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Merge branch 'maint' into next
[tools/e2fsprogs.git] / lib / ext2fs / closefs.c
index dcf244b..0f97704 100644 (file)
@@ -41,10 +41,79 @@ int ext2fs_bg_has_super(ext2_filsys fs, int group_block)
        if (test_root(group_block, 3) || (test_root(group_block, 5)) ||
            test_root(group_block, 7))
                return 1;
-       
+
        return 0;
 }
 
+int ext2fs_super_and_bgd_loc(ext2_filsys fs, 
+                            dgrp_t group,
+                            blk_t *ret_super_blk,
+                            blk_t *ret_old_desc_blk,
+                            blk_t *ret_new_desc_blk,
+                            int *ret_meta_bg)
+{
+       blk_t   group_block, super_blk = 0, old_desc_blk = 0, new_desc_blk = 0;
+       unsigned int meta_bg, meta_bg_size;
+       blk_t   numblocks, old_desc_blocks;
+       int     has_super;
+
+       group_block = ext2fs_group_first_block(fs, group);
+
+       if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
+               old_desc_blocks = fs->super->s_first_meta_bg;
+       else
+               old_desc_blocks = 
+                       fs->desc_blocks + fs->super->s_reserved_gdt_blocks;
+
+       if (group == fs->group_desc_count-1) {
+               numblocks = (fs->super->s_blocks_count -
+                            fs->super->s_first_data_block) %
+                       fs->super->s_blocks_per_group;
+               if (!numblocks)
+                       numblocks = fs->super->s_blocks_per_group;
+       } else
+               numblocks = fs->super->s_blocks_per_group;
+
+       has_super = ext2fs_bg_has_super(fs, group);
+
+       if (has_super) {
+               super_blk = group_block;
+               numblocks--;
+       }
+       meta_bg_size = EXT2_DESC_PER_BLOCK(fs->super);
+       meta_bg = group / meta_bg_size;
+
+       if (!(fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) ||
+           (meta_bg < fs->super->s_first_meta_bg)) {
+               if (has_super) {
+                       old_desc_blk = group_block + 1;
+                       numblocks -= old_desc_blocks;
+               }
+       } else {
+               if (((group % meta_bg_size) == 0) ||
+                   ((group % meta_bg_size) == 1) ||
+                   ((group % meta_bg_size) == (meta_bg_size-1))) {
+                       if (has_super)
+                               has_super = 1;
+                       new_desc_blk = group_block + has_super;
+                       numblocks--;
+               }
+       }
+               
+       numblocks -= 2 + fs->inode_blocks_per_group;
+
+       if (ret_super_blk)
+               *ret_super_blk = super_blk;
+       if (ret_old_desc_blk)
+               *ret_old_desc_blk = old_desc_blk;
+       if (ret_new_desc_blk)
+               *ret_new_desc_blk = new_desc_blk;
+       if (ret_meta_bg)
+               *ret_meta_bg = meta_bg;
+       return (numblocks);
+}
+
+
 /*
  * This function forces out the primary superblock.  We need to only
  * write out those fields which we have changed, since if the
@@ -113,48 +182,6 @@ void ext2fs_update_dynamic_rev(ext2_filsys fs)
        /* other fields should be left alone */
 }
 
-/*
- * This writes out the block group descriptors the original,
- * old-fashioned way.
- */
-static errcode_t write_bgdesc(ext2_filsys fs, dgrp_t group, blk_t group_block,
-                             struct ext2_group_desc *group_shadow)
-{
-       errcode_t       retval;
-       char            *group_ptr = (char *) group_shadow;
-       int             j;
-       int             has_super = ext2fs_bg_has_super(fs, group);
-       dgrp_t          meta_bg_size, meta_bg;
-       blk_t           blk;
-
-       meta_bg_size = (fs->blocksize / sizeof (struct ext2_group_desc));
-       meta_bg = group / meta_bg_size;
-       if (!(fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG) ||
-           (meta_bg < fs->super->s_first_meta_bg)) {
-               if (!has_super)
-                       return 0;
-               for (j=0; j < fs->desc_blocks; j++) {
-                       retval = io_channel_write_blk(fs->io,
-                                                     group_block+1+j, 1,
-                                                     group_ptr);
-                       if (retval)
-                               return retval;
-                       group_ptr += fs->blocksize;
-               }
-       } else {
-               if (has_super)
-                       group_block++;
-               if (((group % meta_bg_size) == 0) ||
-                   ((group % meta_bg_size) == 1) ||
-                   ((group % meta_bg_size) == (meta_bg_size-1))) {
-                       return io_channel_write_blk(fs->io, group_block,
-                               1, group_ptr + (meta_bg*fs->blocksize));
-               }
-       }
-       return 0;
-}
-
-
 static errcode_t write_backup_super(ext2_filsys fs, dgrp_t group,
                                    blk_t group_block,
                                    struct ext2_super_block *super_shadow)
@@ -163,12 +190,11 @@ static errcode_t write_backup_super(ext2_filsys fs, dgrp_t group,
        
        if (sgrp > ((1 << 16) - 1))
                sgrp = (1 << 16) - 1;
-#ifdef EXT2FS_ENABLE_SWAPFS
-       if (fs->flags & EXT2_FLAG_SWAP_BYTES)
-               super_shadow->s_block_group_nr = ext2fs_swab16(sgrp);
-       else
+#ifdef WORDS_BIGENDIAN
+       super_shadow->s_block_group_nr = ext2fs_swab16(sgrp);
+#else
+       fs->super->s_block_group_nr = sgrp;
 #endif
-               fs->super->s_block_group_nr = sgrp;
 
        return io_channel_write_blk(fs->io, group_block, -SUPERBLOCK_SIZE, 
                                    super_shadow);
@@ -177,49 +203,38 @@ static errcode_t write_backup_super(ext2_filsys fs, dgrp_t group,
 
 errcode_t ext2fs_flush(ext2_filsys fs)
 {
-       dgrp_t          i,j,maxgroup;
-       blk_t           group_block;
+       dgrp_t          i,j;
        errcode_t       retval;
-       char            *group_ptr;
        unsigned long   fs_state;
        struct ext2_super_block *super_shadow = 0;
        struct ext2_group_desc *group_shadow = 0;
        struct ext2_group_desc *s, *t;
+       char    *group_ptr;
+       int     old_desc_blocks;
        
        EXT2_CHECK_MAGIC(fs, EXT2_ET_MAGIC_EXT2FS_FILSYS);
 
        fs_state = fs->super->s_state;
 
-       fs->super->s_wtime = time(NULL);
+       fs->super->s_wtime = fs->now ? fs->now : time(NULL);
        fs->super->s_block_group_nr = 0;
-#ifdef EXT2FS_ENABLE_SWAPFS
-       if (fs->flags & EXT2_FLAG_SWAP_BYTES) {
-               retval = EXT2_ET_NO_MEMORY;
-               retval = ext2fs_get_mem(SUPERBLOCK_SIZE,
-                                       (void **) &super_shadow);
-               if (retval)
-                       goto errout;
-               retval = ext2fs_get_mem((size_t)(fs->blocksize *
-                                                fs->desc_blocks),
-                                       (void **) &group_shadow);
-               if (retval)
-                       goto errout;
-               memset(group_shadow, 0, (size_t) fs->blocksize *
-                      fs->desc_blocks);
-
-               /* swap the superblock */
-               *super_shadow = *fs->super;
-               ext2fs_swap_super(super_shadow);
-
-               /* swap the group descriptors */
-               for (j=0, s=fs->group_desc, t=group_shadow;
-                    j < fs->group_desc_count; j++, t++, s++) {
-                       *t = *s;
-                       ext2fs_swap_group_desc(t);
-               }
-       } else {
-               super_shadow = fs->super;
-               group_shadow = fs->group_desc;
+#ifdef WORDS_BIGENDIAN
+       retval = EXT2_ET_NO_MEMORY;
+       retval = ext2fs_get_mem(SUPERBLOCK_SIZE, &super_shadow);
+       if (retval)
+               goto errout;
+       retval = ext2fs_get_array(fs->desc_blocks, fs->blocksize, 
+                                 &group_shadow);
+       if (retval)
+               goto errout;
+       memset(group_shadow, 0, (size_t) fs->blocksize *
+              fs->desc_blocks);
+       
+       /* swap the group descriptors */
+       for (j=0, s=fs->group_desc, t=group_shadow;
+            j < fs->group_desc_count; j++, t++, s++) {
+               *t = *s;
+               ext2fs_swap_group_desc(t);
        }
 #else
        super_shadow = fs->super;
@@ -227,60 +242,63 @@ errcode_t ext2fs_flush(ext2_filsys fs)
 #endif
        
        /*
-        * Write out master superblock.  This has to be done
-        * separately, since it is located at a fixed location
-        * (SUPERBLOCK_OFFSET).
+        * Set the state of the FS to be non-valid.  (The state has
+        * already been backed up earlier, and will be restored after
+        * we write out the backup superblocks.)
         */
-       retval = write_primary_superblock(fs, super_shadow);
-       if (retval)
-               goto errout;
+       fs->super->s_state &= ~EXT2_VALID_FS;
+#ifdef WORDS_BIGENDIAN
+       *super_shadow = *fs->super;
+       ext2fs_swap_super(super_shadow);
+#endif
 
        /*
         * If this is an external journal device, don't write out the
         * block group descriptors or any of the backup superblocks
         */
        if (fs->super->s_feature_incompat &
-           EXT3_FEATURE_INCOMPAT_JOURNAL_DEV) {
-               retval = 0;
-               goto errout;
-       }
-
-       /*
-        * Set the state of the FS to be non-valid.  (The state has
-        * already been backed up earlier, and will be restored when
-        * we exit.)
-        */
-       fs->super->s_state &= ~EXT2_VALID_FS;
-#ifdef EXT2FS_ENABLE_SWAPFS
-       if (fs->flags & EXT2_FLAG_SWAP_BYTES) {
-               *super_shadow = *fs->super;
-               ext2fs_swap_super(super_shadow);
-       }
-#endif
+           EXT3_FEATURE_INCOMPAT_JOURNAL_DEV)
+               goto write_primary_superblock_only;
 
        /*
         * Write out the master group descriptors, and the backup
         * superblocks and group descriptors.
         */
-       group_block = fs->super->s_first_data_block;
-       maxgroup = (fs->flags & EXT2_FLAG_MASTER_SB_ONLY) ? 1 :
-               fs->group_desc_count;
-       for (i = 0; i < maxgroup; i++) {
-               if (i && ext2fs_bg_has_super(fs, i)) {
-                       retval = write_backup_super(fs, i, group_block,
+       group_ptr = (char *) group_shadow;
+       if (fs->super->s_feature_incompat & EXT2_FEATURE_INCOMPAT_META_BG)
+               old_desc_blocks = fs->super->s_first_meta_bg;
+       else
+               old_desc_blocks = fs->desc_blocks;
+
+       for (i = 0; i < fs->group_desc_count; i++) {
+               blk_t   super_blk, old_desc_blk, new_desc_blk;
+               int     meta_bg;
+
+               ext2fs_super_and_bgd_loc(fs, i, &super_blk, &old_desc_blk, 
+                                        &new_desc_blk, &meta_bg);
+
+               if (!(fs->flags & EXT2_FLAG_MASTER_SB_ONLY) &&i && super_blk) {
+                       retval = write_backup_super(fs, i, super_blk,
                                                    super_shadow);
                        if (retval)
                                goto errout;
                }
-               if (!(fs->flags & EXT2_FLAG_SUPER_ONLY)) {
-                       if ((retval = write_bgdesc(fs, i, group_block, 
-                                                  group_shadow)))
+               if (fs->flags & EXT2_FLAG_SUPER_ONLY)
+                       continue;
+               if ((old_desc_blk) && 
+                   (!(fs->flags & EXT2_FLAG_MASTER_SB_ONLY) || (i == 0))) {
+                       retval = io_channel_write_blk(fs->io,
+                             old_desc_blk, old_desc_blocks, group_ptr);
+                       if (retval)
+                               goto errout;
+               }
+               if (new_desc_blk) {
+                       retval = io_channel_write_blk(fs->io, new_desc_blk,
+                               1, group_ptr + (meta_bg*fs->blocksize));
+                       if (retval)
                                goto errout;
                }
-       next_group:
-               group_block += EXT2_BLOCKS_PER_GROUP(fs->super);
        }
-       fs->super->s_block_group_nr = 0;
 
        /*
         * If the write_bitmaps() function is present, call it to
@@ -294,20 +312,38 @@ errcode_t ext2fs_flush(ext2_filsys fs)
                        goto errout;
        }
 
-       fs->flags &= ~EXT2_FLAG_DIRTY;
-
+write_primary_superblock_only:
        /*
-        * Flush the blocks out to disk
+        * Write out master superblock.  This has to be done
+        * separately, since it is located at a fixed location
+        * (SUPERBLOCK_OFFSET).  We flush all other pending changes
+        * out to disk first, just to avoid a race condition with an
+        * insy-tinsy window....
         */
+
+       fs->super->s_block_group_nr = 0;
+       fs->super->s_state = fs_state;
+#ifdef WORDS_BIGENDIAN
+       *super_shadow = *fs->super;
+       ext2fs_swap_super(super_shadow);
+#endif
+
+       retval = io_channel_flush(fs->io);
+       retval = write_primary_superblock(fs, super_shadow);
+       if (retval)
+               goto errout;
+
+       fs->flags &= ~EXT2_FLAG_DIRTY;
+
        retval = io_channel_flush(fs->io);
 errout:
        fs->super->s_state = fs_state;
-       if (fs->flags & EXT2_FLAG_SWAP_BYTES) {
-               if (super_shadow)
-                       ext2fs_free_mem((void **) &super_shadow);
-               if (group_shadow)
-                       ext2fs_free_mem((void **) &group_shadow);
-       }
+#ifdef WORDS_BIGENDIAN
+       if (super_shadow)
+               ext2fs_free_mem(&super_shadow);
+       if (group_shadow)
+               ext2fs_free_mem(&group_shadow);
+#endif
        return retval;
 }