From b74c79e99389cd79b31fcc08f82c24e492e63c7e Mon Sep 17 00:00:00 2001 From: Nick Piggin Date: Fri, 7 Jan 2011 17:49:58 +1100 Subject: fs: provide rcu-walk aware permission i_ops Signed-off-by: Nick Piggin --- Documentation/filesystems/Locking | 6 +-- Documentation/filesystems/path-lookup.txt | 44 ++++++++++++++++-- Documentation/filesystems/porting | 5 +++ Documentation/filesystems/vfs.txt | 10 ++++- drivers/staging/smbfs/file.c | 5 ++- fs/9p/acl.c | 5 ++- fs/9p/acl.h | 2 +- fs/afs/internal.h | 2 +- fs/afs/security.c | 7 ++- fs/bad_inode.c | 5 ++- fs/btrfs/acl.c | 6 ++- fs/btrfs/ctree.h | 2 +- fs/btrfs/inode.c | 7 ++- fs/ceph/inode.c | 11 +++-- fs/ceph/super.h | 2 +- fs/cifs/cifsfs.c | 7 ++- fs/coda/dir.c | 5 ++- fs/coda/pioctl.c | 6 ++- fs/ecryptfs/inode.c | 4 +- fs/ext2/acl.c | 8 +++- fs/ext2/acl.h | 2 +- fs/ext3/acl.c | 8 +++- fs/ext3/acl.h | 2 +- fs/ext4/acl.c | 8 +++- fs/ext4/acl.h | 2 +- fs/fuse/dir.c | 10 +++-- fs/generic_acl.c | 8 +++- fs/gfs2/acl.c | 5 ++- fs/gfs2/acl.h | 2 +- fs/gfs2/file.c | 2 +- fs/gfs2/inode.c | 4 +- fs/gfs2/inode.h | 2 +- fs/gfs2/ops_inode.c | 18 +++++--- fs/hostfs/hostfs_kern.c | 7 ++- fs/hpfs/namei.c | 2 +- fs/jffs2/acl.c | 5 ++- fs/jffs2/acl.h | 2 +- fs/jfs/acl.c | 8 +++- fs/jfs/jfs_acl.h | 2 +- fs/logfs/dir.c | 6 ++- fs/namei.c | 75 ++++++++++++------------------- fs/nfs/dir.c | 7 ++- fs/nilfs2/inode.c | 10 +++-- fs/nilfs2/nilfs.h | 2 +- fs/ocfs2/acl.c | 8 +++- fs/ocfs2/acl.h | 2 +- fs/ocfs2/file.c | 7 ++- fs/ocfs2/file.h | 2 +- fs/proc/base.c | 6 ++- fs/proc/proc_sysctl.c | 5 ++- fs/reiserfs/xattr.c | 14 ++++-- fs/sysfs/inode.c | 11 +++-- fs/sysfs/sysfs.h | 2 +- fs/xfs/linux-2.6/xfs_acl.c | 8 +++- fs/xfs/xfs_acl.h | 2 +- include/linux/coda_linux.h | 2 +- include/linux/fs.h | 10 +++-- include/linux/generic_acl.h | 2 +- include/linux/nfs_fs.h | 2 +- include/linux/reiserfs_xattr.h | 2 +- 60 files changed, 287 insertions(+), 146 deletions(-) diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index e90ffe61eb65..977d8919cc69 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -47,8 +47,8 @@ ata *); void * (*follow_link) (struct dentry *, struct nameidata *); void (*put_link) (struct dentry *, struct nameidata *, void *); void (*truncate) (struct inode *); - int (*permission) (struct inode *, int, struct nameidata *); - int (*check_acl)(struct inode *, int); + int (*permission) (struct inode *, int, unsigned int); + int (*check_acl)(struct inode *, int, unsigned int); int (*setattr) (struct dentry *, struct iattr *); int (*getattr) (struct vfsmount *, struct dentry *, struct kstat *); int (*setxattr) (struct dentry *, const char *,const void *,size_t,int); @@ -76,7 +76,7 @@ follow_link: no put_link: no truncate: yes (see below) setattr: yes -permission: no +permission: no (may not block if called in rcu-walk mode) check_acl: no getattr: no setxattr: yes diff --git a/Documentation/filesystems/path-lookup.txt b/Documentation/filesystems/path-lookup.txt index 8789d1810bed..eb59c8b44be9 100644 --- a/Documentation/filesystems/path-lookup.txt +++ b/Documentation/filesystems/path-lookup.txt @@ -316,11 +316,9 @@ The detailed design for rcu-walk is like this: The cases where rcu-walk cannot continue are: * NULL dentry (ie. any uncached path element) -* parent with d_inode->i_op->permission or ACLs * Following links -In future patches, permission checks become rcu-walk aware. It may be possible -eventually to make following links rcu-walk aware. +It may be possible eventually to make following links rcu-walk aware. Uncached path elements will always require dropping to ref-walk mode, at the very least because i_mutex needs to be grabbed, and objects allocated. @@ -336,9 +334,49 @@ or stored into. The result is massive improvements in performance and scalability of path resolution. +Interesting statistics +====================== + +The following table gives rcu lookup statistics for a few simple workloads +(2s12c24t Westmere, debian non-graphical system). Ungraceful are attempts to +drop rcu that fail due to d_seq failure and requiring the entire path lookup +again. Other cases are successful rcu-drops that are required before the final +element, nodentry for missing dentry, revalidate for filesystem revalidate +routine requiring rcu drop, permission for permission check requiring drop, +and link for symlink traversal requiring drop. + + rcu-lookups restart nodentry link revalidate permission +bootup 47121 0 4624 1010 10283 7852 +dbench 25386793 0 6778659(26.7%) 55 549 1156 +kbuild 2696672 10 64442(2.3%) 108764(4.0%) 1 1590 +git diff 39605 0 28 2 0 106 +vfstest 24185492 4945 708725(2.9%) 1076136(4.4%) 0 2651 + +What this shows is that failed rcu-walk lookups, ie. ones that are restarted +entirely with ref-walk, are quite rare. Even the "vfstest" case which +specifically has concurrent renames/mkdir/rmdir/ creat/unlink/etc to excercise +such races is not showing a huge amount of restarts. + +Dropping from rcu-walk to ref-walk mean that we have encountered a dentry where +the reference count needs to be taken for some reason. This is either because +we have reached the target of the path walk, or because we have encountered a +condition that can't be resolved in rcu-walk mode. Ideally, we drop rcu-walk +only when we have reached the target dentry, so the other statistics show where +this does not happen. + +Note that a graceful drop from rcu-walk mode due to something such as the +dentry not existing (which can be common) is not necessarily a failure of +rcu-walk scheme, because some elements of the path may have been walked in +rcu-walk mode. The further we get from common path elements (such as cwd or +root), the less contended the dentry is likely to be. The closer we are to +common path elements, the more likely they will exist in dentry cache. + + Papers and other documentation on dcache locking ================================================ 1. Scaling dcache with RCU (http://linuxjournal.com/article.php?sid=7124). 2. http://lse.sourceforge.net/locking/dcache/dcache.html + + diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index cd9756a2709d..07a32b42cf9c 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -379,4 +379,9 @@ where possible. the filesystem provides it), which requires dropping out of rcu-walk mode. This may now be called in rcu-walk mode (nd->flags & LOOKUP_RCU). -ECHILD should be returned if the filesystem cannot handle rcu-walk. See +Documentation/filesystems/vfs.txt for more details. + + permission and check_acl are inode permission checks that are called +on many or all directory inodes on the way down a path walk (to check for +exec permission). These must now be rcu-walk aware (flags & IPERM_RCU). See Documentation/filesystems/vfs.txt for more details. diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index c936b4912383..fbb324e2bd43 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -325,7 +325,8 @@ struct inode_operations { void * (*follow_link) (struct dentry *, struct nameidata *); void (*put_link) (struct dentry *, struct nameidata *, void *); void (*truncate) (struct inode *); - int (*permission) (struct inode *, int, struct nameidata *); + int (*permission) (struct inode *, int, unsigned int); + int (*check_acl)(struct inode *, int, unsigned int); int (*setattr) (struct dentry *, struct iattr *); int (*getattr) (struct vfsmount *mnt, struct dentry *, struct kstat *); int (*setxattr) (struct dentry *, const char *,const void *,size_t,int); @@ -414,6 +415,13 @@ otherwise noted. permission: called by the VFS to check for access rights on a POSIX-like filesystem. + May be called in rcu-walk mode (flags & IPERM_RCU). If in rcu-walk + mode, the filesystem must check the permission without blocking or + storing to the inode. + + If a situation is encountered that rcu-walk cannot handle, return + -ECHILD and it will be called again in ref-walk mode. + setattr: called by the VFS to set attributes for a file. This method is called by chmod(2) and related system calls. diff --git a/drivers/staging/smbfs/file.c b/drivers/staging/smbfs/file.c index 5dcd19c60eb9..31372e7b12de 100644 --- a/drivers/staging/smbfs/file.c +++ b/drivers/staging/smbfs/file.c @@ -407,11 +407,14 @@ smb_file_release(struct inode *inode, struct file * file) * privileges, so we need our own check for this. */ static int -smb_file_permission(struct inode *inode, int mask) +smb_file_permission(struct inode *inode, int mask, unsigned int flags) { int mode = inode->i_mode; int error = 0; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + VERBOSE("mode=%x, mask=%x\n", mode, mask); /* Look at user permissions */ diff --git a/fs/9p/acl.c b/fs/9p/acl.c index 12d602351dbe..6e58c4ca1e6e 100644 --- a/fs/9p/acl.c +++ b/fs/9p/acl.c @@ -91,11 +91,14 @@ static struct posix_acl *v9fs_get_cached_acl(struct inode *inode, int type) return acl; } -int v9fs_check_acl(struct inode *inode, int mask) +int v9fs_check_acl(struct inode *inode, int mask, unsigned int flags) { struct posix_acl *acl; struct v9fs_session_info *v9ses; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + v9ses = v9fs_inode2v9ses(inode); if ((v9ses->flags & V9FS_ACCESS_MASK) != V9FS_ACCESS_CLIENT) { /* diff --git a/fs/9p/acl.h b/fs/9p/acl.h index 59e18c2e8c7e..7ef3ac9f6d95 100644 --- a/fs/9p/acl.h +++ b/fs/9p/acl.h @@ -16,7 +16,7 @@ #ifdef CONFIG_9P_FS_POSIX_ACL extern int v9fs_get_acl(struct inode *, struct p9_fid *); -extern int v9fs_check_acl(struct inode *inode, int mask); +extern int v9fs_check_acl(struct inode *inode, int mask, unsigned int flags); extern int v9fs_acl_chmod(struct dentry *); extern int v9fs_set_create_acl(struct dentry *, struct posix_acl *, struct posix_acl *); diff --git a/fs/afs/internal.h b/fs/afs/internal.h index cca8eef736fc..6d4bc1c8ff60 100644 --- a/fs/afs/internal.h +++ b/fs/afs/internal.h @@ -624,7 +624,7 @@ extern void afs_clear_permits(struct afs_vnode *); extern void afs_cache_permit(struct afs_vnode *, struct key *, long); extern void afs_zap_permits(struct rcu_head *); extern struct key *afs_request_key(struct afs_cell *); -extern int afs_permission(struct inode *, int); +extern int afs_permission(struct inode *, int, unsigned int); /* * server.c diff --git a/fs/afs/security.c b/fs/afs/security.c index bb4ed144d0e4..f44b9d355377 100644 --- a/fs/afs/security.c +++ b/fs/afs/security.c @@ -285,13 +285,16 @@ static int afs_check_permit(struct afs_vnode *vnode, struct key *key, * - AFS ACLs are attached to directories only, and a file is controlled by its * parent directory's ACL */ -int afs_permission(struct inode *inode, int mask) +int afs_permission(struct inode *inode, int mask, unsigned int flags) { struct afs_vnode *vnode = AFS_FS_I(inode); afs_access_t uninitialized_var(access); struct key *key; int ret; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + _enter("{{%x:%u},%lx},%x,", vnode->fid.vid, vnode->fid.vnode, vnode->flags, mask); @@ -347,7 +350,7 @@ int afs_permission(struct inode *inode, int mask) } key_put(key); - ret = generic_permission(inode, mask, NULL); + ret = generic_permission(inode, mask, flags, NULL); _leave(" = %d", ret); return ret; diff --git a/fs/bad_inode.c b/fs/bad_inode.c index f024d8aaddef..9ad2369d9e35 100644 --- a/fs/bad_inode.c +++ b/fs/bad_inode.c @@ -229,8 +229,11 @@ static int bad_inode_readlink(struct dentry *dentry, char __user *buffer, return -EIO; } -static int bad_inode_permission(struct inode *inode, int mask) +static int bad_inode_permission(struct inode *inode, int mask, unsigned int flags) { + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + return -EIO; } diff --git a/fs/btrfs/acl.c b/fs/btrfs/acl.c index 2222d161c7b6..cb518a4b917c 100644 --- a/fs/btrfs/acl.c +++ b/fs/btrfs/acl.c @@ -185,13 +185,15 @@ static int btrfs_xattr_acl_set(struct dentry *dentry, const char *name, return ret; } -int btrfs_check_acl(struct inode *inode, int mask) +int btrfs_check_acl(struct inode *inode, int mask, unsigned int flags) { struct posix_acl *acl; int error = -EAGAIN; - acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS); + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + acl = btrfs_get_acl(inode, ACL_TYPE_ACCESS); if (IS_ERR(acl)) return PTR_ERR(acl); if (acl) { diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index af52f6d7a4d8..a142d204b526 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -2544,7 +2544,7 @@ int btrfs_sync_fs(struct super_block *sb, int wait); /* acl.c */ #ifdef CONFIG_BTRFS_FS_POSIX_ACL -int btrfs_check_acl(struct inode *inode, int mask); +int btrfs_check_acl(struct inode *inode, int mask, unsigned int flags); #else #define btrfs_check_acl NULL #endif diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 63e4546b478a..5cf0db0081f9 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -7211,11 +7211,14 @@ static int btrfs_set_page_dirty(struct page *page) return __set_page_dirty_nobuffers(page); } -static int btrfs_permission(struct inode *inode, int mask) +static int btrfs_permission(struct inode *inode, int mask, unsigned int flags) { + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + if ((BTRFS_I(inode)->flags & BTRFS_INODE_READONLY) && (mask & MAY_WRITE)) return -EACCES; - return generic_permission(inode, mask, btrfs_check_acl); + return generic_permission(inode, mask, flags, btrfs_check_acl); } static const struct inode_operations btrfs_dir_inode_operations = { diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c index 47f8c8baf3b5..e61de4f7b99d 100644 --- a/fs/ceph/inode.c +++ b/fs/ceph/inode.c @@ -1781,12 +1781,17 @@ int ceph_do_getattr(struct inode *inode, int mask) * Check inode permissions. We verify we have a valid value for * the AUTH cap, then call the generic handler. */ -int ceph_permission(struct inode *inode, int mask) +int ceph_permission(struct inode *inode, int mask, unsigned int flags) { - int err = ceph_do_getattr(inode, CEPH_CAP_AUTH_SHARED); + int err; + + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + + err = ceph_do_getattr(inode, CEPH_CAP_AUTH_SHARED); if (!err) - err = generic_permission(inode, mask, NULL); + err = generic_permission(inode, mask, flags, NULL); return err; } diff --git a/fs/ceph/super.h b/fs/ceph/super.h index 7f01728a4657..4553d8829edb 100644 --- a/fs/ceph/super.h +++ b/fs/ceph/super.h @@ -665,7 +665,7 @@ extern void ceph_queue_invalidate(struct inode *inode); extern void ceph_queue_writeback(struct inode *inode); extern int ceph_do_getattr(struct inode *inode, int mask); -extern int ceph_permission(struct inode *inode, int mask); +extern int ceph_permission(struct inode *inode, int mask, unsigned int flags); extern int ceph_setattr(struct dentry *dentry, struct iattr *attr); extern int ceph_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat); diff --git a/fs/cifs/cifsfs.c b/fs/cifs/cifsfs.c index 223717dcc401..8e21e0fe65d5 100644 --- a/fs/cifs/cifsfs.c +++ b/fs/cifs/cifsfs.c @@ -283,10 +283,13 @@ cifs_statfs(struct dentry *dentry, struct kstatfs *buf) return 0; } -static int cifs_permission(struct inode *inode, int mask) +static int cifs_permission(struct inode *inode, int mask, unsigned int flags) { struct cifs_sb_info *cifs_sb; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + cifs_sb = CIFS_SB(inode->i_sb); if (cifs_sb->mnt_cifs_flags & CIFS_MOUNT_NO_PERM) { @@ -298,7 +301,7 @@ static int cifs_permission(struct inode *inode, int mask) on the client (above and beyond ACL on servers) for servers which do not support setting and viewing mode bits, so allowing client to check permissions is useful */ - return generic_permission(inode, mask, NULL); + return generic_permission(inode, mask, flags, NULL); } static struct kmem_cache *cifs_inode_cachep; diff --git a/fs/coda/dir.c b/fs/coda/dir.c index 619a8303766e..29badd91360f 100644 --- a/fs/coda/dir.c +++ b/fs/coda/dir.c @@ -135,10 +135,13 @@ exit: } -int coda_permission(struct inode *inode, int mask) +int coda_permission(struct inode *inode, int mask, unsigned int flags) { int error; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + mask &= MAY_READ | MAY_WRITE | MAY_EXEC; if (!mask) diff --git a/fs/coda/pioctl.c b/fs/coda/pioctl.c index 2fd89b5c5c7b..741f0bd03918 100644 --- a/fs/coda/pioctl.c +++ b/fs/coda/pioctl.c @@ -24,7 +24,7 @@ #include /* pioctl ops */ -static int coda_ioctl_permission(struct inode *inode, int mask); +static int coda_ioctl_permission(struct inode *inode, int mask, unsigned int flags); static long coda_pioctl(struct file *filp, unsigned int cmd, unsigned long user_data); @@ -41,8 +41,10 @@ const struct file_operations coda_ioctl_operations = { }; /* the coda pioctl inode ops */ -static int coda_ioctl_permission(struct inode *inode, int mask) +static int coda_ioctl_permission(struct inode *inode, int mask, unsigned int flags) { + if (flags & IPERM_FLAG_RCU) + return -ECHILD; return (mask & MAY_EXEC) ? -EACCES : 0; } diff --git a/fs/ecryptfs/inode.c b/fs/ecryptfs/inode.c index f91b35db4c6e..337352a94751 100644 --- a/fs/ecryptfs/inode.c +++ b/fs/ecryptfs/inode.c @@ -980,8 +980,10 @@ int ecryptfs_truncate(struct dentry *dentry, loff_t new_length) } static int -ecryptfs_permission(struct inode *inode, int mask) +ecryptfs_permission(struct inode *inode, int mask, unsigned int flags) { + if (flags & IPERM_FLAG_RCU) + return -ECHILD; return inode_permission(ecryptfs_inode_to_lower(inode), mask); } diff --git a/fs/ext2/acl.c b/fs/ext2/acl.c index 2bcc0431bada..dd9bb3f0c8d7 100644 --- a/fs/ext2/acl.c +++ b/fs/ext2/acl.c @@ -232,10 +232,14 @@ ext2_set_acl(struct inode *inode, int type, struct posix_acl *acl) } int -ext2_check_acl(struct inode *inode, int mask) +ext2_check_acl(struct inode *inode, int mask, unsigned int flags) { - struct posix_acl *acl = ext2_get_acl(inode, ACL_TYPE_ACCESS); + struct posix_acl *acl; + + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + acl = ext2_get_acl(inode, ACL_TYPE_ACCESS); if (IS_ERR(acl)) return PTR_ERR(acl); if (acl) { diff --git a/fs/ext2/acl.h b/fs/ext2/acl.h index 3ff6cbb9ac44..c939b7b12099 100644 --- a/fs/ext2/acl.h +++ b/fs/ext2/acl.h @@ -54,7 +54,7 @@ static inline int ext2_acl_count(size_t size) #ifdef CONFIG_EXT2_FS_POSIX_ACL /* acl.c */ -extern int ext2_check_acl (struct inode *, int); +extern int ext2_check_acl (struct inode *, int, unsigned int); extern int ext2_acl_chmod (struct inode *); extern int ext2_init_acl (struct inode *, struct inode *); diff --git a/fs/ext3/acl.c b/fs/ext3/acl.c index 8a11fe212183..9e49da8302d3 100644 --- a/fs/ext3/acl.c +++ b/fs/ext3/acl.c @@ -240,10 +240,14 @@ ext3_set_acl(handle_t *handle, struct inode *inode, int type, } int -ext3_check_acl(struct inode *inode, int mask) +ext3_check_acl(struct inode *inode, int mask, unsigned int flags) { - struct posix_acl *acl = ext3_get_acl(inode, ACL_TYPE_ACCESS); + struct posix_acl *acl; + + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + acl = ext3_get_acl(inode, ACL_TYPE_ACCESS); if (IS_ERR(acl)) return PTR_ERR(acl); if (acl) { diff --git a/fs/ext3/acl.h b/fs/ext3/acl.h index 597334626de9..5faf8048e906 100644 --- a/fs/ext3/acl.h +++ b/fs/ext3/acl.h @@ -54,7 +54,7 @@ static inline int ext3_acl_count(size_t size) #ifdef CONFIG_EXT3_FS_POSIX_ACL /* acl.c */ -extern int ext3_check_acl (struct inode *, int); +extern int ext3_check_acl (struct inode *, int, unsigned int); extern int ext3_acl_chmod (struct inode *); extern int ext3_init_acl (handle_t *, struct inode *, struct inode *); diff --git a/fs/ext4/acl.c b/fs/ext4/acl.c index 5e2ed4504ead..373dcaeedba9 100644 --- a/fs/ext4/acl.c +++ b/fs/ext4/acl.c @@ -238,10 +238,14 @@ ext4_set_acl(handle_t *handle, struct inode *inode, int type, } int -ext4_check_acl(struct inode *inode, int mask) +ext4_check_acl(struct inode *inode, int mask, unsigned int flags) { - struct posix_acl *acl = ext4_get_acl(inode, ACL_TYPE_ACCESS); + struct posix_acl *acl; + + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + acl = ext4_get_acl(inode, ACL_TYPE_ACCESS); if (IS_ERR(acl)) return PTR_ERR(acl); if (acl) { diff --git a/fs/ext4/acl.h b/fs/ext4/acl.h index 9d843d5deac4..dec821168fd4 100644 --- a/fs/ext4/acl.h +++ b/fs/ext4/acl.h @@ -54,7 +54,7 @@ static inline int ext4_acl_count(size_t size) #ifdef CONFIG_EXT4_FS_POSIX_ACL /* acl.c */ -extern int ext4_check_acl(struct inode *, int); +extern int ext4_check_acl(struct inode *, int, unsigned int); extern int ext4_acl_chmod(struct inode *); extern int ext4_init_acl(handle_t *, struct inode *, struct inode *); diff --git a/fs/fuse/dir.c b/fs/fuse/dir.c index 07f4b5e675fc..f738599fd8cd 100644 --- a/fs/fuse/dir.c +++ b/fs/fuse/dir.c @@ -985,12 +985,15 @@ static int fuse_access(struct inode *inode, int mask) * access request is sent. Execute permission is still checked * locally based on file mode. */ -static int fuse_permission(struct inode *inode, int mask) +static int fuse_permission(struct inode *inode, int mask, unsigned int flags) { struct fuse_conn *fc = get_fuse_conn(inode); bool refreshed = false; int err = 0; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + if (!fuse_allow_task(fc, current)) return -EACCES; @@ -1005,7 +1008,7 @@ static int fuse_permission(struct inode *inode, int mask) } if (fc->flags & FUSE_DEFAULT_PERMISSIONS) { - err = generic_permission(inode, mask, NULL); + err = generic_permission(inode, mask, flags, NULL); /* If permission is denied, try to refresh file attributes. This is also needed, because the root @@ -1013,7 +1016,8 @@ static int fuse_permission(struct inode *inode, int mask) if (err == -EACCES && !refreshed) { err = fuse_do_getattr(inode, NULL, NULL); if (!err) - err = generic_permission(inode, mask, NULL); + err = generic_permission(inode, mask, + flags, NULL); } /* Note: the opposite of the above test does not diff --git a/fs/generic_acl.c b/fs/generic_acl.c index 6bc9e3a5a693..628004282130 100644 --- a/fs/generic_acl.c +++ b/fs/generic_acl.c @@ -190,10 +190,14 @@ generic_acl_chmod(struct inode *inode) } int -generic_check_acl(struct inode *inode, int mask) +generic_check_acl(struct inode *inode, int mask, unsigned int flags) { - struct posix_acl *acl = get_cached_acl(inode, ACL_TYPE_ACCESS); + struct posix_acl *acl; + + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + acl = get_cached_acl(inode, ACL_TYPE_ACCESS); if (acl) { int error = posix_acl_permission(inode, acl, mask); posix_acl_release(acl); diff --git a/fs/gfs2/acl.c b/fs/gfs2/acl.c index 48171f4c943d..7118f1a780a9 100644 --- a/fs/gfs2/acl.c +++ b/fs/gfs2/acl.c @@ -75,11 +75,14 @@ static struct posix_acl *gfs2_acl_get(struct gfs2_inode *ip, int type) * Returns: errno */ -int gfs2_check_acl(struct inode *inode, int mask) +int gfs2_check_acl(struct inode *inode, int mask, unsigned int flags) { struct posix_acl *acl; int error; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + acl = gfs2_acl_get(GFS2_I(inode), ACL_TYPE_ACCESS); if (IS_ERR(acl)) return PTR_ERR(acl); diff --git a/fs/gfs2/acl.h b/fs/gfs2/acl.h index b522b0cb39ea..a93907c8159b 100644 --- a/fs/gfs2/acl.h +++ b/fs/gfs2/acl.h @@ -16,7 +16,7 @@ #define GFS2_POSIX_ACL_DEFAULT "posix_acl_default" #define GFS2_ACL_MAX_ENTRIES 25 -extern int gfs2_check_acl(struct inode *inode, int mask); +extern int gfs2_check_acl(struct inode *inode, int mask, unsigned int); extern int gfs2_acl_create(struct gfs2_inode *dip, struct inode *inode); extern int gfs2_acl_chmod(struct gfs2_inode *ip, struct iattr *attr); extern const struct xattr_handler gfs2_xattr_system_handler; diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index aa996471ec5c..fca6689e12e6 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -241,7 +241,7 @@ static int do_gfs2_set_flags(struct file *filp, u32 reqflags, u32 mask) !capable(CAP_LINUX_IMMUTABLE)) goto out; if (!IS_IMMUTABLE(inode)) { - error = gfs2_permission(inode, MAY_WRITE); + error = gfs2_permission(inode, MAY_WRITE, 0); if (error) goto out; } diff --git a/fs/gfs2/inode.c b/fs/gfs2/inode.c index e1213f7f9217..6163be9686be 100644 --- a/fs/gfs2/inode.c +++ b/fs/gfs2/inode.c @@ -509,7 +509,7 @@ struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name, } if (!is_root) { - error = gfs2_permission(dir, MAY_EXEC); + error = gfs2_permission(dir, MAY_EXEC, 0); if (error) goto out; } @@ -539,7 +539,7 @@ static int create_ok(struct gfs2_inode *dip, const struct qstr *name, { int error; - error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC); + error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC, 0); if (error) return error; diff --git a/fs/gfs2/inode.h b/fs/gfs2/inode.h index d8499fadcc53..732a183efdb3 100644 --- a/fs/gfs2/inode.h +++ b/fs/gfs2/inode.h @@ -113,7 +113,7 @@ extern struct inode *gfs2_lookupi(struct inode *dir, const struct qstr *name, extern struct inode *gfs2_createi(struct gfs2_holder *ghs, const struct qstr *name, unsigned int mode, dev_t dev); -extern int gfs2_permission(struct inode *inode, int mask); +extern int gfs2_permission(struct inode *inode, int mask, unsigned int flags); extern int gfs2_setattr_simple(struct gfs2_inode *ip, struct iattr *attr); extern struct inode *gfs2_lookup_simple(struct inode *dip, const char *name); extern void gfs2_dinode_out(const struct gfs2_inode *ip, void *buf); diff --git a/fs/gfs2/ops_inode.c b/fs/gfs2/ops_inode.c index f28f89796f4d..5c63a06fcd7c 100644 --- a/fs/gfs2/ops_inode.c +++ b/fs/gfs2/ops_inode.c @@ -166,7 +166,7 @@ static int gfs2_link(struct dentry *old_dentry, struct inode *dir, if (error) goto out_child; - error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC); + error = gfs2_permission(dir, MAY_WRITE | MAY_EXEC, 0); if (error) goto out_gunlock; @@ -289,7 +289,7 @@ static int gfs2_unlink_ok(struct gfs2_inode *dip, const struct qstr *name, if (IS_APPEND(&dip->i_inode)) return -EPERM; - error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC); + error = gfs2_permission(&dip->i_inode, MAY_WRITE | MAY_EXEC, 0); if (error) return error; @@ -822,7 +822,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry, } } } else { - error = gfs2_permission(ndir, MAY_WRITE | MAY_EXEC); + error = gfs2_permission(ndir, MAY_WRITE | MAY_EXEC, 0); if (error) goto out_gunlock; @@ -857,7 +857,7 @@ static int gfs2_rename(struct inode *odir, struct dentry *odentry, /* Check out the dir to be renamed */ if (dir_rename) { - error = gfs2_permission(odentry->d_inode, MAY_WRITE); + error = gfs2_permission(odentry->d_inode, MAY_WRITE, 0); if (error) goto out_gunlock; } @@ -1041,13 +1041,17 @@ static void gfs2_put_link(struct dentry *dentry, struct nameidata *nd, void *p) * Returns: errno */ -int gfs2_permission(struct inode *inode, int mask) +int gfs2_permission(struct inode *inode, int mask, unsigned int flags) { - struct gfs2_inode *ip = GFS2_I(inode); + struct gfs2_inode *ip; struct gfs2_holder i_gh; int error; int unlock = 0; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + + ip = GFS2_I(inode); if (gfs2_glock_is_locked_by_me(ip->i_gl) == NULL) { error = gfs2_glock_nq_init(ip->i_gl, LM_ST_SHARED, LM_FLAG_ANY, &i_gh); if (error) @@ -1058,7 +1062,7 @@ int gfs2_permission(struct inode *inode, int mask) if ((mask & MAY_WRITE) && IS_IMMUTABLE(inode)) error = -EACCES; else - error = generic_permission(inode, mask, gfs2_check_acl); + error = generic_permission(inode, mask, flags, gfs2_check_acl); if (unlock) gfs2_glock_dq_uninit(&i_gh); diff --git a/fs/hostfs/hostfs_kern.c b/fs/hostfs/hostfs_kern.c index 0bc81cf256b8..d3244d949a4e 100644 --- a/fs/hostfs/hostfs_kern.c +++ b/fs/hostfs/hostfs_kern.c @@ -749,11 +749,14 @@ int hostfs_rename(struct inode *from_ino, struct dentry *from, return err; } -int hostfs_permission(struct inode *ino, int desired) +int hostfs_permission(struct inode *ino, int desired, unsigned int flags) { char *name; int r = 0, w = 0, x = 0, err; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + if (desired & MAY_READ) r = 1; if (desired & MAY_WRITE) w = 1; if (desired & MAY_EXEC) x = 1; @@ -768,7 +771,7 @@ int hostfs_permission(struct inode *ino, int desired) err = access_file(name, r, w, x); __putname(name); if (!err) - err = generic_permission(ino, desired, NULL); + err = generic_permission(ino, desired, flags, NULL); return err; } diff --git a/fs/hpfs/namei.c b/fs/hpfs/namei.c index 11c2b4080f65..f4ad9e31ddc4 100644 --- a/fs/hpfs/namei.c +++ b/fs/hpfs/namei.c @@ -419,7 +419,7 @@ again: unlock_kernel(); return -ENOSPC; } - if (generic_permission(inode, MAY_WRITE, NULL) || + if (generic_permission(inode, MAY_WRITE, 0, NULL) || !S_ISREG(inode->i_mode) || get_write_access(inode)) { d_rehash(dentry); diff --git a/fs/jffs2/acl.c b/fs/jffs2/acl.c index 54a92fd02bbd..95b79672150a 100644 --- a/fs/jffs2/acl.c +++ b/fs/jffs2/acl.c @@ -259,11 +259,14 @@ static int jffs2_set_acl(struct inode *inode, int type, struct posix_acl *acl) return rc; } -int jffs2_check_acl(struct inode *inode, int mask) +int jffs2_check_acl(struct inode *inode, int mask, unsigned int flags) { struct posix_acl *acl; int rc; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + acl = jffs2_get_acl(inode, ACL_TYPE_ACCESS); if (IS_ERR(acl)) return PTR_ERR(acl); diff --git a/fs/jffs2/acl.h b/fs/jffs2/acl.h index 5e42de8d9541..3119f59253d3 100644 --- a/fs/jffs2/acl.h +++ b/fs/jffs2/acl.h @@ -26,7 +26,7 @@ struct jffs2_acl_header { #ifdef CONFIG_JFFS2_FS_POSIX_ACL -extern int jffs2_check_acl(struct inode *, int); +extern int jffs2_check_acl(struct inode *, int, unsigned int); extern int jffs2_acl_chmod(struct inode *); extern int jffs2_init_acl_pre(struct inode *, struct inode *, int *); extern int jffs2_init_acl_post(struct inode *); diff --git a/fs/jfs/acl.c b/fs/jfs/acl.c index 1057a4998e4e..e5de9422fa32 100644 --- a/fs/jfs/acl.c +++ b/fs/jfs/acl.c @@ -114,10 +114,14 @@ out: return rc; } -int jfs_check_acl(struct inode *inode, int mask) +int jfs_check_acl(struct inode *inode, int mask, unsigned int flags) { - struct posix_acl *acl = jfs_get_acl(inode, ACL_TYPE_ACCESS); + struct posix_acl *acl; + + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + acl = jfs_get_acl(inode, ACL_TYPE_ACCESS); if (IS_ERR(acl)) return PTR_ERR(acl); if (acl) { diff --git a/fs/jfs/jfs_acl.h b/fs/jfs/jfs_acl.h index 54e07559878d..f9285c4900fa 100644 --- a/fs/jfs/jfs_acl.h +++ b/fs/jfs/jfs_acl.h @@ -20,7 +20,7 @@ #ifdef CONFIG_JFS_POSIX_ACL -int jfs_check_acl(struct inode *, int); +int jfs_check_acl(struct inode *, int, unsigned int flags); int jfs_init_acl(tid_t, struct inode *, struct inode *); int jfs_acl_chmod(struct inode *inode); diff --git a/fs/logfs/dir.c b/fs/logfs/dir.c index 409dfd65e9a1..f9ddf0c388c8 100644 --- a/fs/logfs/dir.c +++ b/fs/logfs/dir.c @@ -555,9 +555,11 @@ static int logfs_symlink(struct inode *dir, struct dentry *dentry, return __logfs_create(dir, dentry, inode, target, destlen); } -static int logfs_permission(struct inode *inode, int mask) +static int logfs_permission(struct inode *inode, int mask, unsigned int flags) { - return generic_permission(inode, mask, NULL); + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + return generic_permission(inode, mask, flags, NULL); } static int logfs_link(struct dentry *old_dentry, struct inode *dir, diff --git a/fs/namei.c b/fs/namei.c index 6e275363e89d..4e957bf744ae 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -169,8 +169,8 @@ EXPORT_SYMBOL(putname); /* * This does basic POSIX ACL permission checking */ -static inline int __acl_permission_check(struct inode *inode, int mask, - int (*check_acl)(struct inode *inode, int mask), int rcu) +static int acl_permission_check(struct inode *inode, int mask, unsigned int flags, + int (*check_acl)(struct inode *inode, int mask, unsigned int flags)) { umode_t mode = inode->i_mode; @@ -180,13 +180,9 @@ static inline int __acl_permission_check(struct inode *inode, int mask, mode >>= 6; else { if (IS_POSIXACL(inode) && (mode & S_IRWXG) && check_acl) { - if (rcu) { - return -ECHILD; - } else { - int error = check_acl(inode, mask); - if (error != -EAGAIN) - return error; - } + int error = check_acl(inode, mask, flags); + if (error != -EAGAIN) + return error; } if (in_group_p(inode->i_gid)) @@ -201,32 +197,31 @@ static inline int __acl_permission_check(struct inode *inode, int mask, return -EACCES; } -static inline int acl_permission_check(struct inode *inode, int mask, - int (*check_acl)(struct inode *inode, int mask)) -{ - return __acl_permission_check(inode, mask, check_acl, 0); -} - /** - * generic_permission - check for access rights on a Posix-like filesystem + * generic_permission - check for access rights on a Posix-like filesystem * @inode: inode to check access rights for * @mask: right to check for (%MAY_READ, %MAY_WRITE, %MAY_EXEC) * @check_acl: optional callback to check for Posix ACLs + * @flags IPERM_FLAG_ flags. * * Used to check for read/write/execute permissions on a file. * We use "fsuid" for this, letting us set arbitrary permissions * for filesystem access without changing the "normal" uids which - * are used for other things.. + * are used for other things. + * + * generic_permission is rcu-walk aware. It returns -ECHILD in case an rcu-walk + * request cannot be satisfied (eg. requires blocking or too much complexity). + * It would then be called again in ref-walk mode. */ -int generic_permission(struct inode *inode, int mask, - int (*check_acl)(struct inode *inode, int mask)) +int generic_permission(struct inode *inode, int mask, unsigned int flags, + int (*check_acl)(struct inode *inode, int mask, unsigned int flags)) { int ret; /* * Do the basic POSIX ACL permission checks. */ - ret = acl_permission_check(inode, mask, check_acl); + ret = acl_permission_check(inode, mask, flags, check_acl); if (ret != -EACCES) return ret; @@ -281,9 +276,10 @@ int inode_permission(struct inode *inode, int mask) } if (inode->i_op->permission) - retval = inode->i_op->permission(inode, mask); + retval = inode->i_op->permission(inode, mask, 0); else - retval = generic_permission(inode, mask, inode->i_op->check_acl); + retval = generic_permission(inode, mask, 0, + inode->i_op->check_acl); if (retval) return retval; @@ -668,22 +664,19 @@ force_reval_path(struct path *path, struct nameidata *nd) * short-cut DAC fails, then call ->permission() to do more * complete permission check. */ -static inline int __exec_permission(struct inode *inode, int rcu) +static inline int exec_permission(struct inode *inode, unsigned int flags) { int ret; if (inode->i_op->permission) { - if (rcu) - return -ECHILD; - ret = inode->i_op->permission(inode, MAY_EXEC); - if (!ret) - goto ok; - return ret; + ret = inode->i_op->permission(inode, MAY_EXEC, flags); + } else { + ret = acl_permission_check(inode, MAY_EXEC, flags, + inode->i_op->check_acl); } - ret = __acl_permission_check(inode, MAY_EXEC, inode->i_op->check_acl, rcu); - if (!ret) + if (likely(!ret)) goto ok; - if (rcu && ret == -ECHILD) + if (ret == -ECHILD) return ret; if (capable(CAP_DAC_OVERRIDE) || capable(CAP_DAC_READ_SEARCH)) @@ -691,17 +684,7 @@ static inline int __exec_permission(struct inode *inode, int rcu) return ret; ok: - return security_inode_exec_permission(inode, rcu); -} - -static int exec_permission(struct inode *inode) -{ - return __exec_permission(inode, 0); -} - -static int exec_permission_rcu(struct inode *inode) -{ - return __exec_permission(inode, 1); + return security_inode_exec_permission(inode, flags); } static __always_inline void set_root(struct nameidata *nd) @@ -1165,7 +1148,7 @@ static int link_path_walk(const char *name, struct nameidata *nd) nd->flags |= LOOKUP_CONTINUE; if (nd->flags & LOOKUP_RCU) { - err = exec_permission_rcu(nd->inode); + err = exec_permission(nd->inode, IPERM_FLAG_RCU); if (err == -ECHILD) { if (nameidata_drop_rcu(nd)) return -ECHILD; @@ -1173,7 +1156,7 @@ static int link_path_walk(const char *name, struct nameidata *nd) } } else { exec_again: - err = exec_permission(nd->inode); + err = exec_permission(nd->inode, 0); } if (err) break; @@ -1620,7 +1603,7 @@ static struct dentry *__lookup_hash(struct qstr *name, struct dentry *dentry; int err; - err = exec_permission(inode); + err = exec_permission(inode, 0); if (err) return ERR_PTR(err); diff --git a/fs/nfs/dir.c b/fs/nfs/dir.c index 58beace14b19..d33da530097a 100644 --- a/fs/nfs/dir.c +++ b/fs/nfs/dir.c @@ -2189,11 +2189,14 @@ int nfs_may_open(struct inode *inode, struct rpc_cred *cred, int openflags) return nfs_do_access(inode, cred, nfs_open_permission_mask(openflags)); } -int nfs_permission(struct inode *inode, int mask) +int nfs_permission(struct inode *inode, int mask, unsigned int flags) { struct rpc_cred *cred; int res = 0; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + nfs_inc_stats(inode, NFSIOS_VFSACCESS); if ((mask & (MAY_READ | MAY_WRITE | MAY_EXEC)) == 0) @@ -2241,7 +2244,7 @@ out: out_notsup: res = nfs_revalidate_inode(NFS_SERVER(inode), inode); if (res == 0) - res = generic_permission(inode, mask, NULL); + res = generic_permission(inode, mask, flags, NULL); goto out; } diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c index 71d4bc8464e0..77b48c8fab17 100644 --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -785,15 +785,19 @@ out_err: return err; } -int nilfs_permission(struct inode *inode, int mask) +int nilfs_permission(struct inode *inode, int mask, unsigned int flags) { - struct nilfs_root *root = NILFS_I(inode)->i_root; + struct nilfs_root *root; + + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + root = NILFS_I(inode)->i_root; if ((mask & MAY_WRITE) && root && root->cno != NILFS_CPTREE_CURRENT_CNO) return -EROFS; /* snapshot is not writable */ - return generic_permission(inode, mask, NULL); + return generic_permission(inode, mask, flags, NULL); } int nilfs_load_inode_block(struct nilfs_sb_info *sbi, struct inode *inode, diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h index f7560da5a567..0ca98823db59 100644 --- a/fs/nilfs2/nilfs.h +++ b/fs/nilfs2/nilfs.h @@ -256,7 +256,7 @@ extern void nilfs_update_inode(struct inode *, struct buffer_head *); extern void nilfs_truncate(struct inode *); extern void nilfs_evict_inode(struct inode *); extern int nilfs_setattr(struct dentry *, struct iattr *); -int nilfs_permission(struct inode *inode, int mask); +int nilfs_permission(struct inode *inode, int mask, unsigned int flags); extern int nilfs_load_inode_block(struct nilfs_sb_info *, struct inode *, struct buffer_head **); extern int nilfs_inode_dirty(struct inode *); diff --git a/fs/ocfs2/acl.c b/fs/ocfs2/acl.c index 391915093fe1..704f6b1742f3 100644 --- a/fs/ocfs2/acl.c +++ b/fs/ocfs2/acl.c @@ -291,13 +291,17 @@ static int ocfs2_set_acl(handle_t *handle, return ret; } -int ocfs2_check_acl(struct inode *inode, int mask) +int ocfs2_check_acl(struct inode *inode, int mask, unsigned int flags) { - struct ocfs2_super *osb = OCFS2_SB(inode->i_sb); + struct ocfs2_super *osb; struct buffer_head *di_bh = NULL; struct posix_acl *acl; int ret = -EAGAIN; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + + osb = OCFS2_SB(inode->i_sb); if (!(osb->s_mount_opt & OCFS2_MOUNT_POSIX_ACL)) return ret; diff --git a/fs/ocfs2/acl.h b/fs/ocfs2/acl.h index 5c5d31f05853..4fe7c9cf4bfb 100644 --- a/fs/ocfs2/acl.h +++ b/fs/ocfs2/acl.h @@ -26,7 +26,7 @@ struct ocfs2_acl_entry { __le32 e_id; }; -extern int ocfs2_check_acl(struct inode *, int); +extern int ocfs2_check_acl(struct inode *, int, unsigned int); extern int ocfs2_acl_chmod(struct inode *); extern int ocfs2_init_acl(handle_t *, struct inode *, struct inode *, struct buffer_head *, struct buffer_head *, diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index f6cba566429d..bdadbae09094 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -1307,10 +1307,13 @@ bail: return err; } -int ocfs2_permission(struct inode *inode, int mask) +int ocfs2_permission(struct inode *inode, int mask, unsigned int flags) { int ret; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + mlog_entry_void(); ret = ocfs2_inode_lock(inode, NULL, 0); @@ -1320,7 +1323,7 @@ int ocfs2_permission(struct inode *inode, int mask) goto out; } - ret = generic_permission(inode, mask, ocfs2_check_acl); + ret = generic_permission(inode, mask, flags, ocfs2_check_acl); ocfs2_inode_unlock(inode, 0); out: diff --git a/fs/ocfs2/file.h b/fs/ocfs2/file.h index 97bf761c9e7c..f5afbbef6703 100644 --- a/fs/ocfs2/file.h +++ b/fs/ocfs2/file.h @@ -61,7 +61,7 @@ int ocfs2_zero_extend(struct inode *inode, struct buffer_head *di_bh, int ocfs2_setattr(struct dentry *dentry, struct iattr *attr); int ocfs2_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat); -int ocfs2_permission(struct inode *inode, int mask); +int ocfs2_permission(struct inode *inode, int mask, unsigned int flags); int ocfs2_should_update_atime(struct inode *inode, struct vfsmount *vfsmnt); diff --git a/fs/proc/base.c b/fs/proc/base.c index dc5b2fcadc3b..b953d41d9abf 100644 --- a/fs/proc/base.c +++ b/fs/proc/base.c @@ -2114,11 +2114,13 @@ static const struct file_operations proc_fd_operations = { * /proc/pid/fd needs a special permission handler so that a process can still * access /proc/self/fd after it has executed a setuid(). */ -static int proc_fd_permission(struct inode *inode, int mask) +static int proc_fd_permission(struct inode *inode, int mask, unsigned int flags) { int rv; - rv = generic_permission(inode, mask, NULL); + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + rv = generic_permission(inode, mask, flags, NULL); if (rv == 0) return 0; if (task_pid(current) == proc_pid(inode)) diff --git a/fs/proc/proc_sysctl.c b/fs/proc/proc_sysctl.c index c9097f43b425..09a1f92a34ef 100644 --- a/fs/proc/proc_sysctl.c +++ b/fs/proc/proc_sysctl.c @@ -295,7 +295,7 @@ out: return ret; } -static int proc_sys_permission(struct inode *inode, int mask) +static int proc_sys_permission(struct inode *inode, int mask,unsigned int flags) { /* * sysctl entries that are not writeable, @@ -305,6 +305,9 @@ static int proc_sys_permission(struct inode *inode, int mask) struct ctl_table *table; int error; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + /* Executable files are not allowed under /proc/sys/ */ if ((mask & MAY_EXEC) && S_ISREG(inode->i_mode)) return -EACCES; diff --git a/fs/reiserfs/xattr.c b/fs/reiserfs/xattr.c index 9ea22a56cdf1..3cfb2e933644 100644 --- a/fs/reiserfs/xattr.c +++ b/fs/reiserfs/xattr.c @@ -870,11 +870,14 @@ out: return err; } -static int reiserfs_check_acl(struct inode *inode, int mask) +static int reiserfs_check_acl(struct inode *inode, int mask, unsigned int flags) { struct posix_acl *acl; int error = -EAGAIN; /* do regular unix permission checks by default */ + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + acl = reiserfs_get_acl(inode, ACL_TYPE_ACCESS); if (acl) { @@ -951,8 +954,10 @@ static int xattr_mount_check(struct super_block *s) return 0; } -int reiserfs_permission(struct inode *inode, int mask) +int reiserfs_permission(struct inode *inode, int mask, unsigned int flags) { + if (flags & IPERM_FLAG_RCU) + return -ECHILD; /* * We don't do permission checks on the internal objects. * Permissions are determined by the "owning" object. @@ -965,9 +970,10 @@ int reiserfs_permission(struct inode *inode, int mask) * Stat data v1 doesn't support ACLs. */ if (get_inode_sd_version(inode) != STAT_DATA_V1) - return generic_permission(inode, mask, reiserfs_check_acl); + return generic_permission(inode, mask, flags, + reiserfs_check_acl); #endif - return generic_permission(inode, mask, NULL); + return generic_permission(inode, mask, flags, NULL); } static int xattr_hide_revalidate(struct dentry *dentry, struct nameidata *nd) diff --git a/fs/sysfs/inode.c b/fs/sysfs/inode.c index cffb1fd8ba33..30ac27345586 100644 --- a/fs/sysfs/inode.c +++ b/fs/sysfs/inode.c @@ -348,13 +348,18 @@ int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const void *ns, const cha return -ENOENT; } -int sysfs_permission(struct inode *inode, int mask) +int sysfs_permission(struct inode *inode, int mask, unsigned int flags) { - struct sysfs_dirent *sd = inode->i_private; + struct sysfs_dirent *sd; + + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + + sd = inode->i_private; mutex_lock(&sysfs_mutex); sysfs_refresh_inode(sd, inode); mutex_unlock(&sysfs_mutex); - return generic_permission(inode, mask, NULL); + return generic_permission(inode, mask, flags, NULL); } diff --git a/fs/sysfs/sysfs.h b/fs/sysfs/sysfs.h index d9be60a2e956..ffaaa816bfba 100644 --- a/fs/sysfs/sysfs.h +++ b/fs/sysfs/sysfs.h @@ -200,7 +200,7 @@ static inline void __sysfs_put(struct sysfs_dirent *sd) struct inode *sysfs_get_inode(struct super_block *sb, struct sysfs_dirent *sd); void sysfs_evict_inode(struct inode *inode); int sysfs_sd_setattr(struct sysfs_dirent *sd, struct iattr *iattr); -int sysfs_permission(struct inode *inode, int mask); +int sysfs_permission(struct inode *inode, int mask, unsigned int flags); int sysfs_setattr(struct dentry *dentry, struct iattr *iattr); int sysfs_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat); int sysfs_setxattr(struct dentry *dentry, const char *name, const void *value, diff --git a/fs/xfs/linux-2.6/xfs_acl.c b/fs/xfs/linux-2.6/xfs_acl.c index b2771862fd3d..4b11eaf6a580 100644 --- a/fs/xfs/linux-2.6/xfs_acl.c +++ b/fs/xfs/linux-2.6/xfs_acl.c @@ -219,12 +219,16 @@ xfs_set_acl(struct inode *inode, int type, struct posix_acl *acl) } int -xfs_check_acl(struct inode *inode, int mask) +xfs_check_acl(struct inode *inode, int mask, unsigned int flags) { - struct xfs_inode *ip = XFS_I(inode); + struct xfs_inode *ip; struct posix_acl *acl; int error = -EAGAIN; + if (flags & IPERM_FLAG_RCU) + return -ECHILD; + + ip = XFS_I(inode); trace_xfs_check_acl(ip); /* diff --git a/fs/xfs/xfs_acl.h b/fs/xfs/xfs_acl.h index 0135e2a669d7..11dd72070cbb 100644 --- a/fs/xfs/xfs_acl.h +++ b/fs/xfs/xfs_acl.h @@ -42,7 +42,7 @@ struct xfs_acl { #define SGI_ACL_DEFAULT_SIZE (sizeof(SGI_ACL_DEFAULT)-1) #ifdef CONFIG_XFS_POSIX_ACL -extern int xfs_check_acl(struct inode *inode, int mask); +extern int xfs_check_acl(struct inode *inode, int mask, unsigned int flags); extern struct posix_acl *xfs_get_acl(struct inode *inode, int type); extern int xfs_inherit_acl(struct inode *inode, struct posix_acl *default_acl); extern int xfs_acl_chmod(struct inode *inode); diff --git a/include/linux/coda_linux.h b/include/linux/coda_linux.h index 2e914d0771b9..4ccc59c1ea82 100644 --- a/include/linux/coda_linux.h +++ b/include/linux/coda_linux.h @@ -37,7 +37,7 @@ extern const struct file_operations coda_ioctl_operations; /* operations shared over more than one file */ int coda_open(struct inode *i, struct file *f); int coda_release(struct inode *i, struct file *f); -int coda_permission(struct inode *inode, int mask); +int coda_permission(struct inode *inode, int mask, unsigned int flags); int coda_revalidate_inode(struct dentry *); int coda_getattr(struct vfsmount *, struct dentry *, struct kstat *); int coda_setattr(struct dentry *, struct iattr *); diff --git a/include/linux/fs.h b/include/linux/fs.h index a04aa96acb71..d5a4d42f655b 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1550,11 +1550,13 @@ struct file_operations { int (*setlease)(struct file *, long, struct file_lock **); }; +#define IPERM_FLAG_RCU 0x0001 + struct inode_operations { struct dentry * (*lookup) (struct inode *,struct dentry *, struct nameidata *); void * (*follow_link) (struct dentry *, struct nameidata *); - int (*permission) (struct inode *, int); - int (*check_acl)(struct inode *, int); + int (*permission) (struct inode *, int, unsigned int); + int (*check_acl)(struct inode *, int, unsigned int); int (*readlink) (struct dentry *, char __user *,int); void (*put_link) (struct dentry *, struct nameidata *, void *); @@ -2165,8 +2167,8 @@ extern sector_t bmap(struct inode *, sector_t); #endif extern int notify_change(struct dentry *, struct iattr *); extern int inode_permission(struct inode *, int); -extern int generic_permission(struct inode *, int, - int (*check_acl)(struct inode *, int)); +extern int generic_permission(struct inode *, int, unsigned int, + int (*check_acl)(struct inode *, int, unsigned int)); static inline bool execute_ok(struct inode *inode) { diff --git a/include/linux/generic_acl.h b/include/linux/generic_acl.h index 574bea4013b6..0437e377b555 100644 --- a/include/linux/generic_acl.h +++ b/include/linux/generic_acl.h @@ -10,6 +10,6 @@ extern const struct xattr_handler generic_acl_default_handler; int generic_acl_init(struct inode *, struct inode *); int generic_acl_chmod(struct inode *); -int generic_check_acl(struct inode *inode, int mask); +int generic_check_acl(struct inode *inode, int mask, unsigned int flags); #endif /* LINUX_GENERIC_ACL_H */ diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h index 29d504d5d1c3..0779bb8f95be 100644 --- a/include/linux/nfs_fs.h +++ b/include/linux/nfs_fs.h @@ -351,7 +351,7 @@ extern int nfs_refresh_inode(struct inode *, struct nfs_fattr *); extern int nfs_post_op_update_inode(struct inode *inode, struct nfs_fattr *fattr); extern int nfs_post_op_update_inode_force_wcc(struct inode *inode, struct nfs_fattr *fattr); extern int nfs_getattr(struct vfsmount *, struct dentry *, struct kstat *); -extern int nfs_permission(struct inode *, int); +extern int nfs_permission(struct inode *, int, unsigned int); extern int nfs_open(struct inode *, struct file *); extern int nfs_release(struct inode *, struct file *); extern int nfs_attribute_timeout(struct inode *inode); diff --git a/include/linux/reiserfs_xattr.h b/include/linux/reiserfs_xattr.h index b2cf2089769b..3b94c91f20a6 100644 --- a/include/linux/reiserfs_xattr.h +++ b/include/linux/reiserfs_xattr.h @@ -41,7 +41,7 @@ int reiserfs_xattr_init(struct super_block *sb, int mount_flags); int reiserfs_lookup_privroot(struct super_block *sb); int reiserfs_delete_xattrs(struct inode *inode); int reiserfs_chown_xattrs(struct inode *inode, struct iattr *attrs); -int reiserfs_permission(struct inode *inode, int mask); +int reiserfs_permission(struct inode *inode, int mask, unsigned int flags); #ifdef CONFIG_REISERFS_FS_XATTR #define has_xattr_dir(inode) (REISERFS_I(inode)->i_flags & i_has_xattr_dir) -- cgit v1.2.3