From mboxrd@z Thu Jan 1 00:00:00 1970 From: Emanuele Giuseppe Esposito Subject: [PATCH 6/8] simplefs: add file creation functions Date: Tue, 14 Apr 2020 14:43:00 +0200 Message-ID: <20200414124304.4470-7-eesposit@redhat.com> References: <20200414124304.4470-1-eesposit@redhat.com> Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1586868262; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: content-transfer-encoding:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=SkKDvUy87926CmAT32HsWjLbIxTbOhqOTHC/vd3O4C0=; b=hAZxlAFxPLBTZ0dZUK4vWmZD8OQC0vEPD1D5Ti07Q295SOclUBU1cdsylWqNDhd+afa7Zu /u0YipRUapWRy/lzMPbv29GK625zc6Eh844BSGMWWkdJMS8daFK6z7+22pgPttM9KCJ0JA /VATwRhULj47dLjREHC+wvgoL2712WI= In-Reply-To: <20200414124304.4470-1-eesposit@redhat.com> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: linuxppc-dev-bounces+glppe-linuxppc-embedded-2=m.gmane-mx.org@lists.ozlabs.org Sender: "Linuxppc-dev" Content-Type: text/plain; charset="us-ascii" To: linux-nfs@vger.kernel.org Cc: Song Liu , linux-usb@vger.kernel.org, bpf@vger.kernel.org, "Rafael J. Wysocki" , David Airlie , Heiko Carstens , Alexei Starovoitov , dri-devel@lists.freedesktop.org, "J. Bruce Fields" , Joseph Qi , Hugh Dickins , Paul Mackerras , John Johansen , netdev@vger.kernel.org, linux-s390@vger.kernel.org, Christoph Hellwig , Andrew Donnellan , Emanuele Giuseppe Esposito , Matthew Garrett , linux-efi@vger.kernel.org, Arnd Bergmann , Daniel Borkmann , Christian Borntraeger , linux-rdma@vger.kernel.org, Mark Fasheh A bunch of code is duplicated between debugfs and tracefs, unify it to the simplefs library. The code is very similar, except that dentry and inode creation are unified into a single function (unlike start_creating in debugfs and tracefs, which only takes care of dentries). This adds an output parameter to the creatio= n functions, but pushes all error recovery into fs/simplefs.c. Signed-off-by: Emanuele Giuseppe Esposito --- fs/simplefs.c | 150 +++++++++++++++++++++++++++++++++++++++ include/linux/simplefs.h | 19 +++++ 2 files changed, 169 insertions(+) diff --git a/fs/simplefs.c b/fs/simplefs.c index c59eb8d996be..3e48a288beb3 100644 --- a/fs/simplefs.c +++ b/fs/simplefs.c @@ -1,6 +1,8 @@ /* SPDX-License-Identifier: GPL-2.0 */ #include #include +#include +#include =20 static DEFINE_SPINLOCK(pin_fs_lock); =20 @@ -42,3 +44,151 @@ struct inode *simple_alloc_anon_inode(struct simple_fs = *fs) =09return alloc_anon_inode(fs->mount->mnt_sb); } EXPORT_SYMBOL(simple_alloc_anon_inode); + +static struct dentry *failed_creating(struct simple_fs *fs, struct dentry = *dentry) +{ +=09inode_unlock(d_inode(dentry->d_parent)); +=09dput(dentry); +=09simple_release_fs(fs); +=09return ERR_PTR(-ENOMEM); +} + +struct dentry *simplefs_create_dentry(struct simple_fs *fs, struct file_sy= stem_type *type, +=09=09=09=09 const char *name, struct dentry *parent, +=09=09=09=09 struct inode **inode) +{ +=09struct dentry *dentry; +=09int error; + +=09pr_debug("creating file '%s'\n", name); + +=09if (IS_ERR(parent)) +=09=09return parent; + +=09error =3D simple_pin_fs(fs, type); +=09if (error) { +=09=09pr_err("Unable to pin filesystem for file '%s'\n", name); +=09=09return ERR_PTR(error); +=09} + +=09/* If the parent is not specified, we create it in the root. +=09 * We need the root dentry to do this, which is in the super +=09 * block. A pointer to that is in the struct vfsmount that we +=09 * have around. +=09 */ +=09if (!parent) +=09=09parent =3D fs->mount->mnt_root; + +=09inode_lock(d_inode(parent)); +=09dentry =3D lookup_one_len(name, parent, strlen(name)); +=09if (!IS_ERR(dentry) && d_really_is_positive(dentry)) { +=09=09if (d_is_dir(dentry)) +=09=09=09pr_err("Directory '%s' with parent '%s' already present!\n", +=09=09=09 name, parent->d_name.name); +=09=09else +=09=09=09pr_err("File '%s' in directory '%s' already present!\n", +=09=09=09 name, parent->d_name.name); +=09=09dput(dentry); +=09=09dentry =3D ERR_PTR(-EEXIST); +=09} + +=09if (IS_ERR(dentry)) { +=09=09inode_unlock(d_inode(parent)); +=09=09simple_release_fs(fs); +=09} + + +=09if (IS_ERR(dentry)) +=09=09return dentry; + +=09*inode =3D simple_new_inode(fs->mount->mnt_sb); +=09if (unlikely(!(*inode))) { +=09=09pr_err("out of free inodes, can not create file '%s'\n", +=09=09 name); +=09=09return failed_creating(fs, dentry); +=09} + +=09return dentry; +} +EXPORT_SYMBOL(simplefs_create_dentry); + +struct dentry *simplefs_create_file(struct simple_fs *fs, struct file_syst= em_type *type, +=09=09=09=09 const char *name, umode_t mode, +=09=09=09=09 struct dentry *parent, void *data, +=09=09=09=09 struct inode **inode) +{ +=09struct dentry *dentry; + +=09WARN_ON((mode & S_IFMT) && !S_ISREG(mode)); +=09mode |=3D S_IFREG; + +=09dentry =3D simplefs_create_dentry(fs, type, name, parent, inode); + +=09if (IS_ERR(dentry)) +=09=09return dentry; + +=09(*inode)->i_mode =3D mode; +=09(*inode)->i_private =3D data; + +=09return dentry; +} +EXPORT_SYMBOL(simplefs_create_file); + +struct dentry *simplefs_finish_dentry(struct dentry *dentry, struct inode = *inode) +{ +=09d_instantiate(dentry, inode); +=09if (S_ISDIR(inode->i_mode)) { +=09=09inc_nlink(d_inode(dentry->d_parent)); +=09=09fsnotify_mkdir(d_inode(dentry->d_parent), dentry); +=09} else { +=09=09fsnotify_create(d_inode(dentry->d_parent), dentry); +=09} +=09inode_unlock(d_inode(dentry->d_parent)); +=09return dentry; +} +EXPORT_SYMBOL(simplefs_finish_dentry); + +struct dentry *simplefs_create_dir(struct simple_fs *fs, struct file_syste= m_type *type, +=09=09=09=09 const char *name, umode_t mode, struct dentry *parent, +=09=09=09=09 struct inode **inode) +{ +=09struct dentry *dentry; + +=09WARN_ON((mode & S_IFMT) && !S_ISDIR(mode)); +=09mode |=3D S_IFDIR; + +=09dentry =3D simplefs_create_dentry(fs, type, name, parent, inode); +=09if (IS_ERR(dentry)) +=09=09return dentry; + +=09(*inode)->i_mode =3D mode; +=09(*inode)->i_op =3D &simple_dir_inode_operations; +=09(*inode)->i_fop =3D &simple_dir_operations; + +=09/* directory inodes start off with i_nlink =3D=3D 2 (for "." entry) */ +=09inc_nlink(*inode); +=09return dentry; +} +EXPORT_SYMBOL(simplefs_create_dir); + +struct dentry *simplefs_create_symlink(struct simple_fs *fs, struct file_s= ystem_type *type, +=09=09=09=09 const char *name, struct dentry *parent, +=09=09=09=09 const char *target, struct inode **inode) +{ +=09struct dentry *dentry; +=09char *link =3D kstrdup(target, GFP_KERNEL); +=09if (!link) +=09=09return ERR_PTR(-ENOMEM); + +=09dentry =3D simplefs_create_dentry(fs, type, name, parent, inode); +=09if (IS_ERR(dentry)) { +=09=09kfree_link(link); +=09=09return dentry; +=09} + +=09(*inode)->i_mode =3D S_IFLNK | S_IRWXUGO; +=09(*inode)->i_link =3D link; +=09(*inode)->i_op =3D &simple_symlink_inode_operations; +=09return dentry; +} +EXPORT_SYMBOL(simplefs_create_symlink); diff --git a/include/linux/simplefs.h b/include/linux/simplefs.h index c62ab526414e..cc53eed0bc3d 100644 --- a/include/linux/simplefs.h +++ b/include/linux/simplefs.h @@ -14,4 +14,23 @@ extern void simple_release_fs(struct simple_fs *); =20 extern struct inode *simple_alloc_anon_inode(struct simple_fs *fs); =20 +extern struct dentry *simplefs_create_dentry(struct simple_fs *fs, +=09=09=09=09=09 struct file_system_type *type, +=09=09=09=09=09 const char *name, struct dentry *parent, +=09=09=09=09=09 struct inode **inode); +struct dentry *simplefs_finish_dentry(struct dentry *dentry, struct inode = *inode); + +extern struct dentry *simplefs_create_file(struct simple_fs *fs, +=09=09=09=09=09 struct file_system_type *type, +=09=09=09=09=09 const char *name, umode_t mode, +=09=09=09=09=09 struct dentry *parent, void *data, +=09=09=09=09=09 struct inode **inode); +extern struct dentry *simplefs_create_dir(struct simple_fs *fs, struct fil= e_system_type *type, +=09=09=09=09=09 const char *name, umode_t mode, struct dentry *parent, +=09=09=09=09=09 struct inode **inode); +extern struct dentry *simplefs_create_symlink(struct simple_fs *fs, struct= file_system_type *type, +=09=09=09=09=09 const char *name, struct dentry *parent, +=09=09=09=09=09 const char *target, struct inode **inode); + + #endif --=20 2.25.2