diff options
| -rw-r--r-- | fs/nfsd/filecache.c | 3 | ||||
| -rw-r--r-- | fs/nfsd/vfs.c | 42 | ||||
| -rw-r--r-- | fs/nfsd/vfs.h | 2 |
3 files changed, 40 insertions, 7 deletions
diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c index f8b100bca6e4..8d9f7b07e35b 100644 --- a/fs/nfsd/filecache.c +++ b/fs/nfsd/filecache.c @@ -280,7 +280,7 @@ nfsd_file_free(struct nfsd_file *nf) nfsd_file_mark_put(nf->nf_mark); if (nf->nf_file) { nfsd_file_check_write_error(nf); - filp_close(nf->nf_file, NULL); + nfsd_filp_close(nf->nf_file); } /* @@ -658,7 +658,6 @@ nfsd_file_close_inode_sync(struct inode *inode) list_del_init(&nf->nf_lru); nfsd_file_free(nf); } - flush_delayed_fput(); } static int diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index b7c7a9273ea0..f57749cd6f0b 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1906,10 +1906,10 @@ out_unlock: 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; @@ -2177,11 +2177,43 @@ 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); + nfsd_filp_close(file); out: return err; } +/** + * nfsd_filp_close: close a file synchronously + * @fp: the file to close + * + * nfsd_filp_close() is similar in behaviour to filp_close(). + * The difference is that if this is the final close on the + * file, the that finalisation happens immediately, rather then + * being handed over to a work_queue, as it the case for + * filp_close(). + * When a user-space process closes a file (even when using + * filp_close() the finalisation happens before returning to + * userspace, so it is effectively synchronous. When a kernel thread + * uses file_close(), on the other hand, the handling is completely + * asynchronous. This means that any cost imposed by that finalisation + * is not imposed on the nfsd thread, and nfsd could potentually + * close files more quickly than the work queue finalises the close, + * which would lead to unbounded growth in the queue. + * + * In some contexts is it not safe to synchronously wait for + * close finalisation (see comment for __fput_sync()), but nfsd + * does not match those contexts. In partcilarly it does not, at the + * time that this function is called, hold and locks and no finalisation + * of any file, socket, or device driver would have any cause to wait + * for nfsd to make progress. + */ +void nfsd_filp_close(struct file *fp) +{ + get_file(fp); + filp_close(fp, NULL); + __fput_sync(fp); +} + /* * Get file system stats * N.B. After this call fhp needs an fh_put diff --git a/fs/nfsd/vfs.h b/fs/nfsd/vfs.h index 702fbc4483bf..1efa4e8dfb03 100644 --- a/fs/nfsd/vfs.h +++ b/fs/nfsd/vfs.h @@ -148,6 +148,8 @@ __be32 nfsd_statfs(struct svc_rqst *, struct svc_fh *, __be32 nfsd_permission(struct svc_rqst *, struct svc_export *, struct dentry *, int); +void nfsd_filp_close(struct file *fp); + static inline int fh_want_write(struct svc_fh *fh) { int ret; |