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Message-ID: <20070507221011.GD15054@lazybastard.org>
Date: Tue, 8 May 2007 00:10:15 +0200
From: Jörn Engel <joern@...ybastard.org>
To: Andrew Morton <akpm@...l.org>
Cc: linux-fsdevel@...r.kernel.org, linux-kernel@...r.kernel.org,
Dave Kleikamp <shaggy@...ux.vnet.ibm.com>,
David Chinner <dgc@....com>
Subject: Re: [PATCH 1/2] LogFS proper
On Tue, 8 May 2007 00:00:36 +0200, Jörn Engel wrote:
>
> Signed-off-by: Jörn Engel <joern@...nheim.fh-wedel.de>
> ---
>
> fs/Kconfig | 15
> fs/Makefile | 1
> fs/logfs/Locking | 45 ++
> fs/logfs/Makefile | 14
> fs/logfs/NAMES | 32 +
> fs/logfs/compr.c | 198 ++++++++
> fs/logfs/dir.c | 705 +++++++++++++++++++++++++++++++
> fs/logfs/file.c | 82 +++
> fs/logfs/gc.c | 350 +++++++++++++++
> fs/logfs/inode.c | 468 ++++++++++++++++++++
> fs/logfs/journal.c | 696 ++++++++++++++++++++++++++++++
> fs/logfs/logfs.h | 626 +++++++++++++++++++++++++++
> fs/logfs/memtree.c | 199 ++++++++
> fs/logfs/progs/fsck.c | 323 ++++++++++++++
> fs/logfs/progs/mkfs.c | 319 ++++++++++++++
> fs/logfs/readwrite.c | 1125 ++++++++++++++++++++++++++++++++++++++++++++++++++
> fs/logfs/segment.c | 533 +++++++++++++++++++++++
> fs/logfs/super.c | 490 +++++++++++++++++++++
> 19 files changed, 6237 insertions(+)
Looks like the mail size limit caught the patch. For review, here's the
first half...
--- linux-2.6.21logfs/fs/Kconfig~logfs 2007-05-07 13:23:51.000000000 +0200
+++ linux-2.6.21logfs/fs/Kconfig 2007-05-07 13:32:12.000000000 +0200
@@ -1351,6 +1351,21 @@ config JFFS2_CMODE_SIZE
endchoice
+config LOGFS
+ tristate "Log Filesystem (EXPERIMENTAL)"
+ depends on EXPERIMENTAL
+ select ZLIB_INFLATE
+ select ZLIB_DEFLATE
+ help
+ Successor of JFFS2, using explicit filesystem hierarchy.
+ Continuing with the long tradition of calling the filesystem
+ exactly what it is not, LogFS is a journaled filesystem,
+ while JFFS and JFFS2 were true log-structured filesystems.
+ The hybrid structure of journaled filesystems promise to
+ scale better to larger sized.
+
+ If unsure, say N.
+
config CRAMFS
tristate "Compressed ROM file system support (cramfs)"
depends on BLOCK
--- linux-2.6.21logfs/fs/Makefile~logfs 2007-05-07 10:28:48.000000000 +0200
+++ linux-2.6.21logfs/fs/Makefile 2007-05-07 13:32:12.000000000 +0200
@@ -95,6 +95,7 @@ obj-$(CONFIG_NTFS_FS) += ntfs/
obj-$(CONFIG_UFS_FS) += ufs/
obj-$(CONFIG_EFS_FS) += efs/
obj-$(CONFIG_JFFS2_FS) += jffs2/
+obj-$(CONFIG_LOGFS) += logfs/
obj-$(CONFIG_AFFS_FS) += affs/
obj-$(CONFIG_ROMFS_FS) += romfs/
obj-$(CONFIG_QNX4FS_FS) += qnx4/
--- /dev/null 2007-04-18 05:32:26.652341749 +0200
+++ linux-2.6.21logfs/fs/logfs/NAMES 2007-05-07 13:32:12.000000000 +0200
@@ -0,0 +1,32 @@
+This filesystem started with the codename "Logfs", which was actually
+a joke at the time. Logfs was to replace JFFS2, the journaling flash
+filesystem (version 2). JFFS2 was actually a log structured
+filesystem in its purest form, so the name described just what it was
+not. Logfs was planned as a journaling filesystem, so its name would
+be in the same tradition of non-description.
+
+Apart from the joke, "Logfs" was only intended as a codename, later to
+be replaced by something better. Some ideas from various people were:
+logfs
+jffs3
+jefs
+engelfs
+poofs
+crapfs
+sweetfs
+cutefs
+dynamic journaling fs - djofs
+tfsfkal - the file system formerly known as logfs
+
+Later it turned out that while having a journal, Logfs has borrowed so
+many concepts from log structured filesystems that the name actually
+made some sense.
+
+Yet later, Arnd noticed that Logfs was to scale logarithmically with
+increasing flash sizes, where JFFS2 scales linearly. What a nice
+coincidence. Even better, its successor can be called Log2fs,
+emphasizing this point.
+
+So to this day, I still like "Logfs" and cannot come up with a better
+name. And unless someone has the stroke of a genius or there is
+massive opposition against this name, I'd like to just keep it.
--- /dev/null 2007-04-18 05:32:26.652341749 +0200
+++ linux-2.6.21logfs/fs/logfs/Makefile 2007-05-07 13:32:12.000000000 +0200
@@ -0,0 +1,14 @@
+obj-$(CONFIG_LOGFS) += logfs.o
+
+logfs-y += compr.o
+logfs-y += dir.o
+logfs-y += file.o
+logfs-y += gc.o
+logfs-y += inode.o
+logfs-y += journal.o
+logfs-y += memtree.o
+logfs-y += readwrite.o
+logfs-y += segment.o
+logfs-y += super.o
+logfs-y += progs/fsck.o
+logfs-y += progs/mkfs.o
--- /dev/null 2007-04-18 05:32:26.652341749 +0200
+++ linux-2.6.21logfs/fs/logfs/logfs.h 2007-05-07 13:32:12.000000000 +0200
@@ -0,0 +1,626 @@
+#ifndef logfs_h
+#define logfs_h
+
+#define __CHECK_ENDIAN__
+
+
+#include <linux/crc32.h>
+#include <linux/fs.h>
+#include <linux/kallsyms.h>
+#include <linux/kernel.h>
+#include <linux/mtd/mtd.h>
+#include <linux/pagemap.h>
+#include <linux/statfs.h>
+
+
+/**
+ * Throughout the logfs code, we're constantly dealing with blocks at
+ * various positions or offsets. To remove confusion, we stricly
+ * distinguish between a "position" - the logical position within a
+ * file and an "offset" - the physical location within the device.
+ *
+ * Any usage of the term offset for a logical location or position for
+ * a physical one is a bug and should get fixed.
+ */
+
+/**
+ * Block are allocated in one of several segments depending on their
+ * level. The following levels are used:
+ * 0 - regular data block
+ * 1 - i1 indirect blocks
+ * 2 - i2 indirect blocks
+ * 3 - i3 indirect blocks
+ * 4 - i4 indirect blocks
+ * 5 - i5 indirect blocks
+ * 6 - ifile data blocks
+ * 7 - ifile i1 indirect blocks
+ * 8 - ifile i2 indirect blocks
+ * 9 - ifile i3 indirect blocks
+ * 10 - ifile i4 indirect blocks
+ * 11 - ifile i5 indirect blocks
+ * Potential levels to be used in the future:
+ * 12 - gc recycled blocks, long-lived data
+ * 13 - replacement blocks, short-lived data
+ *
+ * Levels 1-11 are necessary for robust gc operations and help seperate
+ * short-lived metadata from longer-lived file data. In the future,
+ * file data should get seperated into several segments based on simple
+ * heuristics. Old data recycled during gc operation is expected to be
+ * long-lived. New data is of uncertain life expectancy. New data
+ * used to replace older blocks in existing files is expected to be
+ * short-lived.
+ */
+
+
+typedef __be16 be16;
+typedef __be32 be32;
+typedef __be64 be64;
+
+struct btree_head {
+ struct btree_node *node;
+ int height;
+ void *null_ptr;
+};
+
+#define packed __attribute__((__packed__))
+
+
+#define TRACE() do { \
+ printk("trace: %s:%d: ", __FILE__, __LINE__); \
+ printk("->%s\n", __func__); \
+} while(0)
+
+
+#define LOGFS_MAGIC 0xb21f205ac97e8168ull
+#define LOGFS_MAGIC_U32 0xc97e8168ull
+
+
+#define LOGFS_BLOCK_SECTORS (8)
+#define LOGFS_BLOCK_BITS (9) /* 512 pointers, used for shifts */
+#define LOGFS_BLOCKSIZE (4096ull)
+#define LOGFS_BLOCK_FACTOR (LOGFS_BLOCKSIZE / sizeof(u64))
+#define LOGFS_BLOCK_MASK (LOGFS_BLOCK_FACTOR-1)
+
+#define I0_BLOCKS (4+16)
+#define I1_BLOCKS LOGFS_BLOCK_FACTOR
+#define I2_BLOCKS (LOGFS_BLOCK_FACTOR * I1_BLOCKS)
+#define I3_BLOCKS (LOGFS_BLOCK_FACTOR * I2_BLOCKS)
+#define I4_BLOCKS (LOGFS_BLOCK_FACTOR * I3_BLOCKS)
+#define I5_BLOCKS (LOGFS_BLOCK_FACTOR * I4_BLOCKS)
+
+#define I1_INDEX (4+16)
+#define I2_INDEX (5+16)
+#define I3_INDEX (6+16)
+#define I4_INDEX (7+16)
+#define I5_INDEX (8+16)
+
+#define LOGFS_EMBEDDED_FIELDS (9+16)
+
+#define LOGFS_EMBEDDED_SIZE (LOGFS_EMBEDDED_FIELDS * sizeof(u64))
+#define LOGFS_I0_SIZE (I0_BLOCKS * LOGFS_BLOCKSIZE)
+#define LOGFS_I1_SIZE (I1_BLOCKS * LOGFS_BLOCKSIZE)
+#define LOGFS_I2_SIZE (I2_BLOCKS * LOGFS_BLOCKSIZE)
+#define LOGFS_I3_SIZE (I3_BLOCKS * LOGFS_BLOCKSIZE)
+#define LOGFS_I4_SIZE (I4_BLOCKS * LOGFS_BLOCKSIZE)
+#define LOGFS_I5_SIZE (I5_BLOCKS * LOGFS_BLOCKSIZE)
+
+#define LOGFS_MAX_INDIRECT (5)
+#define LOGFS_MAX_LEVELS (LOGFS_MAX_INDIRECT + 1)
+#define LOGFS_NO_AREAS (2 * LOGFS_MAX_LEVELS)
+
+
+struct logfs_disk_super {
+ be64 ds_magic;
+ be32 ds_crc; /* crc32 of everything below */
+ u8 ds_ifile_levels; /* max level of ifile */
+ u8 ds_iblock_levels; /* max level of regular files */
+ u8 ds_data_levels; /* number of segments to leaf blocks */
+ u8 pad0;
+
+ be64 ds_feature_incompat;
+ be64 ds_feature_ro_compat;
+
+ be64 ds_feature_compat;
+ be64 ds_flags;
+
+ be64 ds_filesystem_size; /* filesystem size in bytes */
+ u8 ds_segment_shift; /* log2 of segment size */
+ u8 ds_block_shift; /* log2 if block size */
+ u8 ds_write_shift; /* log2 of write size */
+ u8 pad1[5];
+
+ /* the segments of the primary journal. if fewer than 4 segments are
+ * used, some fields are set to 0 */
+#define LOGFS_JOURNAL_SEGS 4
+ be64 ds_journal_seg[LOGFS_JOURNAL_SEGS];
+
+ be64 ds_root_reserve; /* bytes reserved for root */
+
+ be64 pad2[19]; /* align to 256 bytes */
+}packed;
+
+
+#define LOGFS_IF_VALID 0x00000001 /* inode exists */
+#define LOGFS_IF_EMBEDDED 0x00000002 /* data embedded in block pointers */
+#define LOGFS_IF_ZOMBIE 0x00000004 /* inode was already deleted */
+#define LOGFS_IF_STILLBORN 0x40000000 /* couldn't write inode in creat() */
+#define LOGFS_IF_INVALID 0x80000000 /* inode does not exist */
+struct logfs_disk_inode {
+ be16 di_mode;
+ be16 di_pad;
+ be32 di_flags;
+ be32 di_uid;
+ be32 di_gid;
+
+ be64 di_ctime;
+ be64 di_mtime;
+
+ be32 di_refcount;
+ be32 di_generation;
+ be64 di_used_bytes;
+
+ be64 di_size;
+ be64 di_data[LOGFS_EMBEDDED_FIELDS];
+}packed;
+
+
+#define LOGFS_MAX_NAMELEN 255
+struct logfs_disk_dentry {
+ be64 ino; /* inode pointer */
+ be16 namelen;
+ u8 type;
+ u8 name[LOGFS_MAX_NAMELEN];
+}packed;
+
+
+#define OBJ_TOP_JOURNAL 1 /* segment header for master journal */
+#define OBJ_JOURNAL 2 /* segment header for journal */
+#define OBJ_OSTORE 3 /* segment header for ostore */
+#define OBJ_BLOCK 4 /* data block */
+#define OBJ_INODE 5 /* inode */
+#define OBJ_DENTRY 6 /* dentry */
+struct logfs_object_header {
+ be32 crc; /* checksum */
+ be16 len; /* length of object, header not included */
+ u8 type; /* node type */
+ u8 compr; /* compression type */
+ be64 ino; /* inode number */
+ be64 pos; /* file position */
+}packed;
+
+
+struct logfs_segment_header {
+ be32 crc; /* checksum */
+ be16 len; /* length of object, header not included */
+ u8 type; /* node type */
+ u8 level; /* GC level */
+ be32 segno; /* segment number */
+ be32 ec; /* erase count */
+ be64 gec; /* global erase count (write time) */
+}packed;
+
+
+struct logfs_object_id {
+ be64 ino;
+ be64 pos;
+}packed;
+
+
+struct logfs_disk_sum {
+ /* footer */
+ be32 erase_count;
+ u8 level;
+ u8 pad[3];
+ union {
+ be64 segno;
+ be64 gec;
+ };
+ struct logfs_object_id oids[0];
+}packed;
+
+
+struct logfs_journal_header {
+ be32 h_crc; /* crc32 of everything */
+ be16 h_len; /* length of compressed journal entry */
+ be16 h_datalen; /* length of uncompressed data */
+ be16 h_type; /* anchor, spillout or delta */
+ be16 h_version; /* a counter, effectively */
+ u8 h_compr; /* compression type */
+ u8 h_pad[3];
+}packed;
+
+
+struct logfs_dynsb {
+ be64 ds_gec; /* global erase count */
+ be64 ds_sweeper; /* current position of gc "sweeper" */
+
+ be64 ds_rename_dir; /* source directory ino */
+ be64 ds_rename_pos; /* position of source dd */
+
+ be64 ds_victim_ino; /* victims of incomplete dir operation, */
+ be64 ds_used_bytes; /* number of used bytes */
+};
+
+
+struct logfs_anchor {
+ be64 da_size; /* size of inode file */
+ be64 da_last_ino;
+
+ be64 da_used_bytes; /* blocks used for inode file */
+ be64 da_data[LOGFS_EMBEDDED_FIELDS];
+}packed;
+
+
+struct logfs_spillout {
+ be64 so_segment[0]; /* length given by h_len field */
+}packed;
+
+
+struct logfs_delta {
+ be64 d_ofs; /* offset of changed block */
+ u8 d_data[0]; /* XOR between on-medium and actual block,
+ zlib compressed */
+}packed;
+
+
+struct logfs_journal_ec {
+ be32 ec[0]; /* length given by h_len field */
+}packed;
+
+
+struct logfs_journal_sum {
+ struct logfs_disk_sum sum[0]; /* length given by h_len field */
+}packed;
+
+
+struct logfs_je_areas {
+ be32 used_bytes[16];
+ be32 segno[16];
+};
+
+
+enum {
+ COMPR_NONE = 0,
+ COMPR_ZLIB = 1,
+};
+
+
+/* Journal entries come in groups of 16. First group contains individual
+ * entries, next groups contain one entry per level */
+enum {
+ JEG_BASE = 0,
+ JE_FIRST = 1,
+
+ JE_COMMIT = 1, /* commits all previous entries */
+ JE_ABORT = 2, /* aborts all previous entries */
+ JE_DYNSB = 3,
+ JE_ANCHOR = 4,
+ JE_ERASECOUNT = 5,
+ JE_SPILLOUT = 6,
+ JE_DELTA = 7,
+ JE_BADSEGMENTS = 8,
+ JE_AREAS = 9, /* area description sans wbuf */
+ JEG_WBUF = 0x10, /* write buffer for segments */
+
+ JE_LAST = 0x1f,
+};
+
+
+////////////////////////////////////////////////////////////////////////////////
+////////////////////////////////////////////////////////////////////////////////
+
+
+#define LOGFS_SUPER(sb) ((struct logfs_super*)(sb->s_fs_info))
+#define LOGFS_INODE(inode) container_of(inode, struct logfs_inode, vfs_inode)
+
+
+ /* 0 reserved for gc markers */
+#define LOGFS_INO_MASTER 1 /* inode file */
+#define LOGFS_INO_ROOT 2 /* root directory */
+#define LOGFS_INO_ATIME 4 /* atime for all inodes */
+#define LOGFS_INO_BAD_BLOCKS 5 /* bad blocks */
+#define LOGFS_INO_OBSOLETE 6 /* obsolete block count */
+#define LOGFS_INO_ERASE_COUNT 7 /* erase count */
+#define LOGFS_RESERVED_INOS 16
+
+
+struct logfs_object {
+ u64 ino; /* inode number */
+ u64 pos; /* position in file */
+};
+
+
+struct logfs_area { /* a segment open for writing */
+ struct super_block *a_sb;
+ int a_is_open;
+ u32 a_segno; /* segment number */
+ u32 a_used_objects; /* number of objects already used */
+ u32 a_used_bytes; /* number of bytes already used */
+ struct logfs_area_ops *a_ops;
+ /* on-medium information */
+ void *a_wbuf;
+ u32 a_erase_count;
+ u8 a_level;
+};
+
+
+struct logfs_area_ops {
+ /* fill area->ofs with the offset of a free segment */
+ void (*get_free_segment)(struct logfs_area *area);
+ /* fill area->erase_count (needs area->ofs) */
+ void (*get_erase_count)(struct logfs_area *area);
+ /* clear area->blocks */
+ void (*clear_blocks)(struct logfs_area *area);
+ /* erase and setup segment */
+ int (*erase_segment)(struct logfs_area *area);
+ /* write summary on tree segments */
+ void (*finish_area)(struct logfs_area *area);
+};
+
+
+struct logfs_segment {
+ struct list_head list;
+ u32 erase_count;
+ u32 valid;
+ u64 write_time;
+ u32 segno;
+};
+
+
+struct logfs_journal_entry {
+ int used;
+ s16 version;
+ u16 len;
+ u64 offset;
+};
+
+
+struct logfs_super {
+ //struct super_block *s_sb; /* should get removed... */
+ struct mtd_info *s_mtd; /* underlying device */
+ struct inode *s_master_inode; /* ifile */
+ struct inode *s_dev_inode; /* device caching */
+ /* dir.c fields */
+ struct mutex s_victim_mutex; /* only one victim at once */
+ u64 s_victim_ino; /* used for atomic dir-ops */
+ struct mutex s_rename_mutex; /* only one rename at once */
+ u64 s_rename_dir; /* source directory ino */
+ u64 s_rename_pos; /* position of source dd */
+ /* gc.c fields */
+ long s_segsize; /* size of a segment */
+ int s_segshift; /* log2 of segment size */
+ long s_no_segs; /* segments on device */
+ long s_no_blocks; /* blocks per segment */
+ long s_writesize; /* minimum write size */
+ int s_writeshift; /* log2 of write size */
+ u64 s_size; /* filesystem size */
+ struct logfs_area *s_area[LOGFS_NO_AREAS]; /* open segment array */
+ u64 s_gec; /* global erase count */
+ u64 s_sweeper; /* current sweeper pos */
+ u8 s_ifile_levels; /* max level of ifile */
+ u8 s_iblock_levels; /* max level of regular files */
+ u8 s_data_levels; /* # of segments to leaf block*/
+ u8 s_total_levels; /* sum of above three */
+ struct list_head s_free_list; /* 100% free segments */
+ struct list_head s_low_list; /* low-resistance segments */
+ int s_free_count; /* # of 100% free segments */
+ int s_low_count; /* # of low-resistance segs */
+ struct btree_head s_reserved_segments; /* sb, journal, bad, etc. */
+ /* inode.c fields */
+ spinlock_t s_ino_lock; /* lock s_last_ino on 32bit */
+ u64 s_last_ino; /* highest ino used */
+ struct list_head s_freeing_list; /* inodes being freed */
+ /* journal.c fields */
+ struct mutex s_log_mutex;
+ void *s_je; /* journal entry to compress */
+ void *s_compressed_je; /* block to write to journal */
+ u64 s_journal_seg[LOGFS_JOURNAL_SEGS]; /* journal segments */
+ u32 s_journal_ec[LOGFS_JOURNAL_SEGS]; /* journal erasecounts */
+ u64 s_last_version;
+ struct logfs_area *s_journal_area; /* open journal segment */
+ struct logfs_journal_entry s_retired[JE_LAST+1]; /* for journal scan */
+ struct logfs_journal_entry s_speculative[JE_LAST+1]; /* dito */
+ struct logfs_journal_entry s_first; /* dito */
+ int s_sum_index; /* for the 12 summaries */
+ be32 *s_bb_array; /* bad segments */
+ /* readwrite.c fields */
+ struct mutex s_r_mutex;
+ struct mutex s_w_mutex;
+ be64 *s_rblock;
+ be64 *s_wblock[LOGFS_MAX_LEVELS];
+ u64 s_free_bytes; /* number of free bytes */
+ u64 s_used_bytes; /* number of bytes used */
+ u64 s_gc_reserve;
+ u64 s_root_reserve;
+ u32 s_bad_segments; /* number of bad segments */
+};
+
+
+struct logfs_inode {
+ struct inode vfs_inode;
+ u64 li_data[LOGFS_EMBEDDED_FIELDS];
+ u64 li_used_bytes;
+ struct list_head li_freeing_list;
+ u32 li_flags;
+};
+
+
+#define journal_for_each(__i) for (__i=0; __i<LOGFS_JOURNAL_SEGS; __i++)
+
+
+void logfs_crash_dump(struct super_block *sb);
+#define LOGFS_BUG(sb) do { \
+ struct super_block *__sb = sb; \
+ logfs_crash_dump(__sb); \
+ BUG(); \
+} while(0)
+
+#define LOGFS_BUG_ON(condition, sb) \
+ do { if (unlikely((condition)!=0)) LOGFS_BUG((sb)); } while(0)
+
+
+static inline be32 logfs_crc32(void *data, size_t len, size_t skip)
+{
+ /* The first four bytes hold the crc, so skip those */
+ return cpu_to_be32(crc32(~0, data+skip, len-skip));
+}
+
+
+static inline u8 logfs_type(struct inode *inode)
+{
+ return (inode->i_mode >> 12) & 15;
+}
+
+
+static inline pgoff_t logfs_index(u64 pos)
+{
+ return pos / LOGFS_BLOCKSIZE;
+}
+
+
+static inline struct logfs_disk_sum *alloc_disk_sum(struct super_block *sb)
+{
+ return kzalloc(sb->s_blocksize, GFP_ATOMIC);
+}
+static inline void free_disk_sum(struct logfs_disk_sum *sum)
+{
+ kfree(sum);
+}
+
+
+static inline u64 logfs_block_ofs(struct super_block *sb, u32 segno,
+ u32 blockno)
+{
+ return (segno << LOGFS_SUPER(sb)->s_segshift)
+ + (blockno << sb->s_blocksize_bits);
+}
+
+
+/* compr.c */
+#define logfs_compress_none logfs_memcpy
+#define logfs_uncompress_none logfs_memcpy
+int logfs_memcpy(void *in, void *out, size_t inlen, size_t outlen);
+int logfs_compress(void *in, void *out, size_t inlen, size_t outlen);
+int logfs_compress_vec(struct kvec *vec, int count, void *out, size_t outlen);
+int logfs_uncompress(void *in, void *out, size_t inlen, size_t outlen);
+int logfs_uncompress_vec(void *in, size_t inlen, struct kvec *vec, int count);
+int __init logfs_compr_init(void);
+void __exit logfs_compr_exit(void);
+
+
+/* dir.c */
+extern struct inode_operations logfs_dir_iops;
+extern struct file_operations logfs_dir_fops;
+int logfs_replay_journal(struct super_block *sb);
+
+
+/* file.c */
+extern struct inode_operations logfs_reg_iops;
+extern struct file_operations logfs_reg_fops;
+extern struct address_space_operations logfs_reg_aops;
+
+int logfs_setattr(struct dentry *dentry, struct iattr *iattr);
+
+
+/* gc.c */
+void logfs_gc_pass(struct super_block *sb);
+int logfs_init_gc(struct logfs_super *super);
+void logfs_cleanup_gc(struct logfs_super *super);
+
+
+/* inode.c */
+extern struct super_operations logfs_super_operations;
+
+struct inode *logfs_iget(struct super_block *sb, ino_t ino, int *cookie);
+void logfs_iput(struct inode *inode, int cookie);
+struct inode *logfs_new_inode(struct inode *dir, int mode);
+struct inode *logfs_new_meta_inode(struct super_block *sb, u64 ino);
+int logfs_init_inode_cache(void);
+void logfs_destroy_inode_cache(void);
+int __logfs_write_inode(struct inode *inode);
+void __logfs_destroy_inode(struct inode *inode);
+
+
+/* journal.c */
+int logfs_write_anchor(struct inode *inode);
+int logfs_init_journal(struct super_block *sb);
+void logfs_cleanup_journal(struct super_block *sb);
+
+
+/* memtree.c */
+void btree_init(struct btree_head *head);
+void *btree_lookup(struct btree_head *head, long val);
+int btree_insert(struct btree_head *head, long val, void *ptr);
+int btree_remove(struct btree_head *head, long val);
+
+
+/* readwrite.c */
+int logfs_inode_read(struct inode *inode, void *buf, size_t n, loff_t _pos);
+int logfs_inode_write(struct inode *inode, const void *buf, size_t n,
+ loff_t pos);
+
+int logfs_readpage_nolock(struct page *page);
+int logfs_write_buf(struct inode *inode, pgoff_t index, void *buf);
+int logfs_delete(struct inode *inode, pgoff_t index);
+int logfs_rewrite_block(struct inode *inode, pgoff_t index, u64 ofs, int level);
+int logfs_is_valid_block(struct super_block *sb, u64 ofs, u64 ino, u64 pos);
+void logfs_truncate(struct inode *inode);
+u64 logfs_seek_data(struct inode *inode, u64 pos);
+
+int logfs_init_rw(struct logfs_super *super);
+void logfs_cleanup_rw(struct logfs_super *super);
+
+/* segment.c */
+int logfs_erase_segment(struct super_block *sb, u32 ofs);
+int wbuf_read(struct super_block *sb, u64 ofs, size_t len, void *buf);
+int logfs_segment_read(struct super_block *sb, void *buf, u64 ofs);
+s64 logfs_segment_write(struct inode *inode, void *buf, u64 pos, int level,
+ int alloc);
+int logfs_segment_delete(struct inode *inode, u64 ofs, u64 pos, int level);
+void logfs_set_blocks(struct inode *inode, u64 no);
+void __logfs_set_blocks(struct inode *inode);
+/* area handling */
+int logfs_init_areas(struct super_block *sb);
+void logfs_cleanup_areas(struct logfs_super *super);
+int logfs_open_area(struct logfs_area *area);
+void logfs_close_area(struct logfs_area *area);
+
+/* super.c */
+int mtdread(struct super_block *sb, loff_t ofs, size_t len, void *buf);
+int mtdwrite(struct super_block *sb, loff_t ofs, size_t len, void *buf);
+int mtderase(struct super_block *sb, loff_t ofs, size_t len);
+void *logfs_device_getpage(struct super_block *sb, u64 offset,
+ struct page **page);
+void logfs_device_putpage(void *buf, struct page *page);
+int logfs_cached_read(struct super_block *sb, u64 ofs, size_t len, void *buf);
+int all_ff(void *buf, size_t len);
+int logfs_statfs(struct dentry *dentry, struct kstatfs *stats);
+
+
+/* progs/mkfs.c */
+int logfs_mkfs(struct super_block *sb, struct logfs_disk_super *ds);
+
+
+/* progs/mkfs.c */
+int logfs_fsck(struct super_block *sb);
+
+
+static inline u64 dev_ofs(struct super_block *sb, u32 segno, u32 ofs)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ return ((u64)segno << super->s_segshift) + ofs;
+}
+
+
+static inline void device_read(struct super_block *sb, u32 segno, u32 ofs,
+ size_t len, void *buf)
+{
+ int err = mtdread(sb, dev_ofs(sb, segno, ofs), len, buf);
+ LOGFS_BUG_ON(err, sb);
+}
+
+
+#define EOF 256
+
+
+#endif
--- /dev/null 2007-04-18 05:32:26.652341749 +0200
+++ linux-2.6.21logfs/fs/logfs/dir.c 2007-05-07 13:32:12.000000000 +0200
@@ -0,0 +1,705 @@
+/**
+ * Atomic dir operations
+ *
+ * Directory operations are by default not atomic. Dentries and Inodes are
+ * created/removed/altered in seperate operations. Therefore we need to do
+ * a small amount of journaling.
+ *
+ * Create, link, mkdir, mknod and symlink all share the same function to do
+ * the work: __logfs_create. This function works in two atomic steps:
+ * 1. allocate inode (remember in journal)
+ * 2. allocate dentry (clear journal)
+ *
+ * As we can only get interrupted between the two, we the inode we just
+ * created is simply stored in the anchor. On next mount, if we were
+ * interrupted, we delete the inode. From a users point of view the
+ * operation never happened.
+ *
+ * Unlink and rmdir also share the same function: unlink. Again, this
+ * function works in two atomic steps
+ * 1. remove dentry (remember inode in journal)
+ * 2. unlink inode (clear journal)
+ *
+ * And again, on the next mount, if we were interrupted, we delete the inode.
+ * From a users point of view the operation succeeded.
+ *
+ * Rename is the real pain to deal with, harder than all the other methods
+ * combined. Depending on the circumstances we can run into three cases.
+ * A "target rename" where the target dentry already existed, a "local
+ * rename" where both parent directories are identical or a "cross-directory
+ * rename" in the remaining case.
+ *
+ * Local rename is atomic, as the old dentry is simply rewritten with a new
+ * name.
+ *
+ * Cross-directory rename works in two steps, similar to __logfs_create and
+ * logfs_unlink:
+ * 1. Write new dentry (remember old dentry in journal)
+ * 2. Remove old dentry (clear journal)
+ *
+ * Here we remember a dentry instead of an inode. On next mount, if we were
+ * interrupted, we delete the dentry. From a users point of view, the
+ * operation succeeded.
+ *
+ * Target rename works in three atomic steps:
+ * 1. Attach old inode to new dentry (remember old dentry and new inode)
+ * 2. Remove old dentry (still remember the new inode)
+ * 3. Remove new inode
+ *
+ * Here we remember both an inode an a dentry. If we get interrupted
+ * between steps 1 and 2, we delete both the dentry and the inode. If
+ * we get interrupted between steps 2 and 3, we delete just the inode.
+ * In either case, the remaining objects are deleted on next mount. From
+ * a users point of view, the operation succeeded.
+ */
+#include "logfs.h"
+
+
+static inline void logfs_inc_count(struct inode *inode)
+{
+ inode->i_nlink++;
+ mark_inode_dirty(inode);
+}
+
+
+static inline void logfs_dec_count(struct inode *inode)
+{
+ inode->i_nlink--;
+ mark_inode_dirty(inode);
+}
+
+
+static int read_dir(struct inode *dir, struct logfs_disk_dentry *dd, loff_t pos)
+{
+ return logfs_inode_read(dir, dd, sizeof(*dd), pos);
+}
+
+
+static int write_dir(struct inode *dir, struct logfs_disk_dentry *dd,
+ loff_t pos)
+{
+ return logfs_inode_write(dir, dd, sizeof(*dd), pos);
+}
+
+
+typedef int (*dir_callback)(struct inode *dir, struct dentry *dentry,
+ struct logfs_disk_dentry *dd, loff_t pos);
+
+
+static s64 dir_seek_data(struct inode *inode, s64 pos)
+{
+ s64 new_pos = logfs_seek_data(inode, pos);
+ return max((s64)pos, new_pos - 1);
+}
+
+
+static int __logfs_dir_walk(struct inode *dir, struct dentry *dentry,
+ dir_callback handler, struct logfs_disk_dentry *dd, loff_t *pos)
+{
+ struct qstr *name = dentry ? &dentry->d_name : NULL;
+ int ret;
+
+ for (; ; (*pos)++) {
+ ret = read_dir(dir, dd, *pos);
+ if (ret == -EOF)
+ return 0;
+ if (ret == -ENODATA) {/* deleted dentry */
+ *pos = dir_seek_data(dir, *pos);
+ continue;
+ }
+ if (ret)
+ return ret;
+ BUG_ON(dd->namelen == 0);
+
+ if (name) {
+ if (name->len != be16_to_cpu(dd->namelen))
+ continue;
+ if (memcmp(name->name, dd->name, name->len))
+ continue;
+ }
+
+ return handler(dir, dentry, dd, *pos);
+ }
+ return ret;
+}
+
+
+static int logfs_dir_walk(struct inode *dir, struct dentry *dentry,
+ dir_callback handler)
+{
+ struct logfs_disk_dentry dd;
+ loff_t pos = 0;
+ return __logfs_dir_walk(dir, dentry, handler, &dd, &pos);
+}
+
+
+static int logfs_lookup_handler(struct inode *dir, struct dentry *dentry,
+ struct logfs_disk_dentry *dd, loff_t pos)
+{
+ struct inode *inode;
+
+ inode = iget(dir->i_sb, be64_to_cpu(dd->ino));
+ if (!inode)
+ return -EIO;
+ return PTR_ERR(d_splice_alias(inode, dentry));
+}
+
+
+static struct dentry *logfs_lookup(struct inode *dir, struct dentry *dentry,
+ struct nameidata *nd)
+{
+ struct dentry *ret;
+
+ ret = ERR_PTR(logfs_dir_walk(dir, dentry, logfs_lookup_handler));
+ return ret;
+}
+
+
+/* unlink currently only makes the name length zero */
+static int logfs_unlink_handler(struct inode *dir, struct dentry *dentry,
+ struct logfs_disk_dentry *dd, loff_t pos)
+{
+ return logfs_delete(dir, pos);
+}
+
+
+static int logfs_remove_inode(struct inode *inode)
+{
+ int ret;
+
+ inode->i_nlink--;
+ if (inode->i_mode & S_IFDIR)
+ inode->i_nlink--;
+ ret = __logfs_write_inode(inode);
+ LOGFS_BUG_ON(ret, inode->i_sb);
+ return ret;
+}
+
+
+static int logfs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ struct logfs_super *super = LOGFS_SUPER(dir->i_sb);
+ struct inode *inode = dentry->d_inode;
+ int ret;
+
+ mutex_lock(&super->s_victim_mutex);
+ super->s_victim_ino = inode->i_ino;
+
+ /* remove dentry */
+ if (inode->i_mode & S_IFDIR)
+ dir->i_nlink--;
+ inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+ ret = logfs_dir_walk(dir, dentry, logfs_unlink_handler);
+ super->s_victim_ino = 0;
+ if (ret)
+ goto out;
+
+ /* remove inode */
+ ret = logfs_remove_inode(inode);
+
+out:
+ mutex_unlock(&super->s_victim_mutex);
+ return ret;
+}
+
+
+static int logfs_empty_handler(struct inode *dir, struct dentry *dentry,
+ struct logfs_disk_dentry *dd, loff_t pos)
+{
+ return -ENOTEMPTY;
+}
+static inline int logfs_empty_dir(struct inode *dir)
+{
+ return logfs_dir_walk(dir, NULL, logfs_empty_handler) == 0;
+}
+
+
+static int logfs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ struct inode *inode = dentry->d_inode;
+
+ if (!logfs_empty_dir(inode))
+ return -ENOTEMPTY;
+
+ return logfs_unlink(dir, dentry);
+}
+
+
+/* FIXME: readdir currently has it's own dir_walk code. I don't see a good
+ * way to combine the two copies */
+#define IMPLICIT_NODES 2
+static int __logfs_readdir(struct file *file, void *buf, filldir_t filldir)
+{
+ struct logfs_disk_dentry dd;
+ loff_t pos = file->f_pos - IMPLICIT_NODES;
+ int err;
+
+ BUG_ON(pos<0);
+ for (;; pos++) {
+ struct inode *dir = file->f_dentry->d_inode;
+ err = read_dir(dir, &dd, pos);
+ if (err == -EOF)
+ break;
+ if (err == -ENODATA) {/* deleted dentry */
+ pos = dir_seek_data(dir, pos);
+ continue;
+ }
+ if (err)
+ return err;
+ BUG_ON(dd.namelen == 0);
+
+ if (filldir(buf, dd.name, be16_to_cpu(dd.namelen), pos,
+ be64_to_cpu(dd.ino), dd.type))
+ break;
+ }
+
+ file->f_pos = pos + IMPLICIT_NODES;
+ return 0;
+}
+
+
+static int logfs_readdir(struct file *file, void *buf, filldir_t filldir)
+{
+ struct inode *inode = file->f_dentry->d_inode;
+ int err;
+
+ if (file->f_pos < 0)
+ return -EINVAL;
+
+ if (file->f_pos == 0) {
+ if (filldir(buf, ".", 1, 1, inode->i_ino, DT_DIR) < 0)
+ return 0;
+ file->f_pos++;
+ }
+ if (file->f_pos == 1) {
+ ino_t pino = parent_ino(file->f_dentry);
+ if (filldir(buf, "..", 2, 2, pino, DT_DIR) < 0)
+ return 0;
+ file->f_pos++;
+ }
+
+ err = __logfs_readdir(file, buf, filldir);
+ if (err)
+ printk("LOGFS readdir error=%x, pos=%llx\n", err, file->f_pos);
+ return err;
+}
+
+
+static inline loff_t file_end(struct inode *inode)
+{
+ return (i_size_read(inode) + inode->i_sb->s_blocksize - 1)
+ >> inode->i_sb->s_blocksize_bits;
+}
+static void logfs_set_name(struct logfs_disk_dentry *dd, struct qstr *name)
+{
+ BUG_ON(name->len > LOGFS_MAX_NAMELEN);
+ dd->namelen = cpu_to_be16(name->len);
+ memcpy(dd->name, name->name, name->len);
+}
+static int logfs_write_dir(struct inode *dir, struct dentry *dentry,
+ struct inode *inode)
+{
+ struct logfs_disk_dentry dd;
+ int err;
+
+ memset(&dd, 0, sizeof(dd));
+ dd.ino = cpu_to_be64(inode->i_ino);
+ dd.type = logfs_type(inode);
+ logfs_set_name(&dd, &dentry->d_name);
+
+ dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+ /* FIXME: the file size should actually get aligned when writing,
+ * not when reading. */
+ err = write_dir(dir, &dd, file_end(dir));
+ if (err)
+ return err;
+ d_instantiate(dentry, inode);
+ return 0;
+}
+
+
+static int __logfs_create(struct inode *dir, struct dentry *dentry,
+ struct inode *inode, const char *dest, long destlen)
+{
+ struct logfs_super *super = LOGFS_SUPER(dir->i_sb);
+ struct logfs_inode *li = LOGFS_INODE(inode);
+ int ret;
+
+ mutex_lock(&super->s_victim_mutex);
+ super->s_victim_ino = inode->i_ino;
+ if (inode->i_mode & S_IFDIR)
+ inode->i_nlink++;
+
+ if (dest) /* symlink */
+ ret = logfs_inode_write(inode, dest, destlen, 0);
+ else /* creat/mkdir/mknod */
+ ret = __logfs_write_inode(inode);
+ super->s_victim_ino = 0;
+ if (ret) {
+ if (!dest)
+ li->li_flags |= LOGFS_IF_STILLBORN;
+ /* FIXME: truncate symlink */
+ inode->i_nlink--;
+ iput(inode);
+ goto out;
+ }
+
+ if (inode->i_mode & S_IFDIR)
+ dir->i_nlink++;
+ ret = logfs_write_dir(dir, dentry, inode);
+
+ if (ret) {
+ if (inode->i_mode & S_IFDIR)
+ dir->i_nlink--;
+ logfs_remove_inode(inode);
+ iput(inode);
+ }
+out:
+ mutex_unlock(&super->s_victim_mutex);
+ return ret;
+}
+
+
+/* FIXME: This should really be somewhere in the 64bit area. */
+#define LOGFS_LINK_MAX (1<<30)
+static int logfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+ struct inode *inode;
+
+ if (dir->i_nlink >= LOGFS_LINK_MAX)
+ return -EMLINK;
+
+ /* FIXME: why do we have to fill in S_IFDIR, while the mode is
+ * correct for mknod, creat, etc.? Smells like the vfs *should*
+ * do it for us but for some reason fails to do so.
+ */
+ inode = logfs_new_inode(dir, S_IFDIR | mode);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ inode->i_op = &logfs_dir_iops;
+ inode->i_fop = &logfs_dir_fops;
+
+ return __logfs_create(dir, dentry, inode, NULL, 0);
+}
+
+
+static int logfs_create(struct inode *dir, struct dentry *dentry, int mode,
+ struct nameidata *nd)
+{
+ struct inode *inode;
+
+ inode = logfs_new_inode(dir, mode);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ inode->i_op = &logfs_reg_iops;
+ inode->i_fop = &logfs_reg_fops;
+ inode->i_mapping->a_ops = &logfs_reg_aops;
+
+ return __logfs_create(dir, dentry, inode, NULL, 0);
+}
+
+
+static int logfs_mknod(struct inode *dir, struct dentry *dentry, int mode,
+ dev_t rdev)
+{
+ struct inode *inode;
+
+ BUG_ON(dentry->d_name.len > LOGFS_MAX_NAMELEN);
+
+ inode = logfs_new_inode(dir, mode);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ init_special_inode(inode, mode, rdev);
+
+ return __logfs_create(dir, dentry, inode, NULL, 0);
+}
+
+
+static struct inode_operations ext2_symlink_iops = {
+ .readlink = generic_readlink,
+ .follow_link = page_follow_link_light,
+};
+
+static int logfs_symlink(struct inode *dir, struct dentry *dentry,
+ const char *target)
+{
+ struct inode *inode;
+ size_t destlen = strlen(target) + 1;
+
+ if (destlen > dir->i_sb->s_blocksize)
+ return -ENAMETOOLONG;
+
+ inode = logfs_new_inode(dir, S_IFLNK | S_IRWXUGO);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ inode->i_op = &ext2_symlink_iops;
+ inode->i_mapping->a_ops = &logfs_reg_aops;
+
+ return __logfs_create(dir, dentry, inode, target, destlen);
+}
+
+
+static int logfs_permission(struct inode *inode, int mask, struct nameidata *nd)
+{
+ return generic_permission(inode, mask, NULL);
+}
+
+
+static int logfs_link(struct dentry *old_dentry, struct inode *dir,
+ struct dentry *dentry)
+{
+ struct inode *inode = old_dentry->d_inode;
+
+ if (inode->i_nlink >= LOGFS_LINK_MAX)
+ return -EMLINK;
+
+ inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+ atomic_inc(&inode->i_count);
+ inode->i_nlink++;
+
+ return __logfs_create(dir, dentry, inode, NULL, 0);
+}
+
+
+static int logfs_nop_handler(struct inode *dir, struct dentry *dentry,
+ struct logfs_disk_dentry *dd, loff_t pos)
+{
+ return 0;
+}
+static inline int logfs_get_dd(struct inode *dir, struct dentry *dentry,
+ struct logfs_disk_dentry *dd, loff_t *pos)
+{
+ *pos = 0;
+ return __logfs_dir_walk(dir, dentry, logfs_nop_handler, dd, pos);
+}
+
+
+/* Easiest case, a local rename and the target doesn't exist. Just change
+ * the name in the old dd.
+ */
+static int logfs_rename_local(struct inode *dir, struct dentry *old_dentry,
+ struct dentry *new_dentry)
+{
+ struct logfs_disk_dentry dd;
+ loff_t pos;
+ int err;
+
+ err = logfs_get_dd(dir, old_dentry, &dd, &pos);
+ if (err)
+ return err;
+
+ logfs_set_name(&dd, &new_dentry->d_name);
+ return write_dir(dir, &dd, pos);
+}
+
+
+static int logfs_delete_dd(struct inode *dir, struct logfs_disk_dentry *dd,
+ loff_t pos)
+{
+ int err;
+
+ err = read_dir(dir, dd, pos);
+ if (err == -EOF) /* don't expose internal errnos */
+ err = -EIO;
+ if (err)
+ return err;
+
+ dir->i_ctime = dir->i_mtime = CURRENT_TIME;
+ if (dd->type == DT_DIR)
+ dir->i_nlink--;
+ return logfs_delete(dir, pos);
+}
+
+
+/* Cross-directory rename, target does not exist. Just a little nasty.
+ * Create a new dentry in the target dir, then remove the old dentry,
+ * all the while taking care to remember our operation in the journal.
+ */
+static int logfs_rename_cross(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
+{
+ struct logfs_super *super = LOGFS_SUPER(old_dir->i_sb);
+ struct logfs_disk_dentry dd;
+ loff_t pos;
+ int err;
+
+ /* 1. locate source dd */
+ err = logfs_get_dd(old_dir, old_dentry, &dd, &pos);
+ if (err)
+ return err;
+ mutex_lock(&super->s_rename_mutex);
+ super->s_rename_dir = old_dir->i_ino;
+ super->s_rename_pos = pos;
+
+ /* FIXME: this cannot be right but it does "fix" a bug of i_count
+ * dropping too low. Needs more thought. */
+ atomic_inc(&old_dentry->d_inode->i_count);
+
+ /* 2. write target dd */
+ if (dd.type == DT_DIR)
+ new_dir->i_nlink++;
+ err = logfs_write_dir(new_dir, new_dentry, old_dentry->d_inode);
+ super->s_rename_dir = 0;
+ super->s_rename_pos = 0;
+ if (err)
+ goto out;
+
+ /* 3. remove source dd */
+ err = logfs_delete_dd(old_dir, &dd, pos);
+ LOGFS_BUG_ON(err, old_dir->i_sb);
+out:
+ mutex_unlock(&super->s_rename_mutex);
+ return err;
+}
+
+
+static int logfs_replace_inode(struct inode *dir, struct dentry *dentry,
+ struct logfs_disk_dentry *dd, struct inode *inode)
+{
+ loff_t pos;
+ int err;
+
+ err = logfs_get_dd(dir, dentry, dd, &pos);
+ if (err)
+ return err;
+ dd->ino = cpu_to_be64(inode->i_ino);
+ dd->type = logfs_type(inode);
+
+ return write_dir(dir, dd, pos);
+}
+
+
+/* Target dentry exists - the worst case. We need to attach the source
+ * inode to the target dentry, then remove the orphaned target inode and
+ * source dentry.
+ */
+static int logfs_rename_target(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
+{
+ struct logfs_super *super = LOGFS_SUPER(old_dir->i_sb);
+ struct inode *old_inode = old_dentry->d_inode;
+ struct inode *new_inode = new_dentry->d_inode;
+ int isdir = S_ISDIR(old_inode->i_mode);
+ struct logfs_disk_dentry dd;
+ loff_t pos;
+ int err;
+
+ BUG_ON(isdir != S_ISDIR(new_inode->i_mode));
+ if (isdir) {
+ if (!logfs_empty_dir(new_inode))
+ return -ENOTEMPTY;
+ }
+
+ /* 1. locate source dd */
+ err = logfs_get_dd(old_dir, old_dentry, &dd, &pos);
+ if (err)
+ return err;
+
+ mutex_lock(&super->s_rename_mutex);
+ mutex_lock(&super->s_victim_mutex);
+ super->s_rename_dir = old_dir->i_ino;
+ super->s_rename_pos = pos;
+ super->s_victim_ino = new_inode->i_ino;
+
+ /* 2. attach source inode to target dd */
+ err = logfs_replace_inode(new_dir, new_dentry, &dd, old_inode);
+ super->s_rename_dir = 0;
+ super->s_rename_pos = 0;
+ if (err) {
+ super->s_victim_ino = 0;
+ goto out;
+ }
+
+ /* 3. remove source dd */
+ err = logfs_delete_dd(old_dir, &dd, pos);
+ LOGFS_BUG_ON(err, old_dir->i_sb);
+
+ /* 4. remove target inode */
+ super->s_victim_ino = 0;
+ err = logfs_remove_inode(new_inode);
+
+out:
+ mutex_unlock(&super->s_victim_mutex);
+ mutex_unlock(&super->s_rename_mutex);
+ return err;
+}
+
+
+static int logfs_rename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
+{
+ if (new_dentry->d_inode) /* target exists */
+ return logfs_rename_target(old_dir, old_dentry, new_dir, new_dentry);
+ else if (old_dir == new_dir) /* local rename */
+ return logfs_rename_local(old_dir, old_dentry, new_dentry);
+ return logfs_rename_cross(old_dir, old_dentry, new_dir, new_dentry);
+}
+
+
+/* No locking done here, as this is called before .get_sb() returns. */
+int logfs_replay_journal(struct super_block *sb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ struct logfs_disk_dentry dd;
+ struct inode *inode;
+ u64 ino, pos;
+ int err;
+
+ if (super->s_victim_ino) { /* delete victim inode */
+ ino = super->s_victim_ino;
+ inode = iget(sb, ino);
+ if (!inode)
+ goto fail;
+
+ super->s_victim_ino = 0;
+ err = logfs_remove_inode(inode);
+ iput(inode);
+ if (err) {
+ super->s_victim_ino = ino;
+ goto fail;
+ }
+ }
+ if (super->s_rename_dir) { /* delete old dd from rename */
+ ino = super->s_rename_dir;
+ pos = super->s_rename_pos;
+ inode = iget(sb, ino);
+ if (!inode)
+ goto fail;
+
+ super->s_rename_dir = 0;
+ super->s_rename_pos = 0;
+ err = logfs_delete_dd(inode, &dd, pos);
+ iput(inode);
+ if (err) {
+ super->s_rename_dir = ino;
+ super->s_rename_pos = pos;
+ goto fail;
+ }
+ }
+ return 0;
+fail:
+ LOGFS_BUG(sb);
+ return -EIO;
+}
+
+
+struct inode_operations logfs_dir_iops = {
+ .create = logfs_create,
+ .link = logfs_link,
+ .lookup = logfs_lookup,
+ .mkdir = logfs_mkdir,
+ .mknod = logfs_mknod,
+ .rename = logfs_rename,
+ .rmdir = logfs_rmdir,
+ .permission = logfs_permission,
+ .symlink = logfs_symlink,
+ .unlink = logfs_unlink,
+};
+struct file_operations logfs_dir_fops = {
+ .readdir = logfs_readdir,
+ .read = generic_read_dir,
+};
--- /dev/null 2007-04-18 05:32:26.652341749 +0200
+++ linux-2.6.21logfs/fs/logfs/file.c 2007-05-07 13:32:12.000000000 +0200
@@ -0,0 +1,82 @@
+#include "logfs.h"
+
+
+static int logfs_prepare_write(struct file *file, struct page *page,
+ unsigned start, unsigned end)
+{
+ if (PageUptodate(page))
+ return 0;
+
+ if ((start == 0) && (end == PAGE_CACHE_SIZE))
+ return 0;
+
+ return logfs_readpage_nolock(page);
+}
+
+
+static int logfs_commit_write(struct file *file, struct page *page,
+ unsigned start, unsigned end)
+{
+ struct inode *inode = page->mapping->host;
+ pgoff_t index = page->index;
+ void *buf;
+ int ret;
+
+ pr_debug("ino: %lu, page:%lu, start: %d, len:%d\n", inode->i_ino,
+ page->index, start, end-start);
+ BUG_ON(PAGE_CACHE_SIZE != inode->i_sb->s_blocksize);
+ BUG_ON(page->index > I3_BLOCKS);
+
+ if (start == end)
+ return 0; /* FIXME: do we need to update inode? */
+
+ if (i_size_read(inode) < (index << PAGE_CACHE_SHIFT) + end) {
+ i_size_write(inode, (index << PAGE_CACHE_SHIFT) + end);
+ mark_inode_dirty(inode);
+ }
+
+ buf = kmap(page);
+ ret = logfs_write_buf(inode, index, buf);
+ kunmap(page);
+ return ret;
+}
+
+
+static int logfs_readpage(struct file *file, struct page *page)
+{
+ int ret = logfs_readpage_nolock(page);
+ unlock_page(page);
+ return ret;
+}
+
+
+static int logfs_writepage(struct page *page, struct writeback_control *wbc)
+{
+ BUG();
+ return 0;
+}
+
+
+struct inode_operations logfs_reg_iops = {
+ .truncate = logfs_truncate,
+};
+
+
+struct file_operations logfs_reg_fops = {
+ .aio_read = generic_file_aio_read,
+ .aio_write = generic_file_aio_write,
+ .llseek = generic_file_llseek,
+ .mmap = generic_file_readonly_mmap,
+ .open = generic_file_open,
+ .read = do_sync_read,
+ .write = do_sync_write,
+};
+
+
+struct address_space_operations logfs_reg_aops = {
+ .commit_write = logfs_commit_write,
+ .prepare_write = logfs_prepare_write,
+ .readpage = logfs_readpage,
+ .set_page_dirty = __set_page_dirty_nobuffers,
+ .writepage = logfs_writepage,
+};
--- /dev/null 2007-04-18 05:32:26.652341749 +0200
+++ linux-2.6.21logfs/fs/logfs/gc.c 2007-05-07 13:32:12.000000000 +0200
@@ -0,0 +1,350 @@
+#include "logfs.h"
+
+#if 0
+/**
+ * When deciding which segment to use next, calculate the resistance
+ * of each segment and pick the lowest. Segments try to resist usage
+ * if
+ * o they are full,
+ * o they have a high erase count or
+ * o they have recently been written.
+ *
+ * Full segments should not get reused, as there is little space to
+ * gain from them. Segments with high erase count should be left
+ * aside as they can wear out sooner than others. Freshly-written
+ * segments contain many blocks that will get obsoleted fairly soon,
+ * so it helps to wait a little before reusing them.
+ *
+ * Total resistance is expressed in erase counts. Formula is:
+ *
+ * R = EC + K1*F + K2*e^(-t/theta)
+ *
+ * R: Resistance
+ * EC: Erase count
+ * K1: Constant, 10,000 might be a good value
+ * K2: Constant, 1,000 might be a good value
+ * F: Segment fill level
+ * t: Time since segment was written to (in number of segments written)
+ * theta: Time constant. Total number of segments might be a good value
+ *
+ * Since the kernel is not allowed to use floating point, the function
+ * decay() is used to approximate exponential decay in fixed point.
+ */
+static long decay(long t0, long t, long theta)
+{
+ long shift, fac;
+
+ if (t >= 32*theta)
+ return 0;
+
+ shift = t/theta;
+ fac = theta - (t%theta)/2;
+ return (t0 >> shift) * fac / theta;
+}
+#endif
+
+
+static u32 logfs_valid_bytes(struct super_block *sb, u32 segno)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ struct logfs_object_header h;
+ u64 ofs, ino, pos;
+ u32 seg_ofs, valid, size;
+ void *reserved;
+ int i;
+
+ /* Some segments are reserved. Just pretend they were all valid */
+ reserved = btree_lookup(&super->s_reserved_segments, segno);
+ if (reserved)
+ return super->s_segsize;
+
+ /* Currently open segments */
+ /* FIXME: just reserve open areas and remove this code */
+ for (i=0; i<LOGFS_NO_AREAS; i++) {
+ struct logfs_area *area = super->s_area[i];
+ if (area->a_is_open && (area->a_segno == segno)) {
+ return super->s_segsize;
+ }
+ }
+
+ device_read(sb, segno, 0, sizeof(h), &h);
+ if (all_ff(&h, sizeof(h)))
+ return 0;
+
+ valid = 0; /* segment header not counted as valid bytes */
+ for (seg_ofs = sizeof(h); seg_ofs + sizeof(h) < super->s_segsize; ) {
+ device_read(sb, segno, seg_ofs, sizeof(h), &h);
+ if (all_ff(&h, sizeof(h)))
+ break;
+
+ ofs = dev_ofs(sb, segno, seg_ofs);
+ ino = be64_to_cpu(h.ino);
+ pos = be64_to_cpu(h.pos);
+ size = (u32)be16_to_cpu(h.len) + sizeof(h);
+ //printk("%x %x (%llx, %llx, %llx)(%x, %x)\n", h.type, h.compr, ofs, ino, pos, valid, size);
+ if (logfs_is_valid_block(sb, ofs, ino, pos))
+ valid += size;
+ seg_ofs += size;
+ }
+ printk("valid(%x) = %x\n", segno, valid);
+ return valid;
+}
+
+
+static void logfs_cleanse_block(struct super_block *sb, u64 ofs, u64 ino,
+ u64 pos, int level)
+{
+ struct inode *inode;
+ int err, cookie;
+
+ inode = logfs_iget(sb, ino, &cookie);
+ BUG_ON(!inode);
+ err = logfs_rewrite_block(inode, pos, ofs, level);
+ BUG_ON(err);
+ logfs_iput(inode, cookie);
+}
+
+
+static void __logfs_gc_segment(struct super_block *sb, u32 segno)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ struct logfs_object_header h;
+ struct logfs_segment_header *sh;
+ u64 ofs, ino, pos;
+ u32 seg_ofs;
+ int level;
+
+ device_read(sb, segno, 0, sizeof(h), &h);
+ sh = (void*)&h;
+ level = sh->level;
+
+ for (seg_ofs = sizeof(h); seg_ofs + sizeof(h) < super->s_segsize; ) {
+ ofs = dev_ofs(sb, segno, seg_ofs);
+ device_read(sb, segno, seg_ofs, sizeof(h), &h);
+ ino = be64_to_cpu(h.ino);
+ pos = be64_to_cpu(h.pos);
+ if (logfs_is_valid_block(sb, ofs, ino, pos))
+ logfs_cleanse_block(sb, ofs, ino, pos, level);
+ seg_ofs += sizeof(h);
+ seg_ofs += be16_to_cpu(h.len);
+ }
+}
+
+
+static void logfs_gc_segment(struct super_block *sb, u32 segno)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ int i;
+ void *reserved;
+
+ /* Some segments are reserved. Just pretend they were all valid */
+ reserved = btree_lookup(&super->s_reserved_segments, segno);
+ LOGFS_BUG_ON(reserved, sb);
+
+ /* Currently open segments */
+ for (i=0; i<LOGFS_NO_AREAS; i++) {
+ struct logfs_area *area = super->s_area[i];
+ BUG_ON(area->a_is_open && (area->a_segno == segno));
+ }
+ __logfs_gc_segment(sb, segno);
+}
+
+
+static void __add_segment(struct list_head *list, int *count, u32 segno,
+ int valid)
+{
+ struct logfs_segment *seg = kzalloc(sizeof(*seg), GFP_KERNEL);
+ if (!seg)
+ return;
+
+ seg->segno = segno;
+ seg->valid = valid;
+ list_add(&seg->list, list);
+ *count += 1;
+}
+
+
+static void add_segment(struct list_head *list, int *count, u32 segno,
+ int valid)
+{
+ struct logfs_segment *seg;
+ list_for_each_entry(seg, list, list)
+ if (seg->segno == segno)
+ return;
+ __add_segment(list, count, segno, valid);
+}
+
+
+static void del_segment(struct list_head *list, int *count, u32 segno)
+{
+ struct logfs_segment *seg;
+ list_for_each_entry(seg, list, list)
+ if (seg->segno == segno) {
+ list_del(&seg->list);
+ *count -= 1;
+ kfree(seg);
+ return;
+ }
+}
+
+
+static void add_free_segment(struct super_block *sb, u32 segno)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ add_segment(&super->s_free_list, &super->s_free_count, segno, 0);
+}
+static void add_low_segment(struct super_block *sb, u32 segno, int valid)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ add_segment(&super->s_low_list, &super->s_low_count, segno, valid);
+}
+static void del_low_segment(struct super_block *sb, u32 segno)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ del_segment(&super->s_low_list, &super->s_low_count, segno);
+}
+
+
+static void scan_segment(struct super_block *sb, u32 segno)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ u32 full = super->s_segsize - sb->s_blocksize - 0x18; /* one header */
+ int valid;
+
+ valid = logfs_valid_bytes(sb, segno);
+ if (valid == 0) {
+ del_low_segment(sb, segno);
+ add_free_segment(sb, segno);
+ } else if (valid < full)
+ add_low_segment(sb, segno, valid);
+}
+
+
+static void free_all_segments(struct logfs_super *super)
+{
+ struct logfs_segment *seg, *next;
+
+ list_for_each_entry_safe(seg, next, &super->s_free_list, list) {
+ list_del(&seg->list);
+ kfree(seg);
+ }
+ list_for_each_entry_safe(seg, next, &super->s_low_list, list) {
+ list_del(&seg->list);
+ kfree(seg);
+ }
+}
+
+
+static void logfs_scan_pass(struct super_block *sb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ int i;
+
+ for (i = super->s_sweeper+1; i != super->s_sweeper; i++) {
+ if (i >= super->s_no_segs)
+ i=1; /* skip superblock */
+
+ scan_segment(sb, i);
+
+ if (super->s_free_count >= super->s_total_levels) {
+ super->s_sweeper = i;
+ return;
+ }
+ }
+ scan_segment(sb, super->s_sweeper);
+}
+
+
+static void logfs_gc_once(struct super_block *sb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ struct logfs_segment *seg, *next;
+ unsigned min_valid = super->s_segsize;
+ u32 segno;
+
+ BUG_ON(list_empty(&super->s_low_list));
+ list_for_each_entry_safe(seg, next, &super->s_low_list, list) {
+ if (seg->valid >= min_valid)
+ continue;
+ min_valid = seg->valid;
+ list_del(&seg->list);
+ list_add(&seg->list, &super->s_low_list);
+ }
+
+ seg = list_entry(super->s_low_list.next, struct logfs_segment, list);
+ list_del(&seg->list);
+ super->s_low_count -= 1;
+
+ segno = seg->segno;
+ logfs_gc_segment(sb, segno);
+ kfree(seg);
+ add_free_segment(sb, segno);
+}
+
+
+/* GC all the low-count segments. If necessary, rescan the medium.
+ * If we made enough room, return */
+static void logfs_gc_several(struct super_block *sb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ int rounds;
+
+ rounds = super->s_low_count;
+
+ for (; rounds; rounds--) {
+ if (super->s_free_count >= super->s_total_levels)
+ return;
+ if (super->s_free_count < 3) {
+ logfs_scan_pass(sb);
+ printk("s");
+ }
+ logfs_gc_once(sb);
+#if 1
+ if (super->s_free_count >= super->s_total_levels)
+ return;
+ printk(".");
+#endif
+ }
+}
+
+
+void logfs_gc_pass(struct super_block *sb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ int i;
+
+ for (i=4; i; i--) {
+ if (super->s_free_count >= super->s_total_levels)
+ return;
+ logfs_scan_pass(sb);
+
+ if (super->s_free_count >= super->s_total_levels)
+ return;
+ printk("free:%8d, low:%8d, sweeper:%8lld\n",
+ super->s_free_count, super->s_low_count,
+ super->s_sweeper);
+ logfs_gc_several(sb);
+ printk("free:%8d, low:%8d, sweeper:%8lld\n",
+ super->s_free_count, super->s_low_count,
+ super->s_sweeper);
+ }
+ logfs_fsck(sb);
+ LOGFS_BUG(sb);
+}
+
+
+int logfs_init_gc(struct logfs_super *super)
+{
+ INIT_LIST_HEAD(&super->s_free_list);
+ INIT_LIST_HEAD(&super->s_low_list);
+ super->s_free_count = 0;
+ super->s_low_count = 0;
+
+ return 0;
+}
+
+
+void logfs_cleanup_gc(struct logfs_super *super)
+{
+ free_all_segments(super);
+}
--- /dev/null 2007-04-18 05:32:26.652341749 +0200
+++ linux-2.6.21logfs/fs/logfs/inode.c 2007-05-07 13:32:12.000000000 +0200
@@ -0,0 +1,468 @@
+#include "logfs.h"
+#include <linux/backing-dev.h>
+#include <linux/writeback.h> /* for inode_lock */
+
+
+static struct kmem_cache *logfs_inode_cache;
+
+
+static int __logfs_read_inode(struct inode *inode);
+
+
+static struct inode *__logfs_iget(struct super_block *sb, unsigned long ino)
+{
+ struct inode *inode = iget_locked(sb, ino);
+ int err;
+
+ if (inode && (inode->i_state & I_NEW)) {
+ err = __logfs_read_inode(inode);
+ unlock_new_inode(inode);
+ if (err) {
+ inode->i_nlink = 0; /* don't cache the inode */
+ LOGFS_INODE(inode)->li_flags |= LOGFS_IF_ZOMBIE;
+ iput(inode);
+ return NULL;
+ }
+ }
+
+ return inode;
+}
+
+
+struct inode *logfs_iget(struct super_block *sb, ino_t ino, int *cookie)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ struct logfs_inode *li;
+
+ if (ino == LOGFS_INO_MASTER) /* never iget this "inode"! */
+ return super->s_master_inode;
+
+ spin_lock(&inode_lock);
+ list_for_each_entry(li, &super->s_freeing_list, li_freeing_list)
+ if (li->vfs_inode.i_ino == ino) {
+ spin_unlock(&inode_lock);
+ *cookie = 1;
+ return &li->vfs_inode;
+ }
+ spin_unlock(&inode_lock);
+
+ *cookie = 0;
+ return __logfs_iget(sb, ino);
+}
+
+
+void logfs_iput(struct inode *inode, int cookie)
+{
+ if (inode->i_ino == LOGFS_INO_MASTER) /* never iput it either! */
+ return;
+
+ if (cookie)
+ return;
+
+ iput(inode);
+}
+
+
+static void logfs_init_inode(struct inode *inode)
+{
+ struct logfs_inode *li = LOGFS_INODE(inode);
+ int i;
+
+ li->li_flags = LOGFS_IF_VALID;
+ li->li_used_bytes = 0;
+ inode->i_uid = 0;
+ inode->i_gid = 0;
+ inode->i_size = 0;
+ inode->i_blocks = 0;
+ inode->i_ctime = CURRENT_TIME;
+ inode->i_mtime = CURRENT_TIME;
+ inode->i_nlink = 1;
+ INIT_LIST_HEAD(&li->li_freeing_list);
+
+ for (i=0; i<LOGFS_EMBEDDED_FIELDS; i++)
+ li->li_data[i] = 0;
+
+ return;
+}
+
+
+static struct inode *logfs_alloc_inode(struct super_block *sb)
+{
+ struct logfs_inode *li;
+
+ li = kmem_cache_alloc(logfs_inode_cache, GFP_KERNEL);
+ if (!li)
+ return NULL;
+ logfs_init_inode(&li->vfs_inode);
+ return &li->vfs_inode;
+}
+
+
+struct inode *logfs_new_meta_inode(struct super_block *sb, u64 ino)
+{
+ struct inode *inode;
+
+ inode = logfs_alloc_inode(sb);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ logfs_init_inode(inode);
+ inode->i_mode = 0;
+ inode->i_ino = ino;
+ inode->i_sb = sb;
+
+ /* This is a blatant copy of alloc_inode code. We'd need alloc_inode
+ * to be nonstatic, alas. */
+ {
+ static const struct address_space_operations empty_aops;
+ struct address_space * const mapping = &inode->i_data;
+
+ mapping->a_ops = &empty_aops;
+ mapping->host = inode;
+ mapping->flags = 0;
+ mapping_set_gfp_mask(mapping, GFP_HIGHUSER);
+ mapping->assoc_mapping = NULL;
+ mapping->backing_dev_info = &default_backing_dev_info;
+ inode->i_mapping = mapping;
+ }
+
+ return inode;
+}
+
+
+static struct timespec be64_to_timespec(be64 betime)
+{
+ u64 time = be64_to_cpu(betime);
+ struct timespec tsp;
+ tsp.tv_sec = time >> 32;
+ tsp.tv_nsec = time & 0xffffffff;
+ return tsp;
+}
+
+
+static be64 timespec_to_be64(struct timespec tsp)
+{
+ u64 time = ((u64)tsp.tv_sec << 32) + (tsp.tv_nsec & 0xffffffff);
+ return cpu_to_be64(time);
+}
+
+
+static void logfs_disk_to_inode(struct logfs_disk_inode *di, struct inode*inode)
+{
+ struct logfs_inode *li = LOGFS_INODE(inode);
+ int i;
+
+ inode->i_mode = be16_to_cpu(di->di_mode);
+ li->li_flags = be32_to_cpu(di->di_flags);
+ inode->i_uid = be32_to_cpu(di->di_uid);
+ inode->i_gid = be32_to_cpu(di->di_gid);
+ inode->i_size = be64_to_cpu(di->di_size);
+ logfs_set_blocks(inode, be64_to_cpu(di->di_used_bytes));
+ inode->i_ctime = be64_to_timespec(di->di_ctime);
+ inode->i_mtime = be64_to_timespec(di->di_mtime);
+ inode->i_nlink = be32_to_cpu(di->di_refcount);
+ inode->i_generation = be32_to_cpu(di->di_generation);
+
+ switch (inode->i_mode & S_IFMT) {
+ case S_IFCHR: /* fall through */
+ case S_IFBLK: /* fall through */
+ case S_IFIFO:
+ inode->i_rdev = be64_to_cpu(di->di_data[0]);
+ break;
+ default:
+ for (i=0; i<LOGFS_EMBEDDED_FIELDS; i++)
+ li->li_data[i] = be64_to_cpu(di->di_data[i]);
+ break;
+ }
+}
+
+
+static void logfs_inode_to_disk(struct inode *inode, struct logfs_disk_inode*di)
+{
+ struct logfs_inode *li = LOGFS_INODE(inode);
+ int i;
+
+ di->di_mode = cpu_to_be16(inode->i_mode);
+ di->di_pad = 0;
+ di->di_flags = cpu_to_be32(li->li_flags);
+ di->di_uid = cpu_to_be32(inode->i_uid);
+ di->di_gid = cpu_to_be32(inode->i_gid);
+ di->di_size = cpu_to_be64(i_size_read(inode));
+ di->di_used_bytes = cpu_to_be64(li->li_used_bytes);
+ di->di_ctime = timespec_to_be64(inode->i_ctime);
+ di->di_mtime = timespec_to_be64(inode->i_mtime);
+ di->di_refcount = cpu_to_be32(inode->i_nlink);
+ di->di_generation = cpu_to_be32(inode->i_generation);
+
+ switch (inode->i_mode & S_IFMT) {
+ case S_IFCHR: /* fall through */
+ case S_IFBLK: /* fall through */
+ case S_IFIFO:
+ di->di_data[0] = cpu_to_be64(inode->i_rdev);
+ break;
+ default:
+ for (i=0; i<LOGFS_EMBEDDED_FIELDS; i++)
+ di->di_data[i] = cpu_to_be64(li->li_data[i]);
+ break;
+ }
+}
+
+
+static int logfs_read_disk_inode(struct logfs_disk_inode *di,
+ struct inode *inode)
+{
+ struct logfs_super *super = LOGFS_SUPER(inode->i_sb);
+ ino_t ino = inode->i_ino;
+ int ret;
+
+ BUG_ON(!super->s_master_inode);
+ ret = logfs_inode_read(super->s_master_inode, di, sizeof(*di), ino);
+ if (ret)
+ return ret;
+
+ if ( !(be32_to_cpu(di->di_flags) & LOGFS_IF_VALID))
+ return -EIO;
+
+ if (be32_to_cpu(di->di_flags) & LOGFS_IF_INVALID)
+ return -EIO;
+
+ return 0;
+}
+
+
+static int __logfs_read_inode(struct inode *inode)
+{
+ struct logfs_inode *li = LOGFS_INODE(inode);
+ struct logfs_disk_inode di;
+ int ret;
+
+ ret = logfs_read_disk_inode(&di, inode);
+ /* FIXME: move back to mkfs when format has settled */
+ if (ret == -ENODATA && inode->i_ino == LOGFS_INO_ROOT) {
+ memset(&di, 0, sizeof(di));
+ di.di_flags = cpu_to_be32(LOGFS_IF_VALID);
+ di.di_mode = cpu_to_be16(S_IFDIR | 0755);
+ di.di_refcount = cpu_to_be32(2);
+ ret = 0;
+ }
+ if (ret)
+ return ret;
+ logfs_disk_to_inode(&di, inode);
+
+ if ( !(li->li_flags&LOGFS_IF_VALID) || (li->li_flags&LOGFS_IF_INVALID))
+ return -EIO;
+
+ switch (inode->i_mode & S_IFMT) {
+ case S_IFDIR:
+ inode->i_op = &logfs_dir_iops;
+ inode->i_fop = &logfs_dir_fops;
+ break;
+ case S_IFREG:
+ inode->i_op = &logfs_reg_iops;
+ inode->i_fop = &logfs_reg_fops;
+ inode->i_mapping->a_ops = &logfs_reg_aops;
+ break;
+ default:
+ ;
+ }
+
+ return 0;
+}
+
+
+static void logfs_read_inode(struct inode *inode)
+{
+ int ret;
+
+ BUG_ON(inode->i_ino == LOGFS_INO_MASTER);
+
+ ret = __logfs_read_inode(inode);
+ if (ret) {
+ printk("%lx, %x\n", inode->i_ino, -ret);
+ BUG();
+ }
+}
+
+
+static int logfs_write_disk_inode(struct logfs_disk_inode *di,
+ struct inode *inode)
+{
+ struct logfs_super *super = LOGFS_SUPER(inode->i_sb);
+
+ return logfs_inode_write(super->s_master_inode, di, sizeof(*di),
+ inode->i_ino);
+}
+
+
+int __logfs_write_inode(struct inode *inode)
+{
+ struct logfs_disk_inode old, new; /* FIXME: move these off the stack */
+
+ BUG_ON(inode->i_ino == LOGFS_INO_MASTER);
+
+ /* read and compare the inode first. If it hasn't changed, don't
+ * bother writing it. */
+ logfs_inode_to_disk(inode, &new);
+ if (logfs_read_disk_inode(&old, inode))
+ return logfs_write_disk_inode(&new, inode);
+ if (memcmp(&old, &new, sizeof(old)))
+ return logfs_write_disk_inode(&new, inode);
+ return 0;
+}
+
+
+static int logfs_write_inode(struct inode *inode, int do_sync)
+{
+ int ret;
+
+ /* Can only happen if creat() failed. Safe to skip. */
+ if (LOGFS_INODE(inode)->li_flags & LOGFS_IF_STILLBORN)
+ return 0;
+
+ ret = __logfs_write_inode(inode);
+ LOGFS_BUG_ON(ret, inode->i_sb);
+ return ret;
+}
+
+
+static void logfs_truncate_inode(struct inode *inode)
+{
+ i_size_write(inode, 0);
+ logfs_truncate(inode);
+ truncate_inode_pages(&inode->i_data, 0);
+}
+
+
+/**
+ * ZOMBIE inodes have already been deleted before and should remain dead,
+ * if it weren't for valid checking. No need to kill them again here.
+ */
+static void logfs_delete_inode(struct inode *inode)
+{
+ struct logfs_super *super = LOGFS_SUPER(inode->i_sb);
+
+ if (! (LOGFS_INODE(inode)->li_flags & LOGFS_IF_ZOMBIE)) {
+ if (i_size_read(inode) > 0)
+ logfs_truncate_inode(inode);
+ logfs_delete(super->s_master_inode, inode->i_ino);
+ }
+ clear_inode(inode);
+}
+
+
+void __logfs_destroy_inode(struct inode *inode)
+{
+ kmem_cache_free(logfs_inode_cache, LOGFS_INODE(inode));
+}
+
+
+/**
+ * We need to remember which inodes are currently being dropped. They
+ * would deadlock the cleaner, if it were to iget() them. So
+ * logfs_drop_inode() adds them to super->s_freeing_list,
+ * logfs_destroy_inode() removes them again and logfs_iget() checks the
+ * list.
+ */
+static void logfs_destroy_inode(struct inode *inode)
+{
+ struct logfs_inode *li = LOGFS_INODE(inode);
+
+ BUG_ON(list_empty(&li->li_freeing_list));
+ spin_lock(&inode_lock);
+ list_del(&li->li_freeing_list);
+ spin_unlock(&inode_lock);
+ kmem_cache_free(logfs_inode_cache, LOGFS_INODE(inode));
+}
+
+
+static void logfs_drop_inode(struct inode *inode)
+{
+ struct logfs_super *super = LOGFS_SUPER(inode->i_sb);
+ struct logfs_inode *li = LOGFS_INODE(inode);
+
+ list_move(&li->li_freeing_list, &super->s_freeing_list);
+ generic_drop_inode(inode);
+}
+
+
+static u64 logfs_get_ino(struct super_block *sb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ u64 ino;
+
+ /* FIXME: ino allocation should work in two modes:
+ * o nonsparse - ifile is mostly occupied, just append
+ * o sparse - ifile has lots of holes, fill them up
+ */
+ spin_lock(&super->s_ino_lock);
+ ino = super->s_last_ino; /* ifile shouldn't be too sparse */
+ super->s_last_ino++;
+ spin_unlock(&super->s_ino_lock);
+ return ino;
+}
+
+
+struct inode *logfs_new_inode(struct inode *dir, int mode)
+{
+ struct super_block *sb = dir->i_sb;
+ struct inode *inode;
+
+ inode = new_inode(sb);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ logfs_init_inode(inode);
+
+ inode->i_mode = mode;
+ inode->i_ino = logfs_get_ino(sb);
+
+ insert_inode_hash(inode);
+
+ return inode;
+}
+
+
+static void logfs_init_once(void *_li, struct kmem_cache *cachep,
+ unsigned long flags)
+{
+ struct logfs_inode *li = _li;
+ int i;
+
+ if ((flags & (SLAB_CTOR_VERIFY|SLAB_CTOR_CONSTRUCTOR)) ==
+ SLAB_CTOR_CONSTRUCTOR) {
+ li->li_flags = 0;
+ li->li_used_bytes = 0;
+ for (i=0; i<LOGFS_EMBEDDED_FIELDS; i++)
+ li->li_data[i] = 0;
+ inode_init_once(&li->vfs_inode);
+ }
+
+}
+
+
+struct super_operations logfs_super_operations = {
+ .alloc_inode = logfs_alloc_inode,
+ .delete_inode = logfs_delete_inode,
+ .destroy_inode = logfs_destroy_inode,
+ .drop_inode = logfs_drop_inode,
+ .read_inode = logfs_read_inode,
+ .write_inode = logfs_write_inode,
+ .statfs = logfs_statfs,
+};
+
+
+int logfs_init_inode_cache(void)
+{
+ logfs_inode_cache = kmem_cache_create("logfs_inode_cache",
+ sizeof(struct logfs_inode), 0, SLAB_RECLAIM_ACCOUNT,
+ logfs_init_once, NULL);
+ if (!logfs_inode_cache)
+ return -ENOMEM;
+ return 0;
+}
+
+
+void logfs_destroy_inode_cache(void)
+{
+ kmem_cache_destroy(logfs_inode_cache);
+}
--- /dev/null 2007-04-18 05:32:26.652341749 +0200
+++ linux-2.6.21logfs/fs/logfs/journal.c 2007-05-07 13:32:12.000000000 +0200
@@ -0,0 +1,696 @@
+#include "logfs.h"
+
+
+static void clear_retired(struct super_block *sb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ int i;
+
+ for (i=0; i<JE_LAST; i++)
+ super->s_retired[i].used = 0;
+ super->s_first.used = 0;
+}
+
+
+static void clear_speculatives(struct super_block *sb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ int i;
+
+ for (i=0; i<JE_LAST; i++)
+ super->s_speculative[i].used = 0;
+}
+
+
+static void retire_speculatives(struct super_block *sb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ int i;
+
+ for (i=0; i<JE_LAST; i++) {
+ struct logfs_journal_entry *spec = super->s_speculative + i;
+ struct logfs_journal_entry *retired = super->s_retired + i;
+ if (! spec->used)
+ continue;
+ if (retired->used && (spec->version <= retired->version))
+ continue;
+ retired->used = 1;
+ retired->version = spec->version;
+ retired->offset = spec->offset;
+ retired->len = spec->len;
+ }
+ clear_speculatives(sb);
+}
+
+
+static void __logfs_scan_journal(struct super_block *sb, void *block,
+ u32 segno, u64 block_ofs, int block_index)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ struct logfs_journal_header *h;
+ struct logfs_area *area = super->s_journal_area;
+
+ for (h = block; (void*)h - block < sb->s_blocksize; h++) {
+ struct logfs_journal_entry *spec, *retired;
+ unsigned long ofs = (void*)h - block;
+ unsigned long remainder = sb->s_blocksize - ofs;
+ u16 len = be16_to_cpu(h->h_len);
+ u16 type = be16_to_cpu(h->h_type);
+ s16 version = be16_to_cpu(h->h_version);
+
+ if ((len < 16) || (len > remainder))
+ continue;
+ if ((type < JE_FIRST) || (type > JE_LAST))
+ continue;
+ if (h->h_crc != logfs_crc32(h, len, 4))
+ continue;
+
+ if (!super->s_first.used) { /* remember first version */
+ super->s_first.used = 1;
+ super->s_first.version = version;
+ }
+ version -= super->s_first.version;
+
+ if (abs(version) > 1<<14) /* all versions should be near */
+ LOGFS_BUG(sb);
+
+ spec = &super->s_speculative[type];
+ retired = &super->s_retired[type];
+ switch (type) {
+ default: /* store speculative entry */
+ if (spec->used && (version <= spec->version))
+ break;
+ spec->used = 1;
+ spec->version = version;
+ spec->offset = block_ofs + ofs;
+ spec->len = len;
+ break;
+ case JE_COMMIT: /* retire speculative entries */
+ if (retired->used && (version <= retired->version))
+ break;
+ retired->used = 1;
+ retired->version = version;
+ retired->offset = block_ofs + ofs;
+ retired->len = len;
+ retire_speculatives(sb);
+ /* and set up journal area */
+ area->a_segno = segno;
+ area->a_used_objects = block_index;
+ area->a_is_open = 0; /* never reuse same segment after
+ mount - wasteful but safe */
+ break;
+ }
+ }
+}
+
+
+static int logfs_scan_journal(struct super_block *sb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ void *block = super->s_compressed_je;
+ u64 ofs;
+ u32 segno;
+ int i, k, err;
+
+ clear_speculatives(sb);
+ clear_retired(sb);
+ journal_for_each(i) {
+ segno = super->s_journal_seg[i];
+ if (!segno)
+ continue;
+ for (k=0; k<super->s_no_blocks; k++) {
+ ofs = logfs_block_ofs(sb, segno, k);
+ err = mtdread(sb, ofs, sb->s_blocksize, block);
+ if (err)
+ return err;
+ __logfs_scan_journal(sb, block, segno, ofs, k);
+ }
+ }
+ return 0;
+}
+
+
+static void logfs_read_commit(struct logfs_super *super,
+ struct logfs_journal_header *h)
+{
+ super->s_last_version = be16_to_cpu(h->h_version);
+}
+
+
+static void logfs_calc_free(struct super_block *sb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ u64 no_segs = super->s_no_segs;
+ u64 no_blocks = super->s_no_blocks;
+ u64 blocksize = sb->s_blocksize;
+ u64 free;
+ int i, reserved_segs;
+
+ reserved_segs = 1; /* super_block */
+ reserved_segs += super->s_bad_segments;
+ journal_for_each(i)
+ if (super->s_journal_seg[i])
+ reserved_segs++;
+
+ free = no_segs * no_blocks * blocksize; /* total size */
+ free -= reserved_segs * no_blocks * blocksize; /* sb & journal */
+ free -= (no_segs - reserved_segs) * blocksize; /* block summary */
+ free -= super->s_used_bytes; /* stored data */
+ super->s_free_bytes = free;
+}
+
+
+static void reserve_sb_and_journal(struct super_block *sb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ struct btree_head *head = &super->s_reserved_segments;
+ int i, err;
+
+ err = btree_insert(head, 0, (void*)1);
+ BUG_ON(err);
+
+ journal_for_each(i) {
+ if (! super->s_journal_seg[i])
+ continue;
+ err = btree_insert(head, super->s_journal_seg[i], (void*)1);
+ BUG_ON(err);
+ }
+}
+
+
+static void logfs_read_dynsb(struct super_block *sb, struct logfs_dynsb *dynsb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+
+ super->s_gec = be64_to_cpu(dynsb->ds_gec);
+ super->s_sweeper = be64_to_cpu(dynsb->ds_sweeper);
+ super->s_victim_ino = be64_to_cpu(dynsb->ds_victim_ino);
+ super->s_rename_dir = be64_to_cpu(dynsb->ds_rename_dir);
+ super->s_rename_pos = be64_to_cpu(dynsb->ds_rename_pos);
+ super->s_used_bytes = be64_to_cpu(dynsb->ds_used_bytes);
+}
+
+
+static void logfs_read_anchor(struct super_block *sb, struct logfs_anchor *da)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ struct inode *inode = super->s_master_inode;
+ struct logfs_inode *li = LOGFS_INODE(inode);
+ int i;
+
+ super->s_last_ino = be64_to_cpu(da->da_last_ino);
+ li->li_flags = LOGFS_IF_VALID;
+ i_size_write(inode, be64_to_cpu(da->da_size));
+ li->li_used_bytes = be64_to_cpu(da->da_used_bytes);
+
+ for (i=0; i<LOGFS_EMBEDDED_FIELDS; i++)
+ li->li_data[i] = be64_to_cpu(da->da_data[i]);
+}
+
+
+static void logfs_read_erasecount(struct super_block *sb,
+ struct logfs_journal_ec *ec)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ int i;
+
+ journal_for_each(i)
+ super->s_journal_ec[i] = be32_to_cpu(ec->ec[i]);
+}
+
+
+static void logfs_read_badsegments(struct super_block *sb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ struct btree_head *head = &super->s_reserved_segments;
+ be32 *seg, *bad = super->s_bb_array;
+ int err;
+
+ super->s_bad_segments = 0;
+ for (seg = bad; seg - bad < sb->s_blocksize >> 2; seg++) {
+ if (*seg == 0)
+ continue;
+ err = btree_insert(head, be32_to_cpu(*seg), (void*)1);
+ BUG_ON(err);
+ super->s_bad_segments++;
+ }
+}
+
+
+static void logfs_read_areas(struct super_block *sb, struct logfs_je_areas *a)
+{
+ struct logfs_area *area;
+ int i;
+
+ for (i=0; i<LOGFS_NO_AREAS; i++) {
+ area = LOGFS_SUPER(sb)->s_area[i];
+ area->a_used_bytes = be32_to_cpu(a->used_bytes[i]);
+ area->a_segno = be32_to_cpu(a->segno[i]);
+ if (area->a_segno)
+ area->a_is_open = 1;
+ }
+}
+
+
+static void *unpack(void *from, void *to)
+{
+ struct logfs_journal_header *h = from;
+ void *data = from + sizeof(struct logfs_journal_header);
+ int err;
+ size_t inlen, outlen;
+
+ if (h->h_compr == COMPR_NONE)
+ return data;
+
+ inlen = be16_to_cpu(h->h_len) - sizeof(*h);
+ outlen = be16_to_cpu(h->h_datalen);
+ err = logfs_uncompress(data, to, inlen, outlen);
+ BUG_ON(err);
+ return to;
+}
+
+
+/* FIXME: make sure there are enough per-area objects in journal */
+static int logfs_read_journal(struct super_block *sb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ void *block = super->s_compressed_je;
+ void *scratch = super->s_je;
+ int i, err, level;
+ struct logfs_area *area;
+
+ for (i=0; i<JE_LAST; i++) {
+ struct logfs_journal_entry *je = super->s_retired + i;
+ if (!super->s_retired[i].used)
+ switch (i) {
+ case JE_COMMIT:
+ case JE_DYNSB:
+ case JE_ANCHOR:
+ printk("LogFS: Missing journal entry %x?\n",
+ i);
+ return -EIO;
+ default:
+ continue;
+ }
+ err = mtdread(sb, je->offset, sb->s_blocksize, block);
+ if (err)
+ return err;
+
+ level = i & 0xf;
+ area = super->s_area[level];
+ switch (i & ~0xf) {
+ case JEG_BASE:
+ switch (i) {
+ case JE_COMMIT:
+ /* just reads the latest version number */
+ logfs_read_commit(super, block);
+ break;
+ case JE_DYNSB:
+ logfs_read_dynsb(sb, unpack(block, scratch));
+ break;
+ case JE_ANCHOR:
+ logfs_read_anchor(sb, unpack(block, scratch));
+ break;
+ case JE_ERASECOUNT:
+ logfs_read_erasecount(sb,unpack(block,scratch));
+ break;
+ case JE_BADSEGMENTS:
+ unpack(block, super->s_bb_array);
+ logfs_read_badsegments(sb);
+ break;
+ case JE_AREAS:
+ logfs_read_areas(sb, unpack(block, scratch));
+ break;
+ default:
+ LOGFS_BUG(sb);
+ return -EIO;
+ }
+ break;
+ case JEG_WBUF:
+ unpack(block, area->a_wbuf);
+ break;
+ default:
+ LOGFS_BUG(sb);
+ return -EIO;
+ }
+
+ }
+ return 0;
+}
+
+
+static void journal_get_free_segment(struct logfs_area *area)
+{
+ struct logfs_super *super = LOGFS_SUPER(area->a_sb);
+ int i;
+
+ journal_for_each(i) {
+ if (area->a_segno != super->s_journal_seg[i])
+ continue;
+empty_seg:
+ i++;
+ if (i == LOGFS_JOURNAL_SEGS)
+ i = 0;
+ if (!super->s_journal_seg[i])
+ goto empty_seg;
+
+ area->a_segno = super->s_journal_seg[i];
+ ++(super->s_journal_ec[i]);
+ return;
+ }
+ BUG();
+}
+
+
+static void journal_get_erase_count(struct logfs_area *area)
+{
+ /* erase count is stored globally and incremented in
+ * journal_get_free_segment() - nothing to do here */
+}
+
+
+static void journal_clear_blocks(struct logfs_area *area)
+{
+ /* nothing needed for journal segments */
+}
+
+
+static int joernal_erase_segment(struct logfs_area *area)
+{
+ return logfs_erase_segment(area->a_sb, area->a_segno);
+}
+
+
+static void journal_finish_area(struct logfs_area *area)
+{
+ if (area->a_used_objects < LOGFS_SUPER(area->a_sb)->s_no_blocks)
+ return;
+ area->a_is_open = 0;
+}
+
+
+static s64 __logfs_get_free_entry(struct super_block *sb)
+{
+ struct logfs_area *area = LOGFS_SUPER(sb)->s_journal_area;
+ u64 ofs;
+ int err;
+
+ err = logfs_open_area(area);
+ BUG_ON(err);
+
+ ofs = logfs_block_ofs(sb, area->a_segno, area->a_used_objects);
+ area->a_used_objects++;
+ logfs_close_area(area);
+
+ BUG_ON(ofs >= LOGFS_SUPER(sb)->s_size);
+ return ofs;
+}
+
+
+/**
+ * logfs_get_free_entry - return free space for journal entry
+ */
+static s64 logfs_get_free_entry(struct super_block *sb)
+{
+ s64 ret;
+
+ mutex_lock(&LOGFS_SUPER(sb)->s_log_mutex);
+ ret = __logfs_get_free_entry(sb);
+ mutex_unlock(&LOGFS_SUPER(sb)->s_log_mutex);
+ BUG_ON(ret <= 0); /* not sure, but it's safer to BUG than to accept */
+ return ret;
+}
+
+
+static size_t __logfs_write_header(struct logfs_super *super,
+ struct logfs_journal_header *h, size_t len, size_t datalen,
+ u16 type, u8 compr)
+{
+ h->h_len = cpu_to_be16(len);
+ h->h_type = cpu_to_be16(type);
+ h->h_version = cpu_to_be16(++super->s_last_version);
+ h->h_datalen = cpu_to_be16(datalen);
+ h->h_compr = compr;
+ h->h_pad[0] = 'H';
+ h->h_pad[1] = 'A';
+ h->h_pad[2] = 'T';
+ h->h_crc = logfs_crc32(h, len, 4);
+ return len;
+}
+
+
+static size_t logfs_write_header(struct logfs_super *super,
+ struct logfs_journal_header *h, size_t datalen, u16 type)
+{
+ size_t len = datalen + sizeof(*h);
+ return __logfs_write_header(super, h, len, datalen, type, COMPR_NONE);
+}
+
+
+static void *logfs_write_bb(struct super_block *sb, void *h,
+ u16 *type, size_t *len)
+{
+ *type = JE_BADSEGMENTS;
+ *len = sb->s_blocksize;
+ return LOGFS_SUPER(sb)->s_bb_array;
+}
+
+
+static inline size_t logfs_journal_erasecount_size(struct logfs_super *super)
+{
+ return LOGFS_JOURNAL_SEGS * sizeof(be32);
+}
+static void *logfs_write_erasecount(struct super_block *sb, void *_ec,
+ u16 *type, size_t *len)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ struct logfs_journal_ec *ec = _ec;
+ int i;
+
+ journal_for_each(i)
+ ec->ec[i] = cpu_to_be32(super->s_journal_ec[i]);
+ *type = JE_ERASECOUNT;
+ *len = logfs_journal_erasecount_size(super);
+ return ec;
+}
+
+
+static void *logfs_write_wbuf(struct super_block *sb, void *h,
+ u16 *type, size_t *len)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ struct logfs_area *area = super->s_area[super->s_sum_index];
+
+ *type = JEG_WBUF + super->s_sum_index;
+ *len = super->s_writesize;
+ return area->a_wbuf;
+}
+
+
+static void *__logfs_write_anchor(struct super_block *sb, void *_da,
+ u16 *type, size_t *len)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ struct logfs_anchor *da = _da;
+ struct inode *inode = super->s_master_inode;
+ struct logfs_inode *li = LOGFS_INODE(inode);
+ int i;
+
+ da->da_last_ino = cpu_to_be64(super->s_last_ino);
+ da->da_size = cpu_to_be64(i_size_read(inode));
+ da->da_used_bytes = cpu_to_be64(li->li_used_bytes);
+ for (i=0; i<LOGFS_EMBEDDED_FIELDS; i++)
+ da->da_data[i] = cpu_to_be64(li->li_data[i]);
+ *type = JE_ANCHOR;
+ *len = sizeof(*da);
+ return da;
+}
+
+
+static void *logfs_write_dynsb(struct super_block *sb, void *_dynsb,
+ u16 *type, size_t *len)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ struct logfs_dynsb *dynsb = _dynsb;
+
+ dynsb->ds_gec = cpu_to_be64(super->s_gec);
+ dynsb->ds_sweeper = cpu_to_be64(super->s_sweeper);
+ dynsb->ds_victim_ino = cpu_to_be64(super->s_victim_ino);
+ dynsb->ds_rename_dir = cpu_to_be64(super->s_rename_dir);
+ dynsb->ds_rename_pos = cpu_to_be64(super->s_rename_pos);
+ dynsb->ds_used_bytes = cpu_to_be64(super->s_used_bytes);
+ *type = JE_DYNSB;
+ *len = sizeof(*dynsb);
+ return dynsb;
+}
+
+
+static void *logfs_write_areas(struct super_block *sb, void *_a,
+ u16 *type, size_t *len)
+{
+ struct logfs_area *area;
+ struct logfs_je_areas *a = _a;
+ int i;
+
+ for (i=0; i<16; i++) { /* FIXME: have all 16 areas */
+ a->used_bytes[i] = 0;
+ a->segno[i] = 0;
+ }
+ for (i=0; i<LOGFS_NO_AREAS; i++) {
+ area = LOGFS_SUPER(sb)->s_area[i];
+ a->used_bytes[i] = cpu_to_be32(area->a_used_bytes);
+ a->segno[i] = cpu_to_be32(area->a_segno);
+ }
+ *type = JE_AREAS;
+ *len = sizeof(*a);
+ return a;
+}
+
+
+static void *logfs_write_commit(struct super_block *sb, void *h,
+ u16 *type, size_t *len)
+{
+ *type = JE_COMMIT;
+ *len = 0;
+ return NULL;
+}
+
+
+static size_t logfs_write_je(struct super_block *sb, size_t jpos,
+ void* (*write)(struct super_block *sb, void *scratch,
+ u16 *type, size_t *len))
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ void *scratch = super->s_je;
+ void *header = super->s_compressed_je + jpos;
+ void *data = header + sizeof(struct logfs_journal_header);
+ ssize_t max, compr_len, pad_len, full_len;
+ size_t len;
+ u16 type;
+ u8 compr = COMPR_ZLIB;
+
+ scratch = write(sb, scratch, &type, &len);
+ if (len == 0)
+ return logfs_write_header(super, header, 0, type);
+
+ max = sb->s_blocksize - jpos;
+ compr_len = logfs_compress(scratch, data, len, max);
+ if (compr_len < 0 || type == JE_ANCHOR) {
+ compr_len = logfs_memcpy(scratch, data, len, max);
+ compr = COMPR_NONE;
+ }
+ BUG_ON(compr_len < 0);
+
+ pad_len = ALIGN(compr_len, 16);
+ memset(data + compr_len, 0, pad_len - compr_len);
+ full_len = pad_len + sizeof(struct logfs_journal_header);
+
+ return __logfs_write_header(super, header, full_len, len, type, compr);
+}
+
+
+int logfs_write_anchor(struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ void *block = super->s_compressed_je;
+ u64 ofs;
+ size_t jpos;
+ int i, ret;
+
+ ofs = logfs_get_free_entry(sb);
+ BUG_ON(ofs >= super->s_size);
+
+ memset(block, 0, sb->s_blocksize);
+ jpos = 0;
+ for (i=0; i<LOGFS_NO_AREAS; i++) {
+ super->s_sum_index = i;
+ jpos += logfs_write_je(sb, jpos, logfs_write_wbuf);
+ }
+ jpos += logfs_write_je(sb, jpos, logfs_write_bb);
+ jpos += logfs_write_je(sb, jpos, logfs_write_erasecount);
+ jpos += logfs_write_je(sb, jpos, __logfs_write_anchor);
+ jpos += logfs_write_je(sb, jpos, logfs_write_dynsb);
+ jpos += logfs_write_je(sb, jpos, logfs_write_areas);
+ jpos += logfs_write_je(sb, jpos, logfs_write_commit);
+
+ BUG_ON(jpos > sb->s_blocksize);
+
+ ret = mtdwrite(sb, ofs, sb->s_blocksize, block);
+ if (ret)
+ return ret;
+ return 0;
+}
+
+
+static struct logfs_area_ops journal_area_ops = {
+ .get_free_segment = journal_get_free_segment,
+ .get_erase_count = journal_get_erase_count,
+ .clear_blocks = journal_clear_blocks,
+ .erase_segment = joernal_erase_segment,
+ .finish_area = journal_finish_area,
+};
+
+
+int logfs_init_journal(struct super_block *sb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+ int ret;
+
+ mutex_init(&super->s_log_mutex);
+
+ super->s_je = kzalloc(sb->s_blocksize, GFP_KERNEL);
+ if (!super->s_je)
+ goto err0;
+
+ super->s_compressed_je = kzalloc(sb->s_blocksize, GFP_KERNEL);
+ if (!super->s_compressed_je)
+ goto err1;
+
+ super->s_bb_array = kzalloc(sb->s_blocksize, GFP_KERNEL);
+ if (!super->s_bb_array)
+ goto err2;
+
+ super->s_master_inode = logfs_new_meta_inode(sb, LOGFS_INO_MASTER);
+ if (!super->s_master_inode)
+ goto err3;
+
+ super->s_master_inode->i_nlink = 1; /* lock it in ram */
+
+ /* logfs_scan_journal() is looking for the latest journal entries, but
+ * doesn't copy them into data structures yet. logfs_read_journal()
+ * then re-reads those entries and copies their contents over. */
+ ret = logfs_scan_journal(sb);
+ if (ret)
+ return ret;
+ ret = logfs_read_journal(sb);
+ if (ret)
+ return ret;
+
+ reserve_sb_and_journal(sb);
+ logfs_calc_free(sb);
+
+ super->s_journal_area->a_ops = &journal_area_ops;
+ return 0;
+err3:
+ kfree(super->s_bb_array);
+err2:
+ kfree(super->s_compressed_je);
+err1:
+ kfree(super->s_je);
+err0:
+ return -ENOMEM;
+}
+
+
+void logfs_cleanup_journal(struct super_block *sb)
+{
+ struct logfs_super *super = LOGFS_SUPER(sb);
+
+ __logfs_destroy_inode(super->s_master_inode);
+ super->s_master_inode = NULL;
+
+ kfree(super->s_bb_array);
+ kfree(super->s_compressed_je);
+ kfree(super->s_je);
+}
Jörn
--
Time? What's that? Time is only worth what you do with it.
-- Theo de Raadt
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