From 0b1d85af1889652cecba0588bf69c4df447258e0 Mon Sep 17 00:00:00 2001 From: Sascha Hauer Date: Wed, 26 Feb 2014 09:02:15 +0100 Subject: [PATCH] fs: tftp: Fix writing files to tftp Copying files to tftp is broken since: | commit d4f5bb1e011ac653a167031554f0ac9e028e9e36 | Author: Sascha Hauer | Date: Sat Sep 28 13:12:50 2013 +0200 | | copy_file: Add missing O_TRUNC | | Without it, when copying a smaller file over a larger file the | resulting file still has the remaining space from the larger file. | | Signed-off-by: Sascha Hauer Since this commit copy_file passes O_TRUNC to open(). This results in the fs layer calling fsdrv->truncate. tftp returns -ENOSYS here and open returns with an error. To fix this return 0 for the truncate callback in tftp. Also enforce the O_TRUNC flag when opening a file for writing on tftp as the files are always truncated on tftp anyway. Signed-off-by: Sascha Hauer Reported-by: andreas.willig@rafi.de --- fs/tftp.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/fs/tftp.c b/fs/tftp.c index b641faf15..9cad18fe8 100644 --- a/fs/tftp.c +++ b/fs/tftp.c @@ -110,7 +110,7 @@ static int tftp_rmdir(struct device_d *dev, const char *pathname) static int tftp_truncate(struct device_d *dev, FILE *f, ulong size) { - return -ENOSYS; + return 0; } static int tftp_send(struct file_priv *priv) @@ -393,6 +393,14 @@ static struct file_priv *tftp_do_open(struct device_d *dev, case O_WRONLY: priv->push = 1; priv->state = STATE_WRQ; + if (!(accmode & O_TRUNC)) { + /* + * TFTP always truncates the existing file, so this + * flag is mandatory when opening a file for writing. + */ + ret = -ENOSYS; + goto out; + } break; case O_RDWR: ret = -ENOSYS;