nfsd: clarify readdir/mountpoint-crossing code

[safe/jmp/linux-2.6] / fs / dquot.c

diff --git a/fs/dquot.c b/fs/dquot.c
index 2809768..41b9dbd 100644 (file)
--- a/fs/dquot.c
+++ b/fs/dquot.c
@@ -696,9 +696,8 @@ static int dqinit_needed(struct inode *inode, int type)
 /* This routine is guarded by dqonoff_mutex mutex */
 static void add_dquot_ref(struct super_block *sb, int type)
 {
-       struct inode *inode;
+       struct inode *inode, *old_inode = NULL;
 
-restart:
        spin_lock(&inode_lock);
        list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
                if (!atomic_read(&inode->i_writecount))
@@ -711,12 +710,18 @@ restart:
                __iget(inode);
                spin_unlock(&inode_lock);
 
+               iput(old_inode);
                sb->dq_op->initialize(inode, type);
-               iput(inode);
-               /* As we may have blocked we had better restart... */
-               goto restart;
+               /* We hold a reference to 'inode' so it couldn't have been
+                * removed from s_inodes list while we dropped the inode_lock.
+                * We cannot iput the inode now as we can be holding the last
+                * reference and we cannot iput it under inode_lock. So we
+                * keep the reference and iput it later. */
+               old_inode = inode;
+               spin_lock(&inode_lock);
        }
        spin_unlock(&inode_lock);
+       iput(old_inode);
 }
 
 /* Return 0 if dqput() won't block (note that 1 doesn't necessarily mean blocking) */
@@ -827,6 +832,18 @@ static inline void dquot_decr_space(struct dquot *dquot, qsize_t number)
        clear_bit(DQ_BLKS_B, &dquot->dq_flags);
 }
 
+static int warning_issued(struct dquot *dquot, const int warntype)
+{
+       int flag = (warntype == QUOTA_NL_BHARDWARN ||
+               warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
+               ((warntype == QUOTA_NL_IHARDWARN ||
+               warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
+
+       if (!flag)
+               return 0;
+       return test_and_set_bit(flag, &dquot->dq_flags);
+}
+
 #ifdef CONFIG_PRINT_QUOTA_WARNING
 static int flag_print_warnings = 1;
 
@@ -845,16 +862,12 @@ static inline int need_print_warning(struct dquot *dquot)
 }
 
 /* Print warning to user which exceeded quota */
-static void print_warning(struct dquot *dquot, const char warntype)
+static void print_warning(struct dquot *dquot, const int warntype)
 {
        char *msg = NULL;
        struct tty_struct *tty;
-       int flag = (warntype == QUOTA_NL_BHARDWARN ||
-               warntype == QUOTA_NL_BSOFTLONGWARN) ? DQ_BLKS_B :
-               ((warntype == QUOTA_NL_IHARDWARN ||
-               warntype == QUOTA_NL_ISOFTLONGWARN) ? DQ_INODES_B : 0);
 
-       if (!need_print_warning(dquot) || (flag && test_and_set_bit(flag, &dquot->dq_flags)))
+       if (!need_print_warning(dquot))
                return;
 
        mutex_lock(&tty_mutex);
@@ -895,9 +908,6 @@ out_lock:
 
 #ifdef CONFIG_QUOTA_NETLINK_INTERFACE
 
-/* Size of quota netlink message - actually an upperbound for buffer size */
-#define QUOTA_NL_MSG_SIZE 32
-
 /* Netlink family structure for quota */
 static struct genl_family quota_genl_family = {
        .id = GENL_ID_GENERATE,
@@ -914,11 +924,13 @@ static void send_warning(const struct dquot *dquot, const char warntype)
        struct sk_buff *skb;
        void *msg_head;
        int ret;
+       int msg_size = 4 * nla_total_size(sizeof(u32)) +
+                      2 * nla_total_size(sizeof(u64));
 
        /* We have to allocate using GFP_NOFS as we are called from a
         * filesystem performing write and thus further recursion into
         * the fs to free some data could cause deadlocks. */
-       skb = genlmsg_new(QUOTA_NL_MSG_SIZE, GFP_NOFS);
+       skb = genlmsg_new(msg_size, GFP_NOFS);
        if (!skb) {
                printk(KERN_ERR
                  "VFS: Not enough memory to send quota warning.\n");
@@ -959,18 +971,19 @@ static void send_warning(const struct dquot *dquot, const char warntype)
                        "VFS: Failed to send notification message: %d\n", ret);
        return;
 attr_err_out:
-       printk(KERN_ERR "VFS: Failed to compose quota message: %d\n", ret);
+       printk(KERN_ERR "VFS: Not enough space to compose quota message!\n");
 err_out:
        kfree_skb(skb);
 }
 #endif
 
-static inline void flush_warnings(struct dquot **dquots, char *warntype)
+static inline void flush_warnings(struct dquot * const *dquots, char *warntype)
 {
        int i;
 
        for (i = 0; i < MAXQUOTAS; i++)
-               if (dquots[i] != NODQUOT && warntype[i] != QUOTA_NL_NOWARN) {
+               if (dquots[i] != NODQUOT && warntype[i] != QUOTA_NL_NOWARN &&
+                   !warning_issued(dquots[i], warntype[i])) {
 #ifdef CONFIG_PRINT_QUOTA_WARNING
                        print_warning(dquots[i], warntype[i]);
 #endif
@@ -1216,7 +1229,7 @@ warn_put_all:
                for (cnt = 0; cnt < MAXQUOTAS; cnt++)
                        if (inode->i_dquot[cnt])
                                mark_dquot_dirty(inode->i_dquot[cnt]);
-       flush_warnings((struct dquot **)inode->i_dquot, warntype);
+       flush_warnings(inode->i_dquot, warntype);
        up_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
        return ret;
 }
@@ -1509,8 +1522,8 @@ int vfs_quota_off(struct super_block *sb, int type)
                                truncate_inode_pages(&toputinode[cnt]->i_data, 0);
                                mutex_unlock(&toputinode[cnt]->i_mutex);
                                mark_inode_dirty(toputinode[cnt]);
-                               iput(toputinode[cnt]);
                        }
+                       iput(toputinode[cnt]);
                        mutex_unlock(&dqopt->dqonoff_mutex);
                }
        if (sb->s_bdev)
@@ -1620,16 +1633,17 @@ int vfs_quota_on(struct super_block *sb, int type, int format_id, char *path)
        error = path_lookup(path, LOOKUP_FOLLOW, &nd);
        if (error < 0)
                return error;
-       error = security_quota_on(nd.dentry);
+       error = security_quota_on(nd.path.dentry);
        if (error)
                goto out_path;
        /* Quota file not on the same filesystem? */
-       if (nd.mnt->mnt_sb != sb)
+       if (nd.path.mnt->mnt_sb != sb)
                error = -EXDEV;
        else
-               error = vfs_quota_on_inode(nd.dentry->d_inode, type, format_id);
+               error = vfs_quota_on_inode(nd.path.dentry->d_inode, type,
+                                          format_id);
 out_path:
-       path_release(&nd);
+       path_put(&nd.path);
        return error;
 }