struct xfs_inode *ip = XFS_I(inode);
loff_t isize = i_size_read(inode);
size_t count = iov_iter_count(to);
+ loff_t end = iocb->ki_pos + count - 1;
struct iov_iter data;
struct xfs_buftarg *target;
ssize_t ret = 0;
file_accessed(iocb->ki_filp);
- /*
- * Locking is a bit tricky here. If we take an exclusive lock for direct
- * IO, we effectively serialise all new concurrent read IO to this file
- * and block it behind IO that is currently in progress because IO in
- * progress holds the IO lock shared. We only need to hold the lock
- * exclusive to blow away the page cache, so only take lock exclusively
- * if the page cache needs invalidation. This allows the normal direct
- * IO case of no page cache pages to proceeed concurrently without
- * serialisation.
- */
xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
if (mapping->nrpages) {
- xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
- xfs_rw_ilock(ip, XFS_IOLOCK_EXCL);
+ ret = filemap_write_and_wait_range(mapping, iocb->ki_pos, end);
+ if (ret)
+ goto out_unlock;
/*
- * The generic dio code only flushes the range of the particular
- * I/O. Because we take an exclusive lock here, this whole
- * sequence is considerably more expensive for us. This has a
- * noticeable performance impact for any file with cached pages,
- * even when outside of the range of the particular I/O.
- *
- * Hence, amortize the cost of the lock against a full file
- * flush and reduce the chances of repeated iolock cycles going
- * forward.
+ * Invalidate whole pages. This can return an error if we fail
+ * to invalidate a page, but this should never happen on XFS.
+ * Warn if it does fail.
*/
- if (mapping->nrpages) {
- ret = filemap_write_and_wait(mapping);
- if (ret) {
- xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL);
- return ret;
- }
-
- /*
- * Invalidate whole pages. This can return an error if
- * we fail to invalidate a page, but this should never
- * happen on XFS. Warn if it does fail.
- */
- ret = invalidate_inode_pages2(mapping);
- WARN_ON_ONCE(ret);
- ret = 0;
- }
- xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
+ ret = invalidate_inode_pages2_range(mapping,
+ iocb->ki_pos >> PAGE_SHIFT, end >> PAGE_SHIFT);
+ WARN_ON_ONCE(ret);
+ ret = 0;
}
data = *to;
iocb->ki_pos += ret;
iov_iter_advance(to, ret);
}
- xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
+out_unlock:
+ xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
return ret;
}
if ((iocb->ki_pos | count) & target->bt_logical_sectormask)
return -EINVAL;
- /* "unaligned" here means not aligned to a filesystem block */
- if ((iocb->ki_pos & mp->m_blockmask) ||
- ((iocb->ki_pos + count) & mp->m_blockmask))
- unaligned_io = 1;
-
/*
- * We don't need to take an exclusive lock unless there page cache needs
- * to be invalidated or unaligned IO is being executed. We don't need to
- * consider the EOF extension case here because
- * xfs_file_aio_write_checks() will relock the inode as necessary for
- * EOF zeroing cases and fill out the new inode size as appropriate.
+ * Don't take the exclusive iolock here unless the I/O is unaligned to
+ * the file system block size. We don't need to consider the EOF
+ * extension case here because xfs_file_aio_write_checks() will relock
+ * the inode as necessary for EOF zeroing cases and fill out the new
+ * inode size as appropriate.
*/
- if (unaligned_io || mapping->nrpages)
+ if ((iocb->ki_pos & mp->m_blockmask) ||
+ ((iocb->ki_pos + count) & mp->m_blockmask)) {
+ unaligned_io = 1;
iolock = XFS_IOLOCK_EXCL;
- else
+ } else {
iolock = XFS_IOLOCK_SHARED;
- xfs_rw_ilock(ip, iolock);
-
- /*
- * Recheck if there are cached pages that need invalidate after we got
- * the iolock to protect against other threads adding new pages while
- * we were waiting for the iolock.
- */
- if (mapping->nrpages && iolock == XFS_IOLOCK_SHARED) {
- xfs_rw_iunlock(ip, iolock);
- iolock = XFS_IOLOCK_EXCL;
- xfs_rw_ilock(ip, iolock);
}
+ xfs_rw_ilock(ip, iolock);
+
ret = xfs_file_aio_write_checks(iocb, from, &iolock);
if (ret)
goto out;
count = iov_iter_count(from);
end = iocb->ki_pos + count - 1;
- /*
- * See xfs_file_dio_aio_read() for why we do a full-file flush here.
- */
if (mapping->nrpages) {
- ret = filemap_write_and_wait(VFS_I(ip)->i_mapping);
+ ret = filemap_write_and_wait_range(mapping, iocb->ki_pos, end);
if (ret)
goto out;
+
/*
* Invalidate whole pages. This can return an error if we fail
* to invalidate a page, but this should never happen on XFS.
* Warn if it does fail.
*/
- ret = invalidate_inode_pages2(VFS_I(ip)->i_mapping);
+ ret = invalidate_inode_pages2_range(mapping,
+ iocb->ki_pos >> PAGE_SHIFT, end >> PAGE_SHIFT);
WARN_ON_ONCE(ret);
ret = 0;
}
/*
* If we are doing unaligned IO, wait for all other IO to drain,
- * otherwise demote the lock if we had to flush cached pages
+ * otherwise demote the lock if we had to take the exclusive lock
+ * for other reasons in xfs_file_aio_write_checks.
*/
if (unaligned_io)
inode_dio_wait(inode);
IS_SWAPFILE(inode_out))
return -ETXTBSY;
- /* Reflink only works within this filesystem. */
- if (inode_in->i_sb != inode_out->i_sb)
- return -EXDEV;
- same_inode = (inode_in->i_ino == inode_out->i_ino);
+ same_inode = (inode_in == inode_out);
/* Don't reflink dirs, pipes, sockets... */
if (S_ISDIR(inode_in->i_mode) || S_ISDIR(inode_out->i_mode))
projects / cascardo / linux.git / blobdiff