I have a question about file access in Linux that I cannot sum it up completely.
Consider that I have a home directory that I backup it using rsync triggered via cron. My home directory is on an EXT4 file system and I'm logged in during the rsync run.
My question is what happens if a file is modified during mid-backup (while rsync is reading it). AFAIK EXT fs family doesn't have any measures against it and that will corrupt (or render it meaningless) the backup of the file I just took.
Is my theory correct or am I missing a small locking mechanism which guarantees sound backups.