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| author |   Al Viro <viro@zeniv.linux.org.uk> | 2019-10-31 01:21:58 -0400 |
|---|---|---|
| committer | Al Viro <viro@zeniv.linux.org.uk> | 2019-11-15 13:49:04 -0500 |
| commit | 6c2d4798a8d16cf4f3a28c3cd4af4f1dcbbb4d04 (patch) | |
| tree | 2b14c83985da30129911f7ad455e4cc587690e58 /fs/nfsd | |
| parent | fs/namei.c: pull positivity check into follow_managed() (diff) | |
| download | linux-dev-6c2d4798a8d16cf4f3a28c3cd4af4f1dcbbb4d04.tar.xz linux-dev-6c2d4798a8d16cf4f3a28c3cd4af4f1dcbbb4d04.zip | |
new helper: lookup_positive_unlocked()
Most of the callers of lookup_one_len_unlocked() treat negatives are
ERR_PTR(-ENOENT). Provide a helper that would do just that. Note
that a pinned positive dentry remains positive - it's ->d_inode is
stable, etc.; a pinned _negative_ dentry can become positive at any
point as long as you are not holding its parent at least shared.
So using lookup_one_len_unlocked() needs to be careful;
lookup_positive_unlocked() is safer and that's what the callers
end up open-coding anyway.
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Diffstat (limited to 'fs/nfsd')
| -rw-r--r-- | fs/nfsd/nfs3xdr.c | 4 | ||||
| -rw-r--r-- | fs/nfsd/nfs4xdr.c | 11 |
2 files changed, 2 insertions, 13 deletions
diff --git a/fs/nfsd/nfs3xdr.c b/fs/nfsd/nfs3xdr.c index 86e5658651f1..195ab7a0fc89 100644 --- a/fs/nfsd/nfs3xdr.c +++ b/fs/nfsd/nfs3xdr.c @@ -863,13 +863,11 @@ compose_entry_fh(struct nfsd3_readdirres *cd, struct svc_fh *fhp, } else dchild = dget(dparent); } else - dchild = lookup_one_len_unlocked(name, dparent, namlen); + dchild = lookup_positive_unlocked(name, dparent, namlen); if (IS_ERR(dchild)) return rv; if (d_mountpoint(dchild)) goto out; - if (d_really_is_negative(dchild)) - goto out; if (dchild->d_inode->i_ino != ino) goto out; rv = fh_compose(fhp, exp, dchild, &cd->fh); diff --git a/fs/nfsd/nfs4xdr.c b/fs/nfsd/nfs4xdr.c index 533d0fc3c96b..b09237431ae2 100644 --- a/fs/nfsd/nfs4xdr.c +++ b/fs/nfsd/nfs4xdr.c @@ -2991,18 +2991,9 @@ nfsd4_encode_dirent_fattr(struct xdr_stream *xdr, struct nfsd4_readdir *cd, __be32 nfserr; int ignore_crossmnt = 0; - dentry = lookup_one_len_unlocked(name, cd->rd_fhp->fh_dentry, namlen); + dentry = lookup_positive_unlocked(name, cd->rd_fhp->fh_dentry, namlen); if (IS_ERR(dentry)) return nfserrno(PTR_ERR(dentry)); - if (d_really_is_negative(dentry)) { - /* - * we're not holding the i_mutex here, so there's - * a window where this directory entry could have gone - * away. - */ - dput(dentry); - return nfserr_noent; - } exp_get(exp); /* |