summaryrefslogtreecommitdiffstats
path: root/fs/quota
diff options
context:
space:
mode:
authorLinus Torvalds <torvalds@linux-foundation.org>2010-08-07 12:57:07 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2010-08-07 12:57:07 -0700
commit90e0c225968f0878e090c7ff3f88323973476cee (patch)
tree30fff5a5cb18b08d40e4d496489be6ce714a6cde /fs/quota
parent938a73b959cf77aadc41bded3bf416b618aa20b3 (diff)
parent5f11e6a44059f728dddd8d0dbe5b4368ea93575b (diff)
Merge branch 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6
* 'for_linus' of git://git.kernel.org/pub/scm/linux/kernel/git/jack/linux-fs-2.6: ext3: Fix dirtying of journalled buffers in data=journal mode ext3: default to ordered mode quota: Use mark_inode_dirty_sync instead of mark_inode_dirty quota: Change quota error message to print out disk and function name MAINTAINERS: Update entries of ext2 and ext3 MAINTAINERS: Update address of Andreas Dilger ext3: Avoid filesystem corruption after a crash under heavy delete load ext3: remove vestiges of nobh support ext3: Fix set but unused variables quota: clean up quota active checks quota: Clean up the namespace in dqblk_xfs.h quota: check quota reservation on remove_dquot_ref
Diffstat (limited to 'fs/quota')
-rw-r--r--fs/quota/dquot.c79
-rw-r--r--fs/quota/quota_tree.c85
-rw-r--r--fs/quota/quota_tree.h6
-rw-r--r--fs/quota/quota_v1.c3
-rw-r--r--fs/quota/quota_v2.c11
5 files changed, 104 insertions, 80 deletions
diff --git a/fs/quota/dquot.c b/fs/quota/dquot.c
index 437d2ca2de9..ef72b169942 100644
--- a/fs/quota/dquot.c
+++ b/fs/quota/dquot.c
@@ -132,6 +132,22 @@ static __cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_state_lock);
__cacheline_aligned_in_smp DEFINE_SPINLOCK(dq_data_lock);
EXPORT_SYMBOL(dq_data_lock);
+void __quota_error(struct super_block *sb, const char *func,
+ const char *fmt, ...)
+{
+ va_list args;
+
+ if (printk_ratelimit()) {
+ va_start(args, fmt);
+ printk(KERN_ERR "Quota error (device %s): %s: ",
+ sb->s_id, func);
+ vprintk(fmt, args);
+ printk("\n");
+ va_end(args);
+ }
+}
+EXPORT_SYMBOL(__quota_error);
+
#if defined(CONFIG_QUOTA_DEBUG) || defined(CONFIG_PRINT_QUOTA_WARNING)
static char *quotatypes[] = INITQFNAMES;
#endif
@@ -705,11 +721,8 @@ void dqput(struct dquot *dquot)
return;
#ifdef CONFIG_QUOTA_DEBUG
if (!atomic_read(&dquot->dq_count)) {
- printk("VFS: dqput: trying to free free dquot\n");
- printk("VFS: device %s, dquot of %s %d\n",
- dquot->dq_sb->s_id,
- quotatypes[dquot->dq_type],
- dquot->dq_id);
+ quota_error(dquot->dq_sb, "trying to free free dquot of %s %d",
+ quotatypes[dquot->dq_type], dquot->dq_id);
BUG();
}
#endif
@@ -732,9 +745,9 @@ we_slept:
/* Commit dquot before releasing */
ret = dquot->dq_sb->dq_op->write_dquot(dquot);
if (ret < 0) {
- printk(KERN_ERR "VFS: cannot write quota structure on "
- "device %s (error %d). Quota may get out of "
- "sync!\n", dquot->dq_sb->s_id, ret);
+ quota_error(dquot->dq_sb, "Can't write quota structure"
+ " (error %d). Quota may get out of sync!",
+ ret);
/*
* We clear dirty bit anyway, so that we avoid
* infinite loop here
@@ -914,9 +927,9 @@ static void add_dquot_ref(struct super_block *sb, int type)
#ifdef CONFIG_QUOTA_DEBUG
if (reserved) {
- printk(KERN_WARNING "VFS (%s): Writes happened before quota"
- " was turned on thus quota information is probably "
- "inconsistent. Please run quotacheck(8).\n", sb->s_id);
+ quota_error(sb, "Writes happened before quota was turned on "
+ "thus quota information is probably inconsistent. "
+ "Please run quotacheck(8)");
}
#endif
}
@@ -947,7 +960,9 @@ static int remove_inode_dquot_ref(struct inode *inode, int type,
if (dqput_blocks(dquot)) {
#ifdef CONFIG_QUOTA_DEBUG
if (atomic_read(&dquot->dq_count) != 1)
- printk(KERN_WARNING "VFS: Adding dquot with dq_count %d to dispose list.\n", atomic_read(&dquot->dq_count));
+ quota_error(inode->i_sb, "Adding dquot with "
+ "dq_count %d to dispose list",
+ atomic_read(&dquot->dq_count));
#endif
spin_lock(&dq_list_lock);
/* As dquot must have currently users it can't be on
@@ -986,6 +1001,7 @@ static void remove_dquot_ref(struct super_block *sb, int type,
struct list_head *tofree_head)
{
struct inode *inode;
+ int reserved = 0;
spin_lock(&inode_lock);
list_for_each_entry(inode, &sb->s_inodes, i_sb_list) {
@@ -995,10 +1011,20 @@ static void remove_dquot_ref(struct super_block *sb, int type,
* only quota pointers and these have separate locking
* (dqptr_sem).
*/
- if (!IS_NOQUOTA(inode))
+ if (!IS_NOQUOTA(inode)) {
+ if (unlikely(inode_get_rsv_space(inode) > 0))
+ reserved = 1;
remove_inode_dquot_ref(inode, type, tofree_head);
+ }
}
spin_unlock(&inode_lock);
+#ifdef CONFIG_QUOTA_DEBUG
+ if (reserved) {
+ printk(KERN_WARNING "VFS (%s): Writes happened after quota"
+ " was disabled thus quota information is probably "
+ "inconsistent. Please run quotacheck(8).\n", sb->s_id);
+ }
+#endif
}
/* Gather all references from inodes and drop them */
@@ -1304,6 +1330,15 @@ static int info_bdq_free(struct dquot *dquot, qsize_t space)
return QUOTA_NL_NOWARN;
}
+static int dquot_active(const struct inode *inode)
+{
+ struct super_block *sb = inode->i_sb;
+
+ if (IS_NOQUOTA(inode))
+ return 0;
+ return sb_any_quota_loaded(sb) & ~sb_any_quota_suspended(sb);
+}
+
/*
* Initialize quota pointers in inode
*
@@ -1323,7 +1358,7 @@ static void __dquot_initialize(struct inode *inode, int type)
/* First test before acquiring mutex - solves deadlocks when we
* re-enter the quota code and are already holding the mutex */
- if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode))
+ if (!dquot_active(inode))
return;
/* First get references to structures we might need. */
@@ -1507,7 +1542,7 @@ int __dquot_alloc_space(struct inode *inode, qsize_t number, int flags)
* First test before acquiring mutex - solves deadlocks when we
* re-enter the quota code and are already holding the mutex
*/
- if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) {
+ if (!dquot_active(inode)) {
inode_incr_space(inode, number, reserve);
goto out;
}
@@ -1559,7 +1594,7 @@ int dquot_alloc_inode(const struct inode *inode)
/* First test before acquiring mutex - solves deadlocks when we
* re-enter the quota code and are already holding the mutex */
- if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode))
+ if (!dquot_active(inode))
return 0;
for (cnt = 0; cnt < MAXQUOTAS; cnt++)
warntype[cnt] = QUOTA_NL_NOWARN;
@@ -1596,7 +1631,7 @@ int dquot_claim_space_nodirty(struct inode *inode, qsize_t number)
{
int cnt;
- if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) {
+ if (!dquot_active(inode)) {
inode_claim_rsv_space(inode, number);
return 0;
}
@@ -1629,7 +1664,7 @@ void __dquot_free_space(struct inode *inode, qsize_t number, int flags)
/* First test before acquiring mutex - solves deadlocks when we
* re-enter the quota code and are already holding the mutex */
- if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode)) {
+ if (!dquot_active(inode)) {
inode_decr_space(inode, number, reserve);
return;
}
@@ -1667,7 +1702,7 @@ void dquot_free_inode(const struct inode *inode)
/* First test before acquiring mutex - solves deadlocks when we
* re-enter the quota code and are already holding the mutex */
- if (!sb_any_quota_active(inode->i_sb) || IS_NOQUOTA(inode))
+ if (!dquot_active(inode))
return;
down_read(&sb_dqopt(inode->i_sb)->dqptr_sem);
@@ -1790,7 +1825,7 @@ int dquot_transfer(struct inode *inode, struct iattr *iattr)
struct super_block *sb = inode->i_sb;
int ret;
- if (!sb_any_quota_active(sb) || IS_NOQUOTA(inode))
+ if (!dquot_active(inode))
return 0;
if (iattr->ia_valid & ATTR_UID && iattr->ia_uid != inode->i_uid)
@@ -1957,7 +1992,7 @@ int dquot_disable(struct super_block *sb, int type, unsigned int flags)
truncate_inode_pages(&toputinode[cnt]->i_data,
0);
mutex_unlock(&toputinode[cnt]->i_mutex);
- mark_inode_dirty(toputinode[cnt]);
+ mark_inode_dirty_sync(toputinode[cnt]);
}
mutex_unlock(&dqopt->dqonoff_mutex);
}
@@ -2270,7 +2305,7 @@ static void do_get_dqblk(struct dquot *dquot, struct fs_disk_quota *di)
memset(di, 0, sizeof(*di));
di->d_version = FS_DQUOT_VERSION;
di->d_flags = dquot->dq_type == USRQUOTA ?
- XFS_USER_QUOTA : XFS_GROUP_QUOTA;
+ FS_USER_QUOTA : FS_GROUP_QUOTA;
di->d_id = dquot->dq_id;
spin_lock(&dq_data_lock);
diff --git a/fs/quota/quota_tree.c b/fs/quota/quota_tree.c
index 24f03407eeb..9e48874eabc 100644
--- a/fs/quota/quota_tree.c
+++ b/fs/quota/quota_tree.c
@@ -65,8 +65,7 @@ static ssize_t write_blk(struct qtree_mem_dqinfo *info, uint blk, char *buf)
ret = sb->s_op->quota_write(sb, info->dqi_type, buf,
info->dqi_usable_bs, blk << info->dqi_blocksize_bits);
if (ret != info->dqi_usable_bs) {
- q_warn(KERN_WARNING "VFS: dquota write failed on "
- "dev %s\n", sb->s_id);
+ quota_error(sb, "dquota write failed");
if (ret >= 0)
ret = -EIO;
}
@@ -160,9 +159,8 @@ static int remove_free_dqentry(struct qtree_mem_dqinfo *info, char *buf,
dh->dqdh_next_free = dh->dqdh_prev_free = cpu_to_le32(0);
/* No matter whether write succeeds block is out of list */
if (write_blk(info, blk, buf) < 0)
- q_warn(KERN_ERR
- "VFS: Can't write block (%u) with free entries.\n",
- blk);
+ quota_error(info->dqi_sb, "Can't write block (%u) "
+ "with free entries", blk);
return 0;
out_buf:
kfree(tmpbuf);
@@ -252,9 +250,8 @@ static uint find_free_dqentry(struct qtree_mem_dqinfo *info,
if (le16_to_cpu(dh->dqdh_entries) + 1 >= qtree_dqstr_in_blk(info)) {
*err = remove_free_dqentry(info, buf, blk);
if (*err < 0) {
- q_warn(KERN_ERR "VFS: find_free_dqentry(): Can't "
- "remove block (%u) from entry free list.\n",
- blk);
+ quota_error(dquot->dq_sb, "Can't remove block (%u) "
+ "from entry free list", blk);
goto out_buf;
}
}
@@ -268,16 +265,15 @@ static uint find_free_dqentry(struct qtree_mem_dqinfo *info,
}
#ifdef __QUOTA_QT_PARANOIA
if (i == qtree_dqstr_in_blk(info)) {
- printk(KERN_ERR "VFS: find_free_dqentry(): Data block full "
- "but it shouldn't.\n");
+ quota_error(dquot->dq_sb, "Data block full but it shouldn't");
*err = -EIO;
goto out_buf;
}
#endif
*err = write_blk(info, blk, buf);
if (*err < 0) {
- q_warn(KERN_ERR "VFS: find_free_dqentry(): Can't write quota "
- "data block %u.\n", blk);
+ quota_error(dquot->dq_sb, "Can't write quota data block %u",
+ blk);
goto out_buf;
}
dquot->dq_off = (blk << info->dqi_blocksize_bits) +
@@ -311,8 +307,8 @@ static int do_insert_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
} else {
ret = read_blk(info, *treeblk, buf);
if (ret < 0) {
- q_warn(KERN_ERR "VFS: Can't read tree quota block "
- "%u.\n", *treeblk);
+ quota_error(dquot->dq_sb, "Can't read tree quota "
+ "block %u", *treeblk);
goto out_buf;
}
}
@@ -323,9 +319,9 @@ static int do_insert_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
if (depth == info->dqi_qtree_depth - 1) {
#ifdef __QUOTA_QT_PARANOIA
if (newblk) {
- printk(KERN_ERR "VFS: Inserting already present quota "
- "entry (block %u).\n",
- le32_to_cpu(ref[get_index(info,
+ quota_error(dquot->dq_sb, "Inserting already present "
+ "quota entry (block %u)",
+ le32_to_cpu(ref[get_index(info,
dquot->dq_id, depth)]));
ret = -EIO;
goto out_buf;
@@ -373,8 +369,8 @@ int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
if (!dquot->dq_off) {
ret = dq_insert_tree(info, dquot);
if (ret < 0) {
- q_warn(KERN_ERR "VFS: Error %zd occurred while "
- "creating quota.\n", ret);
+ quota_error(sb, "Error %zd occurred while creating "
+ "quota", ret);
kfree(ddquot);
return ret;
}
@@ -385,8 +381,7 @@ int qtree_write_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
ret = sb->s_op->quota_write(sb, type, ddquot, info->dqi_entry_size,
dquot->dq_off);
if (ret != info->dqi_entry_size) {
- q_warn(KERN_WARNING "VFS: dquota write failed on dev %s\n",
- sb->s_id);
+ quota_error(sb, "dquota write failed");
if (ret >= 0)
ret = -ENOSPC;
} else {
@@ -410,14 +405,15 @@ static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot,
if (!buf)
return -ENOMEM;
if (dquot->dq_off >> info->dqi_blocksize_bits != blk) {
- q_warn(KERN_ERR "VFS: Quota structure has offset to other "
- "block (%u) than it should (%u).\n", blk,
- (uint)(dquot->dq_off >> info->dqi_blocksize_bits));
+ quota_error(dquot->dq_sb, "Quota structure has offset to "
+ "other block (%u) than it should (%u)", blk,
+ (uint)(dquot->dq_off >> info->dqi_blocksize_bits));
goto out_buf;
}
ret = read_blk(info, blk, buf);
if (ret < 0) {
- q_warn(KERN_ERR "VFS: Can't read quota data block %u\n", blk);
+ quota_error(dquot->dq_sb, "Can't read quota data block %u",
+ blk);
goto out_buf;
}
dh = (struct qt_disk_dqdbheader *)buf;
@@ -427,8 +423,8 @@ static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot,
if (ret >= 0)
ret = put_free_dqblk(info, buf, blk);
if (ret < 0) {
- q_warn(KERN_ERR "VFS: Can't move quota data block (%u) "
- "to free list.\n", blk);
+ quota_error(dquot->dq_sb, "Can't move quota data block "
+ "(%u) to free list", blk);
goto out_buf;
}
} else {
@@ -440,15 +436,15 @@ static int free_dqentry(struct qtree_mem_dqinfo *info, struct dquot *dquot,
/* Insert will write block itself */
ret = insert_free_dqentry(info, buf, blk);
if (ret < 0) {
- q_warn(KERN_ERR "VFS: Can't insert quota data "
- "block (%u) to free entry list.\n", blk);
+ quota_error(dquot->dq_sb, "Can't insert quota "
+ "data block (%u) to free entry list", blk);
goto out_buf;
}
} else {
ret = write_blk(info, blk, buf);
if (ret < 0) {
- q_warn(KERN_ERR "VFS: Can't write quota data "
- "block %u\n", blk);
+ quota_error(dquot->dq_sb, "Can't write quota "
+ "data block %u", blk);
goto out_buf;
}
}
@@ -472,7 +468,8 @@ static int remove_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
return -ENOMEM;
ret = read_blk(info, *blk, buf);
if (ret < 0) {
- q_warn(KERN_ERR "VFS: Can't read quota data block %u\n", *blk);
+ quota_error(dquot->dq_sb, "Can't read quota data "
+ "block %u", blk);
goto out_buf;
}
newblk = le32_to_cpu(ref[get_index(info, dquot->dq_id, depth)]);
@@ -496,8 +493,8 @@ static int remove_tree(struct qtree_mem_dqinfo *info, struct dquot *dquot,
} else {
ret = write_blk(info, *blk, buf);
if (ret < 0)
- q_warn(KERN_ERR "VFS: Can't write quota tree "
- "block %u.\n", *blk);
+ quota_error(dquot->dq_sb, "Can't write quota "
+ "tree block %u", blk);
}
}
out_buf:
@@ -529,7 +526,8 @@ static loff_t find_block_dqentry(struct qtree_mem_dqinfo *info,
return -ENOMEM;
ret = read_blk(info, blk, buf);
if (ret < 0) {
- q_warn(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk);
+ quota_error(dquot->dq_sb, "Can't read quota tree "
+ "block %u", blk);
goto out_buf;
}
ddquot = buf + sizeof(struct qt_disk_dqdbheader);
@@ -539,8 +537,8 @@ static loff_t find_block_dqentry(struct qtree_mem_dqinfo *info,
ddquot += info->dqi_entry_size;
}
if (i == qtree_dqstr_in_blk(info)) {
- q_warn(KERN_ERR "VFS: Quota for id %u referenced "
- "but not present.\n", dquot->dq_id);
+ quota_error(dquot->dq_sb, "Quota for id %u referenced "
+ "but not present", dquot->dq_id);
ret = -EIO;
goto out_buf;
} else {
@@ -564,7 +562,8 @@ static loff_t find_tree_dqentry(struct qtree_mem_dqinfo *info,
return -ENOMEM;
ret = read_blk(info, blk, buf);
if (ret < 0) {
- q_warn(KERN_ERR "VFS: Can't read quota tree block %u.\n", blk);
+ quota_error(dquot->dq_sb, "Can't read quota tree block %u",
+ blk);
goto out_buf;
}
ret = 0;
@@ -598,7 +597,7 @@ int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
#ifdef __QUOTA_QT_PARANOIA
/* Invalidated quota? */
if (!sb_dqopt(dquot->dq_sb)->files[type]) {
- printk(KERN_ERR "VFS: Quota invalidated while reading!\n");
+ quota_error(sb, "Quota invalidated while reading!");
return -EIO;
}
#endif
@@ -607,8 +606,8 @@ int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
offset = find_dqentry(info, dquot);
if (offset <= 0) { /* Entry not present? */
if (offset < 0)
- q_warn(KERN_ERR "VFS: Can't read quota "
- "structure for id %u.\n", dquot->dq_id);
+ quota_error(sb, "Can't read quota structure "
+ "for id %u", dquot->dq_id);
dquot->dq_off = 0;
set_bit(DQ_FAKE_B, &dquot->dq_flags);
memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
@@ -625,8 +624,8 @@ int qtree_read_dquot(struct qtree_mem_dqinfo *info, struct dquot *dquot)
if (ret != info->dqi_entry_size) {
if (ret >= 0)
ret = -EIO;
- q_warn(KERN_ERR "VFS: Error while reading quota "
- "structure for id %u.\n", dquot->dq_id);
+ quota_error(sb, "Error while reading quota structure for id %u",
+ dquot->dq_id);
set_bit(DQ_FAKE_B, &dquot->dq_flags);
memset(&dquot->dq_dqb, 0, sizeof(struct mem_dqblk));
kfree(ddquot);
diff --git a/fs/quota/quota_tree.h b/fs/quota/quota_tree.h
index ccc3e71fb1d..a1ab8db81a5 100644
--- a/fs/quota/quota_tree.h
+++ b/fs/quota/quota_tree.h
@@ -22,10 +22,4 @@ struct qt_disk_dqdbheader {
#define QT_TREEOFF 1 /* Offset of tree in file in blocks */
-#define q_warn(fmt, args...) \
-do { \
- if (printk_ratelimit()) \
- printk(fmt, ## args); \
-} while(0)
-
#endif /* _LINUX_QUOTAIO_TREE_H */
diff --git a/fs/quota/quota_v1.c b/fs/quota/quota_v1.c
index 4af344c5852..34b37a67bb1 100644
--- a/fs/quota/quota_v1.c
+++ b/fs/quota/quota_v1.c
@@ -95,8 +95,7 @@ static int v1_commit_dqblk(struct dquot *dquot)
(char *)&dqblk, sizeof(struct v1_disk_dqblk),
v1_dqoff(dquot->dq_id));
if (ret != sizeof(struct v1_disk_dqblk)) {
- printk(KERN_WARNING "VFS: dquota write failed on dev %s\n",
- dquot->dq_sb->s_id);
+ quota_error(dquot->dq_sb, "dquota write failed");
if (ret >= 0)
ret = -EIO;
goto out;
diff --git a/fs/quota/quota_v2.c b/fs/quota/quota_v2.c
index 135206af145..65444d29406 100644
--- a/fs/quota/quota_v2.c
+++ b/fs/quota/quota_v2.c
@@ -63,9 +63,8 @@ static int v2_read_header(struct super_block *sb, int type,
size = sb->s_op->quota_read(sb, type, (char *)dqhead,
sizeof(struct v2_disk_dqheader), 0);
if (size != sizeof(struct v2_disk_dqheader)) {
- q_warn(KERN_WARNING "quota_v2: Failed header read:"
- " expected=%zd got=%zd\n",
- sizeof(struct v2_disk_dqheader), size);
+ quota_error(sb, "Failed header read: expected=%zd got=%zd",
+ sizeof(struct v2_disk_dqheader), size);
return 0;
}
return 1;
@@ -106,8 +105,7 @@ static int v2_read_file_info(struct super_block *sb, int type)
size = sb->s_op->quota_read(sb, type, (char *)&dinfo,
sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
if (size != sizeof(struct v2_disk_dqinfo)) {
- q_warn(KERN_WARNING "quota_v2: Can't read info structure on device %s.\n",
- sb->s_id);
+ quota_error(sb, "Can't read info structure");
return -1;
}
info->dqi_priv = kmalloc(sizeof(struct qtree_mem_dqinfo), GFP_NOFS);
@@ -167,8 +165,7 @@ static int v2_write_file_info(struct super_block *sb, int type)
size = sb->s_op->quota_write(sb, type, (char *)&dinfo,
sizeof(struct v2_disk_dqinfo), V2_DQINFOOFF);
if (size != sizeof(struct v2_disk_dqinfo)) {
- q_warn(KERN_WARNING "Can't write info structure on device %s.\n",
- sb->s_id);
+ quota_error(sb, "Can't write info structure");
return -1;
}
return 0;