Artem.Bityutskiy at nokia
Mar 27, 2008, 7:55 AM
Post #1 of 8
(129 views)
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[RFC PATCH 20/26] UBIFS: add VFS operations
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This patch adds implementation of most of the VFS callbacks like
->readdir(), ->write_begin(), and so on. In most cases, it just
does budgeting and calls corresponding journal function, because
all new data goes first to the journal.
Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy [at] nokia>
Signed-off-by: Adrian Hunter <ext-adrian.hunter [at] nokia>
---
fs/ubifs/dir.c | 989 ++++++++++++++++++++++++++++++++++++++++++++++++++++++
fs/ubifs/file.c | 790 +++++++++++++++++++++++++++++++++++++++++++
fs/ubifs/ioctl.c | 205 +++++++++++
3 files changed, 1984 insertions(+), 0 deletions(-)
diff --git a/fs/ubifs/dir.c b/fs/ubifs/dir.c
new file mode 100644
index 0000000..672652a
--- /dev/null
+++ b/fs/ubifs/dir.c
@@ -0,0 +1,989 @@
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ * Copyright (C) 2006, 2007 University of Szeged, Hungary
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Authors: Artem Bityutskiy (Битюцкий Артём)
+ * Adrian Hunter
+ * Zoltan Sogor
+ */
+
+/*
+ * This file implements directory operations.
+ *
+ * All FS operations in this file allocate budget before writing anything to the
+ * media. If they fail to allocate it, the error is returned. The only
+ * exceptions are 'ubifs_unlink()' and 'ubifs_rmdir()' which keep working even
+ * if they unable to allocate the budget, because deletion %-ENOSPC failure is
+ * not what users are usually ready to get. UBIFS budgeting subsystem has some
+ * space reserved for these purposes.
+ *
+ * All operations in this file change the parent inode, e.g., 'ubifs_link()'
+ * changes ctime and nlink of the parent inode. The parent inode is written to
+ * the media straight away - it is not marked as dirty and there is no
+ * write-back for it. This was done to simplify file-system recovery which
+ * would otherwise be very difficult to do. So instead of marking the parent
+ * inode dirty, the operations mark it clean.
+ */
+
+#include "ubifs.h"
+
+/*
+ * Provide backing_dev_info in order to disable readahead. For UBIFS, I/O is
+ * not deferred, it is done immediately in readpage, which means the user would
+ * have to wait not just for their own I/O but the readahead I/O as well i.e.
+ * completely pointless.
+ */
+struct backing_dev_info ubifs_backing_dev_info = {
+ .ra_pages = 0, /* Set to zero to disable readahead */
+ .state = 0,
+ .capabilities = BDI_CAP_MAP_COPY,
+ .unplug_io_fn = default_unplug_io_fn,
+};
+
+/**
+ * ubifs_new_inode - allocate new UBIFS inode object.
+ * @c: UBIFS file-system description object
+ * @dir: parent directory inode
+ * @mode: inode mode flags
+ *
+ * This function finds an unused inode number, allocates new inode and
+ * initializes it. Returns new inode in case of success and an error code in
+ * case of failure.
+ */
+struct inode *ubifs_new_inode(struct ubifs_info *c, const struct inode *dir,
+ int mode)
+{
+ struct inode *inode;
+ struct ubifs_inode *ui;
+
+ inode = new_inode(c->vfs_sb);
+ if (!inode)
+ return ERR_PTR(-ENOMEM);
+
+ /*
+ * Set 'S_NOCMTIME' to prevent VFS form updating [mc]time of inodes and
+ * marking them dirty in file write path (see 'file_update_time()').
+ * UBIFS has to fully control "clean <-> dirty" transitions of inodes
+ * to make budgeting work.
+ */
+ inode->i_flags |= (S_NOCMTIME);
+
+ inode->i_uid = current->fsuid;
+ if (dir->i_mode & S_ISGID) {
+ inode->i_gid = dir->i_gid;
+ if (S_ISDIR(mode))
+ mode |= S_ISGID;
+ } else
+ inode->i_gid = current->fsgid;
+ inode->i_mode = mode;
+ inode->i_mtime = inode->i_atime = inode->i_ctime = CURRENT_TIME_SEC;
+ inode->i_mapping->nrpages = 0;
+ /* Disable readahead */
+ inode->i_mapping->backing_dev_info = &ubifs_backing_dev_info;
+
+ switch (mode & S_IFMT) {
+ case S_IFREG:
+ inode->i_mapping->a_ops = &ubifs_file_address_operations;
+ inode->i_op = &ubifs_file_inode_operations;
+ inode->i_fop = &ubifs_file_operations;
+ break;
+ case S_IFDIR:
+ inode->i_op = &ubifs_dir_inode_operations;
+ inode->i_fop = &ubifs_dir_operations;
+ break;
+ case S_IFLNK:
+ inode->i_op = &ubifs_symlink_inode_operations;
+ break;
+ case S_IFSOCK:
+ case S_IFIFO:
+ case S_IFBLK:
+ case S_IFCHR:
+ inode->i_op = &ubifs_file_inode_operations;
+ break;
+ default:
+ BUG();
+ }
+
+ ui = ubifs_inode(inode);
+ ui->flags = ubifs_inode(dir)->flags;
+ if (S_ISLNK(mode))
+ ui->flags &= ~(UBIFS_IMMUTABLE_FL|UBIFS_APPEND_FL);
+ if (!S_ISDIR(mode))
+ /* The "DIRSYNC" flag only applies to directories */
+ ui->flags &= ~UBIFS_DIRSYNC_FL;
+ ubifs_set_inode_flags(inode);
+
+ if (S_ISREG(mode))
+ ui->compr_type = c->default_compr;
+ else
+ ui->compr_type = UBIFS_COMPR_NONE;
+
+ spin_lock(&c->cnt_lock);
+ /* Inode number overflow is currently not supported */
+ if (c->highest_inum >= INUM_WARN_WATERMARK) {
+ if (c->highest_inum >= INUM_WATERMARK) {
+ spin_unlock(&c->cnt_lock);
+ ubifs_err("out of inode numbers");
+ make_bad_inode(inode);
+ iput(inode);
+ return ERR_PTR(-EINVAL);
+ }
+ ubifs_warn("running out of inode numbers (current %lu, max %d)",
+ c->highest_inum, INUM_WATERMARK);
+ }
+
+ inode->i_ino = ++c->highest_inum;
+ inode->i_generation = ++c->vfs_gen;
+ /*
+ * The creation sequence number remains with this inode for its
+ * lifetime. All nodes for this inode have a greater sequence number,
+ * and so it is possible to distinguish obsolete nodes belonging to a
+ * previous incarnation of the same inode number - for example, for the
+ * purpose of rebuilding the index.
+ */
+ ui->creat_sqnum = ++c->max_sqnum;
+ spin_unlock(&c->cnt_lock);
+
+ return inode;
+}
+
+#ifdef CONFIG_UBIFS_FS_DEBUG_CHK_OTHER
+static int dbg_check_name(struct ubifs_dent_node *dent, struct qstr *nm)
+{
+ if (le16_to_cpu(dent->nlen) != nm->len)
+ return -EINVAL;
+ if (memcmp(dent->name, nm->name, nm->len))
+ return -EINVAL;
+ return 0;
+}
+#else
+#define dbg_check_name(dent, nm) 0
+#endif
+
+static struct dentry *ubifs_lookup(struct inode *dir, struct dentry *dentry,
+ struct nameidata *nd)
+{
+ int err;
+ union ubifs_key key;
+ struct inode *inode = NULL;
+ struct ubifs_dent_node *dent;
+ struct ubifs_info *c = dir->i_sb->s_fs_info;
+
+ dbg_gen("'%.*s' in dir ino %lu",
+ dentry->d_name.len, dentry->d_name.name, dir->i_ino);
+ ubifs_assert(mutex_is_locked(&dir->i_mutex));
+
+ if (dentry->d_name.len > UBIFS_MAX_NLEN)
+ return ERR_PTR(-ENAMETOOLONG);
+
+ dent = kmalloc(UBIFS_MAX_DENT_NODE_SZ, GFP_NOFS);
+ if (!dent)
+ return ERR_PTR(-ENOMEM);
+
+ dent_key_init(c, &key, dir->i_ino, &dentry->d_name);
+
+ err = ubifs_tnc_lookup_nm(c, &key, dent, &dentry->d_name);
+ if (err) {
+ if (err == -ENOENT) {
+ dbg_gen("not found");
+ goto done;
+ }
+ goto out;
+ }
+
+ if (dbg_check_name(dent, &dentry->d_name)) {
+ err = -EINVAL;
+ goto out;
+ }
+
+ inode = ubifs_iget(dir->i_sb, le64_to_cpu(dent->inum));
+ if (IS_ERR(inode)) {
+ /*
+ * This should not happen. Probably the file-system needs
+ * checking.
+ */
+ ubifs_err("dead directory entry");
+ ubifs_ro_mode(c);
+ err = PTR_ERR(inode);
+ goto out;
+ }
+
+done:
+ kfree(dent);
+ return d_splice_alias(inode, dentry);
+
+out:
+ kfree(dent);
+ return ERR_PTR(err);
+}
+
+static int ubifs_create(struct inode *dir, struct dentry *dentry, int mode,
+ struct nameidata *nd)
+{
+ struct inode *inode;
+ struct ubifs_info *c = dir->i_sb->s_fs_info;
+ struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
+ int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
+
+ dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
+ dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
+ ubifs_assert(mutex_is_locked(&dir->i_mutex));
+
+ inode = ubifs_new_inode(c, dir, mode);
+ if (IS_ERR(inode))
+ return PTR_ERR(inode);
+
+ err = ubifs_budget_inode_op(c, dir, &req);
+ if (err)
+ goto out;
+
+ dir->i_size += sz_change;
+
+ err = ubifs_jrn_update(c, dir, &dentry->d_name, inode, 0,
+ IS_DIRSYNC(dir), 0);
+ if (err)
+ goto out_budg;
+
+ insert_inode_hash(inode);
+ d_instantiate(dentry, inode);
+ ubifs_release_ino_clean(c, dir, &req);
+ return 0;
+
+out_budg:
+ dir->i_size -= sz_change;
+ ubifs_cancel_ino_op(c, dir, &req);
+ ubifs_err("cannot create regular file, error %d", err);
+out:
+ make_bad_inode(inode);
+ iput(inode);
+ return err;
+}
+
+/**
+ * vfs_dent_type - get VFS directory entry type.
+ * @type: UBIFS directory entry type
+ *
+ * This function converts UBIFS directory entry type into VFS directory entry
+ * type.
+ */
+static unsigned int vfs_dent_type(uint8_t type)
+{
+ switch (type) {
+ case UBIFS_ITYPE_REG:
+ return DT_REG;
+ case UBIFS_ITYPE_DIR:
+ return DT_DIR;
+ case UBIFS_ITYPE_LNK:
+ return DT_LNK;
+ case UBIFS_ITYPE_BLK:
+ return DT_BLK;
+ case UBIFS_ITYPE_CHR:
+ return DT_CHR;
+ case UBIFS_ITYPE_FIFO:
+ return DT_FIFO;
+ case UBIFS_ITYPE_SOCK:
+ return DT_SOCK;
+ default:
+ BUG();
+ }
+ return 0;
+}
+
+/*
+ * The classical Unix view for directory is that it is a linear array of
+ * (name, inode number) entries. Linux/VFS assumes this model as well.
+ * Particularly, readdir() call wants us to return a directory entry offset
+ * which later may be used to continue readdir()-ing the directory or to seek()
+ * to that specific direntry. Obviously UBIFS does not really fit this model
+ * because directory entries are identified by keys, which may collide.
+ *
+ * UBIFS uses directory entry hash value for directory offsets, so
+ * seekdir()/telldir() may not always work because of possible key collisions.
+ * But UBIFS guarantees that consecutive readdir() calls work properly by means
+ * of saving full directory entry name in the private field of the file
+ * description object.
+ */
+static int ubifs_readdir(struct file *filp, void *dirent, filldir_t filldir)
+{
+ int err, over = 0;
+ union ubifs_key key;
+ struct ubifs_dent_node *dent;
+ struct inode *dir = filp->f_path.dentry->d_inode;
+ struct ubifs_info *c = dir->i_sb->s_fs_info;
+ struct ubifs_dent_node *saved = filp->private_data;
+
+ dbg_gen("dir ino %lu, f_pos %#llx", dir->i_ino, filp->f_pos);
+ ubifs_assert(mutex_is_locked(&dir->i_mutex));
+
+ saved = filp->private_data;
+ if (saved)
+ if (filp->f_pos != key_hash_flash(c, &saved->key)) {
+ kfree(saved);
+ filp->private_data = NULL;
+ saved = NULL;
+ }
+
+ /*
+ * File positions 0 and 1 correspond to "." and ".." directory
+ * entries.
+ */
+ if (filp->f_pos == 0) {
+ ubifs_assert(!saved);
+ over = filldir(dirent, ".", 1, 0, dir->i_ino, DT_DIR);
+ if (over)
+ return 0;
+ filp->f_pos = 1;
+ }
+
+ if (filp->f_pos == 1) {
+ ubifs_assert(!saved);
+ over = filldir(dirent, "..", 2, 1,
+ parent_ino(filp->f_path.dentry), DT_DIR);
+ if (over)
+ return 0;
+ filp->f_pos = 2;
+ }
+
+ if (filp->f_pos == 2) {
+ ubifs_assert(!saved);
+
+ lowest_dent_key(c, &key, dir->i_ino);
+ dent = ubifs_tnc_next_ent(c, &key, NULL);
+ if (IS_ERR(dent)) {
+ err = PTR_ERR(dent);
+ goto out;
+ }
+
+ ubifs_assert(dent->ch.sqnum > ubifs_inode(dir)->creat_sqnum);
+
+ dbg_gen("feed '%s', new f_pos %#x",
+ dent->name, key_hash_flash(c, &dent->key));
+ over = filldir(dirent, dent->name,
+ le16_to_cpu(dent->nlen), filp->f_pos,
+ le64_to_cpu(dent->inum),
+ vfs_dent_type(dent->type));
+ if (over) {
+ kfree(dent);
+ return 0;
+ }
+
+ filp->private_data = dent;
+ filp->f_pos = key_hash_flash(c, &dent->key);
+ saved = filp->private_data;
+ }
+
+ while (1) {
+ if (saved) {
+ struct qstr nm;
+
+ key_read(c, &saved->key, &key);
+ nm.name = saved->name;
+ nm.len = le16_to_cpu(saved->nlen);
+ dent = ubifs_tnc_next_ent(c, &key, &nm);
+ } else {
+ dent_key_init_hash(c, &key, dir->i_ino, filp->f_pos);
+ dent = ubifs_tnc_next_ent(c, &key, NULL);
+ }
+ if (unlikely(IS_ERR(dent))) {
+ err = PTR_ERR(dent);
+ goto out;
+ }
+
+ ubifs_assert(dent->ch.sqnum > ubifs_inode(dir)->creat_sqnum);
+ dbg_gen("feed '%s', new f_pos %#x",
+ dent->name, key_hash_flash(c, &dent->key));
+
+ over = filldir(dirent, dent->name, le16_to_cpu(dent->nlen),
+ filp->f_pos, le64_to_cpu(dent->inum),
+ vfs_dent_type(dent->type));
+ if (over) {
+ kfree(dent);
+ return 0;
+ }
+
+ filp->f_pos = key_hash_flash(c, &dent->key);
+ filp->private_data = dent;
+ kfree(saved);
+ saved = filp->private_data;
+ }
+
+ return 0;
+
+out:
+ if (err != -ENOENT) {
+ ubifs_err("cannot find next direntry, error %d", err);
+ return err;
+ }
+
+ return 0;
+}
+
+static int ubifs_dir_release(struct inode *dir, struct file *filp)
+{
+ kfree(filp->private_data);
+ filp->private_data = NULL;
+ return 0;
+}
+
+static int ubifs_link(struct dentry *old_dentry, struct inode *dir,
+ struct dentry *dentry)
+{
+ struct ubifs_info *c = dir->i_sb->s_fs_info;
+ struct inode *inode = old_dentry->d_inode;
+ struct ubifs_inode *ui = ubifs_inode(inode);
+ struct ubifs_budget_req req = { .new_dent = 1, .dirtied_ino = 1,
+ .dirtied_ino_d = ui->data_len };
+ int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
+
+ dbg_gen("dent '%.*s' to ino %lu (nlink %d) in dir ino %lu",
+ dentry->d_name.len, dentry->d_name.name, inode->i_ino,
+ inode->i_nlink, dir->i_ino);
+ ubifs_assert(mutex_is_locked(&dir->i_mutex));
+ ubifs_assert(mutex_is_locked(&inode->i_mutex));
+
+ err = ubifs_budget_inode_op(c, dir, &req);
+ if (err)
+ return err;
+
+ inode->i_ctime = CURRENT_TIME_SEC;
+ inc_nlink(inode);
+
+ dir->i_size += sz_change;
+ dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
+
+ err = ubifs_jrn_update(c, dir, &dentry->d_name, inode, 0,
+ IS_DIRSYNC(dir), 0);
+ if (err)
+ goto out_budg;
+
+ atomic_inc(&inode->i_count);
+ d_instantiate(dentry, inode);
+ ubifs_release_ino_clean(c, dir, &req);
+ return 0;
+
+out_budg:
+ dir->i_size -= sz_change;
+ ubifs_cancel_ino_op(c, dir, &req);
+ drop_nlink(inode);
+ iput(inode);
+ return err;
+}
+
+static int ubifs_unlink(struct inode *dir, struct dentry *dentry)
+{
+ struct ubifs_info *c = dir->i_sb->s_fs_info;
+ struct inode *inode = dentry->d_inode;
+ struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 1 };
+ int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
+ int err, budgeted = 1;
+
+ dbg_gen("dent '%.*s' from ino %lu (nlink %d) in dir ino %lu",
+ dentry->d_name.len, dentry->d_name.name, inode->i_ino,
+ inode->i_nlink, dir->i_ino);
+ ubifs_assert(mutex_is_locked(&dir->i_mutex));
+ ubifs_assert(mutex_is_locked(&inode->i_mutex));
+ ubifs_assert(!S_ISDIR(inode->i_mode));
+
+ err = ubifs_budget_inode_op(c, dir, &req);
+ if (err) {
+ if (err != -ENOSPC)
+ return err;
+ err = 0;
+ budgeted = 0;
+ }
+
+ dir->i_size -= sz_change;
+ dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
+
+ inode->i_ctime = dir->i_ctime;
+ drop_nlink(inode);
+
+ err = ubifs_jrn_update(c, dir, &dentry->d_name, inode, 1,
+ IS_DIRSYNC(dir), 0);
+ if (err)
+ goto out_budg;
+
+ if (budgeted)
+ ubifs_release_ino_clean(c, dir, &req);
+
+ return 0;
+
+out_budg:
+ dir->i_size += sz_change;
+ inc_nlink(inode);
+ if (budgeted)
+ ubifs_cancel_ino_op(c, dir, &req);
+ return err;
+}
+
+/**
+ * check_dir_empty - check if a directory is empty or not.
+ * @c: UBIFS file-system description object
+ * @dir: VFS inode object of the directory to check
+ *
+ * This function checks if directory @dir is empty. Returns zero if the
+ * directory is empty, %-ENOTEMPTY if it is not, and other negative error codes
+ * in case of of errors.
+ */
+static int check_dir_empty(struct ubifs_info *c, struct inode *dir)
+{
+ struct ubifs_dent_node *dent;
+ union ubifs_key key;
+ int err;
+
+ lowest_dent_key(c, &key, dir->i_ino);
+ dent = ubifs_tnc_next_ent(c, &key, NULL);
+ if (IS_ERR(dent)) {
+ err = PTR_ERR(dent);
+ if (err == -ENOENT)
+ err = 0;
+ } else {
+ kfree(dent);
+ err = -ENOTEMPTY;
+ }
+
+ return err;
+}
+
+static int ubifs_rmdir(struct inode *dir, struct dentry *dentry)
+{
+ struct ubifs_info *c = dir->i_sb->s_fs_info;
+ struct inode *inode = dentry->d_inode;
+ struct ubifs_budget_req req = { .mod_dent = 1, .dirtied_ino = 1 };
+ int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
+ int err, budgeted = 0;
+
+ dbg_gen("directory '%.*s', ino %lu in dir ino %lu", dentry->d_name.len,
+ dentry->d_name.name, inode->i_ino, dir->i_ino);
+ ubifs_assert(mutex_is_locked(&dir->i_mutex));
+ ubifs_assert(mutex_is_locked(&inode->i_mutex));
+ ubifs_assert(S_ISDIR(inode->i_mode));
+
+ err = check_dir_empty(c, dentry->d_inode);
+ if (err)
+ return err;
+
+ budgeted = 1;
+ err = ubifs_budget_inode_op(c, dir, &req);
+ if (err) {
+ if (err != -ENOSPC)
+ return err;
+ budgeted = 0;
+ }
+
+ dir->i_size -= sz_change;
+ dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
+ drop_nlink(dir);
+
+ inode->i_size = 0;
+ inode->i_ctime = dir->i_ctime;
+ drop_nlink(inode);
+ drop_nlink(inode);
+
+ err = ubifs_jrn_update(c, dir, &dentry->d_name, inode, 1,
+ IS_DIRSYNC(dir), 0);
+ if (err)
+ goto out_budg;
+
+ if (budgeted)
+ ubifs_release_ino_clean(c, dir, &req);
+
+ return 0;
+
+out_budg:
+ dir->i_size += sz_change;
+ inc_nlink(dir);
+ inc_nlink(inode);
+ inc_nlink(inode);
+ if (budgeted)
+ ubifs_cancel_ino_op(c, dir, &req);
+ return err;
+}
+
+static int ubifs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
+{
+ struct inode *inode;
+ struct ubifs_info *c = dir->i_sb->s_fs_info;
+ struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
+ int err, sz_change = CALC_DENT_SIZE(dentry->d_name.len);
+
+ dbg_gen("dent '%.*s', mode %#x in dir ino %lu",
+ dentry->d_name.len, dentry->d_name.name, mode, dir->i_ino);
+ ubifs_assert(mutex_is_locked(&dir->i_mutex));
+
+ err = ubifs_budget_inode_op(c, dir, &req);
+ if (err)
+ return err;
+
+ inode = ubifs_new_inode(c, dir, S_IFDIR | mode);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_budg;
+ }
+
+ insert_inode_hash(inode);
+ inc_nlink(inode);
+
+ dir->i_mtime = dir->i_ctime = CURRENT_TIME_SEC;
+ dir->i_size += sz_change;
+ inc_nlink(dir);
+
+ err = ubifs_jrn_update(c, dir, &dentry->d_name, inode, 0,
+ IS_DIRSYNC(dir), 0);
+ if (err) {
+ ubifs_err("cannot create directory, error %d", err);
+ goto out_inode;
+ }
+
+ d_instantiate(dentry, inode);
+ ubifs_release_ino_clean(c, dir, &req);
+ return 0;
+
+out_inode:
+ dir->i_size -= sz_change;
+ drop_nlink(dir);
+ make_bad_inode(inode);
+ iput(inode);
+out_budg:
+ ubifs_cancel_ino_op(c, dir, &req);
+ return err;
+}
+
+static int ubifs_mknod(struct inode *dir, struct dentry *dentry,
+ int mode, dev_t rdev)
+{
+ struct inode *inode;
+ struct ubifs_info *c = dir->i_sb->s_fs_info;
+ struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1 };
+ union ubifs_dev_desc *dev = NULL;
+ int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
+ int err, devlen = 0;
+
+ dbg_gen("dent '%.*s' in dir ino %lu",
+ dentry->d_name.len, dentry->d_name.name, dir->i_ino);
+ ubifs_assert(mutex_is_locked(&dir->i_mutex));
+
+ if (!new_valid_dev(rdev))
+ return -EINVAL;
+
+ if (S_ISBLK(mode) || S_ISCHR(mode)) {
+ dev = kmalloc(sizeof(union ubifs_dev_desc), GFP_NOFS);
+ if (!dev)
+ return -ENOMEM;
+ devlen = ubifs_encode_dev(dev, rdev);
+ }
+
+ err = ubifs_budget_inode_op(c, dir, &req);
+ if (err) {
+ kfree(dev);
+ return err;
+ }
+
+ inode = ubifs_new_inode(c, dir, mode);
+ if (IS_ERR(inode)) {
+ kfree(dev);
+ err = PTR_ERR(inode);
+ goto out_budg;
+ }
+
+ init_special_inode(inode, inode->i_mode, rdev);
+
+ inode->i_size = devlen;
+ ubifs_inode(inode)->data = dev;
+ ubifs_inode(inode)->data_len = devlen;
+
+ dir->i_size += sz_change;
+
+ err = ubifs_jrn_update(c, dir, &dentry->d_name, inode, 0,
+ IS_DIRSYNC(dir), 0);
+ if (err)
+ goto out_inode;
+
+ insert_inode_hash(inode);
+ d_instantiate(dentry, inode);
+ ubifs_release_ino_clean(c, dir, &req);
+ return 0;
+
+out_inode:
+ dir->i_size -= sz_change;
+ make_bad_inode(inode);
+ iput(inode);
+out_budg:
+ ubifs_cancel_ino_op(c, dir, &req);
+ return err;
+}
+
+static int ubifs_symlink(struct inode *dir, struct dentry *dentry,
+ const char *symname)
+{
+ struct inode *inode;
+ struct ubifs_inode *ui;
+ struct ubifs_info *c = dir->i_sb->s_fs_info;
+ int err, len = strlen(symname);
+ int sz_change = CALC_DENT_SIZE(dentry->d_name.len);
+ struct ubifs_budget_req req = { .new_ino = 1, .new_dent = 1,
+ .new_ino_d = len };
+
+ dbg_gen("dent '%.*s', target '%s' in dir ino %lu", dentry->d_name.len,
+ dentry->d_name.name, symname, dir->i_ino);
+ ubifs_assert(mutex_is_locked(&dir->i_mutex));
+
+ if (len > UBIFS_MAX_INO_DATA)
+ return -ENAMETOOLONG;
+
+ err = ubifs_budget_inode_op(c, dir, &req);
+ if (err)
+ return err;
+
+ inode = ubifs_new_inode(c, dir, S_IFLNK | S_IRWXUGO);
+ if (IS_ERR(inode)) {
+ err = PTR_ERR(inode);
+ goto out_budg;
+ }
+
+ ui = ubifs_inode(inode);
+ ui->data = kmalloc(len + 1, GFP_KERNEL);
+ if (!ui->data) {
+ err = -ENOMEM;
+ goto out_inode;
+ }
+
+ memcpy(ui->data, symname, len);
+ ((char *)ui->data)[len] = '\0';
+ /*
+ * The terminating zero byte is not written to the flash media and it
+ * is put just to make later in-memory string processing simpler. Thus,
+ * data length is @len, not @len + %1.
+ */
+ ui->data_len = len;
+ inode->i_size = len;
+
+ dir->i_size += sz_change;
+
+ err = ubifs_jrn_update(c, dir, &dentry->d_name, inode, 0,
+ IS_DIRSYNC(dir), 0);
+ if (err)
+ goto out_dir;
+
+ insert_inode_hash(inode);
+ d_instantiate(dentry, inode);
+ ubifs_release_ino_clean(c, dir, &req);
+ return 0;
+
+out_dir:
+ dir->i_size -= sz_change;
+out_inode:
+ make_bad_inode(inode);
+ iput(inode);
+out_budg:
+ ubifs_cancel_ino_op(c, dir, &req);
+ return err;
+}
+
+static int ubifs_rename(struct inode *old_dir, struct dentry *old_dentry,
+ struct inode *new_dir, struct dentry *new_dentry)
+{
+ struct ubifs_info *c = old_dir->i_sb->s_fs_info;
+ struct inode *old_inode = old_dentry->d_inode;
+ struct inode *new_inode = new_dentry->d_inode;
+ int err, move = (new_dir != old_dir);
+ int is_dir = S_ISDIR(old_inode->i_mode);
+ int unlink = !!new_inode;
+ int dirsync = (IS_DIRSYNC(old_dir) || IS_DIRSYNC(new_dir));
+ int new_sz = CALC_DENT_SIZE(new_dentry->d_name.len);
+ int old_sz = CALC_DENT_SIZE(old_dentry->d_name.len);
+ struct ubifs_budget_req req = { .new_dent = 1, .mod_dent = 1 };
+
+ dbg_gen("dent '%.*s' ino %lu in dir ino %lu to dent '%.*s' in "
+ "dir ino %lu", old_dentry->d_name.len, old_dentry->d_name.name,
+ old_inode->i_ino, old_dir->i_ino, new_dentry->d_name.len,
+ new_dentry->d_name.name, new_dir->i_ino);
+ ubifs_assert(mutex_is_locked(&old_dir->i_mutex));
+ ubifs_assert(mutex_is_locked(&new_dir->i_mutex));
+ if (unlink)
+ ubifs_assert(mutex_is_locked(&new_inode->i_mutex));
+
+ if (unlink && is_dir) {
+ err = check_dir_empty(c, new_inode);
+ if (err)
+ return err;
+ }
+
+ if (move) {
+ req.dirtied_ino = 1;
+ if (unlink) {
+ req.dirtied_ino += 2;
+ req.dirtied_ino_d = ubifs_inode(new_inode)->data_len;
+ }
+ }
+
+ /*
+ * Note, rename may write @new_dir inode if the directory entry is
+ * moved there. And if the @new_dir is dirty, we do not bother to make
+ * it clean. It could be done, but requires extra coding which does not
+ * seem to be really worth it.
+ */
+ err = ubifs_budget_inode_op(c, old_dir, &req);
+ if (err)
+ return err;
+
+ /*
+ * Like most other Unix systems, set the ctime for inodes on a
+ * rename.
+ */
+ old_inode->i_ctime = CURRENT_TIME_SEC;
+
+ /*
+ * If we moved a directory to another parent directory, decrement
+ * 'i_nlink' of the old parent. Also, update 'i_size' of the old parent
+ * as well as its [mc]time.
+ */
+ if (is_dir && move)
+ drop_nlink(old_dir);
+ old_dir->i_size -= old_sz;
+ old_dir->i_mtime = old_dir->i_ctime = CURRENT_TIME_SEC;
+ new_dir->i_mtime = new_dir->i_ctime = CURRENT_TIME_SEC;
+
+ /*
+ * If we moved a directory object to new directory, parent's 'i_nlink'
+ * should be adjusted.
+ */
+ if (move && is_dir)
+ inc_nlink(new_dir);
+
+ /*
+ * And finally, if we unlinked a direntry which happened to have the
+ * same name as the moved direntry, we have to decrement 'i_nlink' of
+ * the unlinked inode and change its ctime.
+ */
+ if (unlink) {
+ /*
+ * Directories cannot have hard-links, so if this is a
+ * directory, decrement its 'i_nlink' twice because an empty
+ * directory has 'i_nlink' 2.
+ */
+ if (is_dir)
+ drop_nlink(new_inode);
+ new_inode->i_ctime = CURRENT_TIME_SEC;
+ drop_nlink(new_inode);
+ } else
+ new_dir->i_size += new_sz;
+
+ err = ubifs_jrn_rename(c, old_dir, old_dentry, new_dir, new_dentry,
+ dirsync);
+ if (err)
+ goto out_inode;
+
+ ubifs_release_ino_clean(c, old_dir, &req);
+ return 0;
+
+out_inode:
+ if (unlink) {
+ if (is_dir)
+ inc_nlink(new_inode);
+ inc_nlink(new_inode);
+ } else
+ new_dir->i_size -= new_sz;
+ old_dir->i_size += old_sz;
+ if (is_dir && move) {
+ drop_nlink(new_dir);
+ inc_nlink(old_dir);
+ }
+ ubifs_cancel_ino_op(c, old_dir, &req);
+ return err;
+}
+
+int ubifs_getattr(struct vfsmount *mnt, struct dentry *dentry,
+ struct kstat *stat)
+{
+ struct inode *inode = dentry->d_inode;
+ loff_t size;
+
+ stat->dev = inode->i_sb->s_dev;
+ stat->ino = inode->i_ino;
+ stat->mode = inode->i_mode;
+ stat->nlink = inode->i_nlink;
+ stat->uid = inode->i_uid;
+ stat->gid = inode->i_gid;
+ stat->rdev = inode->i_rdev;
+ stat->atime = inode->i_atime;
+ stat->mtime = inode->i_mtime;
+ stat->ctime = inode->i_ctime;
+ stat->blksize = UBIFS_BLOCK_SIZE;
+ stat->size = i_size_read(inode);
+
+ spin_lock(&inode->i_lock);
+ size = ubifs_inode(inode)->xattr_size;
+ spin_unlock(&inode->i_lock);
+
+ /*
+ * Unfortunately, the 'stat()' system call was designed for block
+ * device based file systems, and it is not appropriate for UBIFS,
+ * because UBIFS does not have notion of "block". For example, it is
+ * difficult to tell how many block a directory takes - it actually
+ * takes less then 300 bytes, but we have to round it to block size,
+ * which introduces large mistake. This makes utilities like 'du' to
+ * report completely senseless numbers. This is the reason why UBIFS
+ * goes the same way as JFFS2 - it reports zero blocks for everything
+ * but regular files, which makes more sense than reporting completely
+ * wrong sizes.
+ */
+ if (S_ISREG(inode->i_mode))
+ size += stat->size;
+
+ size = ALIGN(size, UBIFS_BLOCK_SIZE);
+ /*
+ * Note, userspace expects 512-byte blocks count irrespectively of what
+ * was reported in @stat->size.
+ */
+ stat->blocks = size >> 9;
+
+ return 0;
+}
+
+struct inode_operations ubifs_dir_inode_operations = {
+ .lookup = ubifs_lookup,
+ .create = ubifs_create,
+ .link = ubifs_link,
+ .symlink = ubifs_symlink,
+ .unlink = ubifs_unlink,
+ .mkdir = ubifs_mkdir,
+ .rmdir = ubifs_rmdir,
+ .mknod = ubifs_mknod,
+ .rename = ubifs_rename,
+ .setattr = ubifs_setattr,
+ .getattr = ubifs_getattr,
+#ifdef CONFIG_UBIFS_FS_XATTR
+ .setxattr = ubifs_setxattr,
+ .getxattr = ubifs_getxattr,
+ .listxattr = ubifs_listxattr,
+ .removexattr = ubifs_removexattr,
+#endif
+};
+
+struct file_operations ubifs_dir_operations = {
+ .llseek = generic_file_llseek,
+ .release = ubifs_dir_release,
+ .read = generic_read_dir,
+ .readdir = ubifs_readdir,
+ .fsync = ubifs_fsync,
+ .ioctl = ubifs_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = ubifs_compat_ioctl,
+#endif
+};
diff --git a/fs/ubifs/file.c b/fs/ubifs/file.c
new file mode 100644
index 0000000..2dcd435
--- /dev/null
+++ b/fs/ubifs/file.c
@@ -0,0 +1,790 @@
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Authors: Artem Bityutskiy (Битюцкий Артём)
+ * Adrian Hunter
+ */
+
+/*
+ * This file implements VFS file and inode operations of regular files, device
+ * nodes and symlinks as well as address space operations.
+ *
+ * UBIFS uses 2 page flags: PG_private and PG_checked. PG_private is set if the
+ * page is dirty and is used for budgeting purposes - dirty pages should not be
+ * budgeted. The PG_checked flag is set if full budgeting is required for the
+ * page e.g., when it corresponds to a file hole or it is just beyond the file
+ * size. The budgeting is done in 'ubifs_write_begin()', because it is OK to
+ * fail in this function, and the budget is released in 'ubifs_write_end()'. So
+ * the PG_private and PG_checked flags carry the information about how the page
+ * was budgeted, to make it possible to release the budget properly.
+ *
+ * A thing to keep in mind: inode's 'i_mutex' is locked in most VFS operations
+ * we implement. However, this is not true for '->writepage()', which might be
+ * called with 'i_mutex' unlocked. For example, when pdflush is performing
+ * write-back, it calls 'writepage()' with unlocked 'i_mutex', although the
+ * inode has 'I_LOCK' flag in this case. At "normal" work-paths 'i_mutex' is
+ * locked in '->writepage', e.g. in "sys_write -> alloc_pages -> direct reclaim
+ * path'. So, in '->writepage()' we are only guaranteed that the page is
+ * locked.
+ *
+ * Similarly, 'i_mutex' does not have to be locked in readpage(), e.g.,
+ * readahead path does not have it locked ("sys_read -> generic_file_aio_read
+ * -> ondemand_readahead -> readpage"). In case of readahead, 'I_LOCK' flag is
+ * not set as well.
+ *
+ * This, for example means that there might be 2 concurrent '->writepage()'
+ * calls for the same inode, but different inode dirty pages.
+ */
+
+#include "ubifs.h"
+#include <linux/mount.h>
+
+static int do_readpage(struct page *page)
+{
+ void *addr;
+ int err, len, out_len;
+ union ubifs_key key;
+ struct ubifs_data_node *dn;
+ struct inode *inode = page->mapping->host;
+ struct ubifs_info *c = inode->i_sb->s_fs_info;
+ unsigned int dlen;
+ loff_t i_size = i_size_read(inode);
+
+ dbg_gen("ino %lu, pg %lu, i_size %lld, flags %#lx",
+ inode->i_ino, page->index, i_size, page->flags);
+ ubifs_assert(PageLocked(page));
+ ubifs_assert(!PageChecked(page));
+ ubifs_assert(!PagePrivate(page));
+
+ addr = kmap(page);
+
+ if (((loff_t)page->index << PAGE_CACHE_SHIFT) >= i_size) {
+ /* Reading beyond inode */
+ SetPageChecked(page);
+ memset(addr, 0, PAGE_CACHE_SIZE);
+ goto out;
+ }
+
+ dn = kmalloc(UBIFS_MAX_DATA_NODE_SZ, GFP_NOFS);
+ if (!dn) {
+ err = -ENOMEM;
+ goto error;
+ }
+
+ data_key_init(c, &key, inode->i_ino, page->index);
+ err = ubifs_tnc_lookup(c, &key, dn);
+ if (err) {
+ if (err == -ENOENT) {
+ /* Not found, so it must be a hole */
+ SetPageChecked(page);
+ memset(addr, 0, PAGE_CACHE_SIZE);
+ dbg_gen("hole");
+ goto out_free;
+ }
+ ubifs_err("cannot read page %lu of inode %lu, error %d",
+ page->index, inode->i_ino, err);
+ goto error;
+ }
+
+ ubifs_assert(dn->ch.sqnum > ubifs_inode(inode)->creat_sqnum);
+
+ len = le32_to_cpu(dn->size);
+ if (len <= 0 || len > PAGE_CACHE_SIZE)
+ goto dump;
+
+ dlen = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
+ out_len = PAGE_CACHE_SIZE;
+ err = ubifs_decompress(&dn->data, dlen, addr, &out_len,
+ le16_to_cpu(dn->compr_type));
+ if (err || len != out_len)
+ goto dump;
+
+ /*
+ * Data length can be less than a full page, even for blocks that are
+ * not the last in the file (e.g., as a result of making a hole and
+ * appending data). Ensure that the remainder is zeroed out.
+ */
+ if (len < PAGE_CACHE_SIZE)
+ memset(addr + len, 0, PAGE_CACHE_SIZE - len);
+
+out_free:
+ kfree(dn);
+out:
+ SetPageUptodate(page);
+ ClearPageError(page);
+ flush_dcache_page(page);
+ kunmap(page);
+ return 0;
+
+dump:
+ err = -EINVAL;
+ ubifs_err("bad data node (page %lu, inode %lu)",
+ page->index, inode->i_ino);
+ dbg_dump_node(c, dn);
+error:
+ kfree(dn);
+ ClearPageUptodate(page);
+ SetPageError(page);
+ flush_dcache_page(page);
+ kunmap(page);
+ return err;
+}
+
+static int ubifs_write_begin(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned flags,
+ struct page **pagep, void **fsdata)
+{
+ struct inode *inode = mapping->host;
+ struct ubifs_info *c = inode->i_sb->s_fs_info;
+ pgoff_t index = pos >> PAGE_CACHE_SHIFT;
+ struct ubifs_budget_req req = { .new_page = 1 };
+ loff_t i_size = i_size_read(inode);
+ int uninitialized_var(err);
+ struct page *page;
+
+ ubifs_assert(mutex_is_locked(&inode->i_mutex));
+ ubifs_assert(!(inode->i_sb->s_flags & MS_RDONLY));
+ dbg_eat_memory();
+
+ if (unlikely(c->ro_media))
+ return -EINVAL;
+
+ /*
+ * We are about to have a page of data written and we have to budget for
+ * this. The very important point here is that we have to budget before
+ * locking the page, because budgeting may force write-back, which
+ * would wait on locked pages and deadlock if we had the page locked.
+ *
+ * At this point we do not know anything about the page of data we are
+ * going to change, so assume the biggest budget (i.e., assume that
+ * this is a new page of data and it does not override an older page of
+ * data in the inode). Later the budget will be amended if this is not
+ * true.
+ */
+ if (pos + len > i_size)
+ /*
+ * We are writing beyond the file which means we are going to
+ * change inode size and make the inode dirty. And in turn,
+ * this means we have to budget for making the inode dirty.
+ *
+ * Note, if the inode is already dirty,
+ * 'ubifs_budget_inode_op()' will not allocate any budget,
+ * but will just lock the @budg_mutex of the inode to prevent
+ * it from becoming clean before we have changed its size,
+ * which is going to happen in 'ubifs_write_end()'.
+ */
+ err = ubifs_budget_inode_op(c, inode, &req);
+ else
+ /*
+ * The inode is not going to be marked as dirty by this write
+ * operation, do not budget for this.
+ */
+ err = ubifs_budget_space(c, &req);
+ if (unlikely(err))
+ return err;
+
+ page = __grab_cache_page(mapping, index);
+ if (unlikely(!page)) {
+ err = -ENOMEM;
+ goto out_release;
+ }
+
+ if (!PageUptodate(page)) {
+ /*
+ * The page is not loaded from the flash and has to be loaded
+ * unless we are writing all of it.
+ */
+ if (!(pos & PAGE_CACHE_MASK) && len == PAGE_CACHE_SIZE)
+ /*
+ * Set the PG_checked flag to make the further code
+ * assume the page is new.
+ */
+ SetPageChecked(page);
+ else {
+ err = do_readpage(page);
+ if (err)
+ goto out_unlock;
+ }
+
+ SetPageUptodate(page);
+ ClearPageError(page);
+ }
+
+ if (PagePrivate(page))
+ /*
+ * The page is dirty, which means it was budgeted twice:
+ * o first time the budget was allocated by the task which
+ * made the page dirty and set the PG_private flag;
+ * o and then we budgeted for it for the second time at the
+ * very beginning of this function.
+ *
+ * So what we have to do is to release the page budget we
+ * allocated.
+ *
+ * Note, the page write operation may change the inode length,
+ * which makes it dirty and means the budget should be
+ * allocated. This was done above in the "pos + len > i_size"
+ * case. If this was done, we do not free the the inode budget,
+ * because we cannot as we are really going to mark it dirty in
+ * the 'ubifs_write_end()' function.
+ */
+ ubifs_release_new_page_budget(c);
+ else if (!PageChecked(page))
+ /*
+ * The page is not new, which means we are changing the page
+ * which already exists on the media. This means that changing
+ * the page does not make the amount of indexing information
+ * larger, and this part of the budget which we have already
+ * acquired may be released.
+ */
+ ubifs_convert_page_budget(c);
+
+ *pagep = page;
+ return 0;
+
+out_unlock:
+ unlock_page(page);
+out_release:
+ page_cache_release(page);
+ return err;
+
+}
+
+static int ubifs_write_end(struct file *file, struct address_space *mapping,
+ loff_t pos, unsigned len, unsigned copied,
+ struct page *page, void *fsdata)
+{
+ struct inode *inode = mapping->host;
+ struct ubifs_inode *ui = ubifs_inode(inode);
+ struct ubifs_info *c = inode->i_sb->s_fs_info;
+ loff_t i_size = i_size_read(inode);
+
+ dbg_gen("ino %lu, pos %llu, pg %lu, len %u, copied %d, i_size %lld",
+ inode->i_ino, pos, page->index, len, copied, i_size);
+ ubifs_assert(PageUptodate(page));
+ ubifs_assert(mutex_is_locked(&inode->i_mutex));
+ ubifs_assert(copied <= len);
+
+ if (unlikely(copied < len && len == PAGE_CACHE_SIZE)) {
+ /*
+ * VFS copied less data to the page that it indented and
+ * declared in its '->write_begin()' call via the @len
+ * argument. If the page was not up-to-date, and @len was
+ * @PAGE_CACHE_SIZE, the 'ubifs_write_begin()' function did
+ * not load it from the media (for optimization reasons). This
+ * means that part of the page contains garbage. So read the
+ * page now.
+ */
+ dbg_gen("copied %d instead of %d, read page and repeat",
+ copied, len);
+
+ if (pos > inode->i_size)
+ mutex_unlock(&ui->budg_mutex);
+
+ copied = do_readpage(page);
+
+ /*
+ * Return 0 to force VFS to repeat the whole operation, or the
+ * error code if 'do_readpage()' failed.
+ */
+ goto out;
+ }
+
+ if (!PagePrivate(page)) {
+ SetPagePrivate(page);
+ atomic_long_inc(&c->dirty_pg_cnt);
+ __set_page_dirty_nobuffers(page);
+ }
+
+ if (pos + len > i_size) {
+ i_size_write(inode, pos + len);
+
+ /*
+ * Note, we do not set @I_DIRTY_PAGES (which means that the
+ * inode has dirty pages), this has been done in
+ * '__set_page_dirty_nobuffers()'.
+ */
+ mark_inode_dirty_sync(inode);
+
+ /*
+ * The inode has been marked dirty, unlock it. This is a bit
+ * hacky because normally we would have to call
+ * 'ubifs_release_ino_dirty()'. But we know there is nothing
+ * to release because page's budget will be released in
+ * 'ubifs_write_page()' and inode's budget will be released in
+ * 'ubifs_write_inode()', so just unlock the inode here for
+ * optimization.
+ */
+ mutex_unlock(&ui->budg_mutex);
+ }
+
+out:
+ unlock_page(page);
+ page_cache_release(page);
+ return copied;
+}
+
+static int ubifs_readpage(struct file *file, struct page *page)
+{
+ do_readpage(page);
+ unlock_page(page);
+ return 0;
+}
+
+/**
+ * release_existing_page_budget - release budget of an existing page.
+ * @c: UBIFS file-system description object
+ *
+ * This is a helper function which releases budget corresponding to the budget
+ * of changing one one page of data which already exists on the flash media.
+ *
+ * This function was not moved to "budget.c" because there is only one user.
+ */
+static void release_existing_page_budget(struct ubifs_info *c)
+{
+ struct ubifs_budget_req req = { .dd_growth = c->page_budget};
+
+ ubifs_release_budget(c, &req);
+}
+
+static int do_writepage(struct page *page, int len)
+{
+ int err;
+ void *addr;
+ union ubifs_key key;
+ struct inode *inode = page->mapping->host;
+ struct ubifs_info *c = inode->i_sb->s_fs_info;
+
+ /* Update radix tree tags */
+ set_page_writeback(page);
+
+ /* One page cache page is one UBIFS block */
+ data_key_init(c, &key, inode->i_ino, page->index);
+ addr = kmap(page);
+
+ err = ubifs_jrn_write_data(c, inode, &key, addr, len);
+ if (err) {
+ SetPageError(page);
+ ubifs_err("cannot write page %lu of inode %lu, error %d",
+ page->index, inode->i_ino, err);
+ ubifs_ro_mode(c);
+ }
+
+ ubifs_assert(PagePrivate(page));
+ if (PageChecked(page))
+ ubifs_release_new_page_budget(c);
+ else
+ release_existing_page_budget(c);
+
+ atomic_long_dec(&c->dirty_pg_cnt);
+ ClearPagePrivate(page);
+ ClearPageChecked(page);
+
+ kunmap(page);
+ unlock_page(page);
+ end_page_writeback(page);
+
+ return err;
+}
+
+static int ubifs_writepage(struct page *page, struct writeback_control *wbc)
+{
+ struct inode *inode = page->mapping->host;
+ loff_t i_size = i_size_read(inode);
+ pgoff_t end_index = i_size >> PAGE_CACHE_SHIFT;
+ int len;
+ void *kaddr;
+
+ dbg_gen("ino %lu, pg %lu, pg flags %#lx",
+ inode->i_ino, page->index, page->flags);
+ ubifs_assert(PageUptodate(page));
+ ubifs_assert(!PageWriteback(page));
+ ubifs_assert(PagePrivate(page));
+ ubifs_assert(!(inode->i_sb->s_flags & MS_RDONLY));
+
+ /* Is the page fully inside i_size? */
+ if (page->index < end_index)
+ return do_writepage(page, PAGE_CACHE_SIZE);
+
+ /* Is the page fully outside i_size? (truncate in progress) */
+ len = i_size & (PAGE_CACHE_SIZE - 1);
+ if (page->index >= end_index + 1 || !len) {
+ unlock_page(page);
+ return 0;
+ }
+
+ /*
+ * The page straddles i_size. It must be zeroed out on each and every
+ * writepage invocation because it may be mmapped. "A file is mapped
+ * in multiples of the page size. For a file that is not a multiple of
+ * the page size, the remaining memory is zeroed when mapped, and
+ * writes to that region are not written out to the file."
+ */
+ kaddr = kmap_atomic(page, KM_USER0);
+ memset(kaddr + len, 0, PAGE_CACHE_SIZE - len);
+ flush_dcache_page(page);
+ kunmap_atomic(kaddr, KM_USER0);
+
+ return do_writepage(page, len);
+}
+
+static int ubifs_trunc(struct inode *inode, loff_t new_size)
+{
+ loff_t old_size;
+ int err;
+
+ dbg_gen("ino %lu, size %lld -> %lld",
+ inode->i_ino, inode->i_size, new_size);
+ ubifs_assert(mutex_is_locked(&inode->i_mutex));
+
+ old_size = inode->i_size;
+
+ err = vmtruncate(inode, new_size);
+ if (err)
+ return err;
+
+ if (!S_ISREG(inode->i_mode))
+ return 0;
+
+ if (new_size < old_size) {
+ struct ubifs_info *c = inode->i_sb->s_fs_info;
+ int offset = new_size & (UBIFS_BLOCK_SIZE - 1);
+
+ if (offset) {
+ pgoff_t index = new_size >> PAGE_CACHE_SHIFT;
+ struct page *page;
+
+ page = find_lock_page(inode->i_mapping, index);
+ if (page) {
+ if (PageDirty(page)) {
+ ubifs_assert(PageUptodate(page));
+ ubifs_assert(!PageWriteback(page));
+ ubifs_assert(PagePrivate(page));
+
+ clear_page_dirty_for_io(page);
+ err = do_writepage(page, offset);
+ if (err)
+ return err;
+ /*
+ * We could now tell ubifs_jrn_truncate
+ * not to read the last block.
+ */
+ } else {
+ /*
+ * We could 'kmap()' the page and
+ * pass the data to ubifs_jrn_truncate
+ * to save it from having to read it.
+ */
+ unlock_page(page);
+ page_cache_release(page);
+ }
+ }
+ }
+ err = ubifs_jrn_truncate(c, inode->i_ino, old_size, new_size);
+ if (err)
+ return err;
+ }
+
+ return 0;
+}
+
+int ubifs_setattr(struct dentry *dentry, struct iattr *attr)
+{
+ unsigned int ia_valid = attr->ia_valid;
+ struct inode *inode = dentry->d_inode;
+ struct ubifs_info *c = inode->i_sb->s_fs_info;
+ struct ubifs_budget_req req;
+ int truncation, err = 0;
+
+ dbg_gen("ino %lu, ia_valid %#x", inode->i_ino, ia_valid);
+ ubifs_assert(mutex_is_locked(&inode->i_mutex));
+
+ err = inode_change_ok(inode, attr);
+ if (err)
+ return err;
+
+ memset(&req, 0, sizeof(struct ubifs_budget_req));
+
+ /*
+ * If this is truncation, and we do not truncate on a block boundary,
+ * budget for changing one data block, because the last block will be
+ * re-written.
+ */
+ truncation = (ia_valid & ATTR_SIZE) && attr->ia_size != inode->i_size;
+ if (truncation && (attr->ia_size & (UBIFS_BLOCK_SIZE - 1)))
+ req.dirtied_page = 1;
+
+ err = ubifs_budget_inode_op(c, inode, &req);
+ if (err)
+ return err;
+
+ if (truncation) {
+ err = ubifs_trunc(inode, attr->ia_size);
+ if (err) {
+ ubifs_cancel_ino_op(c, inode, &req);
+ return err;
+ }
+
+ inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
+ }
+
+ if (ia_valid & ATTR_UID)
+ inode->i_uid = attr->ia_uid;
+ if (ia_valid & ATTR_GID)
+ inode->i_gid = attr->ia_gid;
+ if (ia_valid & ATTR_ATIME)
+ inode->i_atime = timespec_trunc(attr->ia_atime,
+ inode->i_sb->s_time_gran);
+ if (ia_valid & ATTR_MTIME)
+ inode->i_mtime = timespec_trunc(attr->ia_mtime,
+ inode->i_sb->s_time_gran);
+ if (ia_valid & ATTR_CTIME)
+ inode->i_ctime = timespec_trunc(attr->ia_ctime,
+ inode->i_sb->s_time_gran);
+ if (ia_valid & ATTR_MODE) {
+ umode_t mode = attr->ia_mode;
+
+ if (!in_group_p(inode->i_gid) && !capable(CAP_FSETID))
+ mode &= ~S_ISGID;
+ inode->i_mode = mode;
+ }
+
+ mark_inode_dirty_sync(inode);
+ ubifs_release_ino_dirty(c, inode, &req);
+
+ if (req.dirtied_page) {
+ /*
+ * Truncation code does not make the reenacted page dirty, it
+ * just changes it on journal level, so we have to release page
+ * change budget.
+ */
+ memset(&req, 0, sizeof(struct ubifs_budget_req));
+ req.dd_growth = c->page_budget;
+ ubifs_release_budget(c, &req);
+ }
+
+ if (IS_SYNC(inode))
+ err = write_inode_now(inode, 1);
+
+ return err;
+}
+
+static void ubifs_invalidatepage(struct page *page, unsigned long offset)
+{
+ struct inode *inode = page->mapping->host;
+ struct ubifs_info *c = inode->i_sb->s_fs_info;
+ struct ubifs_budget_req req;
+
+ ubifs_assert(PagePrivate(page));
+ if (offset)
+ /* Partial page remains dirty */
+ return;
+
+ memset(&req, 0, sizeof(struct ubifs_budget_req));
+ if (PageChecked(page)) {
+ req.new_page = 1;
+ req.idx_growth = -1;
+ req.data_growth = c->page_budget;
+ } else
+ req.dd_growth = c->page_budget;
+ ubifs_release_budget(c, &req);
+
+ atomic_long_dec(&c->dirty_pg_cnt);
+ ClearPagePrivate(page);
+ ClearPageChecked(page);
+}
+
+static void *ubifs_follow_link(struct dentry *dentry, struct nameidata *nd)
+{
+ struct ubifs_inode *ui = ubifs_inode(dentry->d_inode);
+
+ nd_set_link(nd, ui->data);
+ return NULL;
+}
+
+int ubifs_fsync(struct file *filp, struct dentry *dentry, int datasync)
+{
+ struct inode *inode = dentry->d_inode;
+ struct ubifs_info *c = inode->i_sb->s_fs_info;
+ int err;
+
+ dbg_gen("syncing inode %lu", inode->i_ino);
+ ubifs_assert(mutex_is_locked(&inode->i_mutex));
+
+ /* Synchronize the inode and dirty pages */
+ err = write_inode_now(inode, 1);
+ if (err)
+ return err;
+
+ /*
+ * Some data related to this inode may still sit in a write-buffer.
+ * Flush them.
+ */
+ err = ubifs_sync_wbufs_by_inodes(c, &inode, 1);
+ if (err)
+ return err;
+
+ return 0;
+}
+
+/**
+ * update_ctime - update mtime and ctime of an inode.
+ * @c: UBIFS file-system description object
+ * @inode: inode to update
+ *
+ * Time resolution of UBIFS is one second. This function updates mtime and
+ * ctime of the inode if it is not equivalent to current time. Returns zero in
+ * case of success and a negative error code in case of failure.
+ */
+static int update_mctime(struct ubifs_info *c, struct inode *inode)
+{
+ time_t now = get_seconds();
+ struct ubifs_budget_req req;
+ int err;
+
+ if (inode->i_mtime.tv_sec != now || inode->i_ctime.tv_sec != now) {
+ memset(&req, 0, sizeof(struct ubifs_budget_req));
+ err = ubifs_budget_inode_op(c, inode, &req);
+ if (err)
+ return err;
+
+ inode->i_mtime.tv_sec = inode->i_ctime.tv_sec = now;
+ mark_inode_dirty_sync(inode);
+ mutex_unlock(&ubifs_inode(inode)->budg_mutex);
+ }
+
+ return 0;
+}
+
+static ssize_t ubifs_write(struct file *filp, const char __user *buf,
+ size_t len, loff_t *ppos)
+{
+ int err;
+ ssize_t ret;
+ struct inode *inode = filp->f_mapping->host;
+ struct ubifs_info *c = inode->i_sb->s_fs_info;
+
+ err = update_mctime(c, inode);
+ if (err)
+ return err;
+
+ ret = do_sync_write(filp, buf, len, ppos);
+ if (ret < 0)
+ return ret;
+
+ if (ret > 0 && IS_SYNC(inode)) {
+ err = ubifs_sync_wbufs_by_inodes(c, &inode, 1);
+ if (err)
+ return err;
+ }
+
+ return ret;
+}
+
+static ssize_t ubifs_aio_write(struct kiocb *iocb, const struct iovec *iov,
+ unsigned long nr_segs, loff_t pos)
+{
+ int err;
+ ssize_t ret;
+ struct inode *inode = iocb->ki_filp->f_mapping->host;
+ struct ubifs_info *c = inode->i_sb->s_fs_info;
+
+ err = update_mctime(c, inode);
+ if (err)
+ return err;
+
+ ret = generic_file_aio_write(iocb, iov, nr_segs, pos);
+ if (ret < 0)
+ return ret;
+
+ if (ret > 0 && IS_SYNC(inode)) {
+ err = ubifs_sync_wbufs_by_inodes(c, &inode, 1);
+ if (err)
+ return err;
+ }
+
+ return ret;
+}
+
+static int ubifs_set_page_dirty(struct page *page)
+{
+ /*
+ * An attempt to dirty a page without budgeting for it - should not
+ * happen.
+ */
+ ubifs_assert(0);
+ return __set_page_dirty_nobuffers(page);
+}
+
+static int ubifs_releasepage(struct page *page, gfp_t unused_gfp_flags)
+{
+ /*
+ * An attempt to release a dirty page without budgeting for it - should
+ * not happen.
+ */
+ ubifs_assert(PageLocked(page));
+ if (PageWriteback(page))
+ return 0;
+ ubifs_assert(PagePrivate(page));
+ ubifs_assert(0);
+ ClearPagePrivate(page);
+ ClearPageChecked(page);
+ return 1;
+}
+
+struct address_space_operations ubifs_file_address_operations = {
+ .readpage = ubifs_readpage,
+ .writepage = ubifs_writepage,
+ .write_begin = ubifs_write_begin,
+ .write_end = ubifs_write_end,
+ .invalidatepage = ubifs_invalidatepage,
+ .set_page_dirty = ubifs_set_page_dirty,
+ .releasepage = ubifs_releasepage,
+};
+
+struct inode_operations ubifs_file_inode_operations = {
+ .setattr = ubifs_setattr,
+ .getattr = ubifs_getattr,
+#ifdef CONFIG_UBIFS_FS_XATTR
+ .setxattr = ubifs_setxattr,
+ .getxattr = ubifs_getxattr,
+ .listxattr = ubifs_listxattr,
+ .removexattr = ubifs_removexattr,
+#endif
+};
+
+struct inode_operations ubifs_symlink_inode_operations = {
+ .readlink = generic_readlink,
+ .follow_link = ubifs_follow_link,
+ .setattr = ubifs_setattr,
+ .getattr = ubifs_getattr,
+};
+
+struct file_operations ubifs_file_operations = {
+ .llseek = generic_file_llseek,
+ .read = do_sync_read,
+ .write = ubifs_write,
+ .aio_read = generic_file_aio_read,
+ .aio_write = ubifs_aio_write,
+ .mmap = generic_file_mmap,
+ .fsync = ubifs_fsync,
+ .ioctl = ubifs_ioctl,
+#ifdef CONFIG_COMPAT
+ .compat_ioctl = ubifs_compat_ioctl,
+#endif
+};
diff --git a/fs/ubifs/ioctl.c b/fs/ubifs/ioctl.c
new file mode 100644
index 0000000..63c3b60
--- /dev/null
+++ b/fs/ubifs/ioctl.c
@@ -0,0 +1,205 @@
+/*
+ * This file is part of UBIFS.
+ *
+ * Copyright (C) 2006-2008 Nokia Corporation.
+ * Copyright (C) 2006, 2007 University of Szeged, Hungary
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License version 2 as published by
+ * the Free Software Foundation.
+ *
+ * This program is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
+ * more details.
+ *
+ * You should have received a copy of the GNU General Public License along with
+ * this program; if not, write to the Free Software Foundation, Inc., 51
+ * Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
+ *
+ * Authors: Zoltan Sogor
+ * Artem Bityutskiy (Битюцкий Артём)
+ * Adrian Hunter
+ */
+
+/* This file implements EXT2-compatible extended attribute ioctl() calls */
+
+#include <linux/compat.h>
+#include <linux/smp_lock.h>
+#include "ubifs.h"
+
+/**
+ * ubifs_set_inode_flags - set VFS inode flags.
+ * @inode: VFS inode to set flags for
+ *
+ * This function propagates flags from UBIFS inode object to VFS inode object.
+ */
+void ubifs_set_inode_flags(struct inode *inode)
+{
+ unsigned int flags = ubifs_inode(inode)->flags;
+
+ inode->i_flags &= ~(S_SYNC | S_APPEND | S_IMMUTABLE | S_DIRSYNC);
+ if (flags & UBIFS_SYNC_FL)
+ inode->i_flags |= S_SYNC;
+ if (flags & UBIFS_APPEND_FL)
+ inode->i_flags |= S_APPEND;
+ if (flags & UBIFS_IMMUTABLE_FL)
+ inode->i_flags |= S_IMMUTABLE;
+ if (flags & UBIFS_DIRSYNC_FL)
+ inode->i_flags |= S_DIRSYNC;
+}
+
+/*
+ * ioctl2ubifs - convert ioctl inode flags to UBIFS inode flags.
+ * @ioctl_flags: flags to convert
+ *
+ * This function convert ioctl flags (@FS_COMPR_FL, etc) to UBIFS inode flags
+ * (@UBIFS_COMPR_FL, etc).
+ */
+static int ioctl2ubifs(int ioctl_flags)
+{
+ int ubifs_flags = 0;
+
+ if (ioctl_flags & FS_COMPR_FL)
+ ubifs_flags |= UBIFS_COMPR_FL;
+ if (ioctl_flags & FS_SYNC_FL)
+ ubifs_flags |= UBIFS_SYNC_FL;
+ if (ioctl_flags & FS_APPEND_FL)
+ ubifs_flags |= UBIFS_APPEND_FL;
+ if (ioctl_flags & FS_IMMUTABLE_FL)
+ ubifs_flags |= UBIFS_IMMUTABLE_FL;
+ if (ioctl_flags & FS_DIRSYNC_FL)
+ ubifs_flags |= UBIFS_DIRSYNC_FL;
+
+ return ubifs_flags;
+}
+
+/*
+ * ubifs2ioctl - convert UBIFS inode flags to ioctl inode flags.
+ * @ubifs_flags: flags to convert
+ *
+ * This function convert UBIFS (@UBIFS_COMPR_FL, etc) to ioctl flags
+ * (@FS_COMPR_FL, etc).
+ */
+static int ubifs2ioctl(int ubifs_flags)
+{
+ int ioctl_flags = 0;
+
+ if (ubifs_flags & UBIFS_COMPR_FL)
+ ioctl_flags |= FS_COMPR_FL;
+ if (ubifs_flags & UBIFS_SYNC_FL)
+ ioctl_flags |= FS_SYNC_FL;
+ if (ubifs_flags & UBIFS_APPEND_FL)
+ ioctl_flags |= FS_APPEND_FL;
+ if (ubifs_flags & UBIFS_IMMUTABLE_FL)
+ ioctl_flags |= FS_IMMUTABLE_FL;
+ if (ubifs_flags & UBIFS_DIRSYNC_FL)
+ ioctl_flags |= FS_DIRSYNC_FL;
+
+ return ioctl_flags;
+}
+
+static int setflags(struct inode *inode, int flags)
+{
+ struct ubifs_inode *ui = ubifs_inode(inode);
+ struct ubifs_info *c = inode->i_sb->s_fs_info;
+ struct ubifs_budget_req req;
+ int oldflags, err;
+
+ mutex_lock(&inode->i_mutex);
+
+ memset(&req, 0 , sizeof(struct ubifs_budget_req));
+ err = ubifs_budget_inode_op(c, inode, &req);
+ if (err)
+ goto out;
+
+ /*
+ * The IMMUTABLE and APPEND_ONLY flags can only be changed by
+ * the relevant capability.
+ */
+ oldflags = ubifs2ioctl(ui->flags);
+ if ((flags ^ oldflags) & (FS_APPEND_FL | FS_IMMUTABLE_FL)) {
+ if (!capable(CAP_LINUX_IMMUTABLE)) {
+ err = -EPERM;
+ goto out_budg;
+ }
+ }
+
+ ui->flags = ioctl2ubifs(flags);
+ ubifs_set_inode_flags(inode);
+
+ inode->i_ctime = CURRENT_TIME_SEC;
+ mark_inode_dirty_sync(inode);
+
+ ubifs_release_ino_dirty(c, inode, &req);
+
+ if (IS_SYNC(inode))
+ err = write_inode_now(inode, 1);
+
+ mutex_unlock(&inode->i_mutex);
+ return err;
+
+out_budg:
+ ubifs_cancel_ino_op(c, inode, &req);
+out:
+ ubifs_err("can't modify inode %lu attributes", inode->i_ino);
+ mutex_unlock(&inode->i_mutex);
+ return err;
+}
+
+int ubifs_ioctl(struct inode *inode, struct file *filp, unsigned int cmd,
+ unsigned long arg)
+{
+ int flags;
+
+ switch (cmd) {
+ case FS_IOC_GETFLAGS:
+ flags = ubifs2ioctl(ubifs_inode(inode)->flags);
+
+ return put_user(flags, (int __user *) arg);
+
+ case FS_IOC_SETFLAGS: {
+ if (IS_RDONLY(inode))
+ return -EROFS;
+
+ if (!is_owner_or_cap(inode))
+ return -EACCES;
+
+ if (get_user(flags, (int __user *) arg))
+ return -EFAULT;
+
+ if (!S_ISDIR(inode->i_mode))
+ flags &= ~FS_DIRSYNC_FL;
+
+ return setflags(inode, flags);
+ }
+
+ default:
+ return -ENOTTY;
+ }
+}
+
+#ifdef CONFIG_COMPAT
+long ubifs_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
+{
+ struct inode *inode = file->f_path.dentry->d_inode;
+ int err;
+
+ switch (cmd) {
+ case FS_IOC32_GETFLAGS:
+ cmd = FS_IOC_GETFLAGS;
+ break;
+ case FS_IOC32_SETFLAGS:
+ cmd = FS_IOC_SETFLAGS;
+ break;
+ default:
+ return -ENOIOCTLCMD;
+ }
+
+ lock_kernel();
+ err = ubifs_ioctl(inode, file, cmd, (unsigned long)compat_ptr(arg));
+ unlock_kernel();
+
+ return err;
+}
+#endif
--
1.5.4.1
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