struct page **prepared_pages,
struct iov_iter *i)
{
- size_t copied;
+ size_t copied = 0;
int pg = 0;
int offset = pos & (PAGE_CACHE_SIZE - 1);
+ int total_copied = 0;
while (write_bytes > 0) {
size_t count = min_t(size_t,
PAGE_CACHE_SIZE - offset, write_bytes);
struct page *page = prepared_pages[pg];
-again:
- if (unlikely(iov_iter_fault_in_readable(i, count)))
- return -EFAULT;
-
- /* Copy data from userspace to the current page */
- copied = iov_iter_copy_from_user(page, i, offset, count);
+ /*
+ * Copy data from userspace to the current page
+ *
+ * Disable pagefault to avoid recursive lock since
+ * the pages are already locked
+ */
+ pagefault_disable();
+ copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
+ pagefault_enable();
/* Flush processor's dcache for this page */
flush_dcache_page(page);
iov_iter_advance(i, copied);
write_bytes -= copied;
+ total_copied += copied;
+ /* Return to btrfs_file_aio_write to fault page */
if (unlikely(copied == 0)) {
- count = min_t(size_t, PAGE_CACHE_SIZE - offset,
- iov_iter_single_seg_count(i));
- goto again;
+ break;
}
if (unlikely(copied < PAGE_CACHE_SIZE - offset)) {
offset = 0;
}
}
- return 0;
+ return total_copied;
}
/*
split->bdev = em->bdev;
split->flags = flags;
+ split->compress_type = em->compress_type;
ret = add_extent_mapping(em_tree, split);
BUG_ON(ret);
free_extent_map(split);
split->len = em->start + em->len - (start + len);
split->bdev = em->bdev;
split->flags = flags;
+ split->compress_type = em->compress_type;
if (compressed) {
split->block_len = em->block_len;
for (i = 0; i < num_pages; i++) {
pages[i] = grab_cache_page(inode->i_mapping, index + i);
if (!pages[i]) {
- err = -ENOMEM;
- BUG_ON(1);
+ int c;
+ for (c = i - 1; c >= 0; c--) {
+ unlock_page(pages[c]);
+ page_cache_release(pages[c]);
+ }
+ return -ENOMEM;
}
wait_on_page_writeback(pages[i]);
}
unsigned long last_index;
int will_write;
int buffered = 0;
+ int copied = 0;
+ int dirty_pages = 0;
will_write = ((file->f_flags & O_DSYNC) || IS_SYNC(inode) ||
(file->f_flags & O_DIRECT));
if (err)
goto out;
+ /*
+ * If BTRFS flips readonly due to some impossible error
+ * (fs_info->fs_state now has BTRFS_SUPER_FLAG_ERROR),
+ * although we have opened a file as writable, we have
+ * to stop this write operation to ensure FS consistency.
+ */
+ if (root->fs_info->fs_state & BTRFS_SUPER_FLAG_ERROR) {
+ err = -EROFS;
+ goto out;
+ }
+
file_update_time(file);
BTRFS_I(inode)->sequence++;
PAGE_CACHE_SIZE, PAGE_CACHE_SIZE /
(sizeof(struct page *)));
pages = kmalloc(nrptrs * sizeof(struct page *), GFP_KERNEL);
+ if (!pages) {
+ ret = -ENOMEM;
+ goto out;
+ }
/* generic_write_checks can change our pos */
start_pos = pos;
size_t write_bytes = min(iov_iter_count(&i),
nrptrs * (size_t)PAGE_CACHE_SIZE -
offset);
- size_t num_pages = (write_bytes + PAGE_CACHE_SIZE - 1) >>
- PAGE_CACHE_SHIFT;
+ size_t num_pages = (write_bytes + offset +
+ PAGE_CACHE_SIZE - 1) >> PAGE_CACHE_SHIFT;
WARN_ON(num_pages > nrptrs);
memset(pages, 0, sizeof(struct page *) * nrptrs);
- ret = btrfs_delalloc_reserve_space(inode, write_bytes);
+ /*
+ * Fault pages before locking them in prepare_pages
+ * to avoid recursive lock
+ */
+ if (unlikely(iov_iter_fault_in_readable(&i, write_bytes))) {
+ ret = -EFAULT;
+ goto out;
+ }
+
+ ret = btrfs_delalloc_reserve_space(inode,
+ num_pages << PAGE_CACHE_SHIFT);
if (ret)
goto out;
pos, first_index, last_index,
write_bytes);
if (ret) {
- btrfs_delalloc_release_space(inode, write_bytes);
+ btrfs_delalloc_release_space(inode,
+ num_pages << PAGE_CACHE_SHIFT);
goto out;
}
- ret = btrfs_copy_from_user(pos, num_pages,
+ copied = btrfs_copy_from_user(pos, num_pages,
write_bytes, pages, &i);
- if (ret == 0) {
+ dirty_pages = (copied + offset + PAGE_CACHE_SIZE - 1) >>
+ PAGE_CACHE_SHIFT;
+
+ if (num_pages > dirty_pages) {
+ if (copied > 0)
+ atomic_inc(
+ &BTRFS_I(inode)->outstanding_extents);
+ btrfs_delalloc_release_space(inode,
+ (num_pages - dirty_pages) <<
+ PAGE_CACHE_SHIFT);
+ }
+
+ if (copied > 0) {
dirty_and_release_pages(NULL, root, file, pages,
- num_pages, pos, write_bytes);
+ dirty_pages, pos, copied);
}
btrfs_drop_pages(pages, num_pages);
- if (ret) {
- btrfs_delalloc_release_space(inode, write_bytes);
- goto out;
- }
- if (will_write) {
- filemap_fdatawrite_range(inode->i_mapping, pos,
- pos + write_bytes - 1);
- } else {
- balance_dirty_pages_ratelimited_nr(inode->i_mapping,
- num_pages);
- if (num_pages <
- (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
- btrfs_btree_balance_dirty(root, 1);
- btrfs_throttle(root);
+ if (copied > 0) {
+ if (will_write) {
+ filemap_fdatawrite_range(inode->i_mapping, pos,
+ pos + copied - 1);
+ } else {
+ balance_dirty_pages_ratelimited_nr(
+ inode->i_mapping,
+ dirty_pages);
+ if (dirty_pages <
+ (root->leafsize >> PAGE_CACHE_SHIFT) + 1)
+ btrfs_btree_balance_dirty(root, 1);
+ btrfs_throttle(root);
+ }
}
- pos += write_bytes;
- num_written += write_bytes;
+ pos += copied;
+ num_written += copied;
cond_resched();
}
if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) {
trans = btrfs_start_transaction(root, 0);
+ if (IS_ERR(trans)) {
+ num_written = PTR_ERR(trans);
+ goto done;
+ }
+ mutex_lock(&inode->i_mutex);
ret = btrfs_log_dentry_safe(trans, root,
file->f_dentry);
+ mutex_unlock(&inode->i_mutex);
if (ret == 0) {
ret = btrfs_sync_log(trans, root);
if (ret == 0)
(start_pos + num_written - 1) >> PAGE_CACHE_SHIFT);
}
}
+done:
current->backing_dev_info = NULL;
return num_written ? num_written : err;
}
projects / cascardo / linux.git / blobdiff