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Message-Id: <20200421135741.30657-4-eesposit@redhat.com>
Date: Tue, 21 Apr 2020 15:57:40 +0200
From: Emanuele Giuseppe Esposito <eesposit@...hat.com>
To: linux-fsdevel@...r.kernel.org
Cc: Maarten Lankhorst <maarten.lankhorst@...ux.intel.com>,
Maxime Ripard <mripard@...nel.org>,
Thomas Zimmermann <tzimmermann@...e.de>,
David Airlie <airlied@...ux.ie>,
Daniel Vetter <daniel@...ll.ch>,
Frederic Barrat <fbarrat@...ux.ibm.com>,
Andrew Donnellan <ajd@...ux.ibm.com>,
Arnd Bergmann <arnd@...db.de>,
Greg Kroah-Hartman <gregkh@...uxfoundation.org>,
"Manoj N. Kumar" <manoj@...ux.ibm.com>,
"Matthew R. Ochs" <mrochs@...ux.ibm.com>,
Uma Krishnan <ukrishn@...ux.ibm.com>,
"James E.J. Bottomley" <jejb@...ux.ibm.com>,
"Martin K. Petersen" <martin.petersen@...cle.com>,
Alexander Viro <viro@...iv.linux.org.uk>,
Joel Becker <jlbec@...lplan.org>,
Christoph Hellwig <hch@....de>,
"Rafael J. Wysocki" <rafael@...nel.org>,
John Johansen <john.johansen@...onical.com>,
James Morris <jmorris@...ei.org>,
"Serge E. Hallyn" <serge@...lyn.com>,
dri-devel@...ts.freedesktop.org, linux-kernel@...r.kernel.org,
linuxppc-dev@...ts.ozlabs.org, linux-scsi@...r.kernel.org,
linux-security-module@...r.kernel.org,
Paolo Bonzini <pbonzini@...hat.com>,
Emanuele Giuseppe Esposito <eesposit@...hat.com>
Subject: [PATCH v2 6/7] debugfs: switch to simplefs inode creation API
The only difference, compared to the pre-existing code, is that symlink
creation now triggers fsnotify_create. This was a bug in the debugfs
code, since for example vfs_symlink does call fsnotify_create.
Signed-off-by: Emanuele Giuseppe Esposito <eesposit@...hat.com>
---
fs/debugfs/inode.c | 144 +++++----------------------------------------
1 file changed, 15 insertions(+), 129 deletions(-)
diff --git a/fs/debugfs/inode.c b/fs/debugfs/inode.c
index 5dbb74a23e7c..ccbeea9e5f6c 100644
--- a/fs/debugfs/inode.c
+++ b/fs/debugfs/inode.c
@@ -305,68 +305,6 @@ struct dentry *debugfs_lookup(const char *name, struct dentry *parent)
}
EXPORT_SYMBOL_GPL(debugfs_lookup);
-static struct dentry *start_creating(const char *name, struct dentry *parent)
-{
- struct dentry *dentry;
- int error;
-
- pr_debug("creating file '%s'\n", name);
-
- if (IS_ERR(parent))
- return parent;
-
- error = simple_pin_fs(&debugfs, &debug_fs_type);
- if (error) {
- pr_err("Unable to pin filesystem for file '%s'\n", name);
- return ERR_PTR(error);
- }
-
- /* If the parent is not specified, we create it in the root.
- * We need the root dentry to do this, which is in the super
- * block. A pointer to that is in the struct vfsmount that we
- * have around.
- */
- if (!parent)
- parent = debugfs.mount->mnt_root;
-
- inode_lock(d_inode(parent));
- if (unlikely(IS_DEADDIR(d_inode(parent))))
- dentry = ERR_PTR(-ENOENT);
- else
- dentry = lookup_one_len(name, parent, strlen(name));
- if (!IS_ERR(dentry) && d_really_is_positive(dentry)) {
- if (d_is_dir(dentry))
- pr_err("Directory '%s' with parent '%s' already present!\n",
- name, parent->d_name.name);
- else
- pr_err("File '%s' in directory '%s' already present!\n",
- name, parent->d_name.name);
- dput(dentry);
- dentry = ERR_PTR(-EEXIST);
- }
-
- if (IS_ERR(dentry)) {
- inode_unlock(d_inode(parent));
- simple_release_fs(&debugfs);
- }
-
- return dentry;
-}
-
-static struct dentry *failed_creating(struct dentry *dentry)
-{
- inode_unlock(d_inode(dentry->d_parent));
- dput(dentry);
- simple_release_fs(&debugfs);
- return ERR_PTR(-ENOMEM);
-}
-
-static struct dentry *end_creating(struct dentry *dentry)
-{
- inode_unlock(d_inode(dentry->d_parent));
- return dentry;
-}
-
static struct dentry *__debugfs_create_file(const char *name, umode_t mode,
struct dentry *parent, void *data,
const struct file_operations *proxy_fops,
@@ -375,32 +313,17 @@ static struct dentry *__debugfs_create_file(const char *name, umode_t mode,
struct dentry *dentry;
struct inode *inode;
- if (!(mode & S_IFMT))
- mode |= S_IFREG;
- BUG_ON(!S_ISREG(mode));
- dentry = start_creating(name, parent);
-
+ dentry = simplefs_create_file(&debugfs, &debug_fs_type,
+ name, mode, parent, data, &inode);
if (IS_ERR(dentry))
return dentry;
- inode = debugfs_get_inode(dentry->d_sb);
- if (unlikely(!inode)) {
- pr_err("out of free dentries, can not create file '%s'\n",
- name);
- return failed_creating(dentry);
- }
-
- inode->i_mode = mode;
- inode->i_private = data;
-
inode->i_op = &debugfs_file_inode_operations;
inode->i_fop = proxy_fops;
dentry->d_fsdata = (void *)((unsigned long)real_fops |
DEBUGFS_FSDATA_IS_REAL_FOPS_BIT);
- d_instantiate(dentry, inode);
- fsnotify_create(d_inode(dentry->d_parent), dentry);
- return end_creating(dentry);
+ return simplefs_finish_dentry(dentry, inode);
}
/**
@@ -533,29 +456,16 @@ EXPORT_SYMBOL_GPL(debugfs_create_file_size);
*/
struct dentry *debugfs_create_dir(const char *name, struct dentry *parent)
{
- struct dentry *dentry = start_creating(name, parent);
+ struct dentry *dentry;
struct inode *inode;
+ dentry = simplefs_create_dir(&debugfs, &debug_fs_type,
+ name, 0755, parent, &inode);
if (IS_ERR(dentry))
return dentry;
- inode = debugfs_get_inode(dentry->d_sb);
- if (unlikely(!inode)) {
- pr_err("out of free dentries, can not create directory '%s'\n",
- name);
- return failed_creating(dentry);
- }
-
- inode->i_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO;
inode->i_op = &debugfs_dir_inode_operations;
- inode->i_fop = &simple_dir_operations;
-
- /* directory inodes start off with i_nlink == 2 (for "." entry) */
- inc_nlink(inode);
- d_instantiate(dentry, inode);
- inc_nlink(d_inode(dentry->d_parent));
- fsnotify_mkdir(d_inode(dentry->d_parent), dentry);
- return end_creating(dentry);
+ return simplefs_finish_dentry(dentry, inode);
}
EXPORT_SYMBOL_GPL(debugfs_create_dir);
@@ -575,29 +485,19 @@ struct dentry *debugfs_create_automount(const char *name,
debugfs_automount_t f,
void *data)
{
- struct dentry *dentry = start_creating(name, parent);
+ struct dentry *dentry;
struct inode *inode;
+ dentry = simplefs_create_dentry(&debugfs, &debug_fs_type, name, parent,
+ &inode);
if (IS_ERR(dentry))
return dentry;
- inode = debugfs_get_inode(dentry->d_sb);
- if (unlikely(!inode)) {
- pr_err("out of free dentries, can not create automount '%s'\n",
- name);
- return failed_creating(dentry);
- }
-
make_empty_dir_inode(inode);
inode->i_flags |= S_AUTOMOUNT;
inode->i_private = data;
dentry->d_fsdata = (void *)f;
- /* directory inodes start off with i_nlink == 2 (for "." entry) */
- inc_nlink(inode);
- d_instantiate(dentry, inode);
- inc_nlink(d_inode(dentry->d_parent));
- fsnotify_mkdir(d_inode(dentry->d_parent), dentry);
- return end_creating(dentry);
+ return simplefs_finish_dentry(dentry, inode);
}
EXPORT_SYMBOL(debugfs_create_automount);
@@ -629,28 +529,14 @@ struct dentry *debugfs_create_symlink(const char *name, struct dentry *parent,
{
struct dentry *dentry;
struct inode *inode;
- char *link = kstrdup(target, GFP_KERNEL);
- if (!link)
- return ERR_PTR(-ENOMEM);
- dentry = start_creating(name, parent);
- if (IS_ERR(dentry)) {
- kfree(link);
+ dentry = simplefs_create_symlink(&debugfs, &debug_fs_type,
+ name, parent, target, &inode);
+ if (IS_ERR(dentry))
return dentry;
- }
- inode = debugfs_get_inode(dentry->d_sb);
- if (unlikely(!inode)) {
- pr_err("out of free dentries, can not create symlink '%s'\n",
- name);
- kfree(link);
- return failed_creating(dentry);
- }
- inode->i_mode = S_IFLNK | S_IRWXUGO;
inode->i_op = &debugfs_symlink_inode_operations;
- inode->i_link = link;
- d_instantiate(dentry, inode);
- return end_creating(dentry);
+ return simplefs_finish_dentry(dentry, inode);
}
EXPORT_SYMBOL_GPL(debugfs_create_symlink);
--
2.25.2
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