Merge git://git.infradead.org/jffs2-xattr-2.6

Signed-off-by: David Woodhouse <[email protected]>

fs/Kconfig

@@ -1075,6 +1075,44 @@ config JFFS2_FS_DEBUG
 	  If reporting bugs, please try to have available a full dump of the
 	  messages at debug level 1 while the misbehaviour was occurring.
 
+config JFFS2_FS_XATTR
+	bool "JFFS2 XATTR support"
+	depends on JFFS2_FS
+	default n
+	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 JFFS2_FS_POSIX_ACL
+	bool "JFFS2 POSIX Access Control Lists"
+	depends on JFFS2_FS_XATTR
+	default y
+	select FS_POSIX_ACL
+	help
+	  Posix Access Control Lists (ACLs) support permissions for users and
+	  groups 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 JFFS2_FS_SECURITY
+	bool "JFFS2 Security Labels"
+	depends on JFFS2_FS_XATTR
+	default y
+	help
+	  Security labels support alternative access control models
+	  implemented by security modules like SELinux.  This option
+	  enables an extended attribute handler for file security
+	  labels in the jffs2 filesystem.
+
+	  If you are not using a security module that requires using
+	  extended attributes for file security labels, say N.
+
 config JFFS2_FS_WRITEBUFFER
 	bool "JFFS2 write-buffering support"
 	depends on JFFS2_FS

fs/jffs2/Makefile

@@ -12,6 +12,9 @@ jffs2-y	+= symlink.o build.o erase.o background.o fs.o writev.o
 jffs2-y	+= super.o debug.o
 
 jffs2-$(CONFIG_JFFS2_FS_WRITEBUFFER)	+= wbuf.o
+jffs2-$(CONFIG_JFFS2_FS_XATTR)		+= xattr.o xattr_trusted.o xattr_user.o
+jffs2-$(CONFIG_JFFS2_FS_SECURITY)	+= security.o
+jffs2-$(CONFIG_JFFS2_FS_POSIX_ACL)	+= acl.o
 jffs2-$(CONFIG_JFFS2_RUBIN)	+= compr_rubin.o
 jffs2-$(CONFIG_JFFS2_RTIME)	+= compr_rtime.o
 jffs2-$(CONFIG_JFFS2_ZLIB)	+= compr_zlib.o

fs/jffs2/README.Locking

@@ -150,3 +150,24 @@ the buffer.
 
 Ordering constraints:
 	Lock wbuf_sem last, after the alloc_sem or and f->sem.
+
+
+	c->xattr_sem
+	------------
+
+This read/write semaphore protects against concurrent access to the
+xattr related objects which include stuff in superblock and ic->xref.
+In read-only path, write-semaphore is too much exclusion. It's enough
+by read-semaphore. But you must hold write-semaphore when updating,
+creating or deleting any xattr related object.
+
+Once xattr_sem released, there would be no assurance for the existence
+of those objects. Thus, a series of processes is often required to retry,
+when updating such a object is necessary under holding read semaphore.
+For example, do_jffs2_getxattr() holds read-semaphore to scan xref and
+xdatum at first. But it retries this process with holding write-semaphore
+after release read-semaphore, if it's necessary to load name/value pair
+from medium.
+
+Ordering constraints:
+	Lock xattr_sem last, after the alloc_sem.