diff options
| -rw-r--r-- | fs/debugfs/file.c | 13 | ||||
| -rw-r--r-- | include/linux/debugfs.h | 17 |
2 files changed, 22 insertions, 8 deletions
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index 592059f88e04..309f4e9b2419 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -97,9 +97,6 @@ EXPORT_SYMBOL_GPL(debugfs_use_file_finish); #define F_DENTRY(filp) ((filp)->f_path.dentry) -#define REAL_FOPS_DEREF(dentry) \ - ((const struct file_operations *)(dentry)->d_fsdata) - static int open_proxy_open(struct inode *inode, struct file *filp) { const struct dentry *dentry = F_DENTRY(filp); @@ -112,7 +109,7 @@ static int open_proxy_open(struct inode *inode, struct file *filp) goto out; } - real_fops = REAL_FOPS_DEREF(dentry); + real_fops = debugfs_real_fops(filp); real_fops = fops_get(real_fops); if (!real_fops) { /* Huh? Module did not clean up after itself at exit? */ @@ -143,7 +140,7 @@ static ret_type full_proxy_ ## name(proto) \ { \ const struct dentry *dentry = F_DENTRY(filp); \ const struct file_operations *real_fops = \ - REAL_FOPS_DEREF(dentry); \ + debugfs_real_fops(filp); \ int srcu_idx; \ ret_type r; \ \ @@ -176,7 +173,7 @@ static unsigned int full_proxy_poll(struct file *filp, struct poll_table_struct *wait) { const struct dentry *dentry = F_DENTRY(filp); - const struct file_operations *real_fops = REAL_FOPS_DEREF(dentry); + const struct file_operations *real_fops = debugfs_real_fops(filp); int srcu_idx; unsigned int r = 0; @@ -193,7 +190,7 @@ static unsigned int full_proxy_poll(struct file *filp, static int full_proxy_release(struct inode *inode, struct file *filp) { const struct dentry *dentry = F_DENTRY(filp); - const struct file_operations *real_fops = REAL_FOPS_DEREF(dentry); + const struct file_operations *real_fops = debugfs_real_fops(filp); const struct file_operations *proxy_fops = filp->f_op; int r = 0; @@ -241,7 +238,7 @@ static int full_proxy_open(struct inode *inode, struct file *filp) goto out; } - real_fops = REAL_FOPS_DEREF(dentry); + real_fops = debugfs_real_fops(filp); real_fops = fops_get(real_fops); if (!real_fops) { /* Huh? Module did not cleanup after itself at exit? */ diff --git a/include/linux/debugfs.h b/include/linux/debugfs.h index 1438e2322d5c..4d3f0d1aec73 100644 --- a/include/linux/debugfs.h +++ b/include/linux/debugfs.h @@ -45,6 +45,23 @@ extern struct dentry *arch_debugfs_dir; extern struct srcu_struct debugfs_srcu; +/** + * debugfs_real_fops - getter for the real file operation + * @filp: a pointer to a struct file + * + * Must only be called under the protection established by + * debugfs_use_file_start(). + */ +static inline const struct file_operations *debugfs_real_fops(struct file *filp) + __must_hold(&debugfs_srcu) +{ + /* + * Neither the pointer to the struct file_operations, nor its + * contents ever change -- srcu_dereference() is not needed here. + */ + return filp->f_path.dentry->d_fsdata; +} + #if defined(CONFIG_DEBUG_FS) struct dentry *debugfs_create_file(const char *name, umode_t mode, |