}
}
+static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode,
+ const u64 start,
+ const u64 len,
+ struct extent_state **cached_state)
+{
+ u64 search_start = start;
+ const u64 end = start + len - 1;
+
+ while (search_start < end) {
+ const u64 search_len = end - search_start + 1;
+ struct extent_map *em;
+ u64 em_len;
+ int ret = 0;
+
+ em = btrfs_get_extent(inode, NULL, 0, search_start,
+ search_len, 0);
+ if (IS_ERR(em))
+ return PTR_ERR(em);
+
+ if (em->block_start != EXTENT_MAP_HOLE)
+ goto next;
+
+ em_len = em->len;
+ if (em->start < search_start)
+ em_len -= search_start - em->start;
+ if (em_len > search_len)
+ em_len = search_len;
+
+ ret = set_extent_bit(&inode->io_tree, search_start,
+ search_start + em_len - 1,
+ EXTENT_DELALLOC_NEW,
+ NULL, cached_state, GFP_NOFS);
+next:
+ search_start = extent_map_end(em);
+ free_extent_map(em);
+ if (ret)
+ return ret;
+ }
+ return 0;
+}
+
/*
* after copy_from_user, pages need to be dirtied and we need to make
* sure holes are created between the current EOF and the start of
u64 end_of_last_block;
u64 end_pos = pos + write_bytes;
loff_t isize = i_size_read(inode);
+ unsigned int extra_bits = 0;
start_pos = pos & ~((u64) fs_info->sectorsize - 1);
num_bytes = round_up(write_bytes + pos - start_pos,
fs_info->sectorsize);
end_of_last_block = start_pos + num_bytes - 1;
+
+ /*
+ * The pages may have already been dirty, clear out old accounting so
+ * we can set things up properly
+ */
+ clear_extent_bit(&BTRFS_I(inode)->io_tree, start_pos, end_of_last_block,
+ EXTENT_DIRTY | EXTENT_DELALLOC |
+ EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG, 0, 0, cached,
+ GFP_NOFS);
+
+ if (!btrfs_is_free_space_inode(BTRFS_I(inode))) {
+ if (start_pos >= isize &&
+ !(BTRFS_I(inode)->flags & BTRFS_INODE_PREALLOC)) {
+ /*
+ * There can't be any extents following eof in this case
+ * so just set the delalloc new bit for the range
+ * directly.
+ */
+ extra_bits |= EXTENT_DELALLOC_NEW;
+ } else {
+ err = btrfs_find_new_delalloc_bytes(BTRFS_I(inode),
+ start_pos,
+ num_bytes, cached);
+ if (err)
+ return err;
+ }
+ }
+
err = btrfs_set_extent_delalloc(inode, start_pos, end_of_last_block,
- cached, 0);
+ extra_bits, cached, 0);
if (err)
return err;
btrfs_file_extent_num_bytes(leaf, fi);
} else if (extent_type == BTRFS_FILE_EXTENT_INLINE) {
extent_end = key.offset +
- btrfs_file_extent_inline_len(leaf,
- path->slots[0], fi);
+ btrfs_file_extent_ram_bytes(leaf, fi);
} else {
/* can't happen */
BUG();
}
-static int btrfs_find_new_delalloc_bytes(struct btrfs_inode *inode,
- const u64 start,
- const u64 len,
- struct extent_state **cached_state)
-{
- u64 search_start = start;
- const u64 end = start + len - 1;
-
- while (search_start < end) {
- const u64 search_len = end - search_start + 1;
- struct extent_map *em;
- u64 em_len;
- int ret = 0;
-
- em = btrfs_get_extent(inode, NULL, 0, search_start,
- search_len, 0);
- if (IS_ERR(em))
- return PTR_ERR(em);
-
- if (em->block_start != EXTENT_MAP_HOLE)
- goto next;
-
- em_len = em->len;
- if (em->start < search_start)
- em_len -= search_start - em->start;
- if (em_len > search_len)
- em_len = search_len;
-
- ret = set_extent_bit(&inode->io_tree, search_start,
- search_start + em_len - 1,
- EXTENT_DELALLOC_NEW,
- NULL, cached_state, GFP_NOFS);
-next:
- search_start = extent_map_end(em);
- free_extent_map(em);
- if (ret)
- return ret;
- }
- return 0;
-}
-
/*
* This function locks the extent and properly waits for data=ordered extents
* to finish before allowing the pages to be modified if need.
+ round_up(pos + write_bytes - start_pos,
fs_info->sectorsize) - 1;
- if (start_pos < inode->vfs_inode.i_size ||
- (inode->flags & BTRFS_INODE_PREALLOC)) {
+ if (start_pos < inode->vfs_inode.i_size) {
struct btrfs_ordered_extent *ordered;
- unsigned int clear_bits;
lock_extent_bits(&inode->io_tree, start_pos, last_pos,
cached_state);
}
if (ordered)
btrfs_put_ordered_extent(ordered);
- ret = btrfs_find_new_delalloc_bytes(inode, start_pos,
- last_pos - start_pos + 1,
- cached_state);
- clear_bits = EXTENT_DIRTY | EXTENT_DELALLOC |
- EXTENT_DO_ACCOUNTING | EXTENT_DEFRAG;
- if (ret)
- clear_bits |= EXTENT_DELALLOC_NEW | EXTENT_LOCKED;
- clear_extent_bit(&inode->io_tree, start_pos,
- last_pos, clear_bits,
- (clear_bits & EXTENT_LOCKED) ? 1 : 0,
- 0, cached_state, GFP_NOFS);
- if (ret)
- return ret;
+
*lockstart = start_pos;
*lockend = last_pos;
ret = 1;
}
+ /*
+ * It's possible the pages are dirty right now, but we don't want
+ * to clean them yet because copy_from_user may catch a page fault
+ * and we might have to fall back to one page at a time. If that
+ * happens, we'll unlock these pages and we'd have a window where
+ * reclaim could sneak in and drop the once-dirty page on the floor
+ * without writing it.
+ *
+ * We have the pages locked and the extent range locked, so there's
+ * no way someone can start IO on any dirty pages in this range.
+ *
+ * We'll call btrfs_dirty_pages() later on, and that will flip around
+ * delalloc bits and dirty the pages as required.
+ */
for (i = 0; i < num_pages; i++) {
- if (clear_page_dirty_for_io(pages[i]))
- account_page_redirty(pages[i]);
set_page_extent_mapped(pages[i]);
WARN_ON(!PageLocked(pages[i]));
}
struct btrfs_fs_info *fs_info = btrfs_sb(inode->i_sb);
struct btrfs_root *root = BTRFS_I(inode)->root;
struct page **pages = NULL;
- struct extent_state *cached_state = NULL;
struct extent_changeset *data_reserved = NULL;
u64 release_bytes = 0;
u64 lockstart;
while (iov_iter_count(i) > 0) {
size_t offset = pos & (PAGE_SIZE - 1);
+ struct extent_state *cached_state = NULL;
size_t sector_offset;
size_t write_bytes = min(iov_iter_count(i),
nrptrs * (size_t)PAGE_SIZE -
break;
}
+ only_release_metadata = false;
sector_offset = pos & (fs_info->sectorsize - 1);
reserve_bytes = round_up(write_bytes + sector_offset,
fs_info->sectorsize);
if (copied > 0)
ret = btrfs_dirty_pages(inode, pages, dirty_pages,
pos, copied, NULL);
+
+ /*
+ * If we have not locked the extent range, because the range's
+ * start offset is >= i_size, we might still have a non-NULL
+ * cached extent state, acquired while marking the extent range
+ * as delalloc through btrfs_dirty_pages(). Therefore free any
+ * possible cached extent state to avoid a memory leak.
+ */
if (extents_locked)
unlock_extent_cached(&BTRFS_I(inode)->io_tree,
lockstart, lockend, &cached_state,
GFP_NOFS);
+ else
+ free_extent_state(cached_state);
+
btrfs_delalloc_release_extents(BTRFS_I(inode), reserve_bytes);
if (ret) {
btrfs_drop_pages(pages, num_pages);
set_extent_bit(&BTRFS_I(inode)->io_tree, lockstart,
lockend, EXTENT_NORESERVE, NULL,
NULL, GFP_NOFS);
- only_release_metadata = false;
}
btrfs_drop_pages(pages, num_pages);
bool sync = (file->f_flags & O_DSYNC) || IS_SYNC(file->f_mapping->host);
ssize_t err;
loff_t pos;
- size_t count = iov_iter_count(from);
+ size_t count;
loff_t oldsize;
int clean_page = 0;
(iocb->ki_flags & IOCB_NOWAIT))
return -EOPNOTSUPP;
- if (!inode_trylock(inode)) {
- if (iocb->ki_flags & IOCB_NOWAIT)
+ if (iocb->ki_flags & IOCB_NOWAIT) {
+ if (!inode_trylock(inode))
return -EAGAIN;
+ } else {
inode_lock(inode);
}
}
pos = iocb->ki_pos;
+ count = iov_iter_count(from);
if (iocb->ki_flags & IOCB_NOWAIT) {
/*
* We will allocate space in case nodatacow is not set,
static int start_ordered_ops(struct inode *inode, loff_t start, loff_t end)
{
int ret;
+ struct blk_plug plug;
+ /*
+ * This is only called in fsync, which would do synchronous writes, so
+ * a plug can merge adjacent IOs as much as possible. Esp. in case of
+ * multiple disks using raid profile, a large IO can be split to
+ * several segments of stripe length (currently 64K).
+ */
+ blk_start_plug(&plug);
atomic_inc(&BTRFS_I(inode)->sync_writers);
ret = btrfs_fdatawrite_range(inode, start, end);
atomic_dec(&BTRFS_I(inode)->sync_writers);
+ blk_finish_plug(&plug);
return ret;
}
bool full_sync = false;
u64 len;
+ /*
+ * If the inode needs a full sync, make sure we use a full range to
+ * avoid log tree corruption, due to hole detection racing with ordered
+ * extent completion for adjacent ranges, and assertion failures during
+ * hole detection.
+ */
+ if (test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
+ &BTRFS_I(inode)->runtime_flags)) {
+ start = 0;
+ end = LLONG_MAX;
+ }
+
/*
* The range length can be represented by u64, we have to do the typecasts
* to avoid signed overflow if it's [0, LLONG_MAX] eg. from fsync()
len = (u64)end - (u64)start + 1;
trace_btrfs_sync_file(file, datasync);
+ btrfs_init_log_ctx(&ctx, inode);
+
+ /*
+ * Before we acquired the inode's lock, someone may have dirtied more
+ * pages in the target range. We need to make sure that writeback for
+ * any such pages does not start while we are logging the inode, because
+ * if it does, any of the following might happen when we are not doing a
+ * full inode sync:
+ *
+ * 1) We log an extent after its writeback finishes but before its
+ * checksums are added to the csum tree, leading to -EIO errors
+ * when attempting to read the extent after a log replay.
+ *
+ * 2) We can end up logging an extent before its writeback finishes.
+ * Therefore after the log replay we will have a file extent item
+ * pointing to an unwritten extent (and no data checksums as well).
+ *
+ * So trigger writeback for any eventual new dirty pages and then we
+ * wait for all ordered extents to complete below.
+ */
+ ret = start_ordered_ops(inode, start, end);
+ if (ret) {
+ inode_unlock(inode);
+ goto out;
+ }
+
/*
* We write the dirty pages in the range and wait until they complete
* out of the ->i_mutex. If so, we can flush the dirty pages by
goto out;
inode_lock(inode);
+
+ /*
+ * We take the dio_sem here because the tree log stuff can race with
+ * lockless dio writes and get an extent map logged for an extent we
+ * never waited on. We need it this high up for lockdep reasons.
+ */
+ down_write(&BTRFS_I(inode)->dio_sem);
+
atomic_inc(&root->log_batch);
full_sync = test_bit(BTRFS_INODE_NEEDS_FULL_SYNC,
&BTRFS_I(inode)->runtime_flags);
ret = start_ordered_ops(inode, start, end);
}
if (ret) {
+ up_write(&BTRFS_I(inode)->dio_sem);
inode_unlock(inode);
goto out;
}
* checked called fsync.
*/
ret = filemap_check_wb_err(inode->i_mapping, file->f_wb_err);
+ up_write(&BTRFS_I(inode)->dio_sem);
inode_unlock(inode);
goto out;
}
trans = btrfs_start_transaction(root, 0);
if (IS_ERR(trans)) {
ret = PTR_ERR(trans);
+ up_write(&BTRFS_I(inode)->dio_sem);
inode_unlock(inode);
goto out;
}
trans->sync = true;
- btrfs_init_log_ctx(&ctx, inode);
-
ret = btrfs_log_dentry_safe(trans, root, dentry, start, end, &ctx);
if (ret < 0) {
/* Fallthrough and commit/free transaction. */
* file again, but that will end up using the synchronization
* inside btrfs_sync_log to keep things safe.
*/
+ up_write(&BTRFS_I(inode)->dio_sem);
inode_unlock(inode);
/*
ret = btrfs_end_transaction(trans);
}
out:
+ ASSERT(list_empty(&ctx.list));
err = file_check_and_advance_wb_err(file);
if (!ret)
ret = err;
* for detecting, at fsync time, if the inode isn't yet in the
* log tree or it's there but not up to date.
*/
+ struct timespec now = current_time(inode);
+
+ inode_inc_iversion(inode);
+ inode->i_mtime = now;
+ inode->i_ctime = now;
trans = btrfs_start_transaction(root, 1);
if (IS_ERR(trans)) {
err = PTR_ERR(trans);
ret = btrfs_qgroup_reserve_data(inode, &data_reserved,
cur_offset, last_byte - cur_offset);
if (ret < 0) {
+ cur_offset = last_byte;
free_extent_map(em);
break;
}
/* Let go of our reservation. */
if (ret != 0)
btrfs_free_reserved_data_space(inode, data_reserved,
- alloc_start, alloc_end - cur_offset);
+ cur_offset, alloc_end - cur_offset);
extent_changeset_free(data_reserved);
return ret;
}
projects / mirror_ubuntu-bionic-kernel.git / blobdiff