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-rw-r--r--fs/overlayfs/file.c247
1 files changed, 33 insertions, 214 deletions
diff --git a/fs/overlayfs/file.c b/fs/overlayfs/file.c
index 131621daeb..05536964d3 100644
--- a/fs/overlayfs/file.c
+++ b/fs/overlayfs/file.c
@@ -9,25 +9,11 @@
#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>
+#include <linux/backing-file.h>
#include "overlayfs.h"
-#include "../internal.h" /* for sb_init_dio_done_wq */
-
-struct ovl_aio_req {
- struct kiocb iocb;
- refcount_t ref;
- struct kiocb *orig_iocb;
- /* used for aio completion */
- struct work_struct work;
- long res;
-};
-
-static struct kmem_cache *ovl_aio_request_cachep;
-
static char ovl_whatisit(struct inode *inode, struct inode *realinode)
{
if (realinode != ovl_inode_upper(inode))
@@ -274,83 +260,16 @@ static void ovl_file_accessed(struct file *file)
touch_atime(&file->f_path);
}
-#define OVL_IOCB_MASK \
- (IOCB_NOWAIT | IOCB_HIPRI | IOCB_DSYNC | IOCB_SYNC | IOCB_APPEND)
-
-static rwf_t iocb_to_rw_flags(int flags)
-{
- return (__force rwf_t)(flags & OVL_IOCB_MASK);
-}
-
-static inline void ovl_aio_put(struct ovl_aio_req *aio_req)
-{
- if (refcount_dec_and_test(&aio_req->ref)) {
- fput(aio_req->iocb.ki_filp);
- kmem_cache_free(ovl_aio_request_cachep, aio_req);
- }
-}
-
-static void ovl_aio_cleanup_handler(struct ovl_aio_req *aio_req)
-{
- struct kiocb *iocb = &aio_req->iocb;
- struct kiocb *orig_iocb = aio_req->orig_iocb;
-
- if (iocb->ki_flags & IOCB_WRITE) {
- kiocb_end_write(iocb);
- ovl_file_modified(orig_iocb->ki_filp);
- }
-
- orig_iocb->ki_pos = iocb->ki_pos;
- ovl_aio_put(aio_req);
-}
-
-static void ovl_aio_rw_complete(struct kiocb *iocb, long res)
-{
- struct ovl_aio_req *aio_req = container_of(iocb,
- struct ovl_aio_req, iocb);
- struct kiocb *orig_iocb = aio_req->orig_iocb;
-
- ovl_aio_cleanup_handler(aio_req);
- orig_iocb->ki_complete(orig_iocb, res);
-}
-
-static void ovl_aio_complete_work(struct work_struct *work)
-{
- struct ovl_aio_req *aio_req = container_of(work,
- struct ovl_aio_req, work);
-
- ovl_aio_rw_complete(&aio_req->iocb, aio_req->res);
-}
-
-static void ovl_aio_queue_completion(struct kiocb *iocb, long res)
-{
- struct ovl_aio_req *aio_req = container_of(iocb,
- struct ovl_aio_req, iocb);
- struct kiocb *orig_iocb = aio_req->orig_iocb;
-
- /*
- * Punt to a work queue to serialize updates of mtime/size.
- */
- aio_req->res = res;
- INIT_WORK(&aio_req->work, ovl_aio_complete_work);
- queue_work(file_inode(orig_iocb->ki_filp)->i_sb->s_dio_done_wq,
- &aio_req->work);
-}
-
-static int ovl_init_aio_done_wq(struct super_block *sb)
-{
- if (sb->s_dio_done_wq)
- return 0;
-
- return sb_init_dio_done_wq(sb);
-}
-
static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter)
{
struct file *file = iocb->ki_filp;
struct fd real;
- const struct cred *old_cred;
ssize_t ret;
+ struct backing_file_ctx ctx = {
+ .cred = ovl_creds(file_inode(file)->i_sb),
+ .user_file = file,
+ .accessed = ovl_file_accessed,
+ };
if (!iov_iter_count(iter))
return 0;
@@ -359,37 +278,8 @@ static ssize_t ovl_read_iter(struct kiocb *iocb, struct iov_iter *iter)
if (ret)
return ret;
- ret = -EINVAL;
- if (iocb->ki_flags & IOCB_DIRECT &&
- !(real.file->f_mode & FMODE_CAN_ODIRECT))
- goto out_fdput;
-
- old_cred = ovl_override_creds(file_inode(file)->i_sb);
- if (is_sync_kiocb(iocb)) {
- rwf_t rwf = iocb_to_rw_flags(iocb->ki_flags);
-
- ret = vfs_iter_read(real.file, iter, &iocb->ki_pos, rwf);
- } else {
- struct ovl_aio_req *aio_req;
-
- ret = -ENOMEM;
- aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL);
- if (!aio_req)
- goto out;
-
- aio_req->orig_iocb = iocb;
- kiocb_clone(&aio_req->iocb, iocb, get_file(real.file));
- aio_req->iocb.ki_complete = ovl_aio_rw_complete;
- refcount_set(&aio_req->ref, 2);
- ret = vfs_iocb_iter_read(real.file, &aio_req->iocb, iter);
- ovl_aio_put(aio_req);
- if (ret != -EIOCBQUEUED)
- ovl_aio_cleanup_handler(aio_req);
- }
-out:
- revert_creds(old_cred);
- ovl_file_accessed(file);
-out_fdput:
+ ret = backing_file_read_iter(real.file, iter, iocb, iocb->ki_flags,
+ &ctx);
fdput(real);
return ret;
@@ -400,9 +290,13 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
struct file *file = iocb->ki_filp;
struct inode *inode = file_inode(file);
struct fd real;
- const struct cred *old_cred;
ssize_t ret;
int ifl = iocb->ki_flags;
+ struct backing_file_ctx ctx = {
+ .cred = ovl_creds(inode->i_sb),
+ .user_file = file,
+ .end_write = ovl_file_modified,
+ };
if (!iov_iter_count(iter))
return 0;
@@ -410,19 +304,11 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
inode_lock(inode);
/* Update mode */
ovl_copyattr(inode);
- ret = file_remove_privs(file);
- if (ret)
- goto out_unlock;
ret = ovl_real_fdget(file, &real);
if (ret)
goto out_unlock;
- ret = -EINVAL;
- if (iocb->ki_flags & IOCB_DIRECT &&
- !(real.file->f_mode & FMODE_CAN_ODIRECT))
- goto out_fdput;
-
if (!ovl_should_sync(OVL_FS(inode->i_sb)))
ifl &= ~(IOCB_DSYNC | IOCB_SYNC);
@@ -431,42 +317,7 @@ static ssize_t ovl_write_iter(struct kiocb *iocb, struct iov_iter *iter)
* this property in case it is set by the issuer.
*/
ifl &= ~IOCB_DIO_CALLER_COMP;
-
- old_cred = ovl_override_creds(file_inode(file)->i_sb);
- if (is_sync_kiocb(iocb)) {
- rwf_t rwf = iocb_to_rw_flags(ifl);
-
- file_start_write(real.file);
- ret = vfs_iter_write(real.file, iter, &iocb->ki_pos, rwf);
- file_end_write(real.file);
- /* Update size */
- ovl_file_modified(file);
- } else {
- struct ovl_aio_req *aio_req;
-
- ret = ovl_init_aio_done_wq(inode->i_sb);
- if (ret)
- goto out;
-
- ret = -ENOMEM;
- aio_req = kmem_cache_zalloc(ovl_aio_request_cachep, GFP_KERNEL);
- if (!aio_req)
- goto out;
-
- aio_req->orig_iocb = iocb;
- kiocb_clone(&aio_req->iocb, iocb, get_file(real.file));
- aio_req->iocb.ki_flags = ifl;
- aio_req->iocb.ki_complete = ovl_aio_queue_completion;
- refcount_set(&aio_req->ref, 2);
- kiocb_start_write(&aio_req->iocb);
- ret = vfs_iocb_iter_write(real.file, &aio_req->iocb, iter);
- ovl_aio_put(aio_req);
- if (ret != -EIOCBQUEUED)
- ovl_aio_cleanup_handler(aio_req);
- }
-out:
- revert_creds(old_cred);
-out_fdput:
+ ret = backing_file_write_iter(real.file, iter, iocb, ifl, &ctx);
fdput(real);
out_unlock:
@@ -479,20 +330,21 @@ 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;
}
@@ -508,30 +360,23 @@ 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:
@@ -569,23 +414,13 @@ static int ovl_fsync(struct file *file, loff_t start, loff_t end, int datasync)
static int ovl_mmap(struct file *file, struct vm_area_struct *vma)
{
struct file *realfile = file->private_data;
- const struct cred *old_cred;
- int ret;
-
- if (!realfile->f_op->mmap)
- return -ENODEV;
+ struct backing_file_ctx ctx = {
+ .cred = ovl_creds(file_inode(file)->i_sb),
+ .user_file = file,
+ .accessed = ovl_file_accessed,
+ };
- if (WARN_ON(file != vma->vm_file))
- return -EIO;
-
- vma_set_file(vma, realfile);
-
- old_cred = ovl_override_creds(file_inode(file)->i_sb);
- ret = call_mmap(vma->vm_file, vma);
- revert_creds(old_cred);
- ovl_file_accessed(file);
-
- return ret;
+ return backing_file_mmap(realfile, vma, &ctx);
}
static long ovl_fallocate(struct file *file, int mode, loff_t offset, loff_t len)
@@ -778,19 +613,3 @@ const struct file_operations ovl_file_operations = {
.copy_file_range = ovl_copy_file_range,
.remap_file_range = ovl_remap_file_range,
};
-
-int __init ovl_aio_request_cache_init(void)
-{
- ovl_aio_request_cachep = kmem_cache_create("ovl_aio_req",
- sizeof(struct ovl_aio_req),
- 0, SLAB_HWCACHE_ALIGN, NULL);
- if (!ovl_aio_request_cachep)
- return -ENOMEM;
-
- return 0;
-}
-
-void ovl_aio_request_cache_destroy(void)
-{
- kmem_cache_destroy(ovl_aio_request_cachep);
-}