| Message ID | 1473856994-27463-4-git-send-email-amir73il@gmail.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On Wed, Sep 14, 2016 at 3:43 PM, Amir Goldstein <amir73il@gmail.com> wrote: > copy_file_range syscall returns -EXDEV if src and dest > file are not on the same file system. > The vfs_copy_file_range() helper, however, knows how to copy > across file systems with do_splice_direct(). > > Move the enforcement of same file system from the vfs helper > to the syscall code. > > A following patch is going to use the vfs_copy_file_range() > helper in overlayfs to copy up between lower and upper > not on the same file system. > > Signed-off-by: Amir Goldstein <amir73il@gmail.com> > --- > fs/read_write.c | 16 +++++++++++----- > 1 file changed, 11 insertions(+), 5 deletions(-) > > diff --git a/fs/read_write.c b/fs/read_write.c > index 9dc6e52..6975fe8 100644 > --- a/fs/read_write.c > +++ b/fs/read_write.c > @@ -1502,10 +1502,6 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, > (file_out->f_flags & O_APPEND)) > return -EBADF; > > - /* this could be relaxed once a method supports cross-fs copies */ > - if (inode_in->i_sb != inode_out->i_sb) > - return -EXDEV; > - > if (len == 0) > return 0; > > @@ -1514,7 +1510,9 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, > return ret; > > ret = -EOPNOTSUPP; > - if (file_out->f_op->copy_file_range) > + /* copy_file_range() method does not support cross-fs copies */ > + if (inode_in->i_sb == inode_out->i_sb && > + file_out->f_op->copy_file_range) > ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out, > pos_out, len, flags); > if (ret == -EOPNOTSUPP) > @@ -1569,6 +1567,14 @@ SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in, > pos_out = f_out.file->f_pos; > } > > + /* > + * vfs_copy_file_range() can do cross-fs copy, but we want to > + * fulfill the guaranty to userland that copy_file_range syscall > + * does not allow cross-fs copy > + */ > + if (file_inode(f_in.file)->i_sb != file_inode(f_out.file)->i_sb) > + return -EXDEV; Oops, that was supposed to be goto out; Anyway, I am holding back on the vfs_copy_file_range() patches sub set until I have a reliable test on xfs to fall back from clone to copy range > + > ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len, > flags); > if (ret > 0) { > -- > 2.7.4 > -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
On Fri, Sep 23, 2016 at 10:57:56AM +0300, Amir Goldstein wrote: > On Wed, Sep 14, 2016 at 3:43 PM, Amir Goldstein <amir73il@gmail.com> wrote: > > copy_file_range syscall returns -EXDEV if src and dest > > file are not on the same file system. > > The vfs_copy_file_range() helper, however, knows how to copy > > across file systems with do_splice_direct(). > > > > Move the enforcement of same file system from the vfs helper > > to the syscall code. > > > > A following patch is going to use the vfs_copy_file_range() > > helper in overlayfs to copy up between lower and upper > > not on the same file system. > > > > Signed-off-by: Amir Goldstein <amir73il@gmail.com> > > --- > > fs/read_write.c | 16 +++++++++++----- > > 1 file changed, 11 insertions(+), 5 deletions(-) > > > > diff --git a/fs/read_write.c b/fs/read_write.c > > index 9dc6e52..6975fe8 100644 > > --- a/fs/read_write.c > > +++ b/fs/read_write.c > > @@ -1502,10 +1502,6 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, > > (file_out->f_flags & O_APPEND)) > > return -EBADF; > > > > - /* this could be relaxed once a method supports cross-fs copies */ > > - if (inode_in->i_sb != inode_out->i_sb) > > - return -EXDEV; > > - > > if (len == 0) > > return 0; > > > > @@ -1514,7 +1510,9 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, > > return ret; > > > > ret = -EOPNOTSUPP; > > - if (file_out->f_op->copy_file_range) > > + /* copy_file_range() method does not support cross-fs copies */ > > + if (inode_in->i_sb == inode_out->i_sb && > > + file_out->f_op->copy_file_range) > > ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out, > > pos_out, len, flags); > > if (ret == -EOPNOTSUPP) > > @@ -1569,6 +1567,14 @@ SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in, > > pos_out = f_out.file->f_pos; > > } > > > > + /* > > + * vfs_copy_file_range() can do cross-fs copy, but we want to > > + * fulfill the guaranty to userland that copy_file_range syscall > > + * does not allow cross-fs copy > > + */ > > + if (file_inode(f_in.file)->i_sb != file_inode(f_out.file)->i_sb) > > + return -EXDEV; > > Oops, that was supposed to be goto out; > Anyway, I am holding back on the vfs_copy_file_range() patches sub set > until I have a reliable test on xfs to fall back from clone to copy range I could just create another error injection point that'll make XFS pretend that it's out of space. --D > > > + > > ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len, > > flags); > > if (ret > 0) { > > -- > > 2.7.4 > > > -- > To unsubscribe from this list: send the line "unsubscribe linux-xfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/fs/read_write.c b/fs/read_write.c index 9dc6e52..6975fe8 100644 --- a/fs/read_write.c +++ b/fs/read_write.c @@ -1502,10 +1502,6 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, (file_out->f_flags & O_APPEND)) return -EBADF; - /* this could be relaxed once a method supports cross-fs copies */ - if (inode_in->i_sb != inode_out->i_sb) - return -EXDEV; - if (len == 0) return 0; @@ -1514,7 +1510,9 @@ ssize_t vfs_copy_file_range(struct file *file_in, loff_t pos_in, return ret; ret = -EOPNOTSUPP; - if (file_out->f_op->copy_file_range) + /* copy_file_range() method does not support cross-fs copies */ + if (inode_in->i_sb == inode_out->i_sb && + file_out->f_op->copy_file_range) ret = file_out->f_op->copy_file_range(file_in, pos_in, file_out, pos_out, len, flags); if (ret == -EOPNOTSUPP) @@ -1569,6 +1567,14 @@ SYSCALL_DEFINE6(copy_file_range, int, fd_in, loff_t __user *, off_in, pos_out = f_out.file->f_pos; } + /* + * vfs_copy_file_range() can do cross-fs copy, but we want to + * fulfill the guaranty to userland that copy_file_range syscall + * does not allow cross-fs copy + */ + if (file_inode(f_in.file)->i_sb != file_inode(f_out.file)->i_sb) + return -EXDEV; + ret = vfs_copy_file_range(f_in.file, pos_in, f_out.file, pos_out, len, flags); if (ret > 0) {
copy_file_range syscall returns -EXDEV if src and dest file are not on the same file system. The vfs_copy_file_range() helper, however, knows how to copy across file systems with do_splice_direct(). Move the enforcement of same file system from the vfs helper to the syscall code. A following patch is going to use the vfs_copy_file_range() helper in overlayfs to copy up between lower and upper not on the same file system. Signed-off-by: Amir Goldstein <amir73il@gmail.com> --- fs/read_write.c | 16 +++++++++++----- 1 file changed, 11 insertions(+), 5 deletions(-)