From 384f3ced07efdddf6838f6527366089d37843c94 Mon Sep 17 00:00:00 2001 From: Barry Naujok Date: Wed, 21 May 2008 16:58:22 +1000 Subject: [XFS] Return case-insensitive match for dentry cache This implements the code to store the actual filename found during a lookup in the dentry cache and to avoid multiple entries in the dcache pointing to the same inode. To avoid polluting the dcache, we implement a new directory inode operations for lookup. xfs_vn_ci_lookup() stores the correct case name in the dcache. The "actual name" is only allocated and returned for a case- insensitive match and not an actual match. Another unusual interaction with the dcache is not storing negative dentries like other filesystems doing a d_add(dentry, NULL) when an ENOENT is returned. During the VFS lookup, if a dentry returned has no inode, dput is called and ENOENT is returned. By not doing a d_add, this actually removes it completely from the dcache to be reused. create/rename have to be modified to support unhashed dentries being passed in. SGI-PV: 981521 SGI-Modid: xfs-linux-melb:xfs-kern:31208a Signed-off-by: Barry Naujok Signed-off-by: Christoph Hellwig --- fs/xfs/linux-2.6/xfs_export.c | 2 +- fs/xfs/linux-2.6/xfs_iops.c | 57 ++++++++++++++++++++++++++++++++++++++++++- fs/xfs/linux-2.6/xfs_iops.h | 1 + 3 files changed, 58 insertions(+), 2 deletions(-) (limited to 'fs/xfs/linux-2.6') diff --git a/fs/xfs/linux-2.6/xfs_export.c b/fs/xfs/linux-2.6/xfs_export.c index c672b32..987fe84 100644 --- a/fs/xfs/linux-2.6/xfs_export.c +++ b/fs/xfs/linux-2.6/xfs_export.c @@ -215,7 +215,7 @@ xfs_fs_get_parent( struct xfs_inode *cip; struct dentry *parent; - error = xfs_lookup(XFS_I(child->d_inode), &xfs_name_dotdot, &cip); + error = xfs_lookup(XFS_I(child->d_inode), &xfs_name_dotdot, &cip, NULL); if (unlikely(error)) return ERR_PTR(-error); diff --git a/fs/xfs/linux-2.6/xfs_iops.c b/fs/xfs/linux-2.6/xfs_iops.c index 13b6cfd..9f0f8ee 100644 --- a/fs/xfs/linux-2.6/xfs_iops.c +++ b/fs/xfs/linux-2.6/xfs_iops.c @@ -382,7 +382,7 @@ xfs_vn_lookup( return ERR_PTR(-ENAMETOOLONG); xfs_dentry_to_name(&name, dentry); - error = xfs_lookup(XFS_I(dir), &name, &cip); + error = xfs_lookup(XFS_I(dir), &name, &cip, NULL); if (unlikely(error)) { if (unlikely(error != ENOENT)) return ERR_PTR(-error); @@ -393,6 +393,42 @@ xfs_vn_lookup( return d_splice_alias(cip->i_vnode, dentry); } +STATIC struct dentry * +xfs_vn_ci_lookup( + struct inode *dir, + struct dentry *dentry, + struct nameidata *nd) +{ + struct xfs_inode *ip; + struct xfs_name xname; + struct xfs_name ci_name; + struct qstr dname; + int error; + + if (dentry->d_name.len >= MAXNAMELEN) + return ERR_PTR(-ENAMETOOLONG); + + xfs_dentry_to_name(&xname, dentry); + error = xfs_lookup(XFS_I(dir), &xname, &ip, &ci_name); + if (unlikely(error)) { + if (unlikely(error != ENOENT)) + return ERR_PTR(-error); + d_add(dentry, NULL); + return NULL; + } + + /* if exact match, just splice and exit */ + if (!ci_name.name) + return d_splice_alias(ip->i_vnode, dentry); + + /* else case-insensitive match... */ + dname.name = ci_name.name; + dname.len = ci_name.len; + dentry = d_add_ci(ip->i_vnode, dentry, &dname); + kmem_free(ci_name.name); + return dentry; +} + STATIC int xfs_vn_link( struct dentry *old_dentry, @@ -892,6 +928,25 @@ const struct inode_operations xfs_dir_inode_operations = { .removexattr = xfs_vn_removexattr, }; +const struct inode_operations xfs_dir_ci_inode_operations = { + .create = xfs_vn_create, + .lookup = xfs_vn_ci_lookup, + .link = xfs_vn_link, + .unlink = xfs_vn_unlink, + .symlink = xfs_vn_symlink, + .mkdir = xfs_vn_mkdir, + .rmdir = xfs_vn_rmdir, + .mknod = xfs_vn_mknod, + .rename = xfs_vn_rename, + .permission = xfs_vn_permission, + .getattr = xfs_vn_getattr, + .setattr = xfs_vn_setattr, + .setxattr = xfs_vn_setxattr, + .getxattr = xfs_vn_getxattr, + .listxattr = xfs_vn_listxattr, + .removexattr = xfs_vn_removexattr, +}; + const struct inode_operations xfs_symlink_inode_operations = { .readlink = generic_readlink, .follow_link = xfs_vn_follow_link, diff --git a/fs/xfs/linux-2.6/xfs_iops.h b/fs/xfs/linux-2.6/xfs_iops.h index 14d0deb..3b4df58 100644 --- a/fs/xfs/linux-2.6/xfs_iops.h +++ b/fs/xfs/linux-2.6/xfs_iops.h @@ -20,6 +20,7 @@ extern const struct inode_operations xfs_inode_operations; extern const struct inode_operations xfs_dir_inode_operations; +extern const struct inode_operations xfs_dir_ci_inode_operations; extern const struct inode_operations xfs_symlink_inode_operations; extern const struct file_operations xfs_file_operations; -- cgit v1.1