diff options
| -rw-r--r-- | fs/dax.c | 28 |
1 files changed, 10 insertions, 18 deletions
@@ -119,18 +119,6 @@ int dax_clear_sectors(struct block_device *bdev, sector_t _sector, long _size) } EXPORT_SYMBOL_GPL(dax_clear_sectors); -/* the clear_pmem() calls are ordered by a wmb_pmem() in the caller */ -static void dax_new_buf(void __pmem *addr, unsigned size, unsigned first, - loff_t pos, loff_t end) -{ - loff_t final = end - pos + first; /* The final byte of the buffer */ - - if (first > 0) - clear_pmem(addr, first); - if (final < size) - clear_pmem(addr + final, size - final); -} - static bool buffer_written(struct buffer_head *bh) { return buffer_mapped(bh) && !buffer_unwritten(bh); @@ -169,6 +157,9 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, struct blk_dax_ctl dax = { .addr = (void __pmem *) ERR_PTR(-EIO), }; + unsigned blkbits = inode->i_blkbits; + sector_t file_blks = (i_size_read(inode) + (1 << blkbits) - 1) + >> blkbits; if (rw == READ) end = min(end, i_size_read(inode)); @@ -176,7 +167,6 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, while (pos < end) { size_t len; if (pos == max) { - unsigned blkbits = inode->i_blkbits; long page = pos >> PAGE_SHIFT; sector_t block = page << (PAGE_SHIFT - blkbits); unsigned first = pos - (block << blkbits); @@ -192,6 +182,13 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, bh->b_size = 1 << blkbits; bh_max = pos - first + bh->b_size; bdev = bh->b_bdev; + /* + * We allow uninitialized buffers for writes + * beyond EOF as those cannot race with faults + */ + WARN_ON_ONCE( + (buffer_new(bh) && block < file_blks) || + (rw == WRITE && buffer_unwritten(bh))); } else { unsigned done = bh->b_size - (bh_max - (pos - first)); @@ -211,11 +208,6 @@ static ssize_t dax_io(struct inode *inode, struct iov_iter *iter, rc = map_len; break; } - if (buffer_unwritten(bh) || buffer_new(bh)) { - dax_new_buf(dax.addr, map_len, first, - pos, end); - need_wmb = true; - } dax.addr += first; size = map_len - first; } |