From dd308bc355a1aa4f202fe9a3133b6c676cb9606c Mon Sep 17 00:00:00 2001 From: Michael Ellerman Date: Tue, 7 Mar 2006 21:41:59 +1100 Subject: [PATCH] debugfs: Add debugfs_create_blob() helper for exporting binary data I wanted to export a binary blob via debugfs, and although it was pretty easy it seems like it'd be easier if there was a helper for it. It's a pity we need the wrapper struct but I can't see a cleaner way to do it. Signed-off-by: Michael Ellerman Signed-off-by: Greg Kroah-Hartman --- fs/debugfs/file.c | 46 ++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 46 insertions(+) (limited to 'fs/debugfs/file.c') diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index d575452cd9f7..40c4fc973fad 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -251,3 +251,49 @@ struct dentry *debugfs_create_bool(const char *name, mode_t mode, } EXPORT_SYMBOL_GPL(debugfs_create_bool); +static ssize_t read_file_blob(struct file *file, char __user *user_buf, + size_t count, loff_t *ppos) +{ + struct debugfs_blob_wrapper *blob = file->private_data; + return simple_read_from_buffer(user_buf, count, ppos, blob->data, + blob->size); +} + +static struct file_operations fops_blob = { + .read = read_file_blob, + .open = default_open, +}; + +/** + * debugfs_create_blob - create a file in the debugfs filesystem that is + * used to read and write a binary blob. + * + * @name: a pointer to a string containing the name of the file to create. + * @mode: the permission that the file should have + * @parent: a pointer to the parent dentry for this file. This should be a + * directory dentry if set. If this paramater is NULL, then the + * file will be created in the root of the debugfs filesystem. + * @blob: a pointer to a struct debugfs_blob_wrapper which contains a pointer + * to the blob data and the size of the data. + * + * This function creates a file in debugfs with the given name that exports + * @blob->data as a binary blob. If the @mode variable is so set it can be + * read from. Writing is not supported. + * + * This function will return a pointer to a dentry if it succeeds. This + * pointer must be passed to the debugfs_remove() function when the file is + * to be removed (no automatic cleanup happens if your module is unloaded, + * you are responsible here.) If an error occurs, NULL will be returned. + * + * If debugfs is not enabled in the kernel, the value -ENODEV will be + * returned. It is not wise to check for this value, but rather, check for + * NULL or !NULL instead as to eliminate the need for #ifdef in the calling + * code. + */ +struct dentry *debugfs_create_blob(const char *name, mode_t mode, + struct dentry *parent, + struct debugfs_blob_wrapper *blob) +{ + return debugfs_create_file(name, mode, parent, blob, &fops_blob); +} +EXPORT_SYMBOL_GPL(debugfs_create_blob); -- cgit v1.2.3 From 4b6f5d20b04dcbc3d888555522b90ba6d36c4106 Mon Sep 17 00:00:00 2001 From: Arjan van de Ven Date: Tue, 28 Mar 2006 01:56:42 -0800 Subject: [PATCH] Make most file operations structs in fs/ const This is a conversion to make the various file_operations structs in fs/ const. Basically a regexp job, with a few manual fixups The goal is both to increase correctness (harder to accidentally write to shared datastructures) and reducing the false sharing of cachelines with things that get dirty in .data (while .rodata is nicely read only and thus cache clean) Signed-off-by: Arjan van de Ven Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/debugfs/file.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/debugfs/file.c') diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index 40c4fc973fad..66a505422e5c 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -39,7 +39,7 @@ static int default_open(struct inode *inode, struct file *file) return 0; } -struct file_operations debugfs_file_operations = { +const struct file_operations debugfs_file_operations = { .read = default_read_file, .write = default_write_file, .open = default_open, @@ -213,7 +213,7 @@ static ssize_t write_file_bool(struct file *file, const char __user *user_buf, return count; } -static struct file_operations fops_bool = { +static const struct file_operations fops_bool = { .read = read_file_bool, .write = write_file_bool, .open = default_open, -- cgit v1.2.3