Commit 5ca14835 authored by Andrew Morton's avatar Andrew Morton
Browse files

fs: uninline inode_maybe_inc_iversion() 



It has many callsites and is large.

   text	   data	    bss	    dec	    hex	filename
  91796	  15984	    512	 108292	  1a704	mm/shmem.o-before
  91180	  15984	    512	 107676	  1a49c	mm/shmem.o-after

Acked-by: default avatarJeff Layton <jlayton@kernel.org>
Cc: Chuck Lever <chuck.lever@oracle.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Hugh Dickins <hughd@google.com>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
parent 1179083f

fs/libfs.c

+46 −0
Original line number Diff line number Diff line
@@ -15,6 +15,7 @@ 
#include <linux/mutex.h>

#include <linux/namei.h>

#include <linux/exportfs.h>

#include <linux/iversion.h>

#include <linux/writeback.h>

#include <linux/buffer_head.h> /* sync_mapping_buffers */

#include <linux/fs_context.h>
@@ -1520,3 +1521,48 @@ void generic_set_encrypted_ci_d_ops(struct dentry *dentry) 
#endif

}

EXPORT_SYMBOL(generic_set_encrypted_ci_d_ops);



/**

 * inode_maybe_inc_iversion - increments i_version

 * @inode: inode with the i_version that should be updated

 * @force: increment the counter even if it's not necessary?

 *

 * Every time the inode is modified, the i_version field must be seen to have

 * changed by any observer.

 *

 * If "force" is set or the QUERIED flag is set, then ensure that we increment

 * the value, and clear the queried flag.

 *

 * In the common case where neither is set, then we can return "false" without

 * updating i_version.

 *

 * If this function returns false, and no other metadata has changed, then we

 * can avoid logging the metadata.

 */

bool inode_maybe_inc_iversion(struct inode *inode, bool force)

{

	u64 cur, new;



	/*

	 * The i_version field is not strictly ordered with any other inode

	 * information, but the legacy inode_inc_iversion code used a spinlock

	 * to serialize increments.

	 *

	 * Here, we add full memory barriers to ensure that any de-facto

	 * ordering with other info is preserved.

	 *

	 * This barrier pairs with the barrier in inode_query_iversion()

	 */

	smp_mb();

	cur = inode_peek_iversion_raw(inode);

	do {

		/* If flag is clear then we needn't do anything */

		if (!force && !(cur & I_VERSION_QUERIED))

			return false;



		/* Since lowest bit is flag, add 2 to avoid it */

		new = (cur & ~I_VERSION_QUERIED) + I_VERSION_INCREMENT;

	} while (!atomic64_try_cmpxchg(&inode->i_version, &cur, new));

	return true;

}

EXPORT_SYMBOL(inode_maybe_inc_iversion);

include/linux/iversion.h

+1 −45
Original line number Diff line number Diff line
@@ -172,51 +172,7 @@ inode_set_iversion_queried(struct inode *inode, u64 val) 
				I_VERSION_QUERIED);

}



/**

 * inode_maybe_inc_iversion - increments i_version

 * @inode: inode with the i_version that should be updated

 * @force: increment the counter even if it's not necessary?

 *

 * Every time the inode is modified, the i_version field must be seen to have

 * changed by any observer.

 *

 * If "force" is set or the QUERIED flag is set, then ensure that we increment

 * the value, and clear the queried flag.

 *

 * In the common case where neither is set, then we can return "false" without

 * updating i_version.

 *

 * If this function returns false, and no other metadata has changed, then we

 * can avoid logging the metadata.

 */

static inline bool

inode_maybe_inc_iversion(struct inode *inode, bool force)

{

	u64 cur, new;



	/*

	 * The i_version field is not strictly ordered with any other inode

	 * information, but the legacy inode_inc_iversion code used a spinlock

	 * to serialize increments.

	 *

	 * Here, we add full memory barriers to ensure that any de-facto

	 * ordering with other info is preserved.

	 *

	 * This barrier pairs with the barrier in inode_query_iversion()

	 */

	smp_mb();

	cur = inode_peek_iversion_raw(inode);

	do {

		/* If flag is clear then we needn't do anything */

		if (!force && !(cur & I_VERSION_QUERIED))

			return false;



		/* Since lowest bit is flag, add 2 to avoid it */

		new = (cur & ~I_VERSION_QUERIED) + I_VERSION_INCREMENT;

	} while (!atomic64_try_cmpxchg(&inode->i_version, &cur, new));

	return true;

}



bool inode_maybe_inc_iversion(struct inode *inode, bool force);



/**

 * inode_inc_iversion - forcibly increment i_version