do not store Block* pointer in packet descriptor, assumed
pointer would fit in a long. we use pointer table now to
record the Block* pointer and store index instead.
old ramfs had a limit on the number of files it could serve
and file size was limited to maximum allocaiton size.
the new implementation uses multiple memory chunks to back file data
in a private compactable memory pool to overcome these limits.
files can be sparse. file metadata is maintained by 9pfile data
structures of lib9p.
mischief → ; import -p tcp!9.offblast.org!17007 / /n/9
mischief → -> import: can't mount /: EOF receiving fversion reply
mischief → on the console
mischief → bmo Mar 13 18:55:30 dialing tcp!9.offblast.org!17007
mischief → bmo Mar 13 18:55:30 reconnected to tcp!9.offblast.org!17007
mischief → bmo Mar 13 18:55:30 connected from 199.191.58.44
mischief → bmo Mar 13 18:55:34 exiting...bmo Mar 13 18:55:30 dialing tcp!9.offblast.org!17007
mischief → bmo Mar 13 18:55:30 reconnected to tcp!9.offblast.org!17007
mischief → bmo Mar 13 18:55:30 connected from 199.191.58.44
mischief → bmo Mar 13 18:55:34 exiting...
mischief → aan is dialing the *exportfs* port because i explicitly specified it
netfd is initially zero (stdin), when filter() closes fd0,
fd0 is free to be reused. this causes problems with openmount()
that assumes sfd being >2.
instead, we dup the our pipe end over netfd, and close the pipe.
stringwidth() and string() sometimes failed spuriously due
to the wrong assumption that cachechars() will only fail
when a different subfont is needed. in fact, cachechars()
can fail for other reasons like when it resizes the fontcache
(or fails todo so).
theres also the case when loadchar() is unable to translate
a character and returns 0. this case needs to be differentiated
from such temporary conditions like fontcache resize or subfont
load to stop the retry loop in string() and stringwidth().
now cachechars() returns -1 to indicate that it cannot
proceed and we test this in string() and stringwidth()
to skip over untranslatable characters to make progress
instead of retrying.
