On Sun, 27 Apr 2014 21:44:36 +0530 "Aneesh Kumar K.V" <[email protected]> wrote:
> From: Andreas Gruenbacher <[email protected]> > > Some permission models distinguish between the permission to create a > non-directory and a directory. Pass this information down to > inode_permission() as mask flags > > Signed-off-by: Andreas Gruenbacher <[email protected]> > Signed-off-by: Aneesh Kumar K.V <[email protected]> > --- > fs/namei.c | 21 ++++++++++++--------- > include/linux/fs.h | 2 ++ > 2 files changed, 14 insertions(+), 9 deletions(-) > > diff --git a/fs/namei.c b/fs/namei.c > index 7d93d195f0e5..028bc8bcf77c 100644 > --- a/fs/namei.c > +++ b/fs/namei.c > @@ -445,7 +445,8 @@ static int sb_permission(struct super_block *sb, struct > inode *inode, int mask) > * this, letting us set arbitrary permissions for filesystem access without > * changing the "normal" UIDs which are used for other things. > * > - * When checking for MAY_APPEND, MAY_WRITE must also be set in @mask. > + * When checking for MAY_APPEND, MAY_CREATE_FILE, MAY_CREATE_DIR, > + * MAY_WRITE must also be set in @mask. > */ > int inode_permission(struct inode *inode, int mask) > { > @@ -2444,14 +2445,16 @@ static int may_delete(struct inode *dir, struct > dentry *victim, bool isdir) > * 3. We should have write and exec permissions on dir > * 4. We can't do it if dir is immutable (done in permission()) > */ > -static inline int may_create(struct inode *dir, struct dentry *child) > +static inline int may_create(struct inode *dir, struct dentry *child, bool > isdir) > { > + int mask = isdir ? MAY_CREATE_DIR : MAY_CREATE_FILE; > + > audit_inode_child(dir, child, AUDIT_TYPE_CHILD_CREATE); > if (child->d_inode) > return -EEXIST; > if (IS_DEADDIR(dir)) > return -ENOENT; > - return inode_permission(dir, MAY_WRITE | MAY_EXEC); > + return inode_permission(dir, MAY_WRITE | MAY_EXEC | mask); > } > > /* > @@ -2501,7 +2504,7 @@ EXPORT_SYMBOL(unlock_rename); > int vfs_create(struct inode *dir, struct dentry *dentry, umode_t mode, > bool want_excl) > { > - int error = may_create(dir, dentry); > + int error = may_create(dir, dentry, 0); nit: since the third argument here is a bool, this should be "false" and not "0". Ditto for all of the other calls of may_create. > if (error) > return error; > > @@ -3363,7 +3366,7 @@ EXPORT_SYMBOL(user_path_create); > > int vfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t > dev) > { > - int error = may_create(dir, dentry); > + int error = may_create(dir, dentry, 0); > > if (error) > return error; > @@ -3455,7 +3458,7 @@ SYSCALL_DEFINE3(mknod, const char __user *, filename, > umode_t, mode, unsigned, d > > int vfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) > { > - int error = may_create(dir, dentry); > + int error = may_create(dir, dentry, 1); > unsigned max_links = dir->i_sb->s_max_links; > > if (error) > @@ -3785,7 +3788,7 @@ SYSCALL_DEFINE1(unlink, const char __user *, pathname) > > int vfs_symlink(struct inode *dir, struct dentry *dentry, const char > *oldname) > { > - int error = may_create(dir, dentry); > + int error = may_create(dir, dentry, 0); > > if (error) > return error; > @@ -3871,7 +3874,7 @@ int vfs_link(struct dentry *old_dentry, struct inode > *dir, struct dentry *new_de > if (S_ISDIR(inode->i_mode)) > return -EPERM; > > - error = may_create(dir, new_dentry); > + error = may_create(dir, new_dentry, 0); > if (error) > return error; > > @@ -4062,7 +4065,7 @@ int vfs_rename(struct inode *old_dir, struct dentry > *old_dentry, > return error; > > if (!target) { > - error = may_create(new_dir, new_dentry); > + error = may_create(new_dir, new_dentry, is_dir); > } else { > new_is_dir = d_is_dir(new_dentry); > > diff --git a/include/linux/fs.h b/include/linux/fs.h > index 1f524b4b652d..da5521de04ab 100644 > --- a/include/linux/fs.h > +++ b/include/linux/fs.h > @@ -77,6 +77,8 @@ typedef void (dio_iodone_t)(struct kiocb *iocb, loff_t > offset, > #define MAY_CHDIR 0x00000040 > /* called from RCU mode, don't block */ > #define MAY_NOT_BLOCK 0x00000080 > +#define MAY_CREATE_FILE 0x00000100 > +#define MAY_CREATE_DIR 0x00000200 > > /* > * flags in file.f_mode. Note that FMODE_READ and FMODE_WRITE must > correspond -- Jeff Layton <[email protected]> -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
