From 0c949334a9e2581646c6ff0d1470a805b1e5be99 Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 22 Mar 2014 06:51:37 -0400 Subject: iov_iter_truncate() Now It Can Be Done(tm) - we don't need to do iov_shorten() in generic_file_direct_write() anymore, now that all ->direct_IO() instances are converted to proper iov_iter methods and honour iter->count and iter->iov_offset properly. Get rid of count/ocount arguments of generic_file_direct_write(), while we are at it. Signed-off-by: Al Viro diff --git a/fs/btrfs/file.c b/fs/btrfs/file.c index f8cee20..ea63a51c 100644 --- a/fs/btrfs/file.c +++ b/fs/btrfs/file.c @@ -1659,8 +1659,7 @@ again: static ssize_t __btrfs_direct_write(struct kiocb *iocb, struct iov_iter *from, - loff_t pos, - size_t count, size_t ocount) + loff_t pos) { struct file *file = iocb->ki_filp; ssize_t written; @@ -1668,9 +1667,9 @@ static ssize_t __btrfs_direct_write(struct kiocb *iocb, loff_t endbyte; int err; - written = generic_file_direct_write(iocb, from, pos, count, ocount); + written = generic_file_direct_write(iocb, from, pos); - if (written < 0 || written == count) + if (written < 0 || !iov_iter_count(from)) return written; pos += written; @@ -1720,13 +1719,14 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb, u64 end_pos; ssize_t num_written = 0; ssize_t err = 0; - size_t count, ocount; + size_t count; bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host); struct iov_iter i; mutex_lock(&inode->i_mutex); - count = ocount = iov_length(iov, nr_segs); + count = iov_length(iov, nr_segs); + iov_iter_init(&i, WRITE, iov, nr_segs, count); current->backing_dev_info = inode->i_mapping->backing_dev_info; err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); @@ -1740,7 +1740,7 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb, goto out; } - iov_iter_init(&i, WRITE, iov, nr_segs, count); + iov_iter_truncate(&i, count); err = file_remove_suid(file); if (err) { @@ -1783,8 +1783,7 @@ static ssize_t btrfs_file_aio_write(struct kiocb *iocb, atomic_inc(&BTRFS_I(inode)->sync_writers); if (unlikely(file->f_flags & O_DIRECT)) { - num_written = __btrfs_direct_write(iocb, &i, - pos, count, ocount); + num_written = __btrfs_direct_write(iocb, &i, pos); } else { num_written = __btrfs_buffered_write(file, &i, pos); if (num_written > 0) diff --git a/fs/fuse/file.c b/fs/fuse/file.c index 7026014..66d2d5d 100644 --- a/fs/fuse/file.c +++ b/fs/fuse/file.c @@ -1188,8 +1188,7 @@ static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov, { struct file *file = iocb->ki_filp; struct address_space *mapping = file->f_mapping; - size_t count = 0; - size_t ocount = 0; + size_t count; ssize_t written = 0; ssize_t written_buffered = 0; struct inode *inode = mapping->host; @@ -1208,7 +1207,8 @@ static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov, WARN_ON(iocb->ki_pos != pos); - count = ocount = iov_length(iov, nr_segs); + count = iov_length(iov, nr_segs); + iov_iter_init(&i, WRITE, iov, nr_segs, count); mutex_lock(&inode->i_mutex); /* We can write back this queue in page reclaim */ @@ -1217,11 +1217,11 @@ static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov, err = generic_write_checks(file, &pos, &count, S_ISBLK(inode->i_mode)); if (err) goto out; - iov_iter_init(&i, WRITE, iov, nr_segs, count); if (count == 0) goto out; + iov_iter_truncate(&i, count); err = file_remove_suid(file); if (err) goto out; @@ -1231,8 +1231,8 @@ static ssize_t fuse_file_aio_write(struct kiocb *iocb, const struct iovec *iov, goto out; if (file->f_flags & O_DIRECT) { - written = generic_file_direct_write(iocb, &i, pos, count, ocount); - if (written < 0 || written == count) + written = generic_file_direct_write(iocb, &i, pos); + if (written < 0 || !iov_iter_count(&i)) goto out; pos += written; @@ -1469,8 +1469,7 @@ static ssize_t __fuse_direct_write(struct fuse_io_priv *io, res = generic_write_checks(file, ppos, &count, 0); if (!res) { - if (iter->count > count) - iter->count = count; + iov_iter_truncate(iter, count); res = fuse_direct_io(io, iter, ppos, FUSE_DIO_WRITE); } @@ -2896,8 +2895,7 @@ fuse_direct_IO(int rw, struct kiocb *iocb, struct iov_iter *iter, if (offset >= i_size) return 0; count = min_t(loff_t, count, fuse_round_up(i_size - offset)); - if (iter->count > count) - iter->count = count; + iov_iter_truncate(iter, count); } io = kmalloc(sizeof(struct fuse_io_priv), GFP_KERNEL); diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c index 9ce9ed7..06b6a16 100644 --- a/fs/ocfs2/file.c +++ b/fs/ocfs2/file.c @@ -2241,7 +2241,6 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb, int ret, direct_io, appending, rw_level, have_alloc_sem = 0; int can_do_direct, has_refcount = 0; ssize_t written = 0; - size_t ocount; /* original count */ size_t count; /* after file limit checks */ loff_t old_size, *ppos = &iocb->ki_pos; u32 old_clusters; @@ -2253,6 +2252,9 @@ static ssize_t ocfs2_file_aio_write(struct kiocb *iocb, int unaligned_dio = 0; struct iov_iter from; + count = iov_length(iov, nr_segs); + iov_iter_init(&from, WRITE, iov, nr_segs, count); + trace_ocfs2_file_aio_write(inode, file, file->f_path.dentry, (unsigned long long)OCFS2_I(inode)->ip_blkno, file->f_path.dentry->d_name.len, @@ -2355,16 +2357,14 @@ relock: /* communicate with ocfs2_dio_end_io */ ocfs2_iocb_set_rw_locked(iocb, rw_level); - count = ocount = iov_length(iov, nr_segs); ret = generic_write_checks(file, ppos, &count, S_ISBLK(inode->i_mode)); if (ret) goto out_dio; - iov_iter_init(&from, WRITE, iov, nr_segs, count); + iov_iter_truncate(&from, count); if (direct_io) { - written = generic_file_direct_write(iocb, &from, *ppos, - count, ocount); + written = generic_file_direct_write(iocb, &from, *ppos); if (written < 0) { ret = written; goto out_dio; diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c index 762bb3e..c997aa2 100644 --- a/fs/xfs/xfs_file.c +++ b/fs/xfs/xfs_file.c @@ -626,7 +626,7 @@ xfs_file_dio_aio_write( const struct iovec *iovp, unsigned long nr_segs, loff_t pos, - size_t ocount) + size_t count) { struct file *file = iocb->ki_filp; struct address_space *mapping = file->f_mapping; @@ -634,7 +634,6 @@ xfs_file_dio_aio_write( struct xfs_inode *ip = XFS_I(inode); struct xfs_mount *mp = ip->i_mount; ssize_t ret = 0; - size_t count = ocount; int unaligned_io = 0; int iolock; struct xfs_buftarg *target = XFS_IS_REALTIME_INODE(ip) ? @@ -645,6 +644,8 @@ xfs_file_dio_aio_write( if ((pos | count) & target->bt_logical_sectormask) return -XFS_ERROR(EINVAL); + iov_iter_init(&from, WRITE, iovp, nr_segs, count); + /* "unaligned" here means not aligned to a filesystem block */ if ((pos & mp->m_blockmask) || ((pos + count) & mp->m_blockmask)) unaligned_io = 1; @@ -676,6 +677,7 @@ xfs_file_dio_aio_write( ret = xfs_file_aio_write_checks(file, &pos, &count, &iolock); if (ret) goto out; + iov_iter_truncate(&from, count); if (mapping->nrpages) { ret = filemap_write_and_wait_range(VFS_I(ip)->i_mapping, @@ -697,8 +699,7 @@ xfs_file_dio_aio_write( } trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0); - iov_iter_init(&from, WRITE, iovp, nr_segs, count); - ret = generic_file_direct_write(iocb, &from, pos, count, ocount); + ret = generic_file_direct_write(iocb, &from, pos); out: xfs_rw_iunlock(ip, iolock); diff --git a/include/linux/fs.h b/include/linux/fs.h index d096ebc..8153396 100644 --- a/include/linux/fs.h +++ b/include/linux/fs.h @@ -2407,8 +2407,7 @@ extern ssize_t generic_file_aio_read(struct kiocb *, const struct iovec *, unsig extern ssize_t generic_file_read_iter(struct kiocb *, struct iov_iter *); extern ssize_t __generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long); extern ssize_t generic_file_aio_write(struct kiocb *, const struct iovec *, unsigned long, loff_t); -extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *, - loff_t, size_t, size_t); +extern ssize_t generic_file_direct_write(struct kiocb *, struct iov_iter *, loff_t); extern ssize_t generic_perform_write(struct file *, struct iov_iter *, loff_t); extern ssize_t do_sync_read(struct file *filp, char __user *buf, size_t len, loff_t *ppos); extern ssize_t do_sync_write(struct file *filp, const char __user *buf, size_t len, loff_t *ppos); diff --git a/include/linux/uio.h b/include/linux/uio.h index 4876e9f..532f59d 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -82,6 +82,12 @@ static inline size_t iov_iter_count(struct iov_iter *i) return i->count; } +static inline void iov_iter_truncate(struct iov_iter *i, size_t count) +{ + if (i->count > count) + i->count = count; +} + int memcpy_fromiovec(unsigned char *kdata, struct iovec *iov, int len); int memcpy_toiovec(struct iovec *iov, unsigned char *kdata, int len); diff --git a/mm/filemap.c b/mm/filemap.c index 3aeaf2d..c0404b7 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2345,8 +2345,7 @@ int pagecache_write_end(struct file *file, struct address_space *mapping, EXPORT_SYMBOL(pagecache_write_end); ssize_t -generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from, - loff_t pos, size_t count, size_t ocount) +generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos) { struct file *file = iocb->ki_filp; struct address_space *mapping = file->f_mapping; @@ -2356,10 +2355,7 @@ generic_file_direct_write(struct kiocb *iocb, struct iov_iter *from, pgoff_t end; struct iov_iter data; - if (count != ocount) - from->nr_segs = iov_shorten((struct iovec *)from->iov, from->nr_segs, count); - - write_len = iov_length(from->iov, from->nr_segs); + write_len = iov_iter_count(from); end = (pos + write_len - 1) >> PAGE_CACHE_SHIFT; written = filemap_write_and_wait_range(mapping, pos, pos + write_len - 1); @@ -2568,7 +2564,6 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, { struct file *file = iocb->ki_filp; struct address_space * mapping = file->f_mapping; - size_t ocount; /* original count */ size_t count; /* after file limit checks */ struct inode *inode = mapping->host; loff_t pos = iocb->ki_pos; @@ -2577,7 +2572,8 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, ssize_t status; struct iov_iter from; - count = ocount = iov_length(iov, nr_segs); + count = iov_length(iov, nr_segs); + iov_iter_init(&from, WRITE, iov, nr_segs, count); /* We can write back this queue in page reclaim */ current->backing_dev_info = mapping->backing_dev_info; @@ -2588,6 +2584,8 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, if (count == 0) goto out; + iov_iter_truncate(&from, count); + err = file_remove_suid(file); if (err) goto out; @@ -2596,14 +2594,11 @@ ssize_t __generic_file_aio_write(struct kiocb *iocb, const struct iovec *iov, if (err) goto out; - iov_iter_init(&from, WRITE, iov, nr_segs, count); - /* coalesce the iovecs and go direct-to-BIO for O_DIRECT */ if (unlikely(file->f_flags & O_DIRECT)) { loff_t endbyte; - written = generic_file_direct_write(iocb, &from, pos, - count, ocount); + written = generic_file_direct_write(iocb, &from, pos); if (written < 0 || written == count) goto out; -- cgit v0.10.2