@@ -280,7 +280,9 @@ nfsd_file_free(struct nfsd_file *nf)
nfsd_file_mark_put(nf->nf_mark);
if (nf->nf_file) {
nfsd_file_check_write_error(nf);
+ get_file(nf->nf_file);
filp_close(nf->nf_file, NULL);
+ __fput_sync(nf->nf_file);
}
/*
@@ -658,7 +660,6 @@ nfsd_file_close_inode_sync(struct inode *inode)
list_del_init(&nf->nf_lru);
nfsd_file_free(nf);
}
- flush_delayed_fput();
}
static int
@@ -1884,10 +1884,10 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen,
fh_drop_write(ffhp);
/*
- * If the target dentry has cached open files, then we need to try to
- * close them prior to doing the rename. Flushing delayed fput
- * shouldn't be done with locks held however, so we delay it until this
- * point and then reattempt the whole shebang.
+ * If the target dentry has cached open files, then we need to
+ * try to close them prior to doing the rename. Final fput
+ * shouldn't be done with locks held however, so we delay it
+ * until this point and then reattempt the whole shebang.
*/
if (close_cached) {
close_cached = false;
@@ -2141,7 +2141,7 @@ nfsd_readdir(struct svc_rqst *rqstp, struct svc_fh *fhp, loff_t *offsetp,
if (err == nfserr_eof || err == nfserr_toosmall)
err = nfs_ok; /* can still be found in ->err */
out_close:
- fput(file);
+ __fput_sync(file);
out:
return err;
}
Calling fput() directly or though filp_close() from a kernel thread like nfsd causes the final __fput() (if necessary) to be called from a workqueue. This means that nfsd is not forced to wait for any work to complete. If the ->release or ->destroy_inode function is slow for any reason, this can result in nfsd closing files more quickly than the workqueue can complete the close and the queue of pending closes can grow without bounces (30 million has been seen at one customer site, though this was in part due to a slowness in xfs which has since been fixed). nfsd does not need this. It is quite appropriate and safe for nfsd to do its own close work. There is no reason that close should ever wait for nfsd, so no deadlock can occur. It should be safe and sensible to change all fput() calls to __fput_sync(). However in the interests of caution this patch only changes two - the two that can be most directly affected by client behaviour and could occur at high frequency. - the fput() implicitly in flip_close() is changed to __fput_sync() by calling get_file() first to ensure filp_close() doesn't do the final fput() itself. If is where files opened for IO are closed. - the fput() in nfsd_read() is also changed. This is where directories opened for readdir are closed. This ensure that minimal fput work is queued to the workqueue. This removes the need for the flush_delayed_fput() call in nfsd_file_close_inode_sync() Signed-off-by: NeilBrown <neilb@suse.de> --- fs/nfsd/filecache.c | 3 ++- fs/nfsd/vfs.c | 10 +++++----- 2 files changed, 7 insertions(+), 6 deletions(-)