Files
seaweedfs/weed/mount/weedfs_forget.go
T
10f8b2d5b1 mount: guard peer-truncate gaps, stale append EOF, and terminal writeback refusal (#12630)
* 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>
2026-11-14 01:13:37 -08:00

82 lines
2.9 KiB
Go

package mount
import (
"github.com/seaweedfs/seaweedfs/weed/util"
)
// Forget is called when the kernel discards entries from its
// dentry cache. This happens on unmount, and when the kernel
// is short on memory. Since it is not guaranteed to occur at
// any moment, and since there is no return value, Forget
// should not do I/O, as there is no channel to report back
// I/O errors.
// from https://github.com/libfuse/libfuse/blob/master/include/fuse_lowlevel.h
/**
* Forget about an inode
*
* This function is called when the kernel removes an inode
* from its internal caches.
*
* The inode's lookup count increases by one for every call to
* fuse_reply_entry and fuse_reply_create. The nlookup parameter
* indicates by how much the lookup count should be decreased.
*
* Inodes with a non-zero lookup count may receive request from
* the kernel even after calls to unlink, rmdir or (when
* overwriting an existing file) rename. Filesystems must handle
* such requests properly and it is recommended to defer removal
* of the inode until the lookup count reaches zero. Calls to
* unlink, rmdir or rename will be followed closely by forget
* unless the file or directory is open, in which case the
* kernel issues forget only after the release or releasedir
* calls.
*
* Note that if a file system will be exported over NFS the
* inodes lifetime must extend even beyond forget. See the
* generation field in struct fuse_entry_param above.
*
* On unmount the lookup count for all inodes implicitly drops
* to zero. It is not guaranteed that the file system will
* receive corresponding forget messages for the affected
* inodes.
*
* Valid replies:
* fuse_reply_none
*
* @param req request handle
* @param ino the inode number
* @param nlookup the number of lookups to forget
*/
/*
https://libfuse.github.io/doxygen/include_2fuse__lowlevel_8h.html
int fuse_reply_entry ( fuse_req_t req,
const struct fuse_entry_param * e
)
Reply with a directory entry
Possible requests: lookup, mknod, mkdir, symlink, link
Side effects: increments the lookup count on success
*/
func (wfs *WFS) Forget(nodeid, nlookup uint64) {
// Forget only decrements the kernel's inode lookup count. File handle
// lifecycle is driven independently by FUSE Open/Release — touching the
// fhMap here would couple two unrelated refcounts and could tear down a
// still-live handle if Forget ever raced ahead of Release.
wfs.inodeToPath.Forget(nodeid, nlookup,
// Runs at the release, under the table's lock, so a lookup that
// rebuilds the same inode number afterwards keeps the times it sets.
func(inode uint64) {
wfs.forgetInMemoryTimes(inode)
wfs.writebackContentErrors.Delete(inode)
},
func(dir util.FullPath) {
// Runs after Forget releases its lock; a concurrent lookup+rebuild can
// re-cache the directory in that window, so purge through the apply loop
// rather than wiping the store directly.
wfs.purgeDirectoryCache(dir)
})
}