fsck.f2fs: reconnect unreachable files to lost+found
authorSheng Yong <shengyong1@huawei.com>
Tue, 6 Mar 2018 03:39:40 +0000 (11:39 +0800)
committerJaegeuk Kim <jaegeuk@kernel.org>
Mon, 7 May 2018 21:49:38 +0000 (14:49 -0700)
This patch introduces lost_found feature to fsck. If a file is found
unreachable by fsck. Fsck tries to reconnect the file to lost+found
directory:
  1. Scan all unreachable file inodes, ignore non-inodes ones and
     directories.
  2. Check them and fix incorrupted data to make sure filesystem
     metadata (mainly counters and main/nat bitmap) are all consistent.
  3. Reconnect these files to lost+found. If lost+found does not exist,
     create it first. During reconnecting, expand lost+found's dentry
     block automatically. Reconnected files are renamed after its ino
     number.
  4. If reconnect fails drop the node and restore filesystem metadata.

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
Reviewed-by: Chao Yu <yuchao0@huawei.com>
Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
fsck/dir.c
fsck/fsck.c
fsck/fsck.h
fsck/mount.c

index b2ea18f..567a4e9 100644 (file)
@@ -176,6 +176,23 @@ static int f2fs_find_entry(struct f2fs_sb_info *sbi,
        return 0;
 }
 
+/* return ino if file exists, otherwise return 0 */
+nid_t f2fs_lookup(struct f2fs_sb_info *sbi, struct f2fs_node *dir,
+                               u8 *name, int len)
+{
+       int err;
+       struct dentry de = {
+               .name = name,
+               .len = len,
+       };
+
+       err = f2fs_find_entry(sbi, dir, &de);
+       if (err == 1)
+               return de.ino;
+       else
+               return 0;
+}
+
 static void f2fs_update_dentry(nid_t ino, int file_type,
                struct f2fs_dentry_ptr *d,
                const unsigned char *name, int len, f2fs_hash_t name_hash,
@@ -199,7 +216,7 @@ static void f2fs_update_dentry(nid_t ino, int file_type,
 /*
  * f2fs_add_link - Add a new file(dir) to parent dir.
  */
-static int f2fs_add_link(struct f2fs_sb_info *sbi, struct f2fs_node *parent,
+int f2fs_add_link(struct f2fs_sb_info *sbi, struct f2fs_node *parent,
                        const unsigned char *name, int name_len, nid_t ino,
                        int file_type, block_t p_blkaddr, int inc_link)
 {
index 2b3d707..bc14912 100644 (file)
@@ -10,6 +10,7 @@
  */
 #include "fsck.h"
 #include "quotaio.h"
+#include <time.h>
 
 char *tree_mark;
 uint32_t tree_mark_size = 256;
@@ -43,6 +44,14 @@ static inline int f2fs_test_main_bitmap(struct f2fs_sb_info *sbi, u32 blk)
                                                fsck->main_area_bitmap);
 }
 
+static inline int f2fs_clear_main_bitmap(struct f2fs_sb_info *sbi, u32 blk)
+{
+       struct f2fs_fsck *fsck = F2FS_FSCK(sbi);
+
+       return f2fs_clear_bit(BLKOFF_FROM_MAIN(sbi, blk),
+                                               fsck->main_area_bitmap);
+}
+
 static inline int f2fs_test_sit_bitmap(struct f2fs_sb_info *sbi, u32 blk)
 {
        struct f2fs_fsck *fsck = F2FS_FSCK(sbi);
@@ -453,9 +462,11 @@ static int sanity_check_nid(struct f2fs_sb_info *sbi, u32 nid,
 
        /* workaround to fix later */
        if (ftype != F2FS_FT_ORPHAN ||
-                       f2fs_test_bit(nid, fsck->nat_area_bitmap) != 0)
+                       f2fs_test_bit(nid, fsck->nat_area_bitmap) != 0) {
                f2fs_clear_bit(nid, fsck->nat_area_bitmap);
-       else
+               /* avoid reusing nid when reconnecting files */
+               f2fs_set_bit(nid, NM_I(sbi)->nid_bitmap);
+       } else
                ASSERT_MSG("orphan or xattr nid is duplicated [0x%x]\n",
                                nid);
 
@@ -2046,6 +2057,370 @@ int check_sit_types(struct f2fs_sb_info *sbi)
        return err;
 }
 
+static struct f2fs_node *fsck_get_lpf(struct f2fs_sb_info *sbi)
+{
+       struct f2fs_node *node;
+       struct node_info ni;
+       nid_t lpf_ino;
+       int err;
+
+       /* read root inode first */
+       node = calloc(F2FS_BLKSIZE, 1);
+       ASSERT(node);
+       get_node_info(sbi, F2FS_ROOT_INO(sbi), &ni);
+       err = dev_read_block(node, ni.blk_addr);
+       ASSERT(err >= 0);
+
+       /* lookup lost+found in root directory */
+       lpf_ino = f2fs_lookup(sbi, node, (u8 *)LPF, strlen(LPF));
+       if (lpf_ino) { /* found */
+               get_node_info(sbi, lpf_ino, &ni);
+               err = dev_read_block(node, ni.blk_addr);
+               ASSERT(err >= 0);
+               DBG(1, "Found lost+found 0x%x at blkaddr [0x%x]\n",
+                   lpf_ino, ni.blk_addr);
+               if (!S_ISDIR(le16_to_cpu(node->i.i_mode))) {
+                       ASSERT_MSG("lost+found is not directory [0%o]\n",
+                                  le16_to_cpu(node->i.i_mode));
+                       /* FIXME: give up? */
+                       goto out;
+               }
+       } else { /* not found, create it */
+               struct dentry de;
+
+               memset(&de, 0, sizeof(de));
+               de.name = (u8 *) LPF;
+               de.len = strlen(LPF);
+               de.mode = 0x41c0;
+               de.pino = F2FS_ROOT_INO(sbi),
+               de.file_type = F2FS_FT_DIR,
+               de.uid = getuid();
+               de.gid = getgid();
+               de.mtime = time(NULL);
+
+               err = f2fs_mkdir(sbi, &de);
+               if (err) {
+                       ASSERT_MSG("Failed create lost+found");
+                       goto out;
+               }
+
+               get_node_info(sbi, de.ino, &ni);
+               err = dev_read_block(node, ni.blk_addr);
+               ASSERT(err >= 0);
+               DBG(1, "Create lost+found 0x%x at blkaddr [0x%x]\n",
+                   de.ino, ni.blk_addr);
+       }
+
+       c.lpf_ino = le32_to_cpu(node->footer.ino);
+       return node;
+out:
+       free(node);
+       return NULL;
+}
+
+static int fsck_do_reconnect_file(struct f2fs_sb_info *sbi,
+                                 struct f2fs_node *lpf,
+                                 struct f2fs_node *fnode)
+{
+       char name[80];
+       size_t namelen;
+       nid_t ino = le32_to_cpu(fnode->footer.ino);
+       struct node_info ni;
+       int ftype, ret;
+
+       namelen = snprintf(name, 80, "%u", ino);
+       if (namelen >= 80)
+               /* ignore terminating '\0', should never happen */
+               namelen = 79;
+
+       if (f2fs_lookup(sbi, lpf, (u8 *)name, namelen)) {
+               ASSERT_MSG("Name %s already exist in lost+found", name);
+               return -EEXIST;
+       }
+
+       get_node_info(sbi, le32_to_cpu(lpf->footer.ino), &ni);
+       ftype = map_de_type(le16_to_cpu(fnode->i.i_mode));
+       ret = f2fs_add_link(sbi, lpf, (unsigned char *)name, namelen,
+                           ino, ftype, ni.blk_addr, 0);
+       if (ret) {
+               ASSERT_MSG("Failed to add inode [0x%x] to lost+found", ino);
+               return -EINVAL;
+       }
+
+       /* update fnode */
+       memcpy(fnode->i.i_name, name, namelen);
+       fnode->i.i_namelen = cpu_to_le32(namelen);
+       fnode->i.i_pino = c.lpf_ino;
+       get_node_info(sbi, le32_to_cpu(fnode->footer.ino), &ni);
+       ret = dev_write_block(fnode, ni.blk_addr);
+       ASSERT(ret >= 0);
+
+       DBG(1, "Reconnect inode [0x%x] to lost+found\n", ino);
+       return 0;
+}
+
+static void fsck_failed_reconnect_file_dnode(struct f2fs_sb_info *sbi,
+                                            nid_t nid)
+{
+       struct f2fs_fsck *fsck = F2FS_FSCK(sbi);
+       struct f2fs_node *node;
+       struct node_info ni;
+       u32 addr;
+       int i, err;
+
+       node = calloc(F2FS_BLKSIZE, 1);
+       ASSERT(node);
+
+       get_node_info(sbi, nid, &ni);
+       err = dev_read_block(node, ni.blk_addr);
+       ASSERT(err >= 0);
+
+       fsck->chk.valid_node_cnt--;
+       fsck->chk.valid_blk_cnt--;
+       f2fs_clear_main_bitmap(sbi, ni.blk_addr);
+
+       for (i = 0; i < ADDRS_PER_BLOCK; i++) {
+               addr = le32_to_cpu(node->dn.addr[i]);
+               if (!addr)
+                       continue;
+               fsck->chk.valid_blk_cnt--;
+               if (addr == NEW_ADDR)
+                       continue;
+               f2fs_clear_main_bitmap(sbi, addr);
+       }
+
+       free(node);
+}
+
+static void fsck_failed_reconnect_file_idnode(struct f2fs_sb_info *sbi,
+                                             nid_t nid)
+{
+       struct f2fs_fsck *fsck = F2FS_FSCK(sbi);
+       struct f2fs_node *node;
+       struct node_info ni;
+       nid_t tmp;
+       int i, err;
+
+       node = calloc(F2FS_BLKSIZE, 1);
+       ASSERT(node);
+
+       get_node_info(sbi, nid, &ni);
+       err = dev_read_block(node, ni.blk_addr);
+       ASSERT(err >= 0);
+
+       fsck->chk.valid_node_cnt--;
+       fsck->chk.valid_blk_cnt--;
+       f2fs_clear_main_bitmap(sbi, ni.blk_addr);
+
+       for (i = 0; i < NIDS_PER_BLOCK; i++) {
+               tmp = le32_to_cpu(node->in.nid[i]);
+               if (!tmp)
+                       continue;
+               fsck_failed_reconnect_file_dnode(sbi, tmp);
+       }
+
+       free(node);
+}
+
+static void fsck_failed_reconnect_file_didnode(struct f2fs_sb_info *sbi,
+                                              nid_t nid)
+{
+       struct f2fs_fsck *fsck = F2FS_FSCK(sbi);
+       struct f2fs_node *node;
+       struct node_info ni;
+       nid_t tmp;
+       int i, err;
+
+       node = calloc(F2FS_BLKSIZE, 1);
+       ASSERT(node);
+
+       get_node_info(sbi, nid, &ni);
+       err = dev_read_block(node, ni.blk_addr);
+       ASSERT(err >= 0);
+
+       fsck->chk.valid_node_cnt--;
+       fsck->chk.valid_blk_cnt--;
+       f2fs_clear_main_bitmap(sbi, ni.blk_addr);
+
+       for (i = 0; i < NIDS_PER_BLOCK; i++) {
+               tmp = le32_to_cpu(node->in.nid[i]);
+               if (!tmp)
+                       continue;
+               fsck_failed_reconnect_file_idnode(sbi, tmp);
+       }
+
+       free(node);
+}
+
+/*
+ * Counters and main_area_bitmap are already changed during checking
+ * inode block, so clear them. There is no need to clear new blocks
+ * allocted to lost+found.
+ */
+static void fsck_failed_reconnect_file(struct f2fs_sb_info *sbi, nid_t ino)
+{
+       struct f2fs_fsck *fsck = F2FS_FSCK(sbi);
+       struct f2fs_node *node;
+       struct node_info ni;
+       nid_t nid;
+       int ofs, i, err;
+
+       node = calloc(F2FS_BLKSIZE, 1);
+       ASSERT(node);
+
+       get_node_info(sbi, ino, &ni);
+       err = dev_read_block(node, ni.blk_addr);
+       ASSERT(err >= 0);
+
+       /* clear inode counters */
+       fsck->chk.valid_inode_cnt--;
+       fsck->chk.valid_node_cnt--;
+       fsck->chk.valid_blk_cnt--;
+       f2fs_clear_main_bitmap(sbi, ni.blk_addr);
+
+       /* clear xnid counters */
+       if (node->i.i_xattr_nid) {
+               nid = le32_to_cpu(node->i.i_xattr_nid);
+               fsck->chk.valid_node_cnt--;
+               fsck->chk.valid_blk_cnt--;
+               get_node_info(sbi, nid, &ni);
+               f2fs_clear_main_bitmap(sbi, ni.blk_addr);
+       }
+
+       /* clear data counters */
+       if(!(node->i.i_inline & F2FS_INLINE_DATA)) {
+               ofs = get_extra_isize(node);
+               for (i = 0; i < ADDRS_PER_INODE(&node->i); i++) {
+                       block_t addr = le32_to_cpu(node->i.i_addr[ofs + i]);
+                       if (!addr)
+                               continue;
+                       fsck->chk.valid_blk_cnt--;
+                       if (addr == NEW_ADDR)
+                               continue;
+                       f2fs_clear_main_bitmap(sbi, addr);
+               }
+       }
+
+       for (i = 0; i < 5; i++) {
+               nid = le32_to_cpu(node->i.i_nid[i]);
+               if (!nid)
+                       continue;
+
+               switch (i) {
+               case 0: /* direct node */
+               case 1:
+                       fsck_failed_reconnect_file_dnode(sbi, nid);
+                       break;
+               case 2: /* indirect node */
+               case 3:
+                       fsck_failed_reconnect_file_idnode(sbi, nid);
+                       break;
+               case 4: /* double indirect node */
+                       fsck_failed_reconnect_file_didnode(sbi, nid);
+                       break;
+               }
+       }
+
+       free(node);
+}
+
+/*
+ * Scan unreachable nids and find only regular file inodes. If these files
+ * are not corrupted, reconnect them to lost+found.
+ *
+ * Since all unreachable nodes are already checked, we can allocate new
+ * blocks safely.
+ *
+ * This function returns the number of files been reconnected.
+ */
+static int fsck_reconnect_file(struct f2fs_sb_info *sbi)
+{
+       struct f2fs_fsck *fsck = F2FS_FSCK(sbi);
+       struct f2fs_node *lpf_node, *node;
+       struct node_info ni;
+       char *reconnect_bitmap;
+       u32 blk_cnt;
+       nid_t nid;
+       int err, cnt = 0, ftype;
+
+       node = calloc(F2FS_BLKSIZE, 1);
+       ASSERT(node);
+
+       reconnect_bitmap = calloc(fsck->nat_area_bitmap_sz, 1);
+       ASSERT(reconnect_bitmap);
+
+       for (nid = 0; nid < fsck->nr_nat_entries; nid++) {
+               if (f2fs_test_bit(nid, fsck->nat_area_bitmap)) {
+                       if (is_qf_ino(F2FS_RAW_SUPER(sbi), nid)) {
+                               DBG(1, "Not support quota inode [0x%x]\n",
+                                   nid);
+                               continue;
+                       }
+
+                       get_node_info(sbi, nid, &ni);
+                       err = dev_read_block(node, ni.blk_addr);
+                       ASSERT(err >= 0);
+
+                       /* reconnection will restore these nodes if needed */
+                       if (node->footer.ino != node->footer.nid) {
+                               DBG(1, "Not support non-inode node [0x%x]\n",
+                                   nid);
+                               continue;
+                       }
+
+                       if (S_ISDIR(le16_to_cpu(node->i.i_mode))) {
+                               DBG(1, "Not support directory inode [0x%x]\n",
+                                   nid);
+                               continue;
+                       }
+
+                       ftype = map_de_type(le16_to_cpu(node->i.i_mode));
+                       if (sanity_check_nid(sbi, nid, node, ftype,
+                                            TYPE_INODE, &ni)) {
+                               ASSERT_MSG("Invalid nid [0x%x]\n", nid);
+                               continue;
+                       }
+
+                       DBG(1, "Check inode 0x%x\n", nid);
+                       blk_cnt = 1;
+                       fsck_chk_inode_blk(sbi, nid, ftype, node,
+                                          &blk_cnt, &ni, NULL);
+
+                       f2fs_set_bit(nid, reconnect_bitmap);
+               }
+       }
+
+       lpf_node = fsck_get_lpf(sbi);
+       if (!lpf_node)
+               goto out;
+
+       for (nid = 0; nid < fsck->nr_nat_entries; nid++) {
+               if (f2fs_test_bit(nid, reconnect_bitmap)) {
+                       get_node_info(sbi, nid, &ni);
+                       err = dev_read_block(node, ni.blk_addr);
+                       ASSERT(err >= 0);
+
+                       if (fsck_do_reconnect_file(sbi, lpf_node, node)) {
+                               DBG(1, "Failed to reconnect inode [0x%x]\n",
+                                   nid);
+                               fsck_failed_reconnect_file(sbi, nid);
+                               continue;
+                       }
+
+                       quota_add_inode_usage(fsck->qctx, nid, &node->i);
+
+                       DBG(1, "Reconnected inode [0x%x] to lost+found\n", nid);
+                       cnt++;
+               }
+       }
+
+out:
+       free(node);
+       free(lpf_node);
+       free(reconnect_bitmap);
+       return cnt;
+}
+
 int fsck_verify(struct f2fs_sb_info *sbi)
 {
        unsigned int i = 0;
@@ -2057,6 +2432,16 @@ int fsck_verify(struct f2fs_sb_info *sbi)
 
        printf("\n");
 
+       if (c.feature & cpu_to_le32(F2FS_FEATURE_LOST_FOUND)) {
+               for (i = 0; i < fsck->nr_nat_entries; i++)
+                       if (f2fs_test_bit(i, fsck->nat_area_bitmap) != 0)
+                               break;
+               if (i < fsck->nr_nat_entries) {
+                       i = fsck_reconnect_file(sbi);
+                       printf("[FSCK] Reconnect %u files to lost+found\n", i);
+               }
+       }
+
        for (i = 0; i < fsck->nr_nat_entries; i++) {
                if (f2fs_test_bit(i, fsck->nat_area_bitmap) != 0) {
                        printf("NID[0x%x] is unreachable\n", i);
index 648c2db..8e133fa 100644 (file)
@@ -243,6 +243,9 @@ int f2fs_mkdir(struct f2fs_sb_info *, struct dentry *);
 int f2fs_symlink(struct f2fs_sb_info *, struct dentry *);
 int inode_set_selinux(struct f2fs_sb_info *, u32, const char *);
 int f2fs_find_path(struct f2fs_sb_info *, char *, nid_t *);
+nid_t f2fs_lookup(struct f2fs_sb_info *, struct f2fs_node *, u8 *, int);
+int f2fs_add_link(struct f2fs_sb_info *, struct f2fs_node *,
+               const unsigned char *, int, nid_t, int, block_t, int);
 
 /* xattr.c */
 void *read_all_xattrs(struct f2fs_sb_info *, struct f2fs_node *);
index 444d586..a481a1e 100644 (file)
@@ -1600,6 +1600,8 @@ void update_nat_blkaddr(struct f2fs_sb_info *sbi, nid_t ino,
        if (ino)
                nat_block->entries[entry_off].ino = cpu_to_le32(ino);
        nat_block->entries[entry_off].block_addr = cpu_to_le32(newaddr);
+       if (c.func == FSCK)
+               F2FS_FSCK(sbi)->entries[nid] = nat_block->entries[entry_off];
 
        ret = dev_write_block(nat_block, block_addr);
        ASSERT(ret >= 0);