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Message-ID: <20111214011610.20947.18930.stgit@elm3c44.beaverton.ibm.com>
Date: Tue, 13 Dec 2011 17:16:10 -0800
From: "Darrick J. Wong" <djwong@...ibm.com>
To: Andreas Dilger <adilger.kernel@...ger.ca>,
Theodore Tso <tytso@....edu>,
"Darrick J. Wong" <djwong@...ibm.com>
Cc: Sunil Mushran <sunil.mushran@...cle.com>,
Amir Goldstein <amir73il@...il.com>,
Andi Kleen <andi@...stfloor.org>,
Mingming Cao <cmm@...ibm.com>,
Joel Becker <jlbec@...lplan.org>, linux-ext4@...r.kernel.org,
Coly Li <colyli@...il.com>
Subject: [PATCH 26/51] tune2fs: Rebuild and checksum directories when toggling
metadata_csum or changing UUID
Since all the metadata checksums depend on the fs UUID, tune2fs must be able to
rewrite the checksums of _all_ metadata. It's not that hard to add in the bits
to resize the directory block structures at the same time.
Signed-off-by: Darrick J. Wong <djwong@...ibm.com>
---
misc/tune2fs.c | 193 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 files changed, 193 insertions(+), 0 deletions(-)
diff --git a/misc/tune2fs.c b/misc/tune2fs.c
index c7b9fd3..236a324 100644
--- a/misc/tune2fs.c
+++ b/misc/tune2fs.c
@@ -106,6 +106,8 @@ struct blk_move {
static const char *please_fsck = N_("Please run e2fsck on the filesystem.\n");
+static const char *please_dir_fsck =
+ N_("Please run e2fsck -D on the filesystem.\n");
#ifdef CONFIG_BUILD_FINDFS
void do_findfs(int argc, char **argv);
@@ -364,6 +366,18 @@ static int check_fsck_needed(ext2_filsys fs)
return 1;
}
+static void request_dir_fsck_afterwards(ext2_filsys fs)
+{
+ static int requested;
+
+ if (requested++)
+ return;
+ fs->super->s_state &= ~EXT2_VALID_FS;
+ printf("\n%s\n", _(please_dir_fsck));
+ if (mount_flags & EXT2_MF_READONLY)
+ printf(_("(and reboot afterwards!)\n"));
+}
+
static void request_fsck_afterwards(ext2_filsys fs)
{
static int requested = 0;
@@ -419,6 +433,176 @@ static errcode_t rewrite_extents(ext2_filsys fs, ext2_ino_t ino,
}
/*
+ * Rewrite directory blocks with checksums
+ */
+struct rewrite_dir_context {
+ char *buf;
+ errcode_t errcode;
+ ext2_ino_t dir;
+ int is_htree;
+};
+
+static int rewrite_dir_block(ext2_filsys fs,
+ blk64_t *blocknr,
+ e2_blkcnt_t blockcnt,
+ blk64_t ref_block EXT2FS_ATTR((unused)),
+ int ref_offset EXT2FS_ATTR((unused)),
+ void *priv_data)
+{
+ struct ext2_dx_countlimit *dcl = NULL;
+ struct rewrite_dir_context *ctx = priv_data;
+ int dcl_offset, changed = 0;
+
+ ctx->errcode = ext2fs_read_dir_block4(fs, *blocknr, ctx->buf, 0,
+ ctx->dir);
+ if (ctx->errcode)
+ return BLOCK_ABORT;
+
+ /* if htree node... */
+ if (ctx->is_htree)
+ ext2fs_get_dx_countlimit(fs, (struct ext2_dir_entry *)ctx->buf,
+ &dcl, &dcl_offset);
+ if (dcl) {
+ if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
+ /* Ensure limit is the max size */
+ int max_entries = (fs->blocksize - dcl_offset) /
+ sizeof(struct ext2_dx_entry);
+ if (ext2fs_le16_to_cpu(dcl->limit) != max_entries) {
+ changed = 1;
+ dcl->limit = ext2fs_cpu_to_le16(max_entries);
+ }
+ } else {
+ /* If htree block is full then rebuild the dir */
+ if (ext2fs_le16_to_cpu(dcl->count) ==
+ ext2fs_le16_to_cpu(dcl->limit)) {
+ request_dir_fsck_afterwards(fs);
+ return 0;
+ }
+ /*
+ * Ensure dcl->limit is small enough to leave room for
+ * the checksum tail.
+ */
+ int max_entries = (fs->blocksize - (dcl_offset +
+ sizeof(struct ext2_dx_tail))) /
+ sizeof(struct ext2_dx_entry);
+ if (ext2fs_le16_to_cpu(dcl->limit) != max_entries)
+ dcl->limit = ext2fs_cpu_to_le16(max_entries);
+ /* Always rewrite checksum */
+ changed = 1;
+ }
+ } else {
+ unsigned int rec_len, name_size;
+ char *top = ctx->buf + fs->blocksize;
+ struct ext2_dir_entry *de = (struct ext2_dir_entry *)ctx->buf;
+ struct ext2_dir_entry *last_de = NULL, *penultimate_de = NULL;
+
+ /* Find last and penultimate dirent */
+ while ((char *)de < top) {
+ penultimate_de = last_de;
+ last_de = de;
+ ctx->errcode = ext2fs_get_rec_len(fs, de, &rec_len);
+ if (!ctx->errcode && !rec_len)
+ ctx->errcode = EXT2_ET_DIR_CORRUPTED;
+ if (ctx->errcode)
+ return BLOCK_ABORT;
+ de = (struct ext2_dir_entry *)(((void *)de) + rec_len);
+ }
+ ctx->errcode = ext2fs_get_rec_len(fs, last_de, &rec_len);
+ if (ctx->errcode)
+ return BLOCK_ABORT;
+ name_size = last_de->name_len & 0xFF;
+
+ if (!EXT2_HAS_RO_COMPAT_FEATURE(fs->super,
+ EXT4_FEATURE_RO_COMPAT_METADATA_CSUM)) {
+ if (!penultimate_de)
+ return 0;
+ if (last_de->inode ||
+ name_size ||
+ rec_len != sizeof(struct ext2_dir_entry_tail))
+ return 0;
+ /*
+ * The last dirent is unused and the right length to
+ * have stored a checksum. Erase it.
+ */
+ ctx->errcode = ext2fs_get_rec_len(fs, penultimate_de,
+ &rec_len);
+ if (!rec_len)
+ ctx->errcode = EXT2_ET_DIR_CORRUPTED;
+ if (ctx->errcode)
+ return BLOCK_ABORT;
+ ext2fs_set_rec_len(fs, rec_len +
+ sizeof(struct ext2_dir_entry_tail),
+ penultimate_de);
+ changed = 1;
+ } else {
+ int csum_size = sizeof(struct ext2_dir_entry_tail);
+ struct ext2_dir_entry_tail *t;
+
+ /*
+ * If the last dirent looks like the tail, just update
+ * the checksum.
+ */
+ if (!last_de->inode &&
+ rec_len == csum_size) {
+ t = (struct ext2_dir_entry_tail *)last_de;
+ t->reserved_name_len = EXT2_DIR_NAME_LEN_CSUM;
+ changed = 1;
+ goto out;
+ }
+ if (name_size & 3)
+ name_size = (name_size & ~3) + 4;
+ /* If there's not enough space for the tail, e2fsck */
+ if (rec_len <= (8 + name_size + csum_size)) {
+ request_dir_fsck_afterwards(fs);
+ return 0;
+ }
+ /* Shorten that last de and insert the tail */
+ ext2fs_set_rec_len(fs, rec_len - csum_size, last_de);
+ t = EXT2_DIRENT_TAIL(ctx->buf, fs->blocksize);
+ ext2fs_initialize_dirent_tail(fs, t);
+
+ /* Always update checksum */
+ changed = 1;
+ }
+ }
+
+out:
+ if (!changed)
+ return 0;
+
+ ctx->errcode = ext2fs_write_dir_block4(fs, *blocknr, ctx->buf,
+ 0, ctx->dir);
+ if (ctx->errcode)
+ return BLOCK_ABORT;
+
+ return 0;
+}
+
+errcode_t rewrite_directory(ext2_filsys fs, ext2_ino_t dir,
+ struct ext2_inode *inode)
+{
+ errcode_t retval;
+ struct rewrite_dir_context ctx;
+
+ retval = ext2fs_get_mem(fs->blocksize, &ctx.buf);
+ if (retval)
+ return retval;
+
+ ctx.is_htree = (inode->i_flags & EXT2_INDEX_FL);
+ ctx.dir = dir;
+ retval = ext2fs_block_iterate3(fs, dir, BLOCK_FLAG_READ_ONLY |
+ BLOCK_FLAG_DATA_ONLY,
+ 0, rewrite_dir_block, &ctx);
+
+ ext2fs_free_mem(&ctx.buf);
+ if (retval)
+ return retval;
+
+ return ctx.errcode;
+}
+
+/*
* Forcibly set checksums in all inodes.
*/
static void rewrite_inodes(ext2_filsys fs)
@@ -465,6 +649,15 @@ static void rewrite_inodes(ext2_filsys fs)
"while rewriting extents");
exit(1);
}
+
+ if (LINUX_S_ISDIR(inode->i_mode)) {
+ retval = rewrite_directory(fs, ino, inode);
+ if (retval) {
+ com_err("rewrite_directory", retval,
+ "while rewriting directories");
+ exit(1);
+ }
+ }
} while (ino);
ext2fs_free_mem(&inode);
--
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