Commit 47420c79 authored by Ryusuke Konishi's avatar Ryusuke Konishi Committed by Linus Torvalds
Browse files

nilfs2: avoid double error caused by nilfs_transaction_end



Pekka Enberg pointed out that double error handlings found after
nilfs_transaction_end() can be avoided by separating abort operation:

 OK, I don't understand this. The only way nilfs_transaction_end() can
 fail is if we have NILFS_TI_SYNC set and we fail to construct the
 segment. But why do we want to construct a segment if we don't commit?

 I guess what I'm asking is why don't we have a separate
 nilfs_transaction_abort() function that can't fail for the erroneous
 case to avoid this double error value tracking thing?

This does the separation and renames nilfs_transaction_end() to
nilfs_transaction_commit() for clarification.

Since, some calls of these functions were used just for exclusion control
against the segment constructor, they are replaced with semaphore
operations.
Acked-by: default avatarPekka Enberg <penberg@cs.helsinki.fi>
Signed-off-by: default avatarRyusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
Signed-off-by: default avatarAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent a2e7d2df
......@@ -77,7 +77,6 @@ int nilfs_get_block(struct inode *inode, sector_t blkoff,
goto out;
err = nilfs_bmap_insert(ii->i_bmap, (unsigned long)blkoff,
(unsigned long)bh_result);
nilfs_transaction_end(inode->i_sb, !err);
if (unlikely(err != 0)) {
if (err == -EEXIST) {
/*
......@@ -100,8 +99,10 @@ int nilfs_get_block(struct inode *inode, sector_t blkoff,
inode->i_ino);
err = -EIO;
}
nilfs_transaction_abort(inode->i_sb);
goto out;
}
nilfs_transaction_commit(inode->i_sb); /* never fails */
/* Error handling should be detailed */
set_buffer_new(bh_result);
map_bh(bh_result, inode->i_sb, 0); /* dbn must be changed
......@@ -203,7 +204,7 @@ static int nilfs_write_begin(struct file *file, struct address_space *mapping,
err = block_write_begin(file, mapping, pos, len, flags, pagep,
fsdata, nilfs_get_block);
if (unlikely(err))
nilfs_transaction_end(inode->i_sb, 0);
nilfs_transaction_abort(inode->i_sb);
return err;
}
......@@ -221,7 +222,7 @@ static int nilfs_write_end(struct file *file, struct address_space *mapping,
copied = generic_write_end(file, mapping, pos, len, copied, page,
fsdata);
nilfs_set_file_dirty(NILFS_SB(inode->i_sb), inode, nr_dirty);
err = nilfs_transaction_end(inode->i_sb, 1);
err = nilfs_transaction_commit(inode->i_sb);
return err ? : copied;
}
......@@ -641,7 +642,7 @@ void nilfs_truncate(struct inode *inode)
nilfs_set_transaction_flag(NILFS_TI_SYNC);
nilfs_set_file_dirty(NILFS_SB(sb), inode, 0);
nilfs_transaction_end(sb, 1);
nilfs_transaction_commit(sb);
/* May construct a logical segment and may fail in sync mode.
But truncate has no return value. */
}
......@@ -669,7 +670,7 @@ void nilfs_delete_inode(struct inode *inode)
/* nilfs_free_inode() marks inode buffer dirty */
if (IS_SYNC(inode))
nilfs_set_transaction_flag(NILFS_TI_SYNC);
nilfs_transaction_end(sb, 1);
nilfs_transaction_commit(sb);
/* May construct a logical segment and may fail in sync mode.
But delete_inode has no return value. */
}
......@@ -679,7 +680,7 @@ int nilfs_setattr(struct dentry *dentry, struct iattr *iattr)
struct nilfs_transaction_info ti;
struct inode *inode = dentry->d_inode;
struct super_block *sb = inode->i_sb;
int err, err2;
int err;
err = inode_change_ok(inode, iattr);
if (err)
......@@ -691,8 +692,12 @@ int nilfs_setattr(struct dentry *dentry, struct iattr *iattr)
err = inode_setattr(inode, iattr);
if (!err && (iattr->ia_valid & ATTR_MODE))
err = nilfs_acl_chmod(inode);
err2 = nilfs_transaction_end(sb, 1);
return err ? : err2;
if (likely(!err))
err = nilfs_transaction_commit(sb);
else
nilfs_transaction_abort(sb);
return err;
}
int nilfs_load_inode_block(struct nilfs_sb_info *sbi, struct inode *inode,
......@@ -817,5 +822,5 @@ void nilfs_dirty_inode(struct inode *inode)
nilfs_transaction_begin(inode->i_sb, &ti, 0);
if (likely(inode->i_ino != NILFS_SKETCH_INO))
nilfs_mark_inode_dirty(inode);
nilfs_transaction_end(inode->i_sb, 1); /* never fails */
nilfs_transaction_commit(inode->i_sb); /* never fails */
}
......@@ -105,7 +105,11 @@ static int nilfs_ioctl_change_cpmode(struct inode *inode, struct file *filp,
nilfs_transaction_begin(inode->i_sb, &ti, 0);
ret = nilfs_cpfile_change_cpmode(
cpfile, cpmode.cm_cno, cpmode.cm_mode);
nilfs_transaction_end(inode->i_sb, !ret);
if (unlikely(ret < 0)) {
nilfs_transaction_abort(inode->i_sb);
return ret;
}
nilfs_transaction_commit(inode->i_sb); /* never fails */
return ret;
}
......@@ -125,7 +129,11 @@ nilfs_ioctl_delete_checkpoint(struct inode *inode, struct file *filp,
nilfs_transaction_begin(inode->i_sb, &ti, 0);
ret = nilfs_cpfile_delete_checkpoint(cpfile, cno);
nilfs_transaction_end(inode->i_sb, !ret);
if (unlikely(ret < 0)) {
nilfs_transaction_abort(inode->i_sb);
return ret;
}
nilfs_transaction_commit(inode->i_sb); /* never fails */
return ret;
}
......@@ -142,16 +150,17 @@ static int nilfs_ioctl_get_cpinfo(struct inode *inode, struct file *filp,
{
struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
struct nilfs_argv argv;
struct nilfs_transaction_info ti;
int ret;
if (copy_from_user(&argv, argp, sizeof(argv)))
return -EFAULT;
nilfs_transaction_begin(inode->i_sb, &ti, 0);
down_read(&nilfs->ns_segctor_sem);
ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd),
nilfs_ioctl_do_get_cpinfo);
nilfs_transaction_end(inode->i_sb, 0);
up_read(&nilfs->ns_segctor_sem);
if (ret < 0)
return ret;
if (copy_to_user(argp, &argv, sizeof(argv)))
ret = -EFAULT;
......@@ -161,14 +170,13 @@ static int nilfs_ioctl_get_cpinfo(struct inode *inode, struct file *filp,
static int nilfs_ioctl_get_cpstat(struct inode *inode, struct file *filp,
unsigned int cmd, void __user *argp)
{
struct inode *cpfile = NILFS_SB(inode->i_sb)->s_nilfs->ns_cpfile;
struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
struct nilfs_cpstat cpstat;
struct nilfs_transaction_info ti;
int ret;
nilfs_transaction_begin(inode->i_sb, &ti, 0);
ret = nilfs_cpfile_get_stat(cpfile, &cpstat);
nilfs_transaction_end(inode->i_sb, 0);
down_read(&nilfs->ns_segctor_sem);
ret = nilfs_cpfile_get_stat(nilfs->ns_cpfile, &cpstat);
up_read(&nilfs->ns_segctor_sem);
if (ret < 0)
return ret;
......@@ -189,16 +197,17 @@ static int nilfs_ioctl_get_suinfo(struct inode *inode, struct file *filp,
{
struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
struct nilfs_argv argv;
struct nilfs_transaction_info ti;
int ret;
if (copy_from_user(&argv, argp, sizeof(argv)))
return -EFAULT;
nilfs_transaction_begin(inode->i_sb, &ti, 0);
down_read(&nilfs->ns_segctor_sem);
ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd),
nilfs_ioctl_do_get_suinfo);
nilfs_transaction_end(inode->i_sb, 0);
up_read(&nilfs->ns_segctor_sem);
if (ret < 0)
return ret;
if (copy_to_user(argp, &argv, sizeof(argv)))
ret = -EFAULT;
......@@ -208,14 +217,13 @@ static int nilfs_ioctl_get_suinfo(struct inode *inode, struct file *filp,
static int nilfs_ioctl_get_sustat(struct inode *inode, struct file *filp,
unsigned int cmd, void __user *argp)
{
struct inode *sufile = NILFS_SB(inode->i_sb)->s_nilfs->ns_sufile;
struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
struct nilfs_sustat sustat;
struct nilfs_transaction_info ti;
int ret;
nilfs_transaction_begin(inode->i_sb, &ti, 0);
ret = nilfs_sufile_get_stat(sufile, &sustat);
nilfs_transaction_end(inode->i_sb, 0);
down_read(&nilfs->ns_segctor_sem);
ret = nilfs_sufile_get_stat(nilfs->ns_sufile, &sustat);
up_read(&nilfs->ns_segctor_sem);
if (ret < 0)
return ret;
......@@ -236,16 +244,17 @@ static int nilfs_ioctl_get_vinfo(struct inode *inode, struct file *filp,
{
struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
struct nilfs_argv argv;
struct nilfs_transaction_info ti;
int ret;
if (copy_from_user(&argv, argp, sizeof(argv)))
return -EFAULT;
nilfs_transaction_begin(inode->i_sb, &ti, 0);
down_read(&nilfs->ns_segctor_sem);
ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd),
nilfs_ioctl_do_get_vinfo);
nilfs_transaction_end(inode->i_sb, 0);
up_read(&nilfs->ns_segctor_sem);
if (ret < 0)
return ret;
if (copy_to_user(argp, &argv, sizeof(argv)))
ret = -EFAULT;
......@@ -280,16 +289,17 @@ static int nilfs_ioctl_get_bdescs(struct inode *inode, struct file *filp,
{
struct the_nilfs *nilfs = NILFS_SB(inode->i_sb)->s_nilfs;
struct nilfs_argv argv;
struct nilfs_transaction_info ti;
int ret;
if (copy_from_user(&argv, argp, sizeof(argv)))
return -EFAULT;
nilfs_transaction_begin(inode->i_sb, &ti, 0);
down_read(&nilfs->ns_segctor_sem);
ret = nilfs_ioctl_wrap_copy(nilfs, &argv, _IOC_DIR(cmd),
nilfs_ioctl_do_get_bdescs);
nilfs_transaction_end(inode->i_sb, 0);
up_read(&nilfs->ns_segctor_sem);
if (ret < 0)
return ret;
if (copy_to_user(argp, &argv, sizeof(argv)))
ret = -EFAULT;
......
......@@ -123,7 +123,10 @@ static int nilfs_mdt_create_block(struct inode *inode, unsigned long block,
brelse(bh);
failed_unlock:
nilfs_transaction_end(sb, !err);
if (likely(!err))
err = nilfs_transaction_commit(sb);
else
nilfs_transaction_abort(sb);
if (writer)
nilfs_put_writer(nilfs);
out:
......
......@@ -109,7 +109,7 @@ static int nilfs_create(struct inode *dir, struct dentry *dentry, int mode,
{
struct inode *inode;
struct nilfs_transaction_info ti;
int err, err2;
int err;
err = nilfs_transaction_begin(dir->i_sb, &ti, 1);
if (err)
......@@ -123,8 +123,12 @@ static int nilfs_create(struct inode *dir, struct dentry *dentry, int mode,
mark_inode_dirty(inode);
err = nilfs_add_nondir(dentry, inode);
}
err2 = nilfs_transaction_end(dir->i_sb, !err);
return err ? : err2;
if (!err)
err = nilfs_transaction_commit(dir->i_sb);
else
nilfs_transaction_abort(dir->i_sb);
return err;
}
static int
......@@ -132,7 +136,7 @@ nilfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
{
struct inode *inode;
struct nilfs_transaction_info ti;
int err, err2;
int err;
if (!new_valid_dev(rdev))
return -EINVAL;
......@@ -147,8 +151,12 @@ nilfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t rdev)
mark_inode_dirty(inode);
err = nilfs_add_nondir(dentry, inode);
}
err2 = nilfs_transaction_end(dir->i_sb, !err);
return err ? : err2;
if (!err)
err = nilfs_transaction_commit(dir->i_sb);
else
nilfs_transaction_abort(dir->i_sb);
return err;
}
static int nilfs_symlink(struct inode *dir, struct dentry *dentry,
......@@ -158,7 +166,7 @@ static int nilfs_symlink(struct inode *dir, struct dentry *dentry,
struct super_block *sb = dir->i_sb;
unsigned l = strlen(symname)+1;
struct inode *inode;
int err, err2;
int err;
if (l > sb->s_blocksize)
return -ENAMETOOLONG;
......@@ -184,8 +192,12 @@ static int nilfs_symlink(struct inode *dir, struct dentry *dentry,
err = nilfs_add_nondir(dentry, inode);
out:
err2 = nilfs_transaction_end(dir->i_sb, !err);
return err ? : err2;
if (!err)
err = nilfs_transaction_commit(dir->i_sb);
else
nilfs_transaction_abort(dir->i_sb);
return err;
out_fail:
inode_dec_link_count(inode);
......@@ -198,7 +210,7 @@ static int nilfs_link(struct dentry *old_dentry, struct inode *dir,
{
struct inode *inode = old_dentry->d_inode;
struct nilfs_transaction_info ti;
int err, err2;
int err;
if (inode->i_nlink >= NILFS_LINK_MAX)
return -EMLINK;
......@@ -212,15 +224,19 @@ static int nilfs_link(struct dentry *old_dentry, struct inode *dir,
atomic_inc(&inode->i_count);
err = nilfs_add_nondir(dentry, inode);
err2 = nilfs_transaction_end(dir->i_sb, !err);
return err ? : err2;
if (!err)
err = nilfs_transaction_commit(dir->i_sb);
else
nilfs_transaction_abort(dir->i_sb);
return err;
}
static int nilfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
struct inode *inode;
struct nilfs_transaction_info ti;
int err, err2;
int err;
if (dir->i_nlink >= NILFS_LINK_MAX)
return -EMLINK;
......@@ -252,8 +268,12 @@ static int nilfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
d_instantiate(dentry, inode);
out:
err2 = nilfs_transaction_end(dir->i_sb, !err);
return err ? : err2;
if (!err)
err = nilfs_transaction_commit(dir->i_sb);
else
nilfs_transaction_abort(dir->i_sb);
return err;
out_fail:
inode_dec_link_count(inode);
......@@ -270,7 +290,7 @@ static int nilfs_unlink(struct inode *dir, struct dentry *dentry)
struct nilfs_dir_entry *de;
struct page *page;
struct nilfs_transaction_info ti;
int err, err2;
int err;
err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
if (err)
......@@ -300,15 +320,19 @@ static int nilfs_unlink(struct inode *dir, struct dentry *dentry)
inode_dec_link_count(inode);
err = 0;
out:
err2 = nilfs_transaction_end(dir->i_sb, !err);
return err ? : err2;
if (!err)
err = nilfs_transaction_commit(dir->i_sb);
else
nilfs_transaction_abort(dir->i_sb);
return err;
}
static int nilfs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct inode *inode = dentry->d_inode;
struct nilfs_transaction_info ti;
int err, err2;
int err;
err = nilfs_transaction_begin(dir->i_sb, &ti, 0);
if (err)
......@@ -323,8 +347,12 @@ static int nilfs_rmdir(struct inode *dir, struct dentry *dentry)
inode_dec_link_count(dir);
}
}
err2 = nilfs_transaction_end(dir->i_sb, !err);
return err ? : err2;
if (!err)
err = nilfs_transaction_commit(dir->i_sb);
else
nilfs_transaction_abort(dir->i_sb);
return err;
}
static int nilfs_rename(struct inode *old_dir, struct dentry *old_dentry,
......@@ -404,7 +432,7 @@ static int nilfs_rename(struct inode *old_dir, struct dentry *old_dentry,
inode_dec_link_count(old_dir);
}
err = nilfs_transaction_end(old_dir->i_sb, 1);
err = nilfs_transaction_commit(old_dir->i_sb);
return err;
out_dir:
......@@ -416,7 +444,7 @@ static int nilfs_rename(struct inode *old_dir, struct dentry *old_dentry,
kunmap(old_page);
page_cache_release(old_page);
out:
nilfs_transaction_end(old_dir->i_sb, 0);
nilfs_transaction_abort(old_dir->i_sb);
return err;
}
......
......@@ -166,7 +166,8 @@ struct nilfs_transaction_info {
int nilfs_transaction_begin(struct super_block *,
struct nilfs_transaction_info *, int);
int nilfs_transaction_end(struct super_block *, int);
int nilfs_transaction_commit(struct super_block *);
void nilfs_transaction_abort(struct super_block *);
static inline void nilfs_set_transaction_flag(unsigned int flag)
{
......
......@@ -163,8 +163,8 @@ static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti)
else {
/*
* If journal_info field is occupied by other FS,
* we save it and restore on nilfs_transaction_end().
* But this should never happen.
* it is saved and will be restored on
* nilfs_transaction_commit().
*/
printk(KERN_WARNING
"NILFS warning: journal info from a different "
......@@ -195,7 +195,7 @@ static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti)
*
* nilfs_transaction_begin() acquires a reader/writer semaphore, called
* the segment semaphore, to make a segment construction and write tasks
* exclusive. The function is used with nilfs_transaction_end() in pairs.
* exclusive. The function is used with nilfs_transaction_commit() in pairs.
* The region enclosed by these two functions can be nested. To avoid a
* deadlock, the semaphore is only acquired or released in the outermost call.
*
......@@ -212,8 +212,6 @@ static int nilfs_prepare_segment_lock(struct nilfs_transaction_info *ti)
*
* %-ENOMEM - Insufficient memory available.
*
* %-ERESTARTSYS - Interrupted
*
* %-ENOSPC - No space left on device
*/
int nilfs_transaction_begin(struct super_block *sb,
......@@ -248,16 +246,17 @@ int nilfs_transaction_begin(struct super_block *sb,
}
/**
* nilfs_transaction_end - end indivisible file operations.
* nilfs_transaction_commit - commit indivisible file operations.
* @sb: super block
* @commit: commit flag (0 for no change)
*
* nilfs_transaction_end() releases the read semaphore which is
* acquired by nilfs_transaction_begin(). Its releasing is only done
* in outermost call of this function. If the nilfs_transaction_info
* was allocated dynamically, it is given back to a slab cache.
* nilfs_transaction_commit() releases the read semaphore which is
* acquired by nilfs_transaction_begin(). This is only performed
* in outermost call of this function. If a commit flag is set,
* nilfs_transaction_commit() sets a timer to start the segment
* constructor. If a sync flag is set, it starts construction
* directly.
*/
int nilfs_transaction_end(struct super_block *sb, int commit)
int nilfs_transaction_commit(struct super_block *sb)
{
struct nilfs_transaction_info *ti = current->journal_info;
struct nilfs_sb_info *sbi;
......@@ -265,9 +264,7 @@ int nilfs_transaction_end(struct super_block *sb, int commit)
int err = 0;
BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
if (commit)
ti->ti_flags |= NILFS_TI_COMMIT;
ti->ti_flags |= NILFS_TI_COMMIT;
if (ti->ti_count > 0) {
ti->ti_count--;
return 0;
......@@ -291,6 +288,22 @@ int nilfs_transaction_end(struct super_block *sb, int commit)
return err;
}
void nilfs_transaction_abort(struct super_block *sb)
{
struct nilfs_transaction_info *ti = current->journal_info;
BUG_ON(ti == NULL || ti->ti_magic != NILFS_TI_MAGIC);
if (ti->ti_count > 0) {
ti->ti_count--;
return;
}
up_read(&NILFS_SB(sb)->s_nilfs->ns_segctor_sem);
current->journal_info = ti->ti_save;
if (ti->ti_flags & NILFS_TI_DYNAMIC_ALLOC)
kmem_cache_free(nilfs_transaction_cachep, ti);
}
void nilfs_relax_pressure_in_lock(struct super_block *sb)
{
struct nilfs_sb_info *sbi = NILFS_SB(sb);
......
......@@ -112,8 +112,8 @@ struct the_nilfs {
/*
* Following fields are dedicated to a writable FS-instance.
* Except for the period seeking checkpoint, code outside the segment
* constructor must lock a segment semaphore with transaction_begin()
* and transaction_end(), when accessing these fields.
* constructor must lock a segment semaphore while accessing these
* fields.
* The writable FS-instance is sole during a lifetime of the_nilfs.
*/
u64 ns_seg_seq;
......
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