diff options
Diffstat (limited to 'fs/backing-file.c')
| -rw-r--r-- | fs/backing-file.c | 51 |
1 files changed, 51 insertions, 0 deletions
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 @@ out: } 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", |