[PATCH 2/2] pstore: add unlink implementation for deleting pstore files

[Ahmad Fatoum <a.fatoum@pengutronix.de>]

During debugging, it can be useful to delete a pstore file to start
fresh. There's already support for this in the code base using the erase
callback, but it was so far never called. Call it from the newly
introduced unlink operation.

Signed-off-by: Ahmad Fatoum <a.fatoum@pengutronix.de>
---
 fs/pstore/fs.c | 24 ++++++++++++++++++++++++
 1 file changed, 24 insertions(+)

diff --git a/fs/pstore/fs.c b/fs/pstore/fs.c
index f2ffc0ac6251..f11db91582aa 100644
--- a/fs/pstore/fs.c
+++ b/fs/pstore/fs.c
@@ -182,6 +182,29 @@ static int pstore_lseek(struct device *dev, FILE *file, loff_t pos)
 	return 0;
 }
 
+static int pstore_unlink(struct device *dev, const char *filename)
+{
+	struct list_head *head = dev->priv;
+	struct pstore_private *d;
+	int ret;
+
+	d = pstore_get_by_name(head, filename);
+	if (!d)
+		return -ENOENT;
+
+	if (!d->psi->erase)
+		return -EPERM;
+
+	ret = d->psi->erase(d->type, d->id, d->count, d->psi);
+	if (ret)
+		return ret;
+
+	list_del(&d->list);
+	free(d);
+
+	return 0;
+}
+
 static DIR *pstore_opendir(struct device *dev, const char *pathname)
 {
 	DIR *dir;
@@ -256,6 +279,7 @@ static struct fs_driver pstore_driver = {
 	.close     = pstore_close,
 	.read      = pstore_read,
 	.lseek     = pstore_lseek,
+	.unlink    = pstore_unlink,
 	.opendir   = pstore_opendir,
 	.readdir   = pstore_readdir,
 	.closedir  = pstore_closedir,
-- 
2.39.2