From 19fd2df5b1167eeb6ae8912cdfe9532e3b2c8bbe Mon Sep 17 00:00:00 2001 From: Liu Bo Date: Thu, 1 Dec 2016 13:01:02 -0800 Subject: [PATCH] Btrfs: fix btrfs_ordered_update_i_size to update disk_i_size properly btrfs_ordered_update_i_size can be called by truncate and endio, but only endio takes ordered_extent which contains the completed IO. while truncating down a file, if there are some in-flight IOs, btrfs_ordered_update_i_size in endio will set disk_i_size to @orig_offset that is zero. If truncating-down fails somehow, we try to recover in memory isize with this zero'd disk_i_size. Fix it by only updating disk_i_size with @orig_offset when btrfs_ordered_update_i_size is not called from endio while truncating down and waiting for in-flight IOs completing their work before recover in-memory size. Besides fixing the above issue, add an assertion for last_size to double check we truncate down to the desired size. Signed-off-by: Liu Bo Signed-off-by: David Sterba --- fs/btrfs/inode.c | 14 ++++++++++++++ fs/btrfs/ordered-data.c | 14 ++++++++++++-- 2 files changed, 26 insertions(+), 2 deletions(-) diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c index 4727b52c00e1..3944346265e8 100644 --- a/fs/btrfs/inode.c +++ b/fs/btrfs/inode.c @@ -4695,6 +4695,13 @@ int btrfs_truncate_inode_items(struct btrfs_trans_handle *trans, btrfs_free_path(path); + if (err == 0) { + /* only inline file may have last_size != new_size */ + if (new_size >= fs_info->sectorsize || + new_size > fs_info->max_inline) + ASSERT(last_size == new_size); + } + if (be_nice && bytes_deleted > SZ_32M) { unsigned long updates = trans->delayed_ref_updates; if (updates) { @@ -5080,6 +5087,13 @@ static int btrfs_setsize(struct inode *inode, struct iattr *attr) if (ret && inode->i_nlink) { int err; + /* To get a stable disk_i_size */ + err = btrfs_wait_ordered_range(inode, 0, (u64)-1); + if (err) { + btrfs_orphan_del(NULL, inode); + return err; + } + /* * failed to truncate, disk_i_size is only adjusted down * as we remove extents, so it should represent the true diff --git a/fs/btrfs/ordered-data.c b/fs/btrfs/ordered-data.c index 7ae350a64c77..2cdf01667bc8 100644 --- a/fs/btrfs/ordered-data.c +++ b/fs/btrfs/ordered-data.c @@ -984,8 +984,18 @@ int btrfs_ordered_update_i_size(struct inode *inode, u64 offset, } disk_i_size = BTRFS_I(inode)->disk_i_size; - /* truncate file */ - if (disk_i_size > i_size) { + /* + * truncate file. + * If ordered is not NULL, then this is called from endio and + * disk_i_size will be updated by either truncate itself or any + * in-flight IOs which are inside the disk_i_size. + * + * Because btrfs_setsize() may set i_size with disk_i_size if truncate + * fails somehow, we need to make sure we have a precise disk_i_size by + * updating it as usual. + * + */ + if (!ordered && disk_i_size > i_size) { BTRFS_I(inode)->disk_i_size = orig_offset; ret = 0; goto out; -- GitLab