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nfsd: Revert "nfsd: special case truncates some more"

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This patch incorrectly attempted nested mnt_want_write, and incorrectly
disabled nfsd's owner override for truncate.  We'll fix those problems
and make another attempt soon, for the moment I think the safest is to
revert.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
This commit is contained in:
J. Bruce Fields 2017-02-09 14:20:42 -05:00
parent d5adbfcd5f
commit 0839ffb83e
1 changed files with 60 additions and 37 deletions
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97
fs/nfsd/vfs.c
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@ -332,6 +332,37 @@ nfsd_sanitize_attrs(struct inode *inode, struct iattr *iap)
}
}
static __be32
nfsd_get_write_access(struct svc_rqst *rqstp, struct svc_fh *fhp,
struct iattr *iap)
{
struct inode *inode = d_inode(fhp->fh_dentry);
int host_err;
if (iap->ia_size < inode->i_size) {
__be32 err;
err = nfsd_permission(rqstp, fhp->fh_export, fhp->fh_dentry,
NFSD_MAY_TRUNC | NFSD_MAY_OWNER_OVERRIDE);
if (err)
return err;
}
host_err = get_write_access(inode);
if (host_err)
goto out_nfserrno;
host_err = locks_verify_truncate(inode, NULL, iap->ia_size);
if (host_err)
goto out_put_write_access;
return 0;
out_put_write_access:
put_write_access(inode);
out_nfserrno:
return nfserrno(host_err);
}
/*
* Set various file attributes. After this call fhp needs an fh_put.
*/
@ -346,6 +377,7 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
__be32 err;
int host_err;
bool get_write_count;
int size_change = 0;
if (iap->ia_valid & (ATTR_ATIME | ATTR_MTIME | ATTR_SIZE))
accmode |= NFSD_MAY_WRITE|NFSD_MAY_OWNER_OVERRIDE;
@ -358,11 +390,11 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
/* Get inode */
err = fh_verify(rqstp, fhp, ftype, accmode);
if (err)
return err;
goto out;
if (get_write_count) {
host_err = fh_want_write(fhp);
if (host_err)
goto out_host_err;
return nfserrno(host_err);
}
dentry = fhp->fh_dentry;
@ -373,59 +405,50 @@ nfsd_setattr(struct svc_rqst *rqstp, struct svc_fh *fhp, struct iattr *iap,
iap->ia_valid &= ~ATTR_MODE;
if (!iap->ia_valid)
return 0;
goto out;
nfsd_sanitize_attrs(inode, iap);
if (check_guard && guardtime != inode->i_ctime.tv_sec)
return nfserr_notsync;
/*
* The size case is special, it changes the file in addition to the
* attributes, and file systems don't expect it to be mixed with
* "random" attribute changes. We thus split out the size change
* into a separate call for vfs_truncate, and do the rest as a
* a separate setattr call.
* attributes.
*/
if (iap->ia_valid & ATTR_SIZE) {
struct path path = {
.mnt = fhp->fh_export->ex_path.mnt,
.dentry = dentry,
};
bool implicit_mtime = false;
err = nfsd_get_write_access(rqstp, fhp, iap);
if (err)
goto out;
size_change = 1;
/*
* vfs_truncate implicity updates the mtime IFF the file size
* actually changes. Avoid the additional seattr call below if
* the only other attribute that the client sends is the mtime.
* RFC5661, Section 18.30.4:
* Changing the size of a file with SETATTR indirectly
* changes the time_modify and change attributes.
*
* (and similar for the older RFCs)
*/
if (iap->ia_size != i_size_read(inode) &&
((iap->ia_valid & ~(ATTR_SIZE | ATTR_MTIME)) == 0))
implicit_mtime = true;
host_err = vfs_truncate(&path, iap->ia_size);
if (host_err)
goto out_host_err;
iap->ia_valid &= ~ATTR_SIZE;
if (implicit_mtime)
iap->ia_valid &= ~ATTR_MTIME;
if (!iap->ia_valid)
goto done;
if (iap->ia_size != i_size_read(inode))
iap->ia_valid |= ATTR_MTIME;
}
iap->ia_valid |= ATTR_CTIME;
if (check_guard && guardtime != inode->i_ctime.tv_sec) {
err = nfserr_notsync;
goto out_put_write_access;
}
fh_lock(fhp);
host_err = notify_change(dentry, iap, NULL);
fh_unlock(fhp);
if (host_err)
goto out_host_err;
err = nfserrno(host_err);
done:
host_err = commit_metadata(fhp);
out_host_err:
return nfserrno(host_err);
out_put_write_access:
if (size_change)
put_write_access(inode);
if (!err)
err = nfserrno(commit_metadata(fhp));
out:
return err;
}
#if defined(CONFIG_NFSD_V4)