diff options
| -rw-r--r-- | Documentation/filesystems/nfs/exporting.rst | 13 | ||||
| -rw-r--r-- | fs/nfs/export.c | 2 | ||||
| -rw-r--r-- | fs/nfsd/vfs.c | 16 | ||||
| -rw-r--r-- | include/linux/exportfs.h | 5 |
4 files changed, 26 insertions, 10 deletions
diff --git a/Documentation/filesystems/nfs/exporting.rst b/Documentation/filesystems/nfs/exporting.rst index 960be64446cb..0e98edd353b5 100644 --- a/Documentation/filesystems/nfs/exporting.rst +++ b/Documentation/filesystems/nfs/exporting.rst @@ -202,3 +202,16 @@ following flags are defined: This flag exempts the filesystem from subtree checking and causes exportfs to get back an error if it tries to enable subtree checking on it. + + EXPORT_OP_CLOSE_BEFORE_UNLINK - always close cached files before unlinking + On some exportable filesystems (such as NFS) unlinking a file that + is still open can cause a fair bit of extra work. For instance, + the NFS client will do a "sillyrename" to ensure that the file + sticks around while it's still open. When reexporting, that open + file is held by nfsd so we usually end up doing a sillyrename, and + then immediately deleting the sillyrenamed file just afterward when + the link count actually goes to zero. Sometimes this delete can race + with other operations (for instance an rmdir of the parent directory). + This flag causes nfsd to close any open files for this inode _before_ + calling into the vfs to do an unlink or a rename that would replace + an existing file. diff --git a/fs/nfs/export.c b/fs/nfs/export.c index b9ba306bf912..5428713af5fe 100644 --- a/fs/nfs/export.c +++ b/fs/nfs/export.c @@ -171,5 +171,5 @@ const struct export_operations nfs_export_ops = { .encode_fh = nfs_encode_fh, .fh_to_dentry = nfs_fh_to_dentry, .get_parent = nfs_get_parent, - .flags = EXPORT_OP_NOWCC|EXPORT_OP_NOSUBTREECHK, + .flags = EXPORT_OP_NOWCC|EXPORT_OP_NOSUBTREECHK|EXPORT_OP_CLOSE_BEFORE_UNLINK, }; diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index 1ecaceebee13..79cba942087e 100644 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1724,7 +1724,7 @@ nfsd_rename(struct svc_rqst *rqstp, struct svc_fh *ffhp, char *fname, int flen, struct inode *fdir, *tdir; __be32 err; int host_err; - bool has_cached = false; + bool close_cached = false; err = fh_verify(rqstp, ffhp, S_IFDIR, NFSD_MAY_REMOVE); if (err) @@ -1783,8 +1783,9 @@ retry: if (ffhp->fh_export->ex_path.dentry != tfhp->fh_export->ex_path.dentry) goto out_dput_new; - if (nfsd_has_cached_files(ndentry)) { - has_cached = true; + if ((ndentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK) && + nfsd_has_cached_files(ndentry)) { + close_cached = true; goto out_dput_old; } else { host_err = vfs_rename(fdir, odentry, tdir, ndentry, NULL, 0); @@ -1805,7 +1806,7 @@ retry: * as that would do the wrong thing if the two directories * were the same, so again we do it by hand. */ - if (!has_cached) { + if (!close_cached) { fill_post_wcc(ffhp); fill_post_wcc(tfhp); } @@ -1819,8 +1820,8 @@ retry: * shouldn't be done with locks held however, so we delay it until this * point and then reattempt the whole shebang. */ - if (has_cached) { - has_cached = false; + if (close_cached) { + close_cached = false; nfsd_close_cached_files(ndentry); dput(ndentry); goto retry; @@ -1872,7 +1873,8 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, type = d_inode(rdentry)->i_mode & S_IFMT; if (type != S_IFDIR) { - nfsd_close_cached_files(rdentry); + if (rdentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK) + nfsd_close_cached_files(rdentry); host_err = vfs_unlink(dirp, rdentry, NULL); } else { host_err = vfs_rmdir(dirp, rdentry); diff --git a/include/linux/exportfs.h b/include/linux/exportfs.h index 2fcbab0f6b61..d829403ffd3b 100644 --- a/include/linux/exportfs.h +++ b/include/linux/exportfs.h @@ -213,8 +213,9 @@ struct export_operations { bool write, u32 *device_generation); int (*commit_blocks)(struct inode *inode, struct iomap *iomaps, int nr_iomaps, struct iattr *iattr); -#define EXPORT_OP_NOWCC (0x1) /* Don't collect wcc data for NFSv3 replies */ -#define EXPORT_OP_NOSUBTREECHK (0x2) /* Subtree checking is not supported! */ +#define EXPORT_OP_NOWCC (0x1) /* don't collect v3 wcc data */ +#define EXPORT_OP_NOSUBTREECHK (0x2) /* no subtree checking */ +#define EXPORT_OP_CLOSE_BEFORE_UNLINK (0x4) /* close files before unlink */ unsigned long flags; }; |