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由 Jan Kara 提交于
Currently, I_SYNC can never be set when evict_inode() (and thus end_writeback()) is called because flusher thread holds inode reference while inode is under writeback. As a result inode_sync_wait() in those places currently does nothing. However that is going to change and unveils problems with calling inode_sync_wait() from end_writeback(). Several filesystems call end_writeback() after they have deleted the inode (btrfs, gfs2, ...) and other filesystems (ext3, ext4, reiserfs, ...) can deadlock when waiting for I_SYNC because they call end_writeback() from within a transaction. To avoid these issues, we move inode_sync_wait() into evict_inode() before calling ->evict_inode(). That way we preserve the current property that ->evict_inode() and writeback never run in parallel and all filesystems are safe. Signed-off-by: NJan Kara <jack@suse.cz> Signed-off-by: NFengguang Wu <fengguang.wu@intel.com>
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