xfs: optimize inline symlinks

By overallocating the in-core inode fork data buffer and zero
terminating the link target in xfs_init_local_fork we can avoid
the memory allocation in ->follow_link.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
This commit is contained in:
Christoph Hellwig 2016-04-06 07:53:29 +10:00 committed by Dave Chinner
parent bfe8804d90
commit 30ee052e12
4 changed files with 49 additions and 15 deletions

View file

@ -446,6 +446,16 @@ xfs_vn_get_link(
return ERR_PTR(error);
}
STATIC const char *
xfs_vn_get_link_inline(
struct dentry *dentry,
struct inode *inode,
struct delayed_call *done)
{
ASSERT(XFS_I(inode)->i_df.if_flags & XFS_IFINLINE);
return XFS_I(inode)->i_df.if_u1.if_data;
}
STATIC int
xfs_vn_getattr(
struct vfsmount *mnt,
@ -1171,6 +1181,18 @@ static const struct inode_operations xfs_symlink_inode_operations = {
.update_time = xfs_vn_update_time,
};
static const struct inode_operations xfs_inline_symlink_inode_operations = {
.readlink = generic_readlink,
.get_link = xfs_vn_get_link_inline,
.getattr = xfs_vn_getattr,
.setattr = xfs_vn_setattr,
.setxattr = generic_setxattr,
.getxattr = generic_getxattr,
.removexattr = generic_removexattr,
.listxattr = xfs_vn_listxattr,
.update_time = xfs_vn_update_time,
};
STATIC void
xfs_diflags_to_iflags(
struct inode *inode,
@ -1282,9 +1304,10 @@ xfs_setup_iops(
inode->i_fop = &xfs_dir_file_operations;
break;
case S_IFLNK:
inode->i_op = &xfs_symlink_inode_operations;
if (!(ip->i_df.if_flags & XFS_IFINLINE))
inode->i_mapping->a_ops = &xfs_address_space_operations;
if (ip->i_df.if_flags & XFS_IFINLINE)
inode->i_op = &xfs_inline_symlink_inode_operations;
else
inode->i_op = &xfs_symlink_inode_operations;
break;
default:
inode->i_op = &xfs_inode_operations;