From f58ba889106af60f52af792efbe1973e458a2138 Mon Sep 17 00:00:00 2001 From: Miklos Szeredi Date: Wed, 2 Jul 2008 21:12:01 +0200 Subject: [GFS2] don't call permission() GFS2 calls permission() to verify permissions after locks on the files have been taken. For this it's sufficient to call gfs2_permission() instead. This results in the following changes: - IS_RDONLY() check is not performed - IS_IMMUTABLE() check is not performed - devcgroup_inode_permission() is not called - security_inode_permission() is not called IS_RDONLY() should be unnecessary anyway, as the per-mount read-only flag should provide protection against read-only remounts during operations. do_gfs2_set_flags() has been fixed to perform mnt_want_write()/mnt_drop_write() to protect against remounting read-only. IS_IMMUTABLE has been added to gfs2_permission() Repeating the security checks seems to be pointless, as they don't normally change, and if they do, it's independent of the filesystem state. Signed-off-by: Miklos Szeredi Signed-off-by: Steven Whitehouse --- fs/gfs2/ops_inode.c | 25 +++++++++++++++++-------- 1 file changed, 17 insertions(+), 8 deletions(-) (limited to 'fs/gfs2/ops_inode.c') diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c index 2686ad4..1e252df 100644 --- a/fs/gfs2/ops_inode.c +++ b/fs/gfs2/ops_inode.c @@ -163,7 +163,7 @@ static int gfs2_link(struct dentry *old_dentry, struct inode *dir, if (error) goto out; - error = permission(dir, MAY_WRITE | MAY_EXEC, NULL); + error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC); if (error) goto out_gunlock; @@ -669,7 +669,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry, } } } else { - error = permission(ndir, MAY_WRITE | MAY_EXEC, NULL); + error = gfs2_permission(ndir, MAY_WRITE | MAY_EXEC); if (error) goto out_gunlock; @@ -704,7 +704,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry, /* Check out the dir to be renamed */ if (dir_rename) { - error = permission(odentry->d_inode, MAY_WRITE, NULL); + error = gfs2_permission(odentry->d_inode, MAY_WRITE); if (error) goto out_gunlock; } @@ -891,7 +891,7 @@ static void *gfs2_follow_link(struct dentry *dentry, struct nameidata *nd) * Returns: errno */ -static int gfs2_permission(struct inode *inode, int mask, struct nameidata *nd) +int gfs2_permission(struct inode *inode, int mask) { struct gfs2_inode *ip = GFS2_I(inode); struct gfs2_holder i_gh; @@ -905,13 +905,22 @@ static int gfs2_permission(struct inode *inode, int mask, struct nameidata *nd) unlock = 1; } - error = generic_permission(inode, mask, gfs2_check_acl); + if ((mask & MAY_WRITE) && IS_IMMUTABLE(inode)) + error = -EACCES; + else + error = generic_permission(inode, mask, gfs2_check_acl); if (unlock) gfs2_glock_dq_uninit(&i_gh); return error; } +static int gfs2_iop_permission(struct inode *inode, int mask, + struct nameidata *nd) +{ + return gfs2_permission(inode, mask); +} + static int setattr_size(struct inode *inode, struct iattr *attr) { struct gfs2_inode *ip = GFS2_I(inode); @@ -1141,7 +1150,7 @@ static int gfs2_removexattr(struct dentry *dentry, const char *name) } const struct inode_operations gfs2_file_iops = { - .permission = gfs2_permission, + .permission = gfs2_iop_permission, .setattr = gfs2_setattr, .getattr = gfs2_getattr, .setxattr = gfs2_setxattr, @@ -1160,7 +1169,7 @@ const struct inode_operations gfs2_dir_iops = { .rmdir = gfs2_rmdir, .mknod = gfs2_mknod, .rename = gfs2_rename, - .permission = gfs2_permission, + .permission = gfs2_iop_permission, .setattr = gfs2_setattr, .getattr = gfs2_getattr, .setxattr = gfs2_setxattr, @@ -1172,7 +1181,7 @@ const struct inode_operations gfs2_dir_iops = { const struct inode_operations gfs2_symlink_iops = { .readlink = gfs2_readlink, .follow_link = gfs2_follow_link, - .permission = gfs2_permission, + .permission = gfs2_iop_permission, .setattr = gfs2_setattr, .getattr = gfs2_getattr, .setxattr = gfs2_setxattr, -- cgit v1.1