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| author | Nicolai Stange <nicstange@gmail.com> | 2016-03-22 14:11:19 +0100 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2016-04-12 14:14:21 -0700 |
| commit | 83b711cbf4ff42a9996c5f092762b3967d307d73 (patch) | |
| tree | 9907e784c0f08708c52651cedd65bc355106bf06 | |
| parent | 4d45f7974ccf0aa783034fef2661573b3a28609e (diff) | |
| download | linux-83b711cbf4ff42a9996c5f092762b3967d307d73.tar.bz2 | |
debugfs: unproxify files created through debugfs_create_blob()
Currently, the struct file_operations fops_blob associated with files
created through the debugfs_create_blob() helpers are not file
lifetime aware.
Thus, a lifetime managing proxy is created around fops_blob each time such
a file is opened which is an unnecessary waste of resources.
Implement file lifetime management for the fops_bool file_operations.
Namely, make read_file_blob() safe gainst file removals by means of
debugfs_use_file_start() and debugfs_use_file_finish().
Make debugfs_create_blob() create its files in non-proxying operation mode
by means of debugfs_create_file_unsafe().
Signed-off-by: Nicolai Stange <nicstange@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| -rw-r--r-- | fs/debugfs/file.c | 13 |
1 files changed, 10 insertions, 3 deletions
diff --git a/fs/debugfs/file.c b/fs/debugfs/file.c index 8a548bee1b3d..2e86d66f7850 100644 --- a/fs/debugfs/file.c +++ b/fs/debugfs/file.c @@ -842,8 +842,15 @@ 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); + ssize_t r; + int srcu_idx; + + r = debugfs_use_file_start(F_DENTRY(file), &srcu_idx); + if (likely(!r)) + r = simple_read_from_buffer(user_buf, count, ppos, blob->data, + blob->size); + debugfs_use_file_finish(srcu_idx); + return r; } static const struct file_operations fops_blob = { @@ -880,7 +887,7 @@ struct dentry *debugfs_create_blob(const char *name, umode_t mode, struct dentry *parent, struct debugfs_blob_wrapper *blob) { - return debugfs_create_file(name, mode, parent, blob, &fops_blob); + return debugfs_create_file_unsafe(name, mode, parent, blob, &fops_blob); } EXPORT_SYMBOL_GPL(debugfs_create_blob); |