From 47420c799830d4676e544dbec56b2a7f787528f5 Mon Sep 17 00:00:00 2001 From: Ryusuke Konishi Date: Mon, 6 Apr 2009 19:01:45 -0700 Subject: [PATCH] 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: Pekka Enberg Signed-off-by: Ryusuke Konishi Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/nilfs2/inode.c | 23 ++++++++------ fs/nilfs2/ioctl.c | 58 +++++++++++++++++++-------------- fs/nilfs2/mdt.c | 5 ++- fs/nilfs2/namei.c | 74 +++++++++++++++++++++++++++++-------------- fs/nilfs2/nilfs.h | 3 +- fs/nilfs2/segment.c | 43 ++++++++++++++++--------- fs/nilfs2/the_nilfs.h | 4 +-- 7 files changed, 135 insertions(+), 75 deletions(-) diff --git a/fs/nilfs2/inode.c b/fs/nilfs2/inode.c index 289d1798dec..4bf1e2c5bac 100644 --- a/fs/nilfs2/inode.c +++ b/fs/nilfs2/inode.c @@ -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 */ } diff --git a/fs/nilfs2/ioctl.c b/fs/nilfs2/ioctl.c index 02e91e167ca..5ce06a01c7e 100644 --- a/fs/nilfs2/ioctl.c +++ b/fs/nilfs2/ioctl.c @@ -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; diff --git a/fs/nilfs2/mdt.c b/fs/nilfs2/mdt.c index 6ab84757861..e0a632b86fe 100644 --- a/fs/nilfs2/mdt.c +++ b/fs/nilfs2/mdt.c @@ -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: diff --git a/fs/nilfs2/namei.c b/fs/nilfs2/namei.c index 95d1b29bff3..df70dadb336 100644 --- a/fs/nilfs2/namei.c +++ b/fs/nilfs2/namei.c @@ -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 @@ out_old: 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; } diff --git a/fs/nilfs2/nilfs.h b/fs/nilfs2/nilfs.h index 17458ad4a80..48c070676cc 100644 --- a/fs/nilfs2/nilfs.h +++ b/fs/nilfs2/nilfs.h @@ -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) { diff --git a/fs/nilfs2/segment.c b/fs/nilfs2/segment.c index ad65a737aff..6d66c5cb7b5 100644 --- a/fs/nilfs2/segment.c +++ b/fs/nilfs2/segment.c @@ -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); diff --git a/fs/nilfs2/the_nilfs.h b/fs/nilfs2/the_nilfs.h index dee8d83e054..9cd3c113f05 100644 --- a/fs/nilfs2/the_nilfs.h +++ b/fs/nilfs2/the_nilfs.h @@ -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; -- 2.41.0