1e8f889b10
Implement copy-on-write support for hugetlb mappings so MAP_PRIVATE can be
supported. This helps us to safely use hugetlb pages in many more
applications. The patch makes the following changes. If needed, I also have
it broken out according to the following paragraphs.
1. Add a pair of functions to set/clear write access on huge ptes. The
writable check in make_huge_pte is moved out to the caller for use by COW
later.
2. Hugetlb copy-on-write requires special case handling in the following
situations:
- copy_hugetlb_page_range() - Copied pages must be write protected so
a COW fault will be triggered (if necessary) if those pages are written
to.
- find_or_alloc_huge_page() - Only MAP_SHARED pages are added to the
page cache. MAP_PRIVATE pages still need to be locked however.
3. Provide hugetlb_cow() and calls from hugetlb_fault() and
hugetlb_no_page() which handles the COW fault by making the actual copy.
4. Remove the check in hugetlbfs_file_map() so that MAP_PRIVATE mmaps
will be allowed. Make MAP_HUGETLB exempt from the depricated VM_RESERVED
mapping check.
Signed-off-by: David Gibson <david@gibson.dropbear.id.au>
Signed-off-by: Adam Litke <agl@us.ibm.com>
Cc: William Lee Irwin III <wli@holomorphy.com>
Cc: "Seth, Rohit" <rohit.seth@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
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| .. | ||
| 9p | ||
| adfs | ||
| affs | ||
| afs | ||
| autofs | ||
| autofs4 | ||
| befs | ||
| bfs | ||
| cifs | ||
| coda | ||
| configfs | ||
| cramfs | ||
| debugfs | ||
| devfs | ||
| devpts | ||
| efs | ||
| exportfs | ||
| ext2 | ||
| ext3 | ||
| fat | ||
| freevxfs | ||
| fuse | ||
| hfs | ||
| hfsplus | ||
| hostfs | ||
| hpfs | ||
| hppfs | ||
| hugetlbfs | ||
| isofs | ||
| jbd | ||
| jffs | ||
| jffs2 | ||
| jfs | ||
| lockd | ||
| minix | ||
| msdos | ||
| ncpfs | ||
| nfs | ||
| nfs_common | ||
| nfsd | ||
| nls | ||
| ntfs | ||
| ocfs2 | ||
| openpromfs | ||
| partitions | ||
| proc | ||
| qnx4 | ||
| ramfs | ||
| reiserfs | ||
| relayfs | ||
| romfs | ||
| smbfs | ||
| sysfs | ||
| sysv | ||
| udf | ||
| ufs | ||
| vfat | ||
| xfs | ||
| Kconfig | ||
| Kconfig.binfmt | ||
| Makefile | ||
| aio.c | ||
| attr.c | ||
| bad_inode.c | ||
| binfmt_aout.c | ||
| binfmt_elf.c | ||
| binfmt_elf_fdpic.c | ||
| binfmt_em86.c | ||
| binfmt_flat.c | ||
| binfmt_misc.c | ||
| binfmt_script.c | ||
| binfmt_som.c | ||
| bio.c | ||
| block_dev.c | ||
| buffer.c | ||
| char_dev.c | ||
| compat.c | ||
| compat_ioctl.c | ||
| dcache.c | ||
| dcookies.c | ||
| direct-io.c | ||
| dnotify.c | ||
| dquot.c | ||
| eventpoll.c | ||
| exec.c | ||
| fcntl.c | ||
| fifo.c | ||
| file.c | ||
| file_table.c | ||
| filesystems.c | ||
| fs-writeback.c | ||
| inode.c | ||
| inotify.c | ||
| ioctl.c | ||
| ioprio.c | ||
| libfs.c | ||
| locks.c | ||
| mbcache.c | ||
| mpage.c | ||
| namei.c | ||
| namespace.c | ||
| nfsctl.c | ||
| open.c | ||
| pipe.c | ||
| pnode.c | ||
| pnode.h | ||
| posix_acl.c | ||
| quota.c | ||
| quota_v1.c | ||
| quota_v2.c | ||
| read_write.c | ||
| readdir.c | ||
| select.c | ||
| seq_file.c | ||
| stat.c | ||
| super.c | ||
| xattr.c | ||
| xattr_acl.c | ||