From 60545d0d4610b02e55f65d141c95b18ccf855b6e Mon Sep 17 00:00:00 2001 From: Al Viro Date: Fri, 7 Jun 2013 01:20:27 -0400 Subject: [PATCH] [O_TMPFILE] it's still short a few helpers, but infrastructure should be OK now... Signed-off-by: Al Viro --- arch/alpha/include/uapi/asm/fcntl.h | 1 + arch/parisc/include/uapi/asm/fcntl.h | 1 + arch/sparc/include/uapi/asm/fcntl.h | 1 + fs/dcache.c | 16 ++++++++++ fs/ext2/namei.c | 24 +++++++++++++++ fs/minix/namei.c | 13 ++++++++ fs/namei.c | 60 ++++++++++++++++++++++++++++++++++++ fs/open.c | 14 ++++++--- include/linux/dcache.h | 2 ++ include/linux/fs.h | 1 + include/uapi/asm-generic/fcntl.h | 4 +++ mm/shmem.c | 32 +++++++++++++++++++ 12 files changed, 164 insertions(+), 5 deletions(-) diff --git a/arch/alpha/include/uapi/asm/fcntl.h b/arch/alpha/include/uapi/asm/fcntl.h index 6d9e805..dfdadb0 100644 --- a/arch/alpha/include/uapi/asm/fcntl.h +++ b/arch/alpha/include/uapi/asm/fcntl.h @@ -32,6 +32,7 @@ #define O_SYNC (__O_SYNC|O_DSYNC) #define O_PATH 040000000 +#define O_TMPFILE 0100000000 #define F_GETLK 7 #define F_SETLK 8 diff --git a/arch/parisc/include/uapi/asm/fcntl.h b/arch/parisc/include/uapi/asm/fcntl.h index 0304b92..cc61c47 100644 --- a/arch/parisc/include/uapi/asm/fcntl.h +++ b/arch/parisc/include/uapi/asm/fcntl.h @@ -20,6 +20,7 @@ #define O_INVISIBLE 004000000 /* invisible I/O, for DMAPI/XDSM */ #define O_PATH 020000000 +#define O_TMPFILE 040000000 #define F_GETLK64 8 #define F_SETLK64 9 diff --git a/arch/sparc/include/uapi/asm/fcntl.h b/arch/sparc/include/uapi/asm/fcntl.h index d0b83f6..d73e5e0 100644 --- a/arch/sparc/include/uapi/asm/fcntl.h +++ b/arch/sparc/include/uapi/asm/fcntl.h @@ -35,6 +35,7 @@ #define O_SYNC (__O_SYNC|O_DSYNC) #define O_PATH 0x1000000 +#define O_TMPFILE 0x2000000 #define F_GETOWN 5 /* for sockets. */ #define F_SETOWN 6 /* for sockets. */ diff --git a/fs/dcache.c b/fs/dcache.c index f09b908..b7f049c 100644 --- a/fs/dcache.c +++ b/fs/dcache.c @@ -2968,6 +2968,22 @@ rename_retry: goto again; } +void d_tmpfile(struct dentry *dentry, struct inode *inode) +{ + inode_dec_link_count(inode); + BUG_ON(dentry->d_name.name != dentry->d_iname || + !hlist_unhashed(&dentry->d_alias) || + !d_unlinked(dentry)); + spin_lock(&dentry->d_parent->d_lock); + spin_lock_nested(&dentry->d_lock, DENTRY_D_LOCK_NESTED); + dentry->d_name.len = sprintf(dentry->d_iname, "#%llu", + (unsigned long long)inode->i_ino); + spin_unlock(&dentry->d_lock); + spin_unlock(&dentry->d_parent->d_lock); + d_instantiate(dentry, inode); +} +EXPORT_SYMBOL(d_tmpfile); + /** * find_inode_number - check for dentry with name * @dir: directory to check diff --git a/fs/ext2/namei.c b/fs/ext2/namei.c index 73b0d95..256dd5f 100644 --- a/fs/ext2/namei.c +++ b/fs/ext2/namei.c @@ -119,6 +119,29 @@ static int ext2_create (struct inode * dir, struct dentry * dentry, umode_t mode return ext2_add_nondir(dentry, inode); } +static int ext2_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + struct inode *inode = ext2_new_inode(dir, mode, NULL); + if (IS_ERR(inode)) + return PTR_ERR(inode); + + inode->i_op = &ext2_file_inode_operations; + if (ext2_use_xip(inode->i_sb)) { + inode->i_mapping->a_ops = &ext2_aops_xip; + inode->i_fop = &ext2_xip_file_operations; + } else if (test_opt(inode->i_sb, NOBH)) { + inode->i_mapping->a_ops = &ext2_nobh_aops; + inode->i_fop = &ext2_file_operations; + } else { + inode->i_mapping->a_ops = &ext2_aops; + inode->i_fop = &ext2_file_operations; + } + mark_inode_dirty(inode); + d_tmpfile(dentry, inode); + unlock_new_inode(inode); + return 0; +} + static int ext2_mknod (struct inode * dir, struct dentry *dentry, umode_t mode, dev_t rdev) { struct inode * inode; @@ -398,6 +421,7 @@ const struct inode_operations ext2_dir_inode_operations = { #endif .setattr = ext2_setattr, .get_acl = ext2_get_acl, + .tmpfile = ext2_tmpfile, }; const struct inode_operations ext2_special_inode_operations = { diff --git a/fs/minix/namei.c b/fs/minix/namei.c index 0db73d9..cd950e2 100644 --- a/fs/minix/namei.c +++ b/fs/minix/namei.c @@ -54,6 +54,18 @@ static int minix_mknod(struct inode * dir, struct dentry *dentry, umode_t mode, return error; } +static int minix_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + int error; + struct inode *inode = minix_new_inode(dir, mode, &error); + if (inode) { + minix_set_inode(inode, 0); + mark_inode_dirty(inode); + d_tmpfile(dentry, inode); + } + return error; +} + static int minix_create(struct inode *dir, struct dentry *dentry, umode_t mode, bool excl) { @@ -254,4 +266,5 @@ const struct inode_operations minix_dir_inode_operations = { .mknod = minix_mknod, .rename = minix_rename, .getattr = minix_getattr, + .tmpfile = minix_tmpfile, }; diff --git a/fs/namei.c b/fs/namei.c index 402eda3..778e253 100644 --- a/fs/namei.c +++ b/fs/namei.c @@ -2902,6 +2902,61 @@ stale_open: goto retry_lookup; } +static int do_tmpfile(int dfd, struct filename *pathname, + struct nameidata *nd, int flags, + const struct open_flags *op, + struct file *file, int *opened) +{ + static const struct qstr name = QSTR_INIT("/", 1); + struct dentry *dentry, *child; + struct inode *dir; + int error = path_lookupat(dfd, pathname->name, + flags | LOOKUP_DIRECTORY, nd); + if (unlikely(error)) + return error; + error = mnt_want_write(nd->path.mnt); + if (unlikely(error)) + goto out; + /* we want directory to be writable */ + error = inode_permission(nd->inode, MAY_WRITE | MAY_EXEC); + if (error) + goto out2; + dentry = nd->path.dentry; + dir = dentry->d_inode; + if (!dir->i_op->tmpfile) { + error = -EOPNOTSUPP; + goto out2; + } + child = d_alloc(dentry, &name); + if (unlikely(!child)) { + error = -ENOMEM; + goto out2; + } + nd->flags &= ~LOOKUP_DIRECTORY; + nd->flags |= op->intent; + dput(nd->path.dentry); + nd->path.dentry = child; + error = dir->i_op->tmpfile(dir, nd->path.dentry, op->mode); + if (error) + goto out2; + audit_inode(pathname, nd->path.dentry, 0); + error = may_open(&nd->path, op->acc_mode, op->open_flag); + if (error) + goto out2; + file->f_path.mnt = nd->path.mnt; + error = finish_open(file, nd->path.dentry, NULL, opened); + if (error) + goto out2; + error = open_check_o_direct(file); + if (error) + fput(file); +out2: + mnt_drop_write(nd->path.mnt); +out: + path_put(&nd->path); + return error; +} + static struct file *path_openat(int dfd, struct filename *pathname, struct nameidata *nd, const struct open_flags *op, int flags) { @@ -2917,6 +2972,11 @@ static struct file *path_openat(int dfd, struct filename *pathname, file->f_flags = op->open_flag; + if (unlikely(file->f_flags & O_TMPFILE)) { + error = do_tmpfile(dfd, pathname, nd, flags, op, file, &opened); + goto out; + } + error = path_init(dfd, pathname->name, flags | LOOKUP_PARENT, nd, &base); if (unlikely(error)) goto out; diff --git a/fs/open.c b/fs/open.c index 5a40a4a..fca72c4 100644 --- a/fs/open.c +++ b/fs/open.c @@ -840,11 +840,15 @@ static inline int build_open_flags(int flags, umode_t mode, struct open_flags *o if (flags & __O_SYNC) flags |= O_DSYNC; - /* - * If we have O_PATH in the open flag. Then we - * cannot have anything other than the below set of flags - */ - if (flags & O_PATH) { + if (flags & O_TMPFILE) { + if (!(flags & O_CREAT)) + return -EINVAL; + acc_mode = MAY_OPEN | ACC_MODE(flags); + } else if (flags & O_PATH) { + /* + * If we have O_PATH in the open flag. Then we + * cannot have anything other than the below set of flags + */ flags &= O_DIRECTORY | O_NOFOLLOW | O_PATH; acc_mode = 0; } else { diff --git a/include/linux/dcache.h b/include/linux/dcache.h index 1a6bb81f..86da759 100644 --- a/include/linux/dcache.h +++ b/include/linux/dcache.h @@ -246,6 +246,8 @@ extern struct dentry * d_make_root(struct inode *); /* - the ramfs-type tree */ extern void d_genocide(struct dentry *); +extern void d_tmpfile(struct dentry *, struct inode *); + extern struct dentry *d_find_alias(struct inode *); extern void d_prune_aliases(struct inode *); diff --git a/include/linux/fs.h b/include/linux/fs.h index 7c30e3a..dd6615f 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -1580,6 +1580,7 @@ struct inode_operations { int (*atomic_open)(struct inode *, struct dentry *, struct file *, unsigned open_flag, umode_t create_mode, int *opened); + int (*tmpfile) (struct inode *, struct dentry *, umode_t); } ____cacheline_aligned; ssize_t rw_copy_check_uvector(int type, const struct iovec __user * uvector, diff --git a/include/uapi/asm-generic/fcntl.h b/include/uapi/asm-generic/fcntl.h index a48937d..06632be 100644 --- a/include/uapi/asm-generic/fcntl.h +++ b/include/uapi/asm-generic/fcntl.h @@ -84,6 +84,10 @@ #define O_PATH 010000000 #endif +#ifndef O_TMPFILE +#define O_TMPFILE 020000000 +#endif + #ifndef O_NDELAY #define O_NDELAY O_NONBLOCK #endif diff --git a/mm/shmem.c b/mm/shmem.c index 5e6a842..f887358 100644 --- a/mm/shmem.c +++ b/mm/shmem.c @@ -1965,6 +1965,37 @@ shmem_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev) return error; } +static int +shmem_tmpfile(struct inode *dir, struct dentry *dentry, umode_t mode) +{ + struct inode *inode; + int error = -ENOSPC; + + inode = shmem_get_inode(dir->i_sb, dir, mode, 0, VM_NORESERVE); + if (inode) { + error = security_inode_init_security(inode, dir, + NULL, + shmem_initxattrs, NULL); + if (error) { + if (error != -EOPNOTSUPP) { + iput(inode); + return error; + } + } +#ifdef CONFIG_TMPFS_POSIX_ACL + error = generic_acl_init(inode, dir); + if (error) { + iput(inode); + return error; + } +#else + error = 0; +#endif + d_tmpfile(dentry, inode); + } + return error; +} + static int shmem_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode) { int error; @@ -2723,6 +2754,7 @@ static const struct inode_operations shmem_dir_inode_operations = { .rmdir = shmem_rmdir, .mknod = shmem_mknod, .rename = shmem_rename, + .tmpfile = shmem_tmpfile, #endif #ifdef CONFIG_TMPFS_XATTR .setxattr = shmem_setxattr, -- 2.7.4