ext4: Properly update i_disksize.

With delayed allocation we use i_data_sem to update i_disksize.  We need
to update i_disksize only if the new size specified is greater than the
current value and we need to make sure we don't race with other
i_disksize update.  With delayed allocation we will switch to the
write_begin function for non-delayed allocation if we are low on free
blocks.  This means the write_begin function for non-delayed allocation
also needs to use the same locking.

We also need to check and update i_disksize even if the new size is less
that inode.i_size because of delayed allocation.

Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@linux.vnet.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --git a/fs/ext4/ext4.h b/fs/ext4/ext4.h
index e13b9deee866054a12337d49ad134be90e7fc142..3e47b99a763c0a16bc94f48fd13c0bcb12ea1b4c 100644 (file)
--- a/fs/ext4/ext4.h
+++ b/fs/ext4/ext4.h
@@ -1218,6 +1218,17 @@ do {                                                             \
 #define EXT4_FREEBLOCKS_WATERMARK 0
 #endif
 
+static inline void ext4_update_i_disksize(struct inode *inode, loff_t newsize)
+{
+       /*
+        * XXX: replace with spinlock if seen contended -bzzz
+        */
+       down_write(&EXT4_I(inode)->i_data_sem);
+       if (newsize > EXT4_I(inode)->i_disksize)
+               EXT4_I(inode)->i_disksize = newsize;
+       up_write(&EXT4_I(inode)->i_data_sem);
+       return ;
+}
 
 /*
  * Inodes and files operations

diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
index 797f0602a68f9f77b6fee71baea42ed5f64a3f0e..e8758df2617b1ef58b97cfde5a3792a69a6a2d6e 100644 (file)
--- a/fs/ext4/extents.c
+++ b/fs/ext4/extents.c
@@ -2878,10 +2878,11 @@ static void ext4_falloc_update_inode(struct inode *inode,
         * Update only when preallocation was requested beyond
         * the file size.
         */
-       if (!(mode & FALLOC_FL_KEEP_SIZE) &&
-                               new_size > i_size_read(inode)) {
-               i_size_write(inode, new_size);
-               EXT4_I(inode)->i_disksize = new_size;
+       if (!(mode & FALLOC_FL_KEEP_SIZE)) {
+               if (new_size > i_size_read(inode))
+                       i_size_write(inode, new_size);
+               if (new_size > EXT4_I(inode)->i_disksize)
+                       ext4_update_i_disksize(inode, new_size);
        }
 
 }

diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c
index 634f0bc757008d6534944b8dd9115e34a40f0778..22fcbb67cd884649db3ffb6a1f5a302a53834fb1 100644 (file)
--- a/fs/ext4/inode.c
+++ b/fs/ext4/inode.c
@@ -1434,16 +1434,18 @@ static int ext4_ordered_write_end(struct file *file,
        ret = ext4_jbd2_file_inode(handle, inode);
 
        if (ret == 0) {
-               /*
-                * generic_write_end() will run mark_inode_dirty() if i_size
-                * changes.  So let's piggyback the i_disksize mark_inode_dirty
-                * into that.
-                */
                loff_t new_i_size;
 
                new_i_size = pos + copied;
-               if (new_i_size > EXT4_I(inode)->i_disksize)
-                       EXT4_I(inode)->i_disksize = new_i_size;
+               if (new_i_size > EXT4_I(inode)->i_disksize) {
+                       ext4_update_i_disksize(inode, new_i_size);
+                       /* We need to mark inode dirty even if
+                        * new_i_size is less that inode->i_size
+                        * bu greater than i_disksize.(hint delalloc)
+                        */
+                       ext4_mark_inode_dirty(handle, inode);
+               }
+
                ret2 = generic_write_end(file, mapping, pos, len, copied,
                                                        page, fsdata);
                copied = ret2;
@@ -1468,8 +1470,14 @@ static int ext4_writeback_write_end(struct file *file,
        loff_t new_i_size;
 
        new_i_size = pos + copied;
-       if (new_i_size > EXT4_I(inode)->i_disksize)
-               EXT4_I(inode)->i_disksize = new_i_size;
+       if (new_i_size > EXT4_I(inode)->i_disksize) {
+               ext4_update_i_disksize(inode, new_i_size);
+               /* We need to mark inode dirty even if
+                * new_i_size is less that inode->i_size
+                * bu greater than i_disksize.(hint delalloc)
+                */
+               ext4_mark_inode_dirty(handle, inode);
+       }
 
        ret2 = generic_write_end(file, mapping, pos, len, copied,
                                                        page, fsdata);
@@ -1494,6 +1502,7 @@ static int ext4_journalled_write_end(struct file *file,
        int ret = 0, ret2;
        int partial = 0;
        unsigned from, to;
+       loff_t new_i_size;
 
        from = pos & (PAGE_CACHE_SIZE - 1);
        to = from + len;
@@ -1508,11 +1517,12 @@ static int ext4_journalled_write_end(struct file *file,
                                to, &partial, write_end_fn);
        if (!partial)
                SetPageUptodate(page);
-       if (pos+copied > inode->i_size)
+       new_i_size = pos + copied;
+       if (new_i_size > inode->i_size)
                i_size_write(inode, pos+copied);
        EXT4_I(inode)->i_state |= EXT4_STATE_JDATA;
-       if (inode->i_size > EXT4_I(inode)->i_disksize) {
-               EXT4_I(inode)->i_disksize = inode->i_size;
+       if (new_i_size > EXT4_I(inode)->i_disksize) {
+               ext4_update_i_disksize(inode, new_i_size);
                ret2 = ext4_mark_inode_dirty(handle, inode);
                if (!ret)
                        ret = ret2;
@@ -2227,18 +2237,9 @@ static int ext4_da_get_block_write(struct inode *inode, sector_t iblock,
                if (disksize > i_size_read(inode))
                        disksize = i_size_read(inode);
                if (disksize > EXT4_I(inode)->i_disksize) {
-                       /*
-                        * XXX: replace with spinlock if seen contended -bzzz
-                        */
-                       down_write(&EXT4_I(inode)->i_data_sem);
-                       if (disksize > EXT4_I(inode)->i_disksize)
-                               EXT4_I(inode)->i_disksize = disksize;
-                       up_write(&EXT4_I(inode)->i_data_sem);
-
-                       if (EXT4_I(inode)->i_disksize == disksize) {
-                               ret = ext4_mark_inode_dirty(handle, inode);
-                               return ret;
-                       }
+                       ext4_update_i_disksize(inode, disksize);
+                       ret = ext4_mark_inode_dirty(handle, inode);
+                       return ret;
                }
                ret = 0;
        }
@@ -2654,6 +2655,11 @@ static int ext4_da_write_end(struct file *file,
                                EXT4_I(inode)->i_disksize = new_i_size;
                        }
                        up_write(&EXT4_I(inode)->i_data_sem);
+                       /* We need to mark inode dirty even if
+                        * new_i_size is less that inode->i_size
+                        * bu greater than i_disksize.(hint delalloc)
+                        */
+                       ext4_mark_inode_dirty(handle, inode);
                }
        }
        ret2 = generic_write_end(file, mapping, pos, len, copied,