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Merge branch 'maint' into next
[tools/e2fsprogs.git] / lib / ext2fs / closefs.c
index a61f878..0f97704 100644 (file)
  */
 
 #include <stdio.h>
+#if HAVE_UNISTD_H
 #include <unistd.h>
-#include <stdlib.h>
+#endif
 #include <time.h>
 #include <string.h>
-#ifdef HAVE_ERRNO_H
-#include <errno.h>
-#endif
-
-#include <linux/ext2_fs.h>
 
+#include "ext2_fs.h"
 #include "ext2fsP.h"
 
 static int test_root(int a, int b)
@@ -37,114 +34,270 @@ static int test_root(int a, int b)
 
 int ext2fs_bg_has_super(ext2_filsys fs, int group_block)
 {
-#ifdef EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER
-       struct ext2fs_sb        *s;
-
-       s = (struct ext2fs_sb *) fs->super;
-       if (!(s->s_feature_ro_compat & EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER))
+       if (!(fs->super->s_feature_ro_compat &
+             EXT2_FEATURE_RO_COMPAT_SPARSE_SUPER))
                return 1;
 
        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
+ * filesystem is mounted, it may have changed some of the other
+ * fields.
+ *
+ * It takes as input a superblock which has already been byte swapped
+ * (if necessary).
+ *
+ */
+static errcode_t write_primary_superblock(ext2_filsys fs,
+                                         struct ext2_super_block *super)
+{
+       __u16           *old_super, *new_super;
+       int             check_idx, write_idx, size;
+       errcode_t       retval;
+
+       if (!fs->io->manager->write_byte || !fs->orig_super) {
+               io_channel_set_blksize(fs->io, SUPERBLOCK_OFFSET);
+               retval = io_channel_write_blk(fs->io, 1, -SUPERBLOCK_SIZE,
+                                             super);
+               io_channel_set_blksize(fs->io, fs->blocksize);
+               return retval;
+       }
+
+       old_super = (__u16 *) fs->orig_super;
+       new_super = (__u16 *) super;
+
+       for (check_idx = 0; check_idx < SUPERBLOCK_SIZE/2; check_idx++) {
+               if (old_super[check_idx] == new_super[check_idx])
+                       continue;
+               write_idx = check_idx;
+               for (check_idx++; check_idx < SUPERBLOCK_SIZE/2; check_idx++)
+                       if (old_super[check_idx] == new_super[check_idx])
+                               break;
+               size = 2 * (check_idx - write_idx);
+#if 0
+               printf("Writing %d bytes starting at %d\n",
+                      size, write_idx*2);
+#endif
+               retval = io_channel_write_byte(fs->io,
+                              SUPERBLOCK_OFFSET + (2 * write_idx), size,
+                                              new_super + write_idx);
+               if (retval)
+                       return retval;
+       }
+       memcpy(fs->orig_super, super, SUPERBLOCK_SIZE);
        return 0;
+}
+
+
+/*
+ * Updates the revision to EXT2_DYNAMIC_REV
+ */
+void ext2fs_update_dynamic_rev(ext2_filsys fs)
+{
+       struct ext2_super_block *sb = fs->super;
+
+       if (sb->s_rev_level > EXT2_GOOD_OLD_REV)
+               return;
+
+       sb->s_rev_level = EXT2_DYNAMIC_REV;
+       sb->s_first_ino = EXT2_GOOD_OLD_FIRST_INO;
+       sb->s_inode_size = EXT2_GOOD_OLD_INODE_SIZE;
+       /* s_uuid is handled by e2fsck already */
+       /* other fields should be left alone */
+}
+
+static errcode_t write_backup_super(ext2_filsys fs, dgrp_t group,
+                                   blk_t group_block,
+                                   struct ext2_super_block *super_shadow)
+{
+       dgrp_t  sgrp = group;
+       
+       if (sgrp > ((1 << 16) - 1))
+               sgrp = (1 << 16) - 1;
+#ifdef WORDS_BIGENDIAN
+       super_shadow->s_block_group_nr = ext2fs_swab16(sgrp);
 #else
-       return 1;
+       fs->super->s_block_group_nr = sgrp;
 #endif
+
+       return io_channel_write_blk(fs->io, group_block, -SUPERBLOCK_SIZE, 
+                                   super_shadow);
 }
 
+
 errcode_t ext2fs_flush(ext2_filsys fs)
 {
-       int             i,j,maxgroup;
-       int             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);
-       if (fs->flags & EXT2_FLAG_SWAP_BYTES) {
-               retval = ENOMEM;
-               if (!(super_shadow = malloc(SUPERBLOCK_SIZE)))
-                       goto errout;
-               if (!(group_shadow = malloc(fs->blocksize*fs->desc_blocks)))
-                       goto errout;
-               memset(group_shadow, 0, 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;
+       fs->super->s_wtime = fs->now ? fs->now : time(NULL);
+       fs->super->s_block_group_nr = 0;
+#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;
+       group_shadow = fs->group_desc;
+#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.)
         */
-       io_channel_set_blksize(fs->io, SUPERBLOCK_OFFSET);
-       retval = io_channel_write_blk(fs->io, 1, -SUPERBLOCK_SIZE,
-                                     super_shadow);
-       if (retval)
-               goto errout;
-       io_channel_set_blksize(fs->io, fs->blocksize);
+       fs->super->s_state &= ~EXT2_VALID_FS;
+#ifdef WORDS_BIGENDIAN
+       *super_shadow = *fs->super;
+       ext2fs_swap_super(super_shadow);
+#endif
 
        /*
-        * 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.)
+        * If this is an external journal device, don't write out the
+        * block group descriptors or any of the backup superblocks
         */
-       fs->super->s_state &= ~EXT2_VALID_FS;
-       if (fs->flags & EXT2_FLAG_SWAP_BYTES) {
-               *super_shadow = *fs->super;
-               ext2fs_swap_super(super_shadow);
-       }
+       if (fs->super->s_feature_incompat &
+           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 (!ext2fs_bg_has_super(fs, i))
-                       goto next_group;
-
-               if (i !=0 ) {
-                       retval = io_channel_write_blk(fs->io, group_block,
-                                                     -SUPERBLOCK_SIZE,
-                                                     super_shadow);
+       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;
                }
-               group_ptr = (char *) group_shadow;
-               for (j=0; j < fs->desc_blocks; j++) {
+               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,
-                                                     group_block+1+j, 1,
-                                                     group_ptr);
+                             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;
-                       group_ptr += fs->blocksize;
                }
-       next_group:
-               group_block += EXT2_BLOCKS_PER_GROUP(fs->super);
        }
 
        /*
@@ -158,15 +311,39 @@ errcode_t ext2fs_flush(ext2_filsys fs)
                if (retval)
                        goto errout;
        }
-       retval = 0;
+
+write_primary_superblock_only:
+       /*
+        * 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)
-                       free(super_shadow);
-               if (group_shadow)
-                       free(group_shadow);
-       }
+#ifdef WORDS_BIGENDIAN
+       if (super_shadow)
+               ext2fs_free_mem(&super_shadow);
+       if (group_shadow)
+               ext2fs_free_mem(&group_shadow);
+#endif
        return retval;
 }
 
@@ -190,33 +367,3 @@ errcode_t ext2fs_close(ext2_filsys fs)
        return 0;
 }
 
-/*
- * This procedure frees a badblocks list.
- */
-void ext2fs_badblocks_list_free(ext2_badblocks_list bb)
-{
-       if (bb->magic != EXT2_ET_MAGIC_BADBLOCKS_LIST)
-               return;
-
-       if (bb->list)
-               free(bb->list);
-       bb->list = 0;
-       free(bb);
-}
-
-/*
- * Close a directory block list
- */
-void ext2fs_free_dblist(ext2_dblist dblist)
-{
-       if (!dblist || (dblist->magic != EXT2_ET_MAGIC_DBLIST))
-               return;
-
-       if (dblist->list)
-               free(dblist->list);
-       dblist->list = 0;
-       if (dblist->fs && dblist->fs->dblist == dblist)
-               dblist->fs->dblist = 0;
-       dblist->magic = 0;
-       free(dblist);
-}