Revision 6b7339f4c31ad69c8e9c0b2859276e22cf72176d authored by Kirill A. Shutemov on 06 July 2015, 20:18:37 UTC, committed by Linus Torvalds on 09 July 2015, 18:12:48 UTC
Reading page fault handler code I've noticed that under right circumstances kernel would map anonymous pages into file mappings: if the VMA doesn't have vm_ops->fault() and the VMA wasn't fully populated on ->mmap(), kernel would handle page fault to not populated pte with do_anonymous_page(). Let's change page fault handler to use do_anonymous_page() only on anonymous VMA (->vm_ops == NULL) and make sure that the VMA is not shared. For file mappings without vm_ops->fault() or shred VMA without vm_ops, page fault on pte_none() entry would lead to SIGBUS. Signed-off-by: Kirill A. Shutemov <kirill.shutemov@linux.intel.com> Acked-by: Oleg Nesterov <oleg@redhat.com> Cc: Andrew Morton <akpm@linux-foundation.org> Cc: Willy Tarreau <w@1wt.eu> Cc: stable@vger.kernel.org Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
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Kconfig
config F2FS_FS
tristate "F2FS filesystem support"
depends on BLOCK
help
F2FS is based on Log-structured File System (LFS), which supports
versatile "flash-friendly" features. The design has been focused on
addressing the fundamental issues in LFS, which are snowball effect
of wandering tree and high cleaning overhead.
Since flash-based storages show different characteristics according to
the internal geometry or flash memory management schemes aka FTL, F2FS
and tools support various parameters not only for configuring on-disk
layout, but also for selecting allocation and cleaning algorithms.
If unsure, say N.
config F2FS_STAT_FS
bool "F2FS Status Information"
depends on F2FS_FS && DEBUG_FS
default y
help
/sys/kernel/debug/f2fs/ contains information about all the partitions
mounted as f2fs. Each file shows the whole f2fs information.
/sys/kernel/debug/f2fs/status includes:
- major filesystem information managed by f2fs currently
- average SIT information about whole segments
- current memory footprint consumed by f2fs.
config F2FS_FS_XATTR
bool "F2FS extended attributes"
depends on F2FS_FS
default y
help
Extended attributes are name:value pairs associated with inodes by
the kernel or by users (see the attr(5) manual page, or visit
<http://acl.bestbits.at/> for details).
If unsure, say N.
config F2FS_FS_POSIX_ACL
bool "F2FS Access Control Lists"
depends on F2FS_FS_XATTR
select FS_POSIX_ACL
default y
help
Posix Access Control Lists (ACLs) support permissions for users and
gourps beyond the owner/group/world scheme.
To learn more about Access Control Lists, visit the POSIX ACLs for
Linux website <http://acl.bestbits.at/>.
If you don't know what Access Control Lists are, say N
config F2FS_FS_SECURITY
bool "F2FS Security Labels"
depends on F2FS_FS_XATTR
help
Security labels provide an access control facility to support Linux
Security Models (LSMs) accepted by AppArmor, SELinux, Smack and TOMOYO
Linux. This option enables an extended attribute handler for file
security labels in the f2fs filesystem, so that it requires enabling
the extended attribute support in advance.
If you are not using a security module, say N.
config F2FS_CHECK_FS
bool "F2FS consistency checking feature"
depends on F2FS_FS
help
Enables BUG_ONs which check the filesystem consistency in runtime.
If you want to improve the performance, say N.
config F2FS_FS_ENCRYPTION
bool "F2FS Encryption"
depends on F2FS_FS
depends on F2FS_FS_XATTR
select CRYPTO_AES
select CRYPTO_CBC
select CRYPTO_ECB
select CRYPTO_XTS
select CRYPTO_CTS
select CRYPTO_CTR
select CRYPTO_SHA256
select KEYS
select ENCRYPTED_KEYS
help
Enable encryption of f2fs files and directories. This
feature is similar to ecryptfs, but it is more memory
efficient since it avoids caching the encrypted and
decrypted pages in the page cache.
config F2FS_IO_TRACE
bool "F2FS IO tracer"
depends on F2FS_FS
depends on FUNCTION_TRACER
help
F2FS IO trace is based on a function trace, which gathers process
information and block IO patterns in the filesystem level.
If unsure, say N.
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