d75faf18d9
When VM asks a file system to provide a block to satisfy a page fault on a file memory mapping, the file system previously had no way to inform VM that the block is a hole, since there is no corresponding block on the underlying device. To work around this, MFS and ext2 would actually allocate a block for the hole when asked by VM, which not only defeats the point of holes in the first place, but also does not work on read-only file systems. With this patch, a new libminixfs call allows the file system to inform VM about holes. This issue does raise the question as to whether the VM cache is using the right data structures, since there are now two places where we have to fake a device offset. This will have to be revisited in the future. The patch changes file systems accordingly, and adds a test to test74. Change-Id: Ib537d56b3f30a8eb05bc1f63c92b5c7428d18f4c |
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bin | ||
common | ||
distrib | ||
docs | ||
etc | ||
external | ||
games | ||
gnu | ||
include | ||
lib | ||
libexec | ||
minix | ||
releasetools | ||
sbin | ||
share | ||
sys | ||
tests | ||
tools | ||
usr.bin | ||
usr.sbin | ||
.gitignore | ||
.gitreview | ||
build.sh | ||
LICENSE | ||
Makefile | ||
Makefile.inc |