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udf: Don't write integrity descriptor too often
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We update information in logical volume integrity descriptor after each
allocation (as LVID contains free space, number of directories and files on
disk etc.). If the filesystem is on some phase change media, this leads to its
quick degradation as such media is able to handle only 10000 overwrites or so.
We solve the problem by writing new information into LVID only on umount,
remount-ro and sync. This solves the problem at the price of longer media
inconsistency (previously media became consistent after pdflush flushed dirty
LVID buffer) but that should be acceptable.

Report by and patch written in cooperation with
Rich Coe <[email protected]>.

Signed-off-by: Jan Kara <[email protected]>
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@jankara
jankara committed Apr 2, 2009
1 parent 4034600 commit 146bca7
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Showing 5 changed files with 52 additions and 47 deletions.
37 changes: 12 additions & 25 deletions fs/udf/balloc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -140,17 +140,17 @@ static inline int load_block_bitmap(struct super_block *sb,
return slot;
}

static bool udf_add_free_space(struct udf_sb_info *sbi,
u16 partition, u32 cnt)
static void udf_add_free_space(struct super_block *sb, u16 partition, u32 cnt)
{
struct udf_sb_info *sbi = UDF_SB(sb);
struct logicalVolIntegrityDesc *lvid;

if (sbi->s_lvid_bh == NULL)
return false;
if (!sbi->s_lvid_bh)
return;

lvid = (struct logicalVolIntegrityDesc *)sbi->s_lvid_bh->b_data;
le32_add_cpu(&lvid->freeSpaceTable[partition], cnt);
return true;
udf_updated_lvid(sb);
}

static void udf_bitmap_free_blocks(struct super_block *sb,
Expand Down Expand Up @@ -209,7 +209,7 @@ static void udf_bitmap_free_blocks(struct super_block *sb,
} else {
if (inode)
vfs_dq_free_block(inode, 1);
udf_add_free_space(sbi, sbi->s_partition, 1);
udf_add_free_space(sb, sbi->s_partition, 1);
}
}
mark_buffer_dirty(bh);
Expand All @@ -220,9 +220,6 @@ static void udf_bitmap_free_blocks(struct super_block *sb,
} while (overflow);

error_return:
sb->s_dirt = 1;
if (sbi->s_lvid_bh)
mark_buffer_dirty(sbi->s_lvid_bh);
mutex_unlock(&sbi->s_alloc_mutex);
}

Expand Down Expand Up @@ -279,9 +276,7 @@ static int udf_bitmap_prealloc_blocks(struct super_block *sb,
} while (block_count > 0);

out:
if (udf_add_free_space(sbi, partition, -alloc_count))
mark_buffer_dirty(sbi->s_lvid_bh);
sb->s_dirt = 1;
udf_add_free_space(sb, partition, -alloc_count);
mutex_unlock(&sbi->s_alloc_mutex);
return alloc_count;
}
Expand Down Expand Up @@ -411,9 +406,7 @@ static int udf_bitmap_new_block(struct super_block *sb,

mark_buffer_dirty(bh);

if (udf_add_free_space(sbi, partition, -1))
mark_buffer_dirty(sbi->s_lvid_bh);
sb->s_dirt = 1;
udf_add_free_space(sb, partition, -1);
mutex_unlock(&sbi->s_alloc_mutex);
*err = 0;
return newblock;
Expand Down Expand Up @@ -457,8 +450,7 @@ static void udf_table_free_blocks(struct super_block *sb,
could occure, but.. oh well */
if (inode)
vfs_dq_free_block(inode, count);
if (udf_add_free_space(sbi, sbi->s_partition, count))
mark_buffer_dirty(sbi->s_lvid_bh);
udf_add_free_space(sb, sbi->s_partition, count);

start = bloc->logicalBlockNum + offset;
end = bloc->logicalBlockNum + offset + count - 1;
Expand Down Expand Up @@ -657,7 +649,6 @@ static void udf_table_free_blocks(struct super_block *sb,
brelse(oepos.bh);

error_return:
sb->s_dirt = 1;
mutex_unlock(&sbi->s_alloc_mutex);
return;
}
Expand Down Expand Up @@ -722,10 +713,8 @@ static int udf_table_prealloc_blocks(struct super_block *sb,

brelse(epos.bh);

if (alloc_count && udf_add_free_space(sbi, partition, -alloc_count)) {
mark_buffer_dirty(sbi->s_lvid_bh);
sb->s_dirt = 1;
}
if (alloc_count)
udf_add_free_space(sb, partition, -alloc_count);
mutex_unlock(&sbi->s_alloc_mutex);
return alloc_count;
}
Expand Down Expand Up @@ -823,10 +812,8 @@ static int udf_table_new_block(struct super_block *sb,
udf_delete_aext(table, goal_epos, goal_eloc, goal_elen);
brelse(goal_epos.bh);

if (udf_add_free_space(sbi, partition, -1))
mark_buffer_dirty(sbi->s_lvid_bh);
udf_add_free_space(sb, partition, -1);

sb->s_dirt = 1;
mutex_unlock(&sbi->s_alloc_mutex);
*err = 0;
return newblock;
Expand Down
5 changes: 2 additions & 3 deletions fs/udf/ialloc.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -49,8 +49,7 @@ void udf_free_inode(struct inode *inode)
le32_add_cpu(&lvidiu->numDirs, -1);
else
le32_add_cpu(&lvidiu->numFiles, -1);

mark_buffer_dirty(sbi->s_lvid_bh);
udf_updated_lvid(sb);
}
mutex_unlock(&sbi->s_alloc_mutex);

Expand Down Expand Up @@ -122,7 +121,7 @@ struct inode *udf_new_inode(struct inode *dir, int mode, int *err)
if (!(++uniqueID & 0x00000000FFFFFFFFUL))
uniqueID += 16;
lvhd->uniqueID = cpu_to_le64(uniqueID);
mark_buffer_dirty(sbi->s_lvid_bh);
udf_updated_lvid(sb);
}
mutex_unlock(&sbi->s_alloc_mutex);
inode->i_mode = mode;
Expand Down
44 changes: 25 additions & 19 deletions fs/udf/super.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -81,7 +81,7 @@ static char error_buf[1024];
/* These are the "meat" - everything else is stuffing */
static int udf_fill_super(struct super_block *, void *, int);
static void udf_put_super(struct super_block *);
static void udf_write_super(struct super_block *);
static int udf_sync_fs(struct super_block *, int);
static int udf_remount_fs(struct super_block *, int *, char *);
static void udf_load_logicalvolint(struct super_block *, struct kernel_extent_ad);
static int udf_find_fileset(struct super_block *, struct kernel_lb_addr *,
Expand Down Expand Up @@ -178,7 +178,7 @@ static const struct super_operations udf_sb_ops = {
.delete_inode = udf_delete_inode,
.clear_inode = udf_clear_inode,
.put_super = udf_put_super,
.write_super = udf_write_super,
.sync_fs = udf_sync_fs,
.statfs = udf_statfs,
.remount_fs = udf_remount_fs,
.show_options = udf_show_options,
Expand Down Expand Up @@ -553,17 +553,6 @@ static int udf_parse_options(char *options, struct udf_options *uopt,
return 1;
}

static void udf_write_super(struct super_block *sb)
{
lock_kernel();

if (!(sb->s_flags & MS_RDONLY))
udf_open_lvid(sb);
sb->s_dirt = 0;

unlock_kernel();
}

static int udf_remount_fs(struct super_block *sb, int *flags, char *options)
{
struct udf_options uopt;
Expand Down Expand Up @@ -1753,24 +1742,25 @@ static void udf_open_lvid(struct super_block *sb)
struct buffer_head *bh = sbi->s_lvid_bh;
struct logicalVolIntegrityDesc *lvid;
struct logicalVolIntegrityDescImpUse *lvidiu;

if (!bh)
return;

lvid = (struct logicalVolIntegrityDesc *)bh->b_data;
lvidiu = udf_sb_lvidiu(sbi);

lvidiu->impIdent.identSuffix[0] = UDF_OS_CLASS_UNIX;
lvidiu->impIdent.identSuffix[1] = UDF_OS_ID_LINUX;
udf_time_to_disk_stamp(&lvid->recordingDateAndTime,
CURRENT_TIME);
lvid->integrityType = LVID_INTEGRITY_TYPE_OPEN;
lvid->integrityType = cpu_to_le32(LVID_INTEGRITY_TYPE_OPEN);

lvid->descTag.descCRC = cpu_to_le16(
crc_itu_t(0, (char *)lvid + sizeof(struct tag),
le16_to_cpu(lvid->descTag.descCRCLength)));

lvid->descTag.tagChecksum = udf_tag_checksum(&lvid->descTag);
mark_buffer_dirty(bh);
sbi->s_lvid_dirty = 0;
}

static void udf_close_lvid(struct super_block *sb)
Expand All @@ -1784,10 +1774,6 @@ static void udf_close_lvid(struct super_block *sb)
return;

lvid = (struct logicalVolIntegrityDesc *)bh->b_data;

if (lvid->integrityType != LVID_INTEGRITY_TYPE_OPEN)
return;

lvidiu = udf_sb_lvidiu(sbi);
lvidiu->impIdent.identSuffix[0] = UDF_OS_CLASS_UNIX;
lvidiu->impIdent.identSuffix[1] = UDF_OS_ID_LINUX;
Expand All @@ -1806,6 +1792,7 @@ static void udf_close_lvid(struct super_block *sb)

lvid->descTag.tagChecksum = udf_tag_checksum(&lvid->descTag);
mark_buffer_dirty(bh);
sbi->s_lvid_dirty = 0;
}

static void udf_sb_free_bitmap(struct udf_bitmap *bitmap)
Expand Down Expand Up @@ -2092,6 +2079,25 @@ static void udf_put_super(struct super_block *sb)
sb->s_fs_info = NULL;
}

static int udf_sync_fs(struct super_block *sb, int wait)
{
struct udf_sb_info *sbi = UDF_SB(sb);

mutex_lock(&sbi->s_alloc_mutex);
if (sbi->s_lvid_dirty) {
/*
* Blockdevice will be synced later so we don't have to submit
* the buffer for IO
*/
mark_buffer_dirty(sbi->s_lvid_bh);
sb->s_dirt = 0;
sbi->s_lvid_dirty = 0;
}
mutex_unlock(&sbi->s_alloc_mutex);

return 0;
}

static int udf_statfs(struct dentry *dentry, struct kstatfs *buf)
{
struct super_block *sb = dentry->d_sb;
Expand Down
2 changes: 2 additions & 0 deletions fs/udf/udf_sb.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -148,6 +148,8 @@ struct udf_sb_info {
struct inode *s_vat_inode;

struct mutex s_alloc_mutex;
/* Protected by s_alloc_mutex */
unsigned int s_lvid_dirty;
};

static inline struct udf_sb_info *UDF_SB(struct super_block *sb)
Expand Down
11 changes: 11 additions & 0 deletions fs/udf/udfdecl.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -111,6 +111,17 @@ struct extent_position {

/* super.c */
extern void udf_warning(struct super_block *, const char *, const char *, ...);
static inline void udf_updated_lvid(struct super_block *sb)
{
struct buffer_head *bh = UDF_SB(sb)->s_lvid_bh;

BUG_ON(!bh);
WARN_ON_ONCE(((struct logicalVolIntegrityDesc *)
bh->b_data)->integrityType !=
cpu_to_le32(LVID_INTEGRITY_TYPE_OPEN));
sb->s_dirt = 1;
UDF_SB(sb)->s_lvid_dirty = 1;
}

/* namei.c */
extern int udf_write_fi(struct inode *inode, struct fileIdentDesc *,
Expand Down

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