From 574c240441b96a67b5419bf3aeab5f19e369026f Mon Sep 17 00:00:00 2001 From: NeilBrown Date: Tue, 26 Jul 2022 16:45:30 +1000 Subject: [PATCH] NFSD: use explicit lock/unlock for directory ops [ Upstream commit debf16f0c671cb8db154a9ebcd6014cfff683b80 ] When creating or unlinking a name in a directory use explicit inode_lock_nested() instead of fh_lock(), and explicit calls to fh_fill_pre_attrs() and fh_fill_post_attrs(). This is already done for renames, with lock_rename() as the explicit locking. Also move the 'fill' calls closer to the operation that might change the attributes. This way they are avoided on some error paths. For the v2-only code in nfsproc.c, the fill calls are not replaced as they aren't needed. Making the locking explicit will simplify proposed future changes to locking for directories. It also makes it easily visible exactly where pre/post attributes are used - not all callers of fh_lock() actually need the pre/post attributes. Reviewed-by: Jeff Layton Signed-off-by: NeilBrown [ cel: backported to 5.10.y, prior to idmapped mounts ] Signed-off-by: Chuck Lever Signed-off-by: Sasha Levin --- fs/nfsd/nfs3proc.c | 6 ++++-- fs/nfsd/nfs4proc.c | 6 ++++-- fs/nfsd/nfsproc.c | 5 ++--- fs/nfsd/vfs.c | 36 ++++++++++++++++++++++++++---------- 4 files changed, 36 insertions(+), 17 deletions(-) diff --git a/fs/nfsd/nfs3proc.c b/fs/nfsd/nfs3proc.c index d78dbb214..1a52f0b06 100755 --- a/fs/nfsd/nfs3proc.c +++ b/fs/nfsd/nfs3proc.c @@ -260,7 +260,7 @@ nfsd3_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp, if (host_err) return nfserrno(host_err); - fh_lock_nested(fhp, I_MUTEX_PARENT); + inode_lock_nested(inode, I_MUTEX_PARENT); child = lookup_one_len(argp->name, parent, argp->len); if (IS_ERR(child)) { @@ -318,11 +318,13 @@ nfsd3_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp, if (!IS_POSIXACL(inode)) iap->ia_mode &= ~current_umask(); + fh_fill_pre_attrs(fhp); host_err = vfs_create(inode, child, iap->ia_mode, true); if (host_err < 0) { status = nfserrno(host_err); goto out; } + fh_fill_post_attrs(fhp); /* A newly created file already has a file size of zero. */ if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0)) @@ -340,7 +342,7 @@ set_attr: status = nfsd_create_setattr(rqstp, fhp, resfhp, &attrs); out: - fh_unlock(fhp); + inode_unlock(inode); if (child && !IS_ERR(child)) dput(child); fh_drop_write(fhp); diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c index 029f95079..f9b3c17e3 100755 --- a/fs/nfsd/nfs4proc.c +++ b/fs/nfsd/nfs4proc.c @@ -264,7 +264,7 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp, if (is_create_with_attrs(open)) nfsd4_acl_to_attr(NF4REG, open->op_acl, &attrs); - fh_lock_nested(fhp, I_MUTEX_PARENT); + inode_lock_nested(inode, I_MUTEX_PARENT); child = lookup_one_len(open->op_fname, parent, open->op_fnamelen); if (IS_ERR(child)) { @@ -343,10 +343,12 @@ nfsd4_create_file(struct svc_rqst *rqstp, struct svc_fh *fhp, if (!IS_POSIXACL(inode)) iap->ia_mode &= ~current_umask(); + fh_fill_pre_attrs(fhp); status = nfsd4_vfs_create(fhp, child, open); if (status != nfs_ok) goto out; open->op_created = true; + fh_fill_post_attrs(fhp); /* A newly created file already has a file size of zero. */ if ((iap->ia_valid & ATTR_SIZE) && (iap->ia_size == 0)) @@ -368,7 +370,7 @@ set_attr: if (attrs.na_aclerr) open->op_bmval[0] &= ~FATTR4_WORD0_ACL; out: - fh_unlock(fhp); + inode_unlock(inode); nfsd_attrs_free(&attrs); if (child && !IS_ERR(child)) dput(child); diff --git a/fs/nfsd/nfsproc.c b/fs/nfsd/nfsproc.c index 180b84b65..e533550a2 100755 --- a/fs/nfsd/nfsproc.c +++ b/fs/nfsd/nfsproc.c @@ -291,7 +291,7 @@ nfsd_proc_create(struct svc_rqst *rqstp) goto done; } - fh_lock_nested(dirfhp, I_MUTEX_PARENT); + inode_lock_nested(dirfhp->fh_dentry->d_inode, I_MUTEX_PARENT); dchild = lookup_one_len(argp->name, dirfhp->fh_dentry, argp->len); if (IS_ERR(dchild)) { resp->status = nfserrno(PTR_ERR(dchild)); @@ -407,8 +407,7 @@ nfsd_proc_create(struct svc_rqst *rqstp) } out_unlock: - /* We don't really need to unlock, as fh_put does it. */ - fh_unlock(dirfhp); + inode_unlock(dirfhp->fh_dentry->d_inode); fh_drop_write(dirfhp); done: fh_put(dirfhp); diff --git a/fs/nfsd/vfs.c b/fs/nfsd/vfs.c index b41c5076e..8b73d22ee 100755 --- a/fs/nfsd/vfs.c +++ b/fs/nfsd/vfs.c @@ -1391,7 +1391,7 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, if (host_err) return nfserrno(host_err); - fh_lock_nested(fhp, I_MUTEX_PARENT); + inode_lock_nested(dentry->d_inode, I_MUTEX_PARENT); dchild = lookup_one_len(fname, dentry, flen); host_err = PTR_ERR(dchild); if (IS_ERR(dchild)) { @@ -1406,10 +1406,12 @@ nfsd_create(struct svc_rqst *rqstp, struct svc_fh *fhp, dput(dchild); if (err) goto out_unlock; + fh_fill_pre_attrs(fhp); err = nfsd_create_locked(rqstp, fhp, fname, flen, attrs, type, rdev, resfhp); + fh_fill_post_attrs(fhp); out_unlock: - fh_unlock(fhp); + inode_unlock(dentry->d_inode); return err; } @@ -1492,20 +1494,22 @@ nfsd_symlink(struct svc_rqst *rqstp, struct svc_fh *fhp, goto out; } - fh_lock(fhp); dentry = fhp->fh_dentry; + inode_lock_nested(dentry->d_inode, I_MUTEX_PARENT); dnew = lookup_one_len(fname, dentry, flen); if (IS_ERR(dnew)) { err = nfserrno(PTR_ERR(dnew)); - fh_unlock(fhp); + inode_unlock(dentry->d_inode); goto out_drop_write; } + fh_fill_pre_attrs(fhp); host_err = vfs_symlink(d_inode(dentry), dnew, path); err = nfserrno(host_err); cerr = fh_compose(resfhp, fhp->fh_export, dnew, fhp); if (!err) nfsd_create_setattr(rqstp, fhp, resfhp, attrs); - fh_unlock(fhp); + fh_fill_post_attrs(fhp); + inode_unlock(dentry->d_inode); if (!err) err = nfserrno(commit_metadata(fhp)); dput(dnew); @@ -1551,9 +1555,9 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, goto out; } - fh_lock_nested(ffhp, I_MUTEX_PARENT); ddir = ffhp->fh_dentry; dirp = d_inode(ddir); + inode_lock_nested(dirp, I_MUTEX_PARENT); dnew = lookup_one_len(name, ddir, len); if (IS_ERR(dnew)) { @@ -1566,8 +1570,18 @@ nfsd_link(struct svc_rqst *rqstp, struct svc_fh *ffhp, err = nfserr_noent; if (d_really_is_negative(dold)) goto out_dput; +<<<<<<< current host_err = vfs_link(dold, dirp, dnew, NULL); fh_unlock(ffhp); +||||||| constructed merge base + host_err = vfs_link(dold, &init_user_ns, dirp, dnew, NULL); + fh_unlock(ffhp); +======= + fh_fill_pre_attrs(ffhp); + host_err = vfs_link(dold, &init_user_ns, dirp, dnew, NULL); + fh_fill_post_attrs(ffhp); + inode_unlock(dirp); +>>>>>>> patched if (!host_err) { err = nfserrno(commit_metadata(ffhp)); if (!err) @@ -1587,7 +1601,7 @@ out: out_dput: dput(dnew); out_unlock: - fh_unlock(ffhp); + inode_unlock(dirp); goto out_drop_write; } @@ -1760,9 +1774,9 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, if (host_err) goto out_nfserr; - fh_lock_nested(fhp, I_MUTEX_PARENT); dentry = fhp->fh_dentry; dirp = d_inode(dentry); + inode_lock_nested(dirp, I_MUTEX_PARENT); rdentry = lookup_one_len(fname, dentry, flen); host_err = PTR_ERR(rdentry); @@ -1780,6 +1794,7 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, if (!type) type = d_inode(rdentry)->i_mode & S_IFMT; + fh_fill_pre_attrs(fhp); if (type != S_IFDIR) { if (rdentry->d_sb->s_export_op->flags & EXPORT_OP_CLOSE_BEFORE_UNLINK) nfsd_close_cached_files(rdentry); @@ -1787,8 +1802,9 @@ nfsd_unlink(struct svc_rqst *rqstp, struct svc_fh *fhp, int type, } else { host_err = vfs_rmdir(dirp, rdentry); } + fh_fill_post_attrs(fhp); - fh_unlock(fhp); + inode_unlock(dirp); if (!host_err) host_err = commit_metadata(fhp); dput(rdentry); @@ -1811,7 +1827,7 @@ out_nfserr: out: return err; out_unlock: - fh_unlock(fhp); + inode_unlock(dirp); goto out_drop_write; }