From 1a980b8cbf0059a5308eea61522f232fd03002e2 Mon Sep 17 00:00:00 2001 From: Murphy Zhou Date: Fri, 17 Jan 2020 20:49:29 +0800 Subject: ovl: add splice file read write helper Now overlayfs falls back to use default file splice read and write, which is not compatiple with overlayfs, returning EFAULT. xfstests generic/591 can reproduce part of this. Tested this patch with xfstests auto group tests. Signed-off-by: Murphy Zhou Signed-off-by: Miklos Szeredi --- fs/overlayfs/file.c | 47 +++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 47 insertions(+) diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index 4d1796c37dfd..67ef4c8cfdc7 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -9,6 +9,9 @@ #include #include #include +#include +#include +#include #include "overlayfs.h" struct ovl_aio_req { @@ -362,6 +365,48 @@ out_unlock: return ret; } +static ssize_t ovl_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags) +{ + ssize_t ret; + struct fd real; + const struct cred *old_cred; + + ret = ovl_real_fdget(in, &real); + if (ret) + return ret; + + old_cred = ovl_override_creds(file_inode(in)->i_sb); + ret = generic_file_splice_read(real.file, ppos, pipe, len, flags); + revert_creds(old_cred); + + ovl_file_accessed(in); + fdput(real); + return ret; +} + +static ssize_t +ovl_splice_write(struct pipe_inode_info *pipe, struct file *out, + loff_t *ppos, size_t len, unsigned int flags) +{ + struct fd real; + const struct cred *old_cred; + ssize_t ret; + + ret = ovl_real_fdget(out, &real); + if (ret) + return ret; + + old_cred = ovl_override_creds(file_inode(out)->i_sb); + ret = iter_file_splice_write(pipe, real.file, ppos, len, flags); + revert_creds(old_cred); + + ovl_file_accessed(out); + fdput(real); + return ret; +} + static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync) { struct fd real; @@ -718,6 +763,8 @@ const struct file_operations ovl_file_operations = { .fadvise = ovl_fadvise, .unlocked_ioctl = ovl_ioctl, .compat_ioctl = ovl_compat_ioctl, + .splice_read = ovl_splice_read, + .splice_write = ovl_splice_write, .copy_file_range = ovl_copy_file_range, .remap_file_range = ovl_remap_file_range, -- cgit v1.2.1