litmus-rt.git - The LITMUS^RT kernel.

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author	Junxiao Bi <junxiao.bi@oracle.com>	2014-02-10 17:25:53 -0500
committer	Linus Torvalds <torvalds@linux-foundation.org>	2014-02-10 19:01:43 -0500
commit	c7d2cbc364b2a237b0ed1bdd7cbf8a24c8a89dfd (patch)
tree	660ee14df70bb80220b2e8c919b66f9f724890ef /scripts/kernel-doc
parent	d62e74be1270c89fbaf7aada8218bfdf62d00a58 (diff)

ocfs2: update inode size after zeroing the hole

fs-writeback will release the dirty pages without page lock whose offset are over inode size, the release happens at block_write_full_page_endio(). If not update, dirty pages in file holes may be released before flushed to the disk, then file holes will contain some non-zero data, this will cause sparse file md5sum error. To reproduce the bug, find a big sparse file with many holes, like vm image file, its actual size should be bigger than available mem size to make writeback work more frequently, tar it with -S option, then keep untar it and check its md5sum again and again until you get a wrong md5sum. Signed-off-by: Junxiao Bi <junxiao.bi@oracle.com> Cc: Younger Liu <younger.liu@huawei.com> Reviewed-by: Mark Fasheh <mfasheh@suse.de> Cc: Joel Becker <jlbec@evilplan.org> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

Diffstat (limited to 'scripts/kernel-doc')

0 files changed, 0 insertions, 0 deletions

/* * fs/libfs.c * Library for filesystems writers. */ #include <linux/module.h> #include <linux/pagemap.h> #include <linux/mount.h> #include <linux/vfs.h> #include <asm/uaccess.h> int simple_getattr(struct vfsmount *mnt, struct dentry *dentry, struct kstat *stat) { struct inode *inode = dentry->d_inode; generic_fillattr(inode, stat); stat->blocks = inode->i_mapping->nrpages << (PAGE_CACHE_SHIFT - 9); return 0; } int simple_statfs(struct super_block *sb, struct kstatfs *buf) { buf->f_type = sb->s_magic; buf->f_bsize = PAGE_CACHE_SIZE; buf->f_namelen = NAME_MAX; return 0; } /* * Retaining negative dentries for an in-memory filesystem just wastes * memory and lookup time: arrange for them to be deleted immediately. */ static int simple_delete_dentry(struct dentry *dentry) { return 1; } /* * Lookup the data. This is trivial - if the dentry didn't already * exist, we know it is negative. Set d_op to delete negative dentries. */ struct dentry *simple_lookup(struct inode *dir, struct dentry *dentry, struct nameidata *nd) { static struct dentry_operations simple_dentry_operations = { .d_delete = simple_delete_dentry, }; if (dentry->d_name.len > NAME_MAX) return ERR_PTR(-ENAMETOOLONG); dentry->d_op = &simple_dentry_operations; d_add(dentry, NULL); return NULL; } int simple_sync_file(struct file * file, struct dentry *dentry, int datasync) { return 0; } int dcache_dir_open(struct inode *inode, struct file *file) { static struct qstr cursor_name = {.len = 1, .name = "."}; file->private_data = d_alloc(file->f_dentry, &cursor_name); return file->private_data ? 0 : -ENOMEM; } int dcache_dir_close(struct inode *inode, struct file *file) { dput(file->private_data); return 0; } loff_t dcache_dir_lseek(struct file *file, loff_t offset, int origin) { down(&file->f_dentry->d_inode->i_sem); switch (origin) { case 1: offset += file->f_pos; case 0: if (offset >= 0) break; default: up(&file->f_dentry->d_inode->i_sem); return -EINVAL; } if (offset != file->f_pos) { file->f_pos = offset; if (file->f_pos >= 2) { struct list_head *p; struct dentry *cursor = file->private_data; loff_t n = file->f_pos - 2; spin_lock(&dcache_lock); list_del(&cursor->d_child); p = file->f_dentry->d_subdirs.next; while (n && p != &file->f_dentry->d_subdirs) { struct dentry *next; next = list_entry(p, struct dentry, d_child); if (!d_unhashed(next) && next->d_inode) n--; p = p->next; } list_add_tail(&cursor->d_child, p); spin_unlock(&dcache_lock); } } up(&file->f_dentry->d_inode->i_sem); return offset; } /* Relationship between i_mode and the DT_xxx types */ static inline unsigned char dt_type(struct inode *inode) { return (inode->i_mode >> 12) & 15; } /* * Directory is locked and all positive dentries in it are safe, since * for ramfs-type trees they can't go away without unlink() or rmdir(), * both impossible due to the lock on directory. */ int dcache_readdir(struct file * filp, void * dirent, filldir_t filldir) { struct dentry *dentry = filp->f_dentry; struct dentry *cursor = filp->private_data; struct list_head *p, *q = &cursor->d_child; ino_t ino; int i = filp->f_pos; switch (i) { case 0: ino = dentry->d_inode->i_ino; if (filldir(dirent, ".", 1, i, ino, DT_DIR) < 0) break; filp->f_pos++; i++; /* fallthrough */ case 1: ino = parent_ino(dentry); if (filldir(dirent, "..", 2, i, ino, DT_DIR) < 0) break; filp->f_pos++; i++; /* fallthrough */ default: spin_lock(&dcache_lock); if (filp->f_pos == 2) { list_del(q); list_add(q, &dentry->d_subdirs); } for (p=q->next; p != &dentry->d_subdirs; p=p->next) { struct dentry *next; next = list_entry(p, struct dentry, d_child); if (d_unhashed(next) || !next->d_inode) continue; spin_unlock(&dcache_lock); if (filldir(dirent, next->d_name.name, next->d_name.len, filp->f_pos, next->d_inode->i_ino, dt_type(next->d_inode)) < 0) return 0; spin_lock(&dcache_lock); /* next is still alive */ list_del(q); list_add(q, p); p = q; filp->f_pos++; } spin_unlock(&dcache_lock); } return 0; } ssize_t generic_read_dir(struct file *filp, char __user *buf, size_t siz, loff_t *ppos) { return -EISDIR; } struct file_operations simple_dir_operations = { .open = dcache_dir_open, .release = dcache_dir_close, .llseek = dcache_dir_lseek, .read = generic_read_dir, .readdir = dcache_readdir, }; struct inode_operations simple_dir_inode_operations = { .lookup = simple_lookup, }; /* * Common helper for pseudo-filesystems (sockfs, pipefs, bdev - stuff that * will never be mountable) */ struct super_block * get_sb_pseudo(struct file_system_type *fs_type, char *name, struct super_operations *ops, unsigned long magic) { struct super_block *s = sget(fs_type, NULL, set_anon_super, NULL); static struct super_operations default_ops = {.statfs = simple_statfs}; struct dentry *dentry; struct inode *root; struct qstr d_name = {.name = name, .len = strlen(name)}; if (IS_ERR(s)) return s; s->s_flags = MS_NOUSER; s->s_maxbytes = ~0ULL; s->s_blocksize = 1024; s->s_blocksize_bits = 10; s->s_magic = magic; s->s_op = ops ? ops : &default_ops; s->s_time_gran = 1; root = new_inode(s); if (!root) goto Enomem; root->i_mode = S_IFDIR | S_IRUSR | S_IWUSR; root->i_uid = root->i_gid = 0; root->i_atime = root->i_mtime = root->i_ctime = CURRENT_TIME; dentry = d_alloc(NULL, &d_name); if (!dentry) { iput(root); goto Enomem; } dentry->d_sb = s; dentry->d_parent = dentry; d_instantiate(dentry, root); s->s_root = dentry; s->s_flags |= MS_ACTIVE; return s; Enomem: up_write(&s->s_umount); deactivate_super(s); return ERR_PTR(-ENOMEM); } int simple_link(struct dentry *old_dentry, struct inode *dir, struct dentry *dentry) { struct inode *inode = old_dentry->d_inode; inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; inode->i_nlink++; atomic_inc(&inode->i_count); dget(dentry); d_instantiate(dentry, inode); return 0; } static inline int simple_positive(struct dentry *dentry) { return dentry->d_inode && !d_unhashed(dentry); } int simple_empty(struct dentry *dentry) { struct dentry *child; int ret = 0; spin_lock(&dcache_lock); list_for_each_entry(child, &dentry->d_subdirs, d_child) if (simple_positive(child)) goto out; ret = 1; out: spin_unlock(&dcache_lock); return ret; } int simple_unlink(struct inode *dir, struct dentry *dentry) { struct inode *inode = dentry->d_inode; inode->i_ctime = dir->i_ctime = dir->i_mtime = CURRENT_TIME; inode->i_nlink--; dput(dentry); return 0; } int simple_rmdir(struct inode *dir, struct dentry *dentry) { if (!simple_empty(dentry)) return -ENOTEMPTY; dentry->d_inode->i_nlink--; simple_unlink(dir, dentry); dir->i_nlink--; return 0; } int simple_rename(struct inode *old_dir, struct dentry *old_dentry, struct inode *new_dir, struct dentry *new_dentry) { struct inode *inode = old_dentry->d_inode; int they_are_dirs = S_ISDIR(old_dentry->d_inode->i_mode); if (!simple_empty(new_dentry)) return -ENOTEMPTY; if (new_dentry->d_inode) { simple_unlink(new_dir, new_dentry); if (they_are_dirs) old_dir->i_nlink--; } else if (they_are_dirs) { old_dir->i_nlink--; new_dir->i_nlink++; } old_dir->i_ctime = old_dir->i_mtime = new_dir->i_ctime = new_dir->i_mtime = inode->i_ctime = CURRENT_TIME; return 0; } int simple_readpage(struct file *file, struct page *page) { void *kaddr; if (PageUptodate(page)) goto out; kaddr = kmap_atomic(page, KM_USER0); memset(kaddr, 0, PAGE_CACHE_SIZE); kunmap_atomic(kaddr, KM_USER0); flush_dcache_page(page); SetPageUptodate(page); out: unlock_page(page); return 0; } int simple_prepare_write(struct file *file, struct page *page, unsigned from, unsigned to) { if (!PageUptodate(page)) { if (to - from != PAGE_CACHE_SIZE) { void *kaddr = kmap_atomic(page, KM_USER0); memset(kaddr, 0, from); memset(kaddr + to, 0, PAGE_CACHE_SIZE - to); flush_dcache_page(page); kunmap_atomic(kaddr, KM_USER0); } SetPageUptodate(page); } return 0; } int simple_commit_write(struct file *file, struct page *page, unsigned offset, unsigned to) { struct inode *inode = page->mapping->host; loff_t pos = ((loff_t)page->index << PAGE_CACHE_SHIFT) + to; /* * No need to use i_size_read() here, the i_size * cannot change under us because we hold the i_sem. */ if (pos > inode->i_size) i_size_write(inode, pos); set_page_dirty(page); return 0; } int simple_fill_super(struct super_block *s, int magic, struct tree_descr *files) { static struct super_operations s_ops = {.statfs = simple_statfs}; struct inode *inode; struct dentry *root; struct dentry *dentry; int i; s->s_blocksize = PAGE_CACHE_SIZE; s->s_blocksize_bits = PAGE_CACHE_SHIFT; s->s_magic = magic; s->s_op = &s_ops; s->s_time_gran = 1; inode = new_inode(s); if (!inode) return -ENOMEM; inode->i_mode = S_IFDIR | 0755; inode->i_uid = inode->i_gid = 0; inode->i_blksize = PAGE_CACHE_SIZE; inode->i_blocks = 0; inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; inode->i_op = &simple_dir_inode_operations; inode->i_fop = &simple_dir_operations; root = d_alloc_root(inode); if (!root) { iput(inode); return -ENOMEM; } for (i = 0; !files->name || files->name[0]; i++, files++) { if (!files->name) continue; dentry = d_alloc_name(root, files->name); if (!dentry) goto out; inode = new_inode(s); if (!inode) goto out; inode->i_mode = S_IFREG | files->mode; inode->i_uid = inode->i_gid = 0; inode->i_blksize = PAGE_CACHE_SIZE; inode->i_blocks = 0; inode->i_atime = inode->i_mtime = inode->i_ctime = CURRENT_TIME; inode->i_fop = files->ops; inode->i_ino = i; d_add(dentry, inode); } s->s_root = root; return 0; out: d_genocide(root); dput(root); return -ENOMEM; } static DEFINE_SPINLOCK(pin_fs_lock); int simple_pin_fs(char *name, struct vfsmount **mount, int *count) { struct vfsmount *mnt = NULL; spin_lock(&pin_fs_lock); if (unlikely(!*mount)) { spin_unlock(&pin_fs_lock); mnt = do_kern_mount(name, 0, name, NULL); if (IS_ERR(mnt)) return PTR_ERR(mnt); spin_lock(&pin_fs_lock); if (!*mount) *mount = mnt; } mntget(*mount); ++*count; spin_unlock(&pin_fs_lock); mntput(mnt); return 0; } void simple_release_fs(struct vfsmount **mount, int *count) { struct vfsmount *mnt; spin_lock(&pin_fs_lock); mnt = *mount; if (!--*count) *mount = NULL; spin_unlock(&pin_fs_lock); mntput(mnt); } ssize_t simple_read_from_buffer(void __user *to, size_t count, loff_t *ppos,


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