify the access type. By default "rw" access
is given to 9p export.
Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
this patch fix multiple issues with VirtFS tracing.
a) Add tracepoint to the correct code path. We handle error in complete_pdu
b) Fix indentation in python script
c) Fix variable naming issue in python script
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: Blue Swirl <blauwirbel@gmail.com>
Removing the existing debug infrastrucure as proposed to be replaced by
Qemu Tracing infrastructure.
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Plan is to replace the existing debug infrastructure with Qemu tracing
infrastructure so that user can dynamically enable/disable trace events and
therefore a meaningful trace log can be generated which can be further
filtered using an analysis script.
Note: Because of current simpletrace limitations, the trace events are
logging at max 6 args, however, once the more args are supported, we can
change trace events to log more info as well. Also, This initial patch only
provides a replacement for existing debug infra. More trace events to be
added later for newly added handlers and sub-routines.
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
This patch use file system specific ioctl for getting i_generation
value. Not all file system support the ioctl. So we add an export
specific extended operation and assign right callback for the
file system that support i_generation ioctl
["M. Mohan Kumar" <mohan@in.ibm.com> we can do ioctl only for
regular files and directories on the server]
Signed-off-by: Harsh Prateek Bora <harsh@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Some of the flags are OS/arch dependent we need to use
9P defined value on wire,
Based on the original patch from Venkateswararao Jujjuri <jvrao@linux.vnet.ibm.com>
Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Use 9P specific lock constants instead of arch specific lock constants.
Signed-off-by: M. Mohan Kumar <mohan@in.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
writeout=immediate implies the after pwritev we do a sync_file_range.
Reviewed-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Add a new context flag PATHNAME_FSCONTEXT and indicate whether
the fs driver track fid using path names. Also add a private
pointer that help us to track fs driver specific values in there
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
This enables us to add handles to track fids later. The
V9fsPath added is similar to V9fsString except that the
size include the NULL byte also.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
On rename we take the write lock and this ensure path
doesn't change as we operate on them.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
unlinkat - Remove a directory entry
size[4] Tunlinkat tag[2] dirfid[4] name[s] flag[4]
size[4] Runlinkat tag[2]
older Tremove have the below request format
size[4] Tremove tag[2] fid[4]
The remove message is used to remove a directory entry either file or directory
The remove opreation is actually a directory opertation and should ideally have
dirfid, if not we cannot represent the fid on server with anything other than
name. We will have to derive the directory name from fid in the Tremove request.
NOTE: The operation doesn't clunk the unlink fid.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
rename - change name of file or directory
size[4] Trenameat tag[2] olddirfid[4] oldname[s] newdirfid[4] newname[s]
size[4] Rrenameat tag[2]
older Trename have the below request format
size[4] Trename tag[2] fid[4] newdirfid[4] name[s]
The rename message is used to change the name of a file, possibly moving it
to a new directory. The rename opreation is actually a directory opertation
and should ideally have olddirfid, if not we cannot represent the fid on server
with anything other than name. We will have to derive the old directory name
from fid in the Trename request.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Since qid is allocated out of stack we need to intialize
the field to zero. Otherwise we will send wrong qid value
to client.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
We need to update the fidp path before opendir. Since we don't
use the fid returned by mkdir, earlier code should not have
much issue. We do a double v9fs_string_copy here. The later patch
cleanup the entire function.
Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
