the fist problem is that qopen() might return nil and that kstrdup() will
sleep, so we should try to avoid holding the mntalloc lock. so we move
the kstrdup() and qopen() calls before the Mnt allocation, and properly
recover the memory if we fail later.
the second problem was that we error(Eshort) after we already created the Mnt
when returnlen < sizeof(f.version). this check has to happen *before* we
even attempt to allocate the Mnt structures. note that we only copy the
version string once everything is in the clear, so the semantics of the
user buffer not being modified in case of error is not changed.
a little cleanup in muxclose(), getting rid of mntptfree()...
pread does not guarantee that it would read all the data asked for.
But acme usage of disk assumes that. This issues as many reads as
needed to make acme work when read returns less data than it wanted.
pbs failed to load (silently loading garbage) 9BOOTFAT from start
cluster beyond FFFF because we ignored the low word from the
directory entry. now taking the high 16 bit of the directory's
start cluster into account.
Fsprotoclone() is not supposed to raise error, but return nil.
ipopen() seemed to assume otherwise as it setup error label
before calling Fsprotoclone(). fix ipopen(), make Fsprotoclone()
return nil instead of raising error.
Fsprotocone():
qopen() and qbypass() can fail and return nil, so make sure
the connection was not partially created by checking if read
and write queues have been setup by the protocol create hanler.
on error, free any resources of the partial connection and
error out.
netlogopen(): check malloc() error.
the initial fontresize() might fail but its error code is ignored
potentially leaving f->cacheimage == nil. make sure we call
fontresize() in loadchar() when theres no cacheimage and check the
return value to avoid nil pointer dereference.
instead of trying to resize the segment (which will not work when
the kernel picks the address as it will allocate right before
the base of the topmost segment), we create the mux segment with the
maximum size needed (arround 1.4MB) for OPEN_MAX filedescriptors.
buf slots will be reused and slots get demand paged once used.
