ext4: Handle -EDQUOT error on write
Aneesh Kumar K.V [Fri, 22 Jan 2010 22:06:20 +0000 (17:06 -0500)]
We need to release the journal before we do a write_inode.  Otherwise
we could deadlock.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>

fs/ext4/inode.c

index c818972..60b3a19 100644 (file)
@@ -1835,24 +1835,12 @@ repeat:
         * later. Real quota accounting is done at pages writeout
         * time.
         */
-       if (vfs_dq_reserve_block(inode, md_needed + 1)) {
-               /* 
-                * We tend to badly over-estimate the amount of
-                * metadata blocks which are needed, so if we have
-                * reserved any metadata blocks, try to force out the
-                * inode and see if we have any better luck.
-                */
-               if (md_reserved && retries++ <= 3)
-                       goto retry;
+       if (vfs_dq_reserve_block(inode, md_needed + 1))
                return -EDQUOT;
-       }
 
        if (ext4_claim_free_blocks(sbi, md_needed + 1)) {
                vfs_dq_release_reservation_block(inode, md_needed + 1);
                if (ext4_should_retry_alloc(inode->i_sb, &retries)) {
-               retry:
-                       if (md_reserved)
-                               write_inode_now(inode, (retries == 3));
                        yield();
                        goto repeat;
                }
@@ -3032,7 +3020,7 @@ static int ext4_da_write_begin(struct file *file, struct address_space *mapping,
                               loff_t pos, unsigned len, unsigned flags,
                               struct page **pagep, void **fsdata)
 {
-       int ret, retries = 0;
+       int ret, retries = 0, quota_retries = 0;
        struct page *page;
        pgoff_t index;
        unsigned from, to;
@@ -3091,6 +3079,22 @@ retry:
 
        if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries))
                goto retry;
+
+       if ((ret == -EDQUOT) &&
+           EXT4_I(inode)->i_reserved_meta_blocks &&
+           (quota_retries++ < 3)) {
+               /*
+                * Since we often over-estimate the number of meta
+                * data blocks required, we may sometimes get a
+                * spurios out of quota error even though there would
+                * be enough space once we write the data blocks and
+                * find out how many meta data blocks were _really_
+                * required.  So try forcing the inode write to see if
+                * that helps.
+                */
+               write_inode_now(inode, (quota_retries == 3));
+               goto retry;
+       }
 out:
        return ret;
 }