ext4: fix xattr shifting when expanding inodes

[firefly-linux-kernel-4.4.55.git] / fs / ext4 / xattr.c

diff --git a/fs/ext4/xattr.c b/fs/ext4/xattr.c
index 6b6b3e751f8c77ebc9089c412f9019b4774a4301..bf3130e275ee741361cd102de1ad25246fa39c0e 100644 (file)
--- a/fs/ext4/xattr.c
+++ b/fs/ext4/xattr.c
@@ -1264,11 +1264,13 @@ int ext4_expand_extra_isize_ea(struct inode *inode, int new_extra_isize,
        size_t min_offs, free;
        int total_ino;
        void *base, *start, *end;
-       int extra_isize = 0, error = 0, tried_min_extra_isize = 0;
+       int error = 0, tried_min_extra_isize = 0;
        int s_min_extra_isize = le16_to_cpu(EXT4_SB(inode->i_sb)->s_es->s_min_extra_isize);
+       int isize_diff; /* How much do we need to grow i_extra_isize */
 
        down_write(&EXT4_I(inode)->xattr_sem);
 retry:
+       isize_diff = new_extra_isize - EXT4_I(inode)->i_extra_isize;
        if (EXT4_I(inode)->i_extra_isize >= new_extra_isize) {
                up_write(&EXT4_I(inode)->xattr_sem);
                return 0;
@@ -1289,7 +1291,7 @@ retry:
        total_ino = sizeof(struct ext4_xattr_ibody_header);
 
        free = ext4_xattr_free_space(last, &min_offs, base, &total_ino);
-       if (free >= new_extra_isize) {
+       if (free >= isize_diff) {
                entry = IFIRST(header);
                ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize
                                - new_extra_isize, (void *)raw_inode +
@@ -1321,7 +1323,7 @@ retry:
                end = bh->b_data + bh->b_size;
                min_offs = end - base;
                free = ext4_xattr_free_space(first, &min_offs, base, NULL);
-               if (free < new_extra_isize) {
+               if (free < isize_diff) {
                        if (!tried_min_extra_isize && s_min_extra_isize) {
                                tried_min_extra_isize++;
                                new_extra_isize = s_min_extra_isize;
@@ -1335,7 +1337,7 @@ retry:
                free = inode->i_sb->s_blocksize;
        }
 
-       while (new_extra_isize > 0) {
+       while (isize_diff > 0) {
                size_t offs, size, entry_size;
                struct ext4_xattr_entry *small_entry = NULL;
                struct ext4_xattr_info i = {
@@ -1366,7 +1368,7 @@ retry:
                        EXT4_XATTR_SIZE(le32_to_cpu(last->e_value_size)) +
                                        EXT4_XATTR_LEN(last->e_name_len);
                        if (total_size <= free && total_size < min_total_size) {
-                               if (total_size < new_extra_isize) {
+                               if (total_size < isize_diff) {
                                        small_entry = last;
                                } else {
                                        entry = last;
@@ -1423,20 +1425,19 @@ retry:
                        goto cleanup;
 
                entry = IFIRST(header);
-               if (entry_size + EXT4_XATTR_SIZE(size) >= new_extra_isize)
-                       shift_bytes = new_extra_isize;
+               if (entry_size + EXT4_XATTR_SIZE(size) >= isize_diff)
+                       shift_bytes = isize_diff;
                else
                        shift_bytes = entry_size + size;
                /* Adjust the offsets and shift the remaining entries ahead */
-               ext4_xattr_shift_entries(entry, EXT4_I(inode)->i_extra_isize -
-                       shift_bytes, (void *)raw_inode +
-                       EXT4_GOOD_OLD_INODE_SIZE + extra_isize + shift_bytes,
+               ext4_xattr_shift_entries(entry, -shift_bytes,
+                       (void *)raw_inode + EXT4_GOOD_OLD_INODE_SIZE +
+                       EXT4_I(inode)->i_extra_isize + shift_bytes,
                        (void *)header, total_ino - entry_size,
                        inode->i_sb->s_blocksize);
 
-               extra_isize += shift_bytes;
-               new_extra_isize -= shift_bytes;
-               EXT4_I(inode)->i_extra_isize = extra_isize;
+               isize_diff -= shift_bytes;
+               EXT4_I(inode)->i_extra_isize += shift_bytes;
 
                i.name = b_entry_name;
                i.value = buffer;