Remove excl arg to ->create inode_operation

The only time that 'false' is passed as the 'excl' arg to the ->create
inode_operation is in lookup_open() when ->atomic_open is not provided
by the parent directory.
*all* directory inode_operations which do not have ->atomic_open
completely ignore the 'excl' arg.

Therefore we don't need the 'excl' arg.  Those few ->create operations
which pay attention to the arg are only ever called with a value of
'true'.

We remove that arg and change all ->create operations to behave as those
thhe arg were 'true'.

Signed-off-by: NeilBrown <neil@brown.name>
Link: https://patch.msgid.link/178290671516.27465.15984496764174914338@noble.neil.brown.name
Reviewed-by: Jori Koolstra <jkoolstra@xs4all.nl>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>

Documentation/filesystems/locking.rst

@@ -61,7 +61,7 @@ inode_operations
 
 prototypes::
 
-	int (*create) (struct mnt_idmap *, struct inode *,struct dentry *,umode_t, bool);
+	int (*create) (struct mnt_idmap *, struct inode *,struct dentry *,umode_t);
 	struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
 	int (*link) (struct dentry *,struct inode *,struct dentry *);
 	int (*unlink) (struct inode *,struct dentry *);

Documentation/filesystems/porting.rst

@@ -1401,3 +1401,11 @@ as with d_dispose_if_unused() these are not trivial; with this variant
 of API it's more explicit, since grabbing ->d_lock is caller-side, but
 d_dispose_if_unused() had all the same issues.  It's a low-level primitive;
 use only if you have no alternative.
+
+---
+
+**mandatory**
+
+The .create inode_operation no longer receives the 'excl' arg.  It must
+always assume the file does not already exist.  If the filesystem needs
+to be involved in non-exclusive create, it should provide atomic_open.

Documentation/filesystems/vfs.rst

@@ -415,7 +415,7 @@ As of kernel 2.6.22, the following members are defined:
 .. code-block:: c
 
 	struct inode_operations {
-		int (*create) (struct mnt_idmap *, struct inode *,struct dentry *, umode_t, bool);
+		int (*create) (struct mnt_idmap *, struct inode *,struct dentry *, umode_t);
 		struct dentry * (*lookup) (struct inode *,struct dentry *, unsigned int);
 		int (*link) (struct dentry *,struct inode *,struct dentry *);
 		int (*unlink) (struct inode *,struct dentry *);

fs/9p/vfs_inode.c

@@ -645,7 +645,6 @@ error:
  * @dir: The parent directory
  * @dentry: The name of file to be created
  * @mode: The UNIX file mode to set
- * @excl: True if the file must not yet exist
  *
  * open(.., O_CREAT) is handled in v9fs_vfs_atomic_open().  This is only called
  * for mknod(2).
@@ -654,7 +653,7 @@ error:
 
 static int
 v9fs_vfs_create(struct mnt_idmap *idmap, struct inode *dir,
-		struct dentry *dentry, umode_t mode, bool excl)
+		struct dentry *dentry, umode_t mode)
 {
 	struct v9fs_session_info *v9ses = v9fs_inode2v9ses(dir);
 	u32 perm = unixmode2p9mode(v9ses, mode);

fs/9p/vfs_inode_dotl.c

@@ -213,12 +213,11 @@ int v9fs_open_to_dotl_flags(int flags)
  * @dir: directory inode that is being created
  * @dentry:  dentry that is being deleted
  * @omode: create permissions
- * @excl: True if the file must not yet exist
  *
  */
 static int
 v9fs_vfs_create_dotl(struct mnt_idmap *idmap, struct inode *dir,
-		     struct dentry *dentry, umode_t omode, bool excl)
+		     struct dentry *dentry, umode_t omode)
 {
 	return v9fs_vfs_mknod_dotl(idmap, dir, dentry, omode, 0);
 }

fs/affs/affs.h

@@ -169,7 +169,7 @@ extern int	affs_hash_name(struct super_block *sb, const u8 *name, unsigned int l
 extern struct dentry *affs_lookup(struct inode *dir, struct dentry *dentry, unsigned int);
 extern int	affs_unlink(struct inode *dir, struct dentry *dentry);
 extern int	affs_create(struct mnt_idmap *idmap, struct inode *dir,
-			struct dentry *dentry, umode_t mode, bool);
+			struct dentry *dentry, umode_t mode);
 extern struct dentry *affs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 			struct dentry *dentry, umode_t mode);
 extern int	affs_rmdir(struct inode *dir, struct dentry *dentry);

fs/affs/namei.c

@@ -243,7 +243,7 @@ affs_unlink(struct inode *dir, struct dentry *dentry)
 
 int
 affs_create(struct mnt_idmap *idmap, struct inode *dir,
-	    struct dentry *dentry, umode_t mode, bool excl)
+	    struct dentry *dentry, umode_t mode)
 {
 	struct super_block *sb = dir->i_sb;
 	struct inode	*inode;

fs/afs/dir.c

@@ -32,7 +32,7 @@ static bool afs_lookup_one_filldir(struct dir_context *ctx, const char *name, in
 static bool afs_lookup_filldir(struct dir_context *ctx, const char *name, int nlen,
 			      loff_t fpos, u64 ino, unsigned dtype);
 static int afs_create(struct mnt_idmap *idmap, struct inode *dir,
-		      struct dentry *dentry, umode_t mode, bool excl);
+		      struct dentry *dentry, umode_t mode);
 static struct dentry *afs_mkdir(struct mnt_idmap *idmap, struct inode *dir,
 				struct dentry *dentry, umode_t mode);
 static int afs_rmdir(struct inode *dir, struct dentry *dentry);
@@ -1623,7 +1623,7 @@ static const struct afs_operation_ops afs_create_operation = {
  * create a regular file on an AFS filesystem
  */
 static int afs_create(struct mnt_idmap *idmap, struct inode *dir,
-		      struct dentry *dentry, umode_t mode, bool excl)
+		      struct dentry *dentry, umode_t mode)
 {
 	struct afs_operation *op;
 	struct afs_vnode *dvnode = AFS_FS_I(dir);

fs/bad_inode.c

@@ -29,7 +29,7 @@ static const struct file_operations bad_file_ops =
 
 static int bad_inode_create(struct mnt_idmap *idmap,
 			    struct inode *dir, struct dentry *dentry,
-			    umode_t mode, bool excl)
+			    umode_t mode)
 {
 	return -EIO;
 }

fs/bfs/dir.c

@@ -83,7 +83,7 @@ const struct file_operations bfs_dir_operations = {
 };
 
 static int bfs_create(struct mnt_idmap *idmap, struct inode *dir,
-		      struct dentry *dentry, umode_t mode, bool excl)
+		      struct dentry *dentry, umode_t mode)
 {
 	int err;
 	struct inode *inode;

fs/btrfs/inode.c

@@ -6832,7 +6832,7 @@ static int btrfs_mknod(struct mnt_idmap *idmap, struct inode *dir,
 }
 
 static int btrfs_create(struct mnt_idmap *idmap, struct inode *dir,
-			struct dentry *dentry, umode_t mode, bool excl)
+			struct dentry *dentry, umode_t mode)
 {
 	struct inode *inode;
 

fs/ceph/dir.c

@@ -978,7 +978,7 @@ out:
 }
 
 static int ceph_create(struct mnt_idmap *idmap, struct inode *dir,
-		       struct dentry *dentry, umode_t mode, bool excl)
+		       struct dentry *dentry, umode_t mode)
 {
 	return ceph_mknod(idmap, dir, dentry, mode, 0);
 }

fs/coda/dir.c

@@ -134,7 +134,7 @@ static inline void coda_dir_drop_nlink(struct inode *dir)
 
 /* creation routines: create, mknod, mkdir, link, symlink */
 static int coda_create(struct mnt_idmap *idmap, struct inode *dir,
-		       struct dentry *de, umode_t mode, bool excl)
+		       struct dentry *de, umode_t mode)
 {
 	int error;
 	const char *name=de->d_name.name;

fs/ecryptfs/inode.c

@@ -268,7 +268,7 @@ out:
 static int
 ecryptfs_create(struct mnt_idmap *idmap,
 		struct inode *directory_inode, struct dentry *ecryptfs_dentry,
-		umode_t mode, bool excl)
+		umode_t mode)
 {
 	struct inode *ecryptfs_inode;
 	int rc;

fs/efivarfs/inode.c

@@ -75,7 +75,7 @@ static bool efivarfs_valid_name(const char *str, int len)
 }
 
 static int efivarfs_create(struct mnt_idmap *idmap, struct inode *dir,
-			   struct dentry *dentry, umode_t mode, bool excl)
+			   struct dentry *dentry, umode_t mode)
 {
 	struct inode *inode = NULL;
 	struct efivar_entry *var;

fs/exfat/namei.c

@@ -538,7 +538,7 @@ out:
 }
 
 static int exfat_create(struct mnt_idmap *idmap, struct inode *dir,
-			struct dentry *dentry, umode_t mode, bool excl)
+			struct dentry *dentry, umode_t mode)
 {
 	struct super_block *sb = dir->i_sb;
 	struct inode *inode;

fs/ext2/namei.c

@@ -99,7 +99,7 @@ struct dentry *ext2_get_parent(struct dentry *child)
  */
 static int ext2_create (struct mnt_idmap * idmap,
 			struct inode * dir, struct dentry * dentry,
-			umode_t mode, bool excl)
+			umode_t mode)
 {
 	struct inode *inode;
 	int err;

fs/ext4/namei.c

@@ -2811,7 +2811,7 @@ static int ext4_add_nondir(handle_t *handle,
  * with d_instantiate().
  */
 static int ext4_create(struct mnt_idmap *idmap, struct inode *dir,
-		       struct dentry *dentry, umode_t mode, bool excl)
+		       struct dentry *dentry, umode_t mode)
 {
 	handle_t *handle;
 	struct inode *inode;

fs/f2fs/namei.c

@@ -366,7 +366,7 @@ fail_drop:
 }
 
 static int f2fs_create(struct mnt_idmap *idmap, struct inode *dir,
-		       struct dentry *dentry, umode_t mode, bool excl)
+		       struct dentry *dentry, umode_t mode)
 {
 	struct f2fs_sb_info *sbi = F2FS_I_SB(dir);
 	struct f2fs_lock_context lc;

fs/fat/namei_msdos.c

@@ -262,7 +262,7 @@ static int msdos_add_entry(struct inode *dir, const unsigned char *name,
 
 /***** Create a file */
 static int msdos_create(struct mnt_idmap *idmap, struct inode *dir,
-			struct dentry *dentry, umode_t mode, bool excl)
+			struct dentry *dentry, umode_t mode)
 {
 	struct super_block *sb = dir->i_sb;
 	struct inode *inode = NULL;