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| author | Dmitry Monakhov <dmonakhov@openvz.org> | 2012-09-28 23:36:25 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2012-09-28 23:36:25 -0400 |
| commit | 82e54229118785badffb4ef5ba4803df25fe007f (patch) | |
| tree | 270d0afb27dce342b7508cd05bb0db45cdad089d /fs/ext4 | |
| parent | e27f41e1b789e60e7d8cc9c81fd93ca49ef31f13 (diff) | |
| download | linux-82e54229118785badffb4ef5ba4803df25fe007f.tar.bz2 | |
ext4: fix unwritten counter leakage
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
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Dmitry Monakhov <dmonakhov@openvz.org>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/ext4')
| -rw-r--r-- | fs/ext4/extents.c | 21 | ||||
| -rw-r--r-- | 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 a1f56c3e773b..54a94426ef7b 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -3633,6 +3633,8 @@ 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 @@ -3878,6 +3880,7 @@ 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); @@ -4100,13 +4103,8 @@ 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; } @@ -4118,6 +4116,15 @@ 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 de77e31cc119..997002218228 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); |