ext4_set_io_unwritten_flag() will increment i_unwritten counter, so
once we mark end_io with EXT4_END_IO_UNWRITTEN we have to revert it back
on error path.
- add missed error checks to prevent counter leakage
- ext4_end_io_nolock() will clear EXT4_END_IO_UNWRITTEN flag to signal
that conversion finished.
- add BUG_ON to ext4_free_end_io() to prevent similar leakage in future.
Visible effect of this bug is that unaligned aio_stress may deadlock
Signed-off-by: Dmitry Monakhov <dmonakhov@xxxxxxxxxx>
---
fs/ext4/extents.c | 21 ++++++++++++++-------
fs/ext4/page-io.c | 6 +++++-
2 files changed, 19 insertions(+), 8 deletions(-)
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index e9549f9..69e2d13 100644
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -3545,6 +3545,8 @@ ext4_ext_handle_uninitialized_extents(handle_t *handle, struct inode *inode,
if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
ret = ext4_split_unwritten_extents(handle, inode, map,
path, flags);
+ if (ret <= 0)
+ goto out;
/*
* Flag the inode(non aio case) or end_io struct (aio case)
* that this IO needs to conversion to written when IO is
@@ -3790,6 +3792,7 @@ int ext4_ext_map_blocks(handle_t *handle, struct inode *inode,
struct ext4_allocation_request ar;
ext4_io_end_t *io = ext4_inode_aio(inode);
ext4_lblk_t cluster_offset;
+ int set_unwritten = 0;
ext_debug("blocks %u/%u requested for inode %lu\n",
map->m_lblk, map->m_len, inode->i_ino);
@@ -4012,13 +4015,8 @@ got_allocated_blocks:
* For non asycn direct IO case, flag the inode state
* that we need to perform conversion when IO is done.
*/
- if ((flags & EXT4_GET_BLOCKS_PRE_IO)) {
- if (io)
- ext4_set_io_unwritten_flag(inode, io);
- else
- ext4_set_inode_state(inode,
- EXT4_STATE_DIO_UNWRITTEN);
- }
+ if ((flags & EXT4_GET_BLOCKS_PRE_IO))
+ set_unwritten = 1;
if (ext4_should_dioread_nolock(inode))
map->m_flags |= EXT4_MAP_UNINIT;
}
@@ -4030,6 +4028,15 @@ got_allocated_blocks:
if (!err)
err = ext4_ext_insert_extent(handle, inode, path,
&newex, flags);
+
+ if (!err && set_unwritten) {
+ if (io)
+ ext4_set_io_unwritten_flag(inode, io);
+ else
+ ext4_set_inode_state(inode,
+ EXT4_STATE_DIO_UNWRITTEN);
+ }
+
if (err && free_on_err) {
int fb_flags = flags & EXT4_GET_BLOCKS_DELALLOC_RESERVE ?
EXT4_FREE_BLOCKS_NO_QUOT_UPDATE : 0;
diff --git a/fs/ext4/page-io.c b/fs/ext4/page-io.c
index de77e31..9970022 100644
--- a/fs/ext4/page-io.c
+++ b/fs/ext4/page-io.c
@@ -71,6 +71,8 @@ void ext4_free_io_end(ext4_io_end_t *io)
int i;
BUG_ON(!io);
+ BUG_ON(io->flag & EXT4_IO_END_UNWRITTEN);
+
if (io->page)
put_page(io->page);
for (i = 0; i < io->num_io_pages; i++)
@@ -94,6 +96,8 @@ int ext4_end_io_nolock(ext4_io_end_t *io)
ssize_t size = io->size;
int ret = 0;
+ BUG_ON(!(io->flag & EXT4_IO_END_UNWRITTEN));
+
ext4_debug("ext4_end_io_nolock: io 0x%p from inode %lu,list->next 0x%p,"
"list->prev 0x%p\n",
io, inode->i_ino, io->list.next, io->list.prev);
@@ -106,7 +110,7 @@ int ext4_end_io_nolock(ext4_io_end_t *io)
"(inode %lu, offset %llu, size %zd, error %d)",
inode->i_ino, offset, size, ret);
}
-
+ io->flag &= ~EXT4_IO_END_UNWRITTEN;
if (io->iocb)
aio_complete(io->iocb, io->result, 0);
--
1.7.7.6
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