Merge tag 'pull-work.iov_iter-base' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs

Pull vfs iov_iter updates from Al Viro:
 "Part 1 - isolated cleanups and optimizations.

  One of the goals is to reduce the overhead of using ->read_iter() and
  ->write_iter() instead of ->read()/->write().

  new_sync_{read,write}() has a surprising amount of overhead, in
  particular inside iocb_flags(). That's the explanation for the
  beginning of the series is in this pile; it's not directly
  iov_iter-related, but it's a part of the same work..."

* tag 'pull-work.iov_iter-base' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  first_iovec_segment(): just return address
  iov_iter: massage calling conventions for first_{iovec,bvec}_segment()
  iov_iter: first_{iovec,bvec}_segment() - simplify a bit
  iov_iter: lift dealing with maxpages out of first_{iovec,bvec}_segment()
  iov_iter_get_pages{,_alloc}(): cap the maxsize with MAX_RW_COUNT
  iov_iter_bvec_advance(): don't bother with bvec_iter
  copy_page_{to,from}_iter(): switch iovec variants to generic
  keep iocb_flags() result cached in struct file
  iocb: delay evaluation of IS_SYNC(...) until we want to check IOCB_DSYNC
  struct file: use anonymous union member for rcuhead and llist
  btrfs: use IOMAP_DIO_NOSYNC
  teach iomap_dio_rw() to suppress dsync
  No need of likely/unlikely on calls of check_copy_size()
This commit is contained in:
Linus Torvalds
2022-08-03 13:50:22 -07:00
20 changed files with 113 additions and 296 deletions

View File

@@ -943,9 +943,10 @@ static inline int ra_has_index(struct file_ra_state *ra, pgoff_t index)
struct file {
union {
struct llist_node fu_llist;
struct rcu_head fu_rcuhead;
} f_u;
struct llist_node f_llist;
struct rcu_head f_rcuhead;
unsigned int f_iocb_flags;
};
struct path f_path;
struct inode *f_inode; /* cached value */
const struct file_operations *f_op;
@@ -2328,13 +2329,11 @@ static inline bool HAS_UNMAPPED_ID(struct user_namespace *mnt_userns,
!vfsgid_valid(i_gid_into_vfsgid(mnt_userns, inode));
}
static inline int iocb_flags(struct file *file);
static inline void init_sync_kiocb(struct kiocb *kiocb, struct file *filp)
{
*kiocb = (struct kiocb) {
.ki_filp = filp,
.ki_flags = iocb_flags(filp),
.ki_flags = filp->f_iocb_flags,
.ki_ioprio = get_current_ioprio(),
};
}
@@ -2850,6 +2849,12 @@ extern int vfs_fsync(struct file *file, int datasync);
extern int sync_file_range(struct file *file, loff_t offset, loff_t nbytes,
unsigned int flags);
static inline bool iocb_is_dsync(const struct kiocb *iocb)
{
return (iocb->ki_flags & IOCB_DSYNC) ||
IS_SYNC(iocb->ki_filp->f_mapping->host);
}
/*
* Sync the bytes written if this was a synchronous write. Expect ki_pos
* to already be updated for the write, and will return either the amount
@@ -2857,7 +2862,7 @@ extern int sync_file_range(struct file *file, loff_t offset, loff_t nbytes,
*/
static inline ssize_t generic_write_sync(struct kiocb *iocb, ssize_t count)
{
if (iocb->ki_flags & IOCB_DSYNC) {
if (iocb_is_dsync(iocb)) {
int ret = vfs_fsync_range(iocb->ki_filp,
iocb->ki_pos - count, iocb->ki_pos - 1,
(iocb->ki_flags & IOCB_SYNC) ? 0 : 1);
@@ -3380,7 +3385,7 @@ static inline int iocb_flags(struct file *file)
res |= IOCB_APPEND;
if (file->f_flags & O_DIRECT)
res |= IOCB_DIRECT;
if ((file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host))
if (file->f_flags & O_DSYNC)
res |= IOCB_DSYNC;
if (file->f_flags & __O_SYNC)
res |= IOCB_SYNC;