fork of 9front i guess
Find a file
cinap_lenrek cb35d1a132 kernel: avoid inconsistent reads in /proc/#/fd and /proc/#/ns
to allow bytewise access to /proc/#/fd, the contents of the file where
recreated on each call. if fd's had been closed or reassigned between
the reads, the offset would be inconsistent and a read could start off
in the middle of a line. this happens when you cat /proc/#/fd file of
a busy process that mutates its filedescriptor table.

to fix this, we now return one line record at a time. if the line
fits in the read size, then this means the next read will always start
at the beginning of the next line record. we remember the consumed
byte count in Chan.mrock and the current record in Chan.nrock. (these
fields are free to usefor non-directory files)

if a read comes in and the offset is the same as c->mrock, we do not
need to regenerate the file and just render the next c->nrock's record.

for reads smaller than the line count, we have to regenerate the content
up to the offset and the race is still possible, but this should not
be the common case.

the same algorithm is now used for /proc/#/ns file, allowing a simpler
reimplementation and getting rid of Mntwalk state strcture.
2014-12-21 04:46:22 +01:00
386 change Rune from ushort to uint for to 21 bit runes (thanks mischief!) 2013-10-17 12:02:45 +02:00
68000 change Rune from ushort to uint for to 21 bit runes (thanks mischief!) 2013-10-17 12:02:45 +02:00
68020 change Rune from ushort to uint for to 21 bit runes (thanks mischief!) 2013-10-17 12:02:45 +02:00
acme acme/win: fix mistake 2014-12-12 21:18:31 +01:00
adm/timezone add Uruguay timezone (from sources) 2013-01-25 14:13:01 +01:00
alpha change Rune from ushort to uint for to 21 bit runes (thanks mischief!) 2013-10-17 12:02:45 +02:00
amd64 libc and ape support for amd64 2014-02-01 10:31:41 +01:00
arm change Rune from ushort to uint for to 21 bit runes (thanks mischief!) 2013-10-17 12:02:45 +02:00
lib fortunes: oh really. 2014-12-18 16:07:17 -05:00
mips change Rune from ushort to uint for to 21 bit runes (thanks mischief!) 2013-10-17 12:02:45 +02:00
power change Rune from ushort to uint for to 21 bit runes (thanks mischief!) 2013-10-17 12:02:45 +02:00
power64 change Rune from ushort to uint for to 21 bit runes (thanks mischief!) 2013-10-17 12:02:45 +02:00
rc hpost: break up tags with newlines to avoid sed line buffer limit 2014-11-16 01:59:29 +01:00
sparc change Rune from ushort to uint for to 21 bit runes (thanks mischief!) 2013-10-17 12:02:45 +02:00
sparc64 change Rune from ushort to uint for to 21 bit runes (thanks mischief!) 2013-10-17 12:02:45 +02:00
sys kernel: avoid inconsistent reads in /proc/#/fd and /proc/#/ns 2014-12-21 04:46:22 +01:00
.hgignore hgignore: ignore amd64 kernel and init 2014-09-27 01:35:06 -07:00