3f706c8c92
I hit ENOSPC error when creating new file in a newly created ext4
with ea_inode feature enabled, if selinux is enabled and ext4 is
mounted without any selinux context. e.g.
mkfs -t ext4 -O ea_inode -F /dev/sda5
mount /dev/sda5 /mnt/ext4
touch /mnt/ext4/testfile # got ENOSPC here
It turns out that we run out of journal credits in
ext4_xattr_set_handle() when creating new selinux label for the
newly created inode.
This is because that in __ext4_new_inode() we use
__ext4_xattr_set_credits() to calculate the reserved credits for new
xattr, with the 'is_create' argument being true, which implies less
credits in the ea_inode case. But we calculate the required credits
in ext4_xattr_set_handle() with 'is_create' being false, which means
we need more credits if ea_inode feature is enabled. So we don't
have enough credits and error out with ENOSPC.
Fix it by simply calling ext4_xattr_set_handle() with XATTR_CREATE
flag in ext4_initxattrs(), so we end up with requiring less credits
than reserved. The semantic of XATTR_CREATE is "Perform a pure
create, which fails if the named attribute exists already." (from
setxattr(2)), which is fine in this case, because we only call
ext4_initxattrs() on newly created inode.
Fixes: af65207c76 ("ext4: fix __ext4_new_inode() journal credits calculation")
Cc: Tahsin Erdogan <tahsin@google.com>
Signed-off-by: Eryu Guan <guaneryu@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
66 lines
1.6 KiB
C
66 lines
1.6 KiB
C
// SPDX-License-Identifier: GPL-2.0
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/*
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* linux/fs/ext4/xattr_security.c
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* Handler for storing security labels as extended attributes.
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*/
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#include <linux/string.h>
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#include <linux/fs.h>
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#include <linux/security.h>
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#include <linux/slab.h>
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#include "ext4_jbd2.h"
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#include "ext4.h"
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#include "xattr.h"
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static int
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ext4_xattr_security_get(const struct xattr_handler *handler,
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struct dentry *unused, struct inode *inode,
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const char *name, void *buffer, size_t size)
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{
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return ext4_xattr_get(inode, EXT4_XATTR_INDEX_SECURITY,
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name, buffer, size);
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}
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static int
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ext4_xattr_security_set(const struct xattr_handler *handler,
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struct dentry *unused, struct inode *inode,
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const char *name, const void *value,
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size_t size, int flags)
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{
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return ext4_xattr_set(inode, EXT4_XATTR_INDEX_SECURITY,
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name, value, size, flags);
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}
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static int
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ext4_initxattrs(struct inode *inode, const struct xattr *xattr_array,
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void *fs_info)
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{
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const struct xattr *xattr;
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handle_t *handle = fs_info;
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int err = 0;
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for (xattr = xattr_array; xattr->name != NULL; xattr++) {
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err = ext4_xattr_set_handle(handle, inode,
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EXT4_XATTR_INDEX_SECURITY,
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xattr->name, xattr->value,
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xattr->value_len, XATTR_CREATE);
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if (err < 0)
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break;
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}
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return err;
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}
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int
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ext4_init_security(handle_t *handle, struct inode *inode, struct inode *dir,
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const struct qstr *qstr)
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{
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return security_inode_init_security(inode, dir, qstr,
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&ext4_initxattrs, handle);
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}
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const struct xattr_handler ext4_xattr_security_handler = {
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.prefix = XATTR_SECURITY_PREFIX,
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.get = ext4_xattr_security_get,
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.set = ext4_xattr_security_set,
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};
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