From f569aee1087fa3da9712952fc00daa72b028424c Mon Sep 17 00:00:00 2001 From: Linus Torvalds Date: Sat, 07 Jan 2017 19:14:29 +0100 Subject: [PATCH] splice: introduce FMODE_SPLICE_READ and FMODE_SPLICE_WRITE Introduce FMODE_SPLICE_READ and FMODE_SPLICE_WRITE. These modes check whether it is legal to read or write a file using splice. Both get automatically set on regular files and are not checked when a 'struct fileoperations' includes the splice_{read,write} methods. Change-Id: Ice6a3fab20bf0ac131f8d908f4bb0f7dc34bf4e3 Suggested-by: Linus Torvalds Cc: Al Viro Signed-off-by: Johannes Thumshirn --- diff --git a/fs/open.c b/fs/open.c index 9bf7fa0..e0e2a37 100644 --- a/fs/open.c +++ b/fs/open.c @@ -680,6 +680,10 @@ return 0; } + if (S_ISREG(inode->i_mode)) + f->f_mode |= FMODE_SPLICE_WRITE | FMODE_SPLICE_READ; + + f->f_op = fops_get(inode->i_fop); error = security_file_open(f, cred); diff --git a/fs/splice.c b/fs/splice.c index f183f13..8ba78ce 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -381,6 +381,9 @@ index++; } + if (unlikely(!(in->f_mode & FMODE_SPLICE_READ))) + return -EINVAL; + /* * Now loop over the map and see if we need to start IO on any * pages, fill in the partial map, etc. @@ -1084,6 +1087,9 @@ { ssize_t ret; + if (unlikely(!(out->f_mode & FMODE_SPLICE_WRITE))) + return -EINVAL; + ret = splice_from_pipe(pipe, out, ppos, len, flags, write_pipe_buf); if (ret > 0) *ppos += ret; diff --git a/include/linux/fs.h b/include/linux/fs.h index e6f1180..78300ef 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -125,6 +125,11 @@ /* File was opened by fanotify and shouldn't generate fanotify events */ #define FMODE_NONOTIFY ((__force fmode_t)0x1000000) +/* File can be read using splice */ +#define FMODE_SPLICE_READ ((__force fmode_t)0x8000000) +/* File can be written using splice */ +#define FMODE_SPLICE_WRITE ((__force fmode_t)0x10000000) + /* * Flag for rw_copy_check_uvector and compat_rw_copy_check_uvector * that indicates that they should check the contents of the iovec are