* mount: guard append gaps over concurrent content merges
* mount: fence a writeback inode when its async publication is abandoned
A drain that gives up on a non-precondition error left the token clear, so a
reopened writeback handle could publish past the stored EOF.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* mount: fence a writeback inode when its async data flush fails
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
* mount: fence the inode when its last handle drops uncommitted content
A synchronous release whose final flush fails destroys the handle's dirty
pages, while under writeback the kernel EOF already counts them.
Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
---------
Co-authored-by: Chris Lu <chrislusf@users.noreply.github.com>
Co-authored-by: Claude Opus 5.5 <noreply@anthropic.com>
