ext4: teach ext4_ext_split to calculate extents efficiently

[~andy/linux] / fs / ext4 / dir.c

diff --git a/fs/ext4/dir.c b/fs/ext4/dir.c
index ece76fb6a40cefb559ee4db138dfe28c7ef3b348..164c56092e5865a99238893c5717efc60a7aea4e 100644 (file)
--- a/fs/ext4/dir.c
+++ b/fs/ext4/dir.c
@@ -60,9 +60,13 @@ static unsigned char get_dtype(struct super_block *sb, int filetype)
        return (ext4_filetype_table[filetype]);
 }
 
-
+/*
+ * Return 0 if the directory entry is OK, and 1 if there is a problem
+ *
+ * Note: this is the opposite of what ext2 and ext3 historically returned...
+ */
 int __ext4_check_dir_entry(const char *function, unsigned int line,
-                          struct inode *dir,
+                          struct inode *dir, struct file *filp,
                           struct ext4_dir_entry_2 *de,
                           struct buffer_head *bh,
                           unsigned int offset)
@@ -71,26 +75,37 @@ int __ext4_check_dir_entry(const char *function, unsigned int line,
        const int rlen = ext4_rec_len_from_disk(de->rec_len,
                                                dir->i_sb->s_blocksize);
 
-       if (rlen < EXT4_DIR_REC_LEN(1))
+       if (unlikely(rlen < EXT4_DIR_REC_LEN(1)))
                error_msg = "rec_len is smaller than minimal";
-       else if (rlen % 4 != 0)
+       else if (unlikely(rlen % 4 != 0))
                error_msg = "rec_len % 4 != 0";
-       else if (rlen < EXT4_DIR_REC_LEN(de->name_len))
+       else if (unlikely(rlen < EXT4_DIR_REC_LEN(de->name_len)))
                error_msg = "rec_len is too small for name_len";
-       else if (((char *) de - bh->b_data) + rlen > dir->i_sb->s_blocksize)
+       else if (unlikely(((char *) de - bh->b_data) + rlen >
+                         dir->i_sb->s_blocksize))
                error_msg = "directory entry across blocks";
-       else if (le32_to_cpu(de->inode) >
-                       le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count))
+       else if (unlikely(le32_to_cpu(de->inode) >
+                       le32_to_cpu(EXT4_SB(dir->i_sb)->s_es->s_inodes_count)))
                error_msg = "inode out of bounds";
+       else
+               return 0;
 
-       if (error_msg != NULL)
-               ext4_error_inode(dir, function, line, bh->b_blocknr,
-                       "bad entry in directory: %s - "
-                       "offset=%u(%u), inode=%u, rec_len=%d, name_len=%d",
-                       error_msg, (unsigned) (offset%bh->b_size), offset,
-                       le32_to_cpu(de->inode),
-                       rlen, de->name_len);
-       return error_msg == NULL ? 1 : 0;
+       if (filp)
+               ext4_error_file(filp, function, line, bh ? bh->b_blocknr : 0,
+                               "bad entry in directory: %s - offset=%u(%u), "
+                               "inode=%u, rec_len=%d, name_len=%d",
+                               error_msg, (unsigned) (offset%bh->b_size),
+                               offset, le32_to_cpu(de->inode),
+                               rlen, de->name_len);
+       else
+               ext4_error_inode(dir, function, line, bh ? bh->b_blocknr : 0,
+                               "bad entry in directory: %s - offset=%u(%u), "
+                               "inode=%u, rec_len=%d, name_len=%d",
+                               error_msg, (unsigned) (offset%bh->b_size),
+                               offset, le32_to_cpu(de->inode),
+                               rlen, de->name_len);
+
+       return 1;
 }
 
 static int ext4_readdir(struct file *filp,
@@ -152,8 +167,9 @@ static int ext4_readdir(struct file *filp,
                 */
                if (!bh) {
                        if (!dir_has_error) {
-                               EXT4_ERROR_INODE(inode, "directory "
-                                          "contains a hole at offset %Lu",
+                               EXT4_ERROR_FILE(filp, 0,
+                                               "directory contains a "
+                                               "hole at offset %llu",
                                           (unsigned long long) filp->f_pos);
                                dir_has_error = 1;
                        }
@@ -194,8 +210,8 @@ revalidate:
                while (!error && filp->f_pos < inode->i_size
                       && offset < sb->s_blocksize) {
                        de = (struct ext4_dir_entry_2 *) (bh->b_data + offset);
-                       if (!ext4_check_dir_entry(inode, de,
-                                                 bh, offset)) {
+                       if (ext4_check_dir_entry(inode, filp, de,
+                                                bh, offset)) {
                                /*
                                 * On error, skip the f_pos to the next block
                                 */