From 7995bd287134f6c8f80d94bebe7396f05a9bc42b Mon Sep 17 00:00:00 2001 From: Al Viro Date: Thu, 20 Jun 2013 18:58:36 +0400 Subject: [PATCH] splice: don't pass the address of ->f_pos to methods Signed-off-by: Al Viro --- fs/internal.h | 6 ++++++ fs/read_write.c | 24 ++++++++++++++++-------- fs/splice.c | 31 ++++++++++++++++++------------- include/linux/fs.h | 2 -- include/linux/splice.h | 1 + 5 files changed, 41 insertions(+), 23 deletions(-) diff --git a/fs/internal.h b/fs/internal.h index eaa75f75b625..68121584ae37 100644 --- a/fs/internal.h +++ b/fs/internal.h @@ -131,6 +131,12 @@ extern struct dentry *__d_alloc(struct super_block *, const struct qstr *); */ extern ssize_t __kernel_write(struct file *, const char *, size_t, loff_t *); +/* + * splice.c + */ +extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, + loff_t *opos, size_t len, unsigned int flags); + /* * pipe.c */ diff --git a/fs/read_write.c b/fs/read_write.c index 03430008704e..2cefa417be34 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1064,6 +1064,7 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, struct fd in, out; struct inode *in_inode, *out_inode; loff_t pos; + loff_t out_pos; ssize_t retval; int fl; @@ -1077,12 +1078,14 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, if (!(in.file->f_mode & FMODE_READ)) goto fput_in; retval = -ESPIPE; - if (!ppos) - ppos = &in.file->f_pos; - else + if (!ppos) { + pos = in.file->f_pos; + } else { + pos = *ppos; if (!(in.file->f_mode & FMODE_PREAD)) goto fput_in; - retval = rw_verify_area(READ, in.file, ppos, count); + } + retval = rw_verify_area(READ, in.file, &pos, count); if (retval < 0) goto fput_in; count = retval; @@ -1099,7 +1102,8 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, retval = -EINVAL; in_inode = file_inode(in.file); out_inode = file_inode(out.file); - retval = rw_verify_area(WRITE, out.file, &out.file->f_pos, count); + out_pos = out.file->f_pos; + retval = rw_verify_area(WRITE, out.file, &out_pos, count); if (retval < 0) goto fput_out; count = retval; @@ -1107,7 +1111,6 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, if (!max) max = min(in_inode->i_sb->s_maxbytes, out_inode->i_sb->s_maxbytes); - pos = *ppos; if (unlikely(pos + count > max)) { retval = -EOVERFLOW; if (pos >= max) @@ -1126,18 +1129,23 @@ static ssize_t do_sendfile(int out_fd, int in_fd, loff_t *ppos, if (in.file->f_flags & O_NONBLOCK) fl = SPLICE_F_NONBLOCK; #endif - retval = do_splice_direct(in.file, ppos, out.file, count, fl); + retval = do_splice_direct(in.file, &pos, out.file, &out_pos, count, fl); if (retval > 0) { add_rchar(current, retval); add_wchar(current, retval); fsnotify_access(in.file); fsnotify_modify(out.file); + out.file->f_pos = out_pos; + if (ppos) + *ppos = pos; + else + in.file->f_pos = pos; } inc_syscr(current); inc_syscw(current); - if (*ppos > max) + if (pos > max) retval = -EOVERFLOW; fput_out: diff --git a/fs/splice.c b/fs/splice.c index e6b25598c8c4..9eca476227d5 100644 --- a/fs/splice.c +++ b/fs/splice.c @@ -1274,7 +1274,7 @@ static int direct_splice_actor(struct pipe_inode_info *pipe, { struct file *file = sd->u.file; - return do_splice_from(pipe, file, &file->f_pos, sd->total_len, + return do_splice_from(pipe, file, sd->opos, sd->total_len, sd->flags); } @@ -1294,7 +1294,7 @@ static int direct_splice_actor(struct pipe_inode_info *pipe, * */ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, - size_t len, unsigned int flags) + loff_t *opos, size_t len, unsigned int flags) { struct splice_desc sd = { .len = len, @@ -1302,6 +1302,7 @@ long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, .flags = flags, .pos = *ppos, .u.file = out, + .opos = opos, }; long ret; @@ -1325,7 +1326,7 @@ static long do_splice(struct file *in, loff_t __user *off_in, { struct pipe_inode_info *ipipe; struct pipe_inode_info *opipe; - loff_t offset, *off; + loff_t offset; long ret; ipipe = get_pipe_info(in); @@ -1356,13 +1357,15 @@ static long do_splice(struct file *in, loff_t __user *off_in, return -EINVAL; if (copy_from_user(&offset, off_out, sizeof(loff_t))) return -EFAULT; - off = &offset; - } else - off = &out->f_pos; + } else { + offset = out->f_pos; + } - ret = do_splice_from(ipipe, out, off, len, flags); + ret = do_splice_from(ipipe, out, &offset, len, flags); - if (off_out && copy_to_user(off_out, off, sizeof(loff_t))) + if (!off_out) + out->f_pos = offset; + else if (copy_to_user(off_out, &offset, sizeof(loff_t))) ret = -EFAULT; return ret; @@ -1376,13 +1379,15 @@ static long do_splice(struct file *in, loff_t __user *off_in, return -EINVAL; if (copy_from_user(&offset, off_in, sizeof(loff_t))) return -EFAULT; - off = &offset; - } else - off = &in->f_pos; + } else { + offset = in->f_pos; + } - ret = do_splice_to(in, off, opipe, len, flags); + ret = do_splice_to(in, &offset, opipe, len, flags); - if (off_in && copy_to_user(off_in, off, sizeof(loff_t))) + if (!off_in) + in->f_pos = offset; + else if (copy_to_user(off_in, &offset, sizeof(loff_t))) ret = -EFAULT; return ret; diff --git a/include/linux/fs.h b/include/linux/fs.h index 43db02e9c9fa..65c2be22b601 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2414,8 +2414,6 @@ extern ssize_t generic_file_splice_write(struct pipe_inode_info *, struct file *, loff_t *, size_t, unsigned int); extern ssize_t generic_splice_sendpage(struct pipe_inode_info *pipe, struct file *out, loff_t *, size_t len, unsigned int flags); -extern long do_splice_direct(struct file *in, loff_t *ppos, struct file *out, - size_t len, unsigned int flags); extern void file_ra_state_init(struct file_ra_state *ra, struct address_space *mapping); diff --git a/include/linux/splice.h b/include/linux/splice.h index 09a545a7dfa3..74575cbf2d6f 100644 --- a/include/linux/splice.h +++ b/include/linux/splice.h @@ -35,6 +35,7 @@ struct splice_desc { void *data; /* cookie */ } u; loff_t pos; /* file position */ + loff_t *opos; /* sendfile: output position */ size_t num_spliced; /* number of bytes already spliced */ bool need_wakeup; /* need to wake up writer */ }; -- 2.20.1