431f19744d
Modify quota_send_warning to take struct kqid instead a type and identifier pair. When sending netlink broadcasts always convert uids and quota identifiers into the intial user namespace. There is as yet no way to send a netlink broadcast message with different contents to receivers in different namespaces, so for the time being just map all of the identifiers into the initial user namespace which preserves the current behavior. Change the callers of quota_send_warning in gfs2, xfs and dquot to generate a struct kqid to pass to quota send warning. When all of the user namespaces convesions are complete a struct kqid values will be availbe without need for conversion, but a conversion is needed now to avoid needing to convert everything at once. Cc: Ben Myers <bpm@sgi.com> Cc: Alex Elder <elder@kernel.org> Cc: Dave Chinner <david@fromorbit.com> Cc: Jan Kara <jack@suse.cz> Cc: Steven Whitehouse <swhiteho@redhat.com> Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
98 lines
2.7 KiB
C
98 lines
2.7 KiB
C
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#include <linux/cred.h>
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#include <linux/init.h>
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#include <linux/module.h>
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#include <linux/kernel.h>
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#include <linux/quotaops.h>
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#include <linux/sched.h>
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#include <linux/slab.h>
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#include <net/netlink.h>
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#include <net/genetlink.h>
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/* Netlink family structure for quota */
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static struct genl_family quota_genl_family = {
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.id = GENL_ID_GENERATE,
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.hdrsize = 0,
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.name = "VFS_DQUOT",
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.version = 1,
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.maxattr = QUOTA_NL_A_MAX,
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};
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/**
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* quota_send_warning - Send warning to userspace about exceeded quota
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* @type: The quota type: USRQQUOTA, GRPQUOTA,...
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* @id: The user or group id of the quota that was exceeded
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* @dev: The device on which the fs is mounted (sb->s_dev)
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* @warntype: The type of the warning: QUOTA_NL_...
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*
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* This can be used by filesystems (including those which don't use
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* dquot) to send a message to userspace relating to quota limits.
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*
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*/
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void quota_send_warning(struct kqid qid, dev_t dev,
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const char warntype)
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{
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static atomic_t seq;
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struct sk_buff *skb;
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void *msg_head;
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int ret;
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int msg_size = 4 * nla_total_size(sizeof(u32)) +
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2 * nla_total_size(sizeof(u64));
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/* We have to allocate using GFP_NOFS as we are called from a
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* filesystem performing write and thus further recursion into
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* the fs to free some data could cause deadlocks. */
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skb = genlmsg_new(msg_size, GFP_NOFS);
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if (!skb) {
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printk(KERN_ERR
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"VFS: Not enough memory to send quota warning.\n");
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return;
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}
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msg_head = genlmsg_put(skb, 0, atomic_add_return(1, &seq),
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"a_genl_family, 0, QUOTA_NL_C_WARNING);
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if (!msg_head) {
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printk(KERN_ERR
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"VFS: Cannot store netlink header in quota warning.\n");
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goto err_out;
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}
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ret = nla_put_u32(skb, QUOTA_NL_A_QTYPE, qid.type);
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if (ret)
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goto attr_err_out;
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ret = nla_put_u64(skb, QUOTA_NL_A_EXCESS_ID,
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from_kqid_munged(&init_user_ns, qid));
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if (ret)
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goto attr_err_out;
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ret = nla_put_u32(skb, QUOTA_NL_A_WARNING, warntype);
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if (ret)
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goto attr_err_out;
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ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MAJOR, MAJOR(dev));
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if (ret)
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goto attr_err_out;
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ret = nla_put_u32(skb, QUOTA_NL_A_DEV_MINOR, MINOR(dev));
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if (ret)
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goto attr_err_out;
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ret = nla_put_u64(skb, QUOTA_NL_A_CAUSED_ID,
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from_kuid_munged(&init_user_ns, current_uid()));
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if (ret)
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goto attr_err_out;
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genlmsg_end(skb, msg_head);
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genlmsg_multicast(skb, 0, quota_genl_family.id, GFP_NOFS);
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return;
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attr_err_out:
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printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
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err_out:
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kfree_skb(skb);
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}
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EXPORT_SYMBOL(quota_send_warning);
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static int __init quota_init(void)
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{
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if (genl_register_family("a_genl_family) != 0)
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printk(KERN_ERR
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"VFS: Failed to create quota netlink interface.\n");
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return 0;
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};
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module_init(quota_init);
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