From: Amir Goldstein <amir73il@gmail.com> mainline inclusion from mainline-v6.8-rc1 commit 9b7e9e2f5d5c3d079ec46bc71b114012e362ea6e category: feature bugzilla: https://gitee.com/src-openeuler/kernel/issues/IBHLU4 Reference: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?i... -------------------------------- There is not much in those helpers, but it makes sense to have them logically next to the backing_file_{read,write}_iter() helpers as they may grow more common logic in the future. Signed-off-by: Amir Goldstein <amir73il@gmail.com> Signed-off-by: Yifan Qiao <qiaoyifan4@huawei.com> --- include/linux/backing-file.h | 8 ++++++ fs/backing-file.c | 51 ++++++++++++++++++++++++++++++++++++ fs/overlayfs/file.c | 33 +++++++++-------------- 3 files changed, 72 insertions(+), 20 deletions(-) diff --git a/include/linux/backing-file.h b/include/linux/backing-file.h index 0648d548a418..0546d5b1c9f5 100644 --- a/include/linux/backing-file.h +++ b/include/linux/backing-file.h @@ -28,5 +28,13 @@ ssize_t backing_file_read_iter(struct file *file, struct iov_iter *iter, ssize_t backing_file_write_iter(struct file *file, struct iov_iter *iter, struct kiocb *iocb, int flags, struct backing_file_ctx *ctx); +ssize_t backing_file_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags, + struct backing_file_ctx *ctx); +ssize_t backing_file_splice_write(struct pipe_inode_info *pipe, + struct file *out, loff_t *ppos, size_t len, + unsigned int flags, + struct backing_file_ctx *ctx); #endif /* _LINUX_BACKING_FILE_H */ diff --git a/fs/backing-file.c b/fs/backing-file.c index 323187a49da3..ddd35c1d6c71 100644 --- a/fs/backing-file.c +++ b/fs/backing-file.c @@ -10,6 +10,7 @@ #include <linux/fs.h> #include <linux/backing-file.h> +#include <linux/splice.h> #include "internal.h" @@ -245,6 +246,56 @@ ssize_t backing_file_write_iter(struct file *file, struct iov_iter *iter, } EXPORT_SYMBOL_GPL(backing_file_write_iter); +ssize_t backing_file_splice_read(struct file *in, loff_t *ppos, + struct pipe_inode_info *pipe, size_t len, + unsigned int flags, + struct backing_file_ctx *ctx) +{ + const struct cred *old_cred; + ssize_t ret; + + if (WARN_ON_ONCE(!(in->f_mode & FMODE_BACKING))) + return -EIO; + + old_cred = override_creds(ctx->cred); + ret = vfs_splice_read(in, ppos, pipe, len, flags); + revert_creds(old_cred); + + if (ctx->accessed) + ctx->accessed(ctx->user_file); + + return ret; +} +EXPORT_SYMBOL_GPL(backing_file_splice_read); + +ssize_t backing_file_splice_write(struct pipe_inode_info *pipe, + struct file *out, loff_t *ppos, size_t len, + unsigned int flags, + struct backing_file_ctx *ctx) +{ + const struct cred *old_cred; + ssize_t ret; + + if (WARN_ON_ONCE(!(out->f_mode & FMODE_BACKING))) + return -EIO; + + ret = file_remove_privs(ctx->user_file); + if (ret) + return ret; + + old_cred = override_creds(ctx->cred); + file_start_write(out); + ret = iter_file_splice_write(pipe, out, ppos, len, flags); + file_end_write(out); + revert_creds(old_cred); + + if (ctx->end_write) + ctx->end_write(ctx->user_file); + + return ret; +} +EXPORT_SYMBOL_GPL(backing_file_splice_write); + static int __init backing_aio_init(void) { backing_aio_cachep = kmem_cache_create("backing_aio", diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c index 4405458b82fa..5ca2fab77cc1 100644 --- a/fs/overlayfs/file.c +++ b/fs/overlayfs/file.c @@ -9,7 +9,6 @@ #include <linux/xattr.h> #include <linux/uio.h> #include <linux/uaccess.h> -#include <linux/splice.h> #include <linux/security.h> #include <linux/mm.h> #include <linux/fs.h> @@ -329,20 +328,21 @@ static ssize_t ovl_splice_read(struct file *in, loff_t *ppos, struct pipe_inode_info *pipe, size_t len, unsigned int flags) { - const struct cred *old_cred; struct fd real; ssize_t ret; + struct backing_file_ctx ctx = { + .cred = ovl_creds(file_inode(in)->i_sb), + .user_file = in, + .accessed = ovl_file_accessed, + }; ret = ovl_real_fdget(in, &real); if (ret) return ret; - old_cred = ovl_override_creds(file_inode(in)->i_sb); - ret = vfs_splice_read(real.file, ppos, pipe, len, flags); - revert_creds(old_cred); - ovl_file_accessed(in); - + ret = backing_file_splice_read(real.file, ppos, pipe, len, flags, &ctx); fdput(real); + return ret; } @@ -358,30 +358,23 @@ 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; struct inode *inode = file_inode(out); ssize_t ret; + struct backing_file_ctx ctx = { + .cred = ovl_creds(inode->i_sb), + .user_file = out, + .end_write = ovl_file_modified, + }; inode_lock(inode); /* Update mode */ ovl_copyattr(inode); - ret = file_remove_privs(out); - if (ret) - goto out_unlock; ret = ovl_real_fdget(out, &real); if (ret) goto out_unlock; - old_cred = ovl_override_creds(inode->i_sb); - file_start_write(real.file); - - ret = iter_file_splice_write(pipe, real.file, ppos, len, flags); - - file_end_write(real.file); - /* Update size */ - ovl_file_modified(out); - revert_creds(old_cred); + ret = backing_file_splice_write(pipe, real.file, ppos, len, flags, &ctx); fdput(real); out_unlock: -- 2.39.2