if (error <= 0)
return error;
- error = xfs_break_layouts(inode, iolock);
+ error = xfs_break_layouts(inode, iolock, true);
if (error)
return error;
* write. If zeroing is needed and we are currently holding the
* iolock shared, we need to update it to exclusive which implies
* having to redo all checks before.
+ *
+ * We need to serialise against EOF updates that occur in IO
+ * completions here. We want to make sure that nobody is changing the
+ * size while we do this check until we have placed an IO barrier (i.e.
+ * hold the XFS_IOLOCK_EXCL) that prevents new IO from being dispatched.
+ * The spinlock effectively forms a memory barrier once we have the
+ * XFS_IOLOCK_EXCL so we are guaranteed to see the latest EOF value
+ * and hence be able to correctly determine if we need to run zeroing.
*/
+ spin_lock(&ip->i_flags_lock);
if (iocb->ki_pos > i_size_read(inode)) {
bool zero = false;
+ spin_unlock(&ip->i_flags_lock);
if (*iolock == XFS_IOLOCK_SHARED) {
xfs_rw_iunlock(ip, *iolock);
*iolock = XFS_IOLOCK_EXCL;
xfs_rw_ilock(ip, *iolock);
iov_iter_reexpand(from, count);
+
+ /*
+ * We now have an IO submission barrier in place, but
+ * AIO can do EOF updates during IO completion and hence
+ * we now need to wait for all of them to drain. Non-AIO
+ * DIO will have drained before we are given the
+ * XFS_IOLOCK_EXCL, and so for most cases this wait is a
+ * no-op.
+ */
+ inode_dio_wait(inode);
goto restart;
}
error = xfs_zero_eof(ip, iocb->ki_pos, i_size_read(inode), &zero);
if (error)
return error;
- }
+ } else
+ spin_unlock(&ip->i_flags_lock);
/*
* Updating the timestamps will grab the ilock again from
int iolock;
size_t count = iov_iter_count(from);
loff_t pos = iocb->ki_pos;
+ loff_t end;
+ struct iov_iter data;
struct xfs_buftarg *target = XFS_IS_REALTIME_INODE(ip) ?
mp->m_rtdev_targp : mp->m_ddev_targp;
goto out;
count = iov_iter_count(from);
pos = iocb->ki_pos;
+ end = pos + count - 1;
if (mapping->nrpages) {
ret = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
- pos, pos + count - 1);
+ pos, end);
if (ret)
goto out;
/*
*/
ret = invalidate_inode_pages2_range(VFS_I(ip)->i_mapping,
pos >> PAGE_CACHE_SHIFT,
- (pos + count - 1) >> PAGE_CACHE_SHIFT);
+ end >> PAGE_CACHE_SHIFT);
WARN_ON_ONCE(ret);
ret = 0;
}
}
trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0);
- ret = generic_file_direct_write(iocb, from, pos);
+ data = *from;
+ ret = mapping->a_ops->direct_IO(iocb, &data, pos);
+
+ /* see generic_file_direct_write() for why this is necessary */
+ if (mapping->nrpages) {
+ invalidate_inode_pages2_range(mapping,
+ pos >> PAGE_CACHE_SHIFT,
+ end >> PAGE_CACHE_SHIFT);
+ }
+
+ if (ret > 0) {
+ pos += ret;
+ iov_iter_advance(from, ret);
+ iocb->ki_pos = pos;
+ }
out:
xfs_rw_iunlock(ip, iolock);
return ret;
}
+#define XFS_FALLOC_FL_SUPPORTED \
+ (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
+ FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | \
+ FALLOC_FL_INSERT_RANGE)
+
STATIC long
xfs_file_fallocate(
struct file *file,
enum xfs_prealloc_flags flags = 0;
uint iolock = XFS_IOLOCK_EXCL;
loff_t new_size = 0;
+ bool do_file_insert = 0;
if (!S_ISREG(inode->i_mode))
return -EINVAL;
- if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |
- FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE))
+ if (mode & ~XFS_FALLOC_FL_SUPPORTED)
return -EOPNOTSUPP;
xfs_ilock(ip, iolock);
- error = xfs_break_layouts(inode, &iolock);
+ error = xfs_break_layouts(inode, &iolock, false);
if (error)
goto out_unlock;
+ xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
+ iolock |= XFS_MMAPLOCK_EXCL;
+
if (mode & FALLOC_FL_PUNCH_HOLE) {
error = xfs_free_file_space(ip, offset, len);
if (error)
error = xfs_collapse_file_space(ip, offset, len);
if (error)
goto out_unlock;
+ } else if (mode & FALLOC_FL_INSERT_RANGE) {
+ unsigned blksize_mask = (1 << inode->i_blkbits) - 1;
+
+ new_size = i_size_read(inode) + len;
+ if (offset & blksize_mask || len & blksize_mask) {
+ error = -EINVAL;
+ goto out_unlock;
+ }
+
+ /* check the new inode size does not wrap through zero */
+ if (new_size > inode->i_sb->s_maxbytes) {
+ error = -EFBIG;
+ goto out_unlock;
+ }
+
+ /* Offset should be less than i_size */
+ if (offset >= i_size_read(inode)) {
+ error = -EINVAL;
+ goto out_unlock;
+ }
+ do_file_insert = 1;
} else {
flags |= XFS_PREALLOC_SET;
iattr.ia_valid = ATTR_SIZE;
iattr.ia_size = new_size;
error = xfs_setattr_size(ip, &iattr);
+ if (error)
+ goto out_unlock;
}
+ /*
+ * Perform hole insertion now that the file size has been
+ * updated so that if we crash during the operation we don't
+ * leave shifted extents past EOF and hence losing access to
+ * the data that is contained within them.
+ */
+ if (do_file_insert)
+ error = xfs_insert_file_space(ip, offset, len);
+
out_unlock:
xfs_iunlock(ip, iolock);
return error;
return 0;
}
-/*
- * mmap()d file has taken write protection fault and is being made
- * writable. We can set the page state up correctly for a writable
- * page, which means we can do correct delalloc accounting (ENOSPC
- * checking!) and unwritten extent mapping.
- */
-STATIC int
-xfs_vm_page_mkwrite(
- struct vm_area_struct *vma,
- struct vm_fault *vmf)
-{
- return block_page_mkwrite(vma, vmf, xfs_get_blocks);
-}
-
/*
* This type is designed to indicate the type of offset we would like
* to search from page cache for xfs_seek_hole_data().
}
}
+/*
+ * Locking for serialisation of IO during page faults. This results in a lock
+ * ordering of:
+ *
+ * mmap_sem (MM)
+ * i_mmap_lock (XFS - truncate serialisation)
+ * page_lock (MM)
+ * i_lock (XFS - extent map serialisation)
+ */
+STATIC int
+xfs_filemap_fault(
+ struct vm_area_struct *vma,
+ struct vm_fault *vmf)
+{
+ struct xfs_inode *ip = XFS_I(vma->vm_file->f_mapping->host);
+ int error;
+
+ trace_xfs_filemap_fault(ip);
+
+ xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
+ error = filemap_fault(vma, vmf);
+ xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
+
+ return error;
+}
+
+/*
+ * mmap()d file has taken write protection fault and is being made writable. We
+ * can set the page state up correctly for a writable page, which means we can
+ * do correct delalloc accounting (ENOSPC checking!) and unwritten extent
+ * mapping.
+ */
+STATIC int
+xfs_filemap_page_mkwrite(
+ struct vm_area_struct *vma,
+ struct vm_fault *vmf)
+{
+ struct xfs_inode *ip = XFS_I(vma->vm_file->f_mapping->host);
+ int error;
+
+ trace_xfs_filemap_page_mkwrite(ip);
+
+ xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
+ error = block_page_mkwrite(vma, vmf, xfs_get_blocks);
+ xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
+
+ return error;
+}
+
const struct file_operations xfs_file_operations = {
.llseek = xfs_file_llseek,
.read_iter = xfs_file_read_iter,
};
static const struct vm_operations_struct xfs_file_vm_ops = {
- .fault = filemap_fault,
+ .fault = xfs_filemap_fault,
.map_pages = filemap_map_pages,
- .page_mkwrite = xfs_vm_page_mkwrite,
+ .page_mkwrite = xfs_filemap_page_mkwrite,
};
projects / karo-tx-linux.git / blobdiff