From: Vyacheslav Dubeyko <slava@xxxxxxxxxxx>
Subject: [PATCH v2 03/15] hfsplus: implement init/destroy journal object functionality
The patch implements functionality of initialization (hfsplus_init_journal()
method) and destruction (hfsplus_destroy_journal() method) of HFS+ journal
object in memory.
The hfsplus_init_journal():
(1) checks that HFS+ has journal;
(2) allocate memory for main incapsulated objects;
(3) check that journal is located inside file system's volume;
(4) initialize journal's on-disk structures (in the case of necessity).
The hfsplus_destroy_journal() method frees allocated memory.
Signed-off-by: Vyacheslav Dubeyko <slava@xxxxxxxxxxx>
CC: Al Viro <viro@xxxxxxxxxxxxxxxxxx>
CC: Christoph Hellwig <hch@xxxxxxxxxxxxx>
Tested-by: Hin-Tak Leung <htl10@xxxxxxxxxxxxxxxxxxxxx>
---
fs/hfsplus/journal.c | 168 ++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 168 insertions(+)
create mode 100644 fs/hfsplus/journal.c
diff --git a/fs/hfsplus/journal.c b/fs/hfsplus/journal.c
new file mode 100644
index 0000000..d748fd4
--- /dev/null
+++ b/fs/hfsplus/journal.c
@@ -0,0 +1,168 @@
+/*
+ * linux/fs/hfsplus/journal.c
+ *
+ * Vyacheslav Dubeyko <slava@xxxxxxxxxxx>
+ *
+ * Logic of HFS+ journalling
+ */
+
+#include "hfsplus_fs.h"
+
+#define HFSPLUS_HAS_JOURNAL(sb) \
+ (HFSPLUS_SB(sb)->s_vhdr->attributes & \
+ cpu_to_be32(HFSPLUS_VOL_JOURNALED))
+
+#define JIB_BLOCK(sb) \
+ (be32_to_cpu(HFSPLUS_SB(sb)->s_vhdr->journal_info_block))
+#define JIB_FLAGS(jnl) \
+ (be32_to_cpu(((struct hfsplus_journal *)(jnl))->jib->flags))
+
+#define JH_BLOCK(sb, jnl) \
+ (be64_to_cpu(((struct hfsplus_journal *)(jnl))->jib->offset) >> \
+ HFSPLUS_SB(sb)->alloc_blksz_shift)
+
+#define BLOCK_TO_SEC(sb, blk) \
+ ((sector_t)(blk) << \
+ (HFSPLUS_SB(sb)->alloc_blksz_shift - HFSPLUS_SECTOR_SHIFT))
+
+static int hfsplus_create_journal(struct super_block *sb,
+ struct hfsplus_journal *jnl);
+
+/*
+ * hfsplus_init_journal - initialize journal object
+ *
+ * @sb: superblock
+ *
+ * Check presence of journal on volume and initialize journal object.
+ * It is assumed that superblock and volume header are initialized yet.
+ */
+int hfsplus_init_journal(struct super_block *sb)
+{
+ struct hfsplus_journal *jnl;
+ sector_t jib_blk;
+ sector_t jh_blk;
+ int err = 0;
+
+ HFSPLUS_SB(sb)->jnl = NULL;
+
+ if (!HFSPLUS_HAS_JOURNAL(sb))
+ return 0; /* journal absent */
+
+ hfs_dbg(JOURNAL, "try to init journal subsystem\n");
+
+ jnl = kzalloc(sizeof(*jnl), GFP_KERNEL);
+ if (unlikely(!jnl))
+ return -ENOMEM;
+
+ hfs_dbg(JOURNAL, "HFS+ filesystem has journal\n");
+
+ jnl->jib_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL);
+ if (unlikely(!jnl->jib_buf)) {
+ pr_err("unable to allocate jib_buf\n");
+ err = -ENOMEM;
+ goto init_failed;
+ }
+
+ jnl->jh_buf = kmalloc(hfsplus_min_io_size(sb), GFP_KERNEL);
+ if (unlikely(!jnl->jh_buf)) {
+ pr_err("unable to allocate jh_buf\n");
+ err = -ENOMEM;
+ goto free_jib_buf;
+ }
+
+ jib_blk = HFSPLUS_SB(sb)->blockoffset + JIB_BLOCK(sb);
+
+ err = hfsplus_submit_bio(sb, BLOCK_TO_SEC(sb, jib_blk),
+ jnl->jib_buf, (void **)&jnl->jib, READ, NULL);
+ if (err) {
+ pr_err("unable to read journal info block %lu\n", jib_blk);
+ goto free_jh_buf;
+ }
+
+ hfs_dbg(JOURNAL, "jib_flags %#x\n", JIB_FLAGS(jnl));
+ hfs_dbg(JOURNAL, "journal size %u\n", be32_to_cpu(jnl->jib->size));
+
+ if ((JIB_FLAGS(jnl) & HFSPLUS_JOURNAL_ON_OTHER_DEVICE) &&
+ !(JIB_FLAGS(jnl) & HFSPLUS_JOURNAL_IN_FS)) {
+ err = -EOPNOTSUPP;
+ goto free_jh_buf;
+ }
+
+ jh_blk = JH_BLOCK(sb, jnl);
+
+ hfs_dbg(JOURNAL, "read journal header: jh_bkl %lu\n", jh_blk);
+
+ err = hfsplus_submit_bio(sb, BLOCK_TO_SEC(sb, jh_blk),
+ jnl->jh_buf, (void **)&jnl->jh, READ, NULL);
+ if (err) {
+ pr_err("unable to read journal header block %lu\n", jh_blk);
+ goto free_jh_buf;
+ }
+
+ if (JIB_FLAGS(jnl) & HFSPLUS_JOURNAL_NEED_INIT) {
+ hfs_dbg(JOURNAL, "create HFS+ journal\n");
+
+ err = hfsplus_create_journal(sb, jnl);
+ if (unlikely(err)) {
+ pr_err("fail to create HFS+ journal\n");
+ goto free_jh_buf;
+ }
+
+ jnl->jib->flags &= be32_to_cpu(~HFSPLUS_JOURNAL_NEED_INIT);
+
+ err = hfsplus_submit_bio(sb, BLOCK_TO_SEC(sb, jh_blk),
+ jnl->jh_buf, NULL, WRITE_SYNC, NULL);
+ if (err) {
+ pr_err("unable to write journal header block %lu\n",
+ jh_blk);
+ goto free_jh_buf;
+ }
+
+ err = hfsplus_submit_bio(sb, BLOCK_TO_SEC(sb, jib_blk),
+ jnl->jib_buf, NULL, WRITE_SYNC, NULL);
+ if (err) {
+ pr_err("unable to write journal info block %lu\n",
+ jib_blk);
+ goto free_jh_buf;
+ }
+ }
+
+ mutex_init(&jnl->jnl_lock);
+ jnl->sbp = sb;
+ HFSPLUS_SB(sb)->jnl = jnl;
+
+ return err;
+
+free_jh_buf:
+ kfree(jnl->jh_buf);
+
+free_jib_buf:
+ kfree(jnl->jib_buf);
+
+init_failed:
+ kfree(jnl);
+
+ return err;
+}
+
+/*
+ * hfsplus_destroy_journal - deinitialize journal (if it is present).
+ *
+ * @sb: superblock
+ */
+void hfsplus_destroy_journal(struct super_block *sb)
+{
+ struct hfsplus_sb_info *sbi = HFSPLUS_SB(sb);
+ struct hfsplus_journal *jnl = sbi->jnl;
+
+ if (!jnl)
+ return;
+
+ hfs_dbg(JOURNAL, "destroy journal subsystem\n");
+
+ /* TODO: stop journal thread */
+
+ kfree(jnl->jh_buf);
+ kfree(jnl->jib_buf);
+ kfree(jnl);
+}
--
1.7.9.5
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