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authorAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
committerAndré Fabian Silva Delgado <emulatorman@parabola.nu>2015-08-05 17:04:01 -0300
commit57f0f512b273f60d52568b8c6b77e17f5636edc0 (patch)
tree5e910f0e82173f4ef4f51111366a3f1299037a7b /fs/ubifs/journal.c
Initial import
Diffstat (limited to 'fs/ubifs/journal.c')
-rw-r--r--fs/ubifs/journal.c1466
1 files changed, 1466 insertions, 0 deletions
diff --git a/fs/ubifs/journal.c b/fs/ubifs/journal.c
new file mode 100644
index 000000000..0b9da5b6e
--- /dev/null
+++ b/fs/ubifs/journal.c
@@ -0,0 +1,1466 @@
+/*
+ * 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 UBIFS journal.
+ *
+ * The journal consists of 2 parts - the log and bud LEBs. The log has fixed
+ * length and position, while a bud logical eraseblock is any LEB in the main
+ * area. Buds contain file system data - data nodes, inode nodes, etc. The log
+ * contains only references to buds and some other stuff like commit
+ * start node. The idea is that when we commit the journal, we do
+ * not copy the data, the buds just become indexed. Since after the commit the
+ * nodes in bud eraseblocks become leaf nodes of the file system index tree, we
+ * use term "bud". Analogy is obvious, bud eraseblocks contain nodes which will
+ * become leafs in the future.
+ *
+ * The journal is multi-headed because we want to write data to the journal as
+ * optimally as possible. It is nice to have nodes belonging to the same inode
+ * in one LEB, so we may write data owned by different inodes to different
+ * journal heads, although at present only one data head is used.
+ *
+ * For recovery reasons, the base head contains all inode nodes, all directory
+ * entry nodes and all truncate nodes. This means that the other heads contain
+ * only data nodes.
+ *
+ * Bud LEBs may be half-indexed. For example, if the bud was not full at the
+ * time of commit, the bud is retained to continue to be used in the journal,
+ * even though the "front" of the LEB is now indexed. In that case, the log
+ * reference contains the offset where the bud starts for the purposes of the
+ * journal.
+ *
+ * The journal size has to be limited, because the larger is the journal, the
+ * longer it takes to mount UBIFS (scanning the journal) and the more memory it
+ * takes (indexing in the TNC).
+ *
+ * All the journal write operations like 'ubifs_jnl_update()' here, which write
+ * multiple UBIFS nodes to the journal at one go, are atomic with respect to
+ * unclean reboots. Should the unclean reboot happen, the recovery code drops
+ * all the nodes.
+ */
+
+#include "ubifs.h"
+
+/**
+ * zero_ino_node_unused - zero out unused fields of an on-flash inode node.
+ * @ino: the inode to zero out
+ */
+static inline void zero_ino_node_unused(struct ubifs_ino_node *ino)
+{
+ memset(ino->padding1, 0, 4);
+ memset(ino->padding2, 0, 26);
+}
+
+/**
+ * zero_dent_node_unused - zero out unused fields of an on-flash directory
+ * entry node.
+ * @dent: the directory entry to zero out
+ */
+static inline void zero_dent_node_unused(struct ubifs_dent_node *dent)
+{
+ dent->padding1 = 0;
+ memset(dent->padding2, 0, 4);
+}
+
+/**
+ * zero_data_node_unused - zero out unused fields of an on-flash data node.
+ * @data: the data node to zero out
+ */
+static inline void zero_data_node_unused(struct ubifs_data_node *data)
+{
+ memset(data->padding, 0, 2);
+}
+
+/**
+ * zero_trun_node_unused - zero out unused fields of an on-flash truncation
+ * node.
+ * @trun: the truncation node to zero out
+ */
+static inline void zero_trun_node_unused(struct ubifs_trun_node *trun)
+{
+ memset(trun->padding, 0, 12);
+}
+
+/**
+ * reserve_space - reserve space in the journal.
+ * @c: UBIFS file-system description object
+ * @jhead: journal head number
+ * @len: node length
+ *
+ * This function reserves space in journal head @head. If the reservation
+ * succeeded, the journal head stays locked and later has to be unlocked using
+ * 'release_head()'. 'write_node()' and 'write_head()' functions also unlock
+ * it. Returns zero in case of success, %-EAGAIN if commit has to be done, and
+ * other negative error codes in case of other failures.
+ */
+static int reserve_space(struct ubifs_info *c, int jhead, int len)
+{
+ int err = 0, err1, retries = 0, avail, lnum, offs, squeeze;
+ struct ubifs_wbuf *wbuf = &c->jheads[jhead].wbuf;
+
+ /*
+ * Typically, the base head has smaller nodes written to it, so it is
+ * better to try to allocate space at the ends of eraseblocks. This is
+ * what the squeeze parameter does.
+ */
+ ubifs_assert(!c->ro_media && !c->ro_mount);
+ squeeze = (jhead == BASEHD);
+again:
+ mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
+
+ if (c->ro_error) {
+ err = -EROFS;
+ goto out_unlock;
+ }
+
+ avail = c->leb_size - wbuf->offs - wbuf->used;
+ if (wbuf->lnum != -1 && avail >= len)
+ return 0;
+
+ /*
+ * Write buffer wasn't seek'ed or there is no enough space - look for an
+ * LEB with some empty space.
+ */
+ lnum = ubifs_find_free_space(c, len, &offs, squeeze);
+ if (lnum >= 0)
+ goto out;
+
+ err = lnum;
+ if (err != -ENOSPC)
+ goto out_unlock;
+
+ /*
+ * No free space, we have to run garbage collector to make
+ * some. But the write-buffer mutex has to be unlocked because
+ * GC also takes it.
+ */
+ dbg_jnl("no free space in jhead %s, run GC", dbg_jhead(jhead));
+ mutex_unlock(&wbuf->io_mutex);
+
+ lnum = ubifs_garbage_collect(c, 0);
+ if (lnum < 0) {
+ err = lnum;
+ if (err != -ENOSPC)
+ return err;
+
+ /*
+ * GC could not make a free LEB. But someone else may
+ * have allocated new bud for this journal head,
+ * because we dropped @wbuf->io_mutex, so try once
+ * again.
+ */
+ dbg_jnl("GC couldn't make a free LEB for jhead %s",
+ dbg_jhead(jhead));
+ if (retries++ < 2) {
+ dbg_jnl("retry (%d)", retries);
+ goto again;
+ }
+
+ dbg_jnl("return -ENOSPC");
+ return err;
+ }
+
+ mutex_lock_nested(&wbuf->io_mutex, wbuf->jhead);
+ dbg_jnl("got LEB %d for jhead %s", lnum, dbg_jhead(jhead));
+ avail = c->leb_size - wbuf->offs - wbuf->used;
+
+ if (wbuf->lnum != -1 && avail >= len) {
+ /*
+ * Someone else has switched the journal head and we have
+ * enough space now. This happens when more than one process is
+ * trying to write to the same journal head at the same time.
+ */
+ dbg_jnl("return LEB %d back, already have LEB %d:%d",
+ lnum, wbuf->lnum, wbuf->offs + wbuf->used);
+ err = ubifs_return_leb(c, lnum);
+ if (err)
+ goto out_unlock;
+ return 0;
+ }
+
+ offs = 0;
+
+out:
+ /*
+ * Make sure we synchronize the write-buffer before we add the new bud
+ * to the log. Otherwise we may have a power cut after the log
+ * reference node for the last bud (@lnum) is written but before the
+ * write-buffer data are written to the next-to-last bud
+ * (@wbuf->lnum). And the effect would be that the recovery would see
+ * that there is corruption in the next-to-last bud.
+ */
+ err = ubifs_wbuf_sync_nolock(wbuf);
+ if (err)
+ goto out_return;
+ err = ubifs_add_bud_to_log(c, jhead, lnum, offs);
+ if (err)
+ goto out_return;
+ err = ubifs_wbuf_seek_nolock(wbuf, lnum, offs);
+ if (err)
+ goto out_unlock;
+
+ return 0;
+
+out_unlock:
+ mutex_unlock(&wbuf->io_mutex);
+ return err;
+
+out_return:
+ /* An error occurred and the LEB has to be returned to lprops */
+ ubifs_assert(err < 0);
+ err1 = ubifs_return_leb(c, lnum);
+ if (err1 && err == -EAGAIN)
+ /*
+ * Return original error code only if it is not %-EAGAIN,
+ * which is not really an error. Otherwise, return the error
+ * code of 'ubifs_return_leb()'.
+ */
+ err = err1;
+ mutex_unlock(&wbuf->io_mutex);
+ return err;
+}
+
+/**
+ * write_node - write node to a journal head.
+ * @c: UBIFS file-system description object
+ * @jhead: journal head
+ * @node: node to write
+ * @len: node length
+ * @lnum: LEB number written is returned here
+ * @offs: offset written is returned here
+ *
+ * This function writes a node to reserved space of journal head @jhead.
+ * Returns zero in case of success and a negative error code in case of
+ * failure.
+ */
+static int write_node(struct ubifs_info *c, int jhead, void *node, int len,
+ int *lnum, int *offs)
+{
+ struct ubifs_wbuf *wbuf = &c->jheads[jhead].wbuf;
+
+ ubifs_assert(jhead != GCHD);
+
+ *lnum = c->jheads[jhead].wbuf.lnum;
+ *offs = c->jheads[jhead].wbuf.offs + c->jheads[jhead].wbuf.used;
+
+ dbg_jnl("jhead %s, LEB %d:%d, len %d",
+ dbg_jhead(jhead), *lnum, *offs, len);
+ ubifs_prepare_node(c, node, len, 0);
+
+ return ubifs_wbuf_write_nolock(wbuf, node, len);
+}
+
+/**
+ * write_head - write data to a journal head.
+ * @c: UBIFS file-system description object
+ * @jhead: journal head
+ * @buf: buffer to write
+ * @len: length to write
+ * @lnum: LEB number written is returned here
+ * @offs: offset written is returned here
+ * @sync: non-zero if the write-buffer has to by synchronized
+ *
+ * This function is the same as 'write_node()' but it does not assume the
+ * buffer it is writing is a node, so it does not prepare it (which means
+ * initializing common header and calculating CRC).
+ */
+static int write_head(struct ubifs_info *c, int jhead, void *buf, int len,
+ int *lnum, int *offs, int sync)
+{
+ int err;
+ struct ubifs_wbuf *wbuf = &c->jheads[jhead].wbuf;
+
+ ubifs_assert(jhead != GCHD);
+
+ *lnum = c->jheads[jhead].wbuf.lnum;
+ *offs = c->jheads[jhead].wbuf.offs + c->jheads[jhead].wbuf.used;
+ dbg_jnl("jhead %s, LEB %d:%d, len %d",
+ dbg_jhead(jhead), *lnum, *offs, len);
+
+ err = ubifs_wbuf_write_nolock(wbuf, buf, len);
+ if (err)
+ return err;
+ if (sync)
+ err = ubifs_wbuf_sync_nolock(wbuf);
+ return err;
+}
+
+/**
+ * make_reservation - reserve journal space.
+ * @c: UBIFS file-system description object
+ * @jhead: journal head
+ * @len: how many bytes to reserve
+ *
+ * This function makes space reservation in journal head @jhead. The function
+ * takes the commit lock and locks the journal head, and the caller has to
+ * unlock the head and finish the reservation with 'finish_reservation()'.
+ * Returns zero in case of success and a negative error code in case of
+ * failure.
+ *
+ * Note, the journal head may be unlocked as soon as the data is written, while
+ * the commit lock has to be released after the data has been added to the
+ * TNC.
+ */
+static int make_reservation(struct ubifs_info *c, int jhead, int len)
+{
+ int err, cmt_retries = 0, nospc_retries = 0;
+
+again:
+ down_read(&c->commit_sem);
+ err = reserve_space(c, jhead, len);
+ if (!err)
+ return 0;
+ up_read(&c->commit_sem);
+
+ if (err == -ENOSPC) {
+ /*
+ * GC could not make any progress. We should try to commit
+ * once because it could make some dirty space and GC would
+ * make progress, so make the error -EAGAIN so that the below
+ * will commit and re-try.
+ */
+ if (nospc_retries++ < 2) {
+ dbg_jnl("no space, retry");
+ err = -EAGAIN;
+ }
+
+ /*
+ * This means that the budgeting is incorrect. We always have
+ * to be able to write to the media, because all operations are
+ * budgeted. Deletions are not budgeted, though, but we reserve
+ * an extra LEB for them.
+ */
+ }
+
+ if (err != -EAGAIN)
+ goto out;
+
+ /*
+ * -EAGAIN means that the journal is full or too large, or the above
+ * code wants to do one commit. Do this and re-try.
+ */
+ if (cmt_retries > 128) {
+ /*
+ * This should not happen unless the journal size limitations
+ * are too tough.
+ */
+ ubifs_err(c, "stuck in space allocation");
+ err = -ENOSPC;
+ goto out;
+ } else if (cmt_retries > 32)
+ ubifs_warn(c, "too many space allocation re-tries (%d)",
+ cmt_retries);
+
+ dbg_jnl("-EAGAIN, commit and retry (retried %d times)",
+ cmt_retries);
+ cmt_retries += 1;
+
+ err = ubifs_run_commit(c);
+ if (err)
+ return err;
+ goto again;
+
+out:
+ ubifs_err(c, "cannot reserve %d bytes in jhead %d, error %d",
+ len, jhead, err);
+ if (err == -ENOSPC) {
+ /* This are some budgeting problems, print useful information */
+ down_write(&c->commit_sem);
+ dump_stack();
+ ubifs_dump_budg(c, &c->bi);
+ ubifs_dump_lprops(c);
+ cmt_retries = dbg_check_lprops(c);
+ up_write(&c->commit_sem);
+ }
+ return err;
+}
+
+/**
+ * release_head - release a journal head.
+ * @c: UBIFS file-system description object
+ * @jhead: journal head
+ *
+ * This function releases journal head @jhead which was locked by
+ * the 'make_reservation()' function. It has to be called after each successful
+ * 'make_reservation()' invocation.
+ */
+static inline void release_head(struct ubifs_info *c, int jhead)
+{
+ mutex_unlock(&c->jheads[jhead].wbuf.io_mutex);
+}
+
+/**
+ * finish_reservation - finish a reservation.
+ * @c: UBIFS file-system description object
+ *
+ * This function finishes journal space reservation. It must be called after
+ * 'make_reservation()'.
+ */
+static void finish_reservation(struct ubifs_info *c)
+{
+ up_read(&c->commit_sem);
+}
+
+/**
+ * get_dent_type - translate VFS inode mode to UBIFS directory entry type.
+ * @mode: inode mode
+ */
+static int get_dent_type(int mode)
+{
+ switch (mode & S_IFMT) {
+ case S_IFREG:
+ return UBIFS_ITYPE_REG;
+ case S_IFDIR:
+ return UBIFS_ITYPE_DIR;
+ case S_IFLNK:
+ return UBIFS_ITYPE_LNK;
+ case S_IFBLK:
+ return UBIFS_ITYPE_BLK;
+ case S_IFCHR:
+ return UBIFS_ITYPE_CHR;
+ case S_IFIFO:
+ return UBIFS_ITYPE_FIFO;
+ case S_IFSOCK:
+ return UBIFS_ITYPE_SOCK;
+ default:
+ BUG();
+ }
+ return 0;
+}
+
+/**
+ * pack_inode - pack an inode node.
+ * @c: UBIFS file-system description object
+ * @ino: buffer in which to pack inode node
+ * @inode: inode to pack
+ * @last: indicates the last node of the group
+ */
+static void pack_inode(struct ubifs_info *c, struct ubifs_ino_node *ino,
+ const struct inode *inode, int last)
+{
+ int data_len = 0, last_reference = !inode->i_nlink;
+ struct ubifs_inode *ui = ubifs_inode(inode);
+
+ ino->ch.node_type = UBIFS_INO_NODE;
+ ino_key_init_flash(c, &ino->key, inode->i_ino);
+ ino->creat_sqnum = cpu_to_le64(ui->creat_sqnum);
+ ino->atime_sec = cpu_to_le64(inode->i_atime.tv_sec);
+ ino->atime_nsec = cpu_to_le32(inode->i_atime.tv_nsec);
+ ino->ctime_sec = cpu_to_le64(inode->i_ctime.tv_sec);
+ ino->ctime_nsec = cpu_to_le32(inode->i_ctime.tv_nsec);
+ ino->mtime_sec = cpu_to_le64(inode->i_mtime.tv_sec);
+ ino->mtime_nsec = cpu_to_le32(inode->i_mtime.tv_nsec);
+ ino->uid = cpu_to_le32(i_uid_read(inode));
+ ino->gid = cpu_to_le32(i_gid_read(inode));
+ ino->mode = cpu_to_le32(inode->i_mode);
+ ino->flags = cpu_to_le32(ui->flags);
+ ino->size = cpu_to_le64(ui->ui_size);
+ ino->nlink = cpu_to_le32(inode->i_nlink);
+ ino->compr_type = cpu_to_le16(ui->compr_type);
+ ino->data_len = cpu_to_le32(ui->data_len);
+ ino->xattr_cnt = cpu_to_le32(ui->xattr_cnt);
+ ino->xattr_size = cpu_to_le32(ui->xattr_size);
+ ino->xattr_names = cpu_to_le32(ui->xattr_names);
+ zero_ino_node_unused(ino);
+
+ /*
+ * Drop the attached data if this is a deletion inode, the data is not
+ * needed anymore.
+ */
+ if (!last_reference) {
+ memcpy(ino->data, ui->data, ui->data_len);
+ data_len = ui->data_len;
+ }
+
+ ubifs_prep_grp_node(c, ino, UBIFS_INO_NODE_SZ + data_len, last);
+}
+
+/**
+ * mark_inode_clean - mark UBIFS inode as clean.
+ * @c: UBIFS file-system description object
+ * @ui: UBIFS inode to mark as clean
+ *
+ * This helper function marks UBIFS inode @ui as clean by cleaning the
+ * @ui->dirty flag and releasing its budget. Note, VFS may still treat the
+ * inode as dirty and try to write it back, but 'ubifs_write_inode()' would
+ * just do nothing.
+ */
+static void mark_inode_clean(struct ubifs_info *c, struct ubifs_inode *ui)
+{
+ if (ui->dirty)
+ ubifs_release_dirty_inode_budget(c, ui);
+ ui->dirty = 0;
+}
+
+/**
+ * ubifs_jnl_update - update inode.
+ * @c: UBIFS file-system description object
+ * @dir: parent inode or host inode in case of extended attributes
+ * @nm: directory entry name
+ * @inode: inode to update
+ * @deletion: indicates a directory entry deletion i.e unlink or rmdir
+ * @xent: non-zero if the directory entry is an extended attribute entry
+ *
+ * This function updates an inode by writing a directory entry (or extended
+ * attribute entry), the inode itself, and the parent directory inode (or the
+ * host inode) to the journal.
+ *
+ * The function writes the host inode @dir last, which is important in case of
+ * extended attributes. Indeed, then we guarantee that if the host inode gets
+ * synchronized (with 'fsync()'), and the write-buffer it sits in gets flushed,
+ * the extended attribute inode gets flushed too. And this is exactly what the
+ * user expects - synchronizing the host inode synchronizes its extended
+ * attributes. Similarly, this guarantees that if @dir is synchronized, its
+ * directory entry corresponding to @nm gets synchronized too.
+ *
+ * If the inode (@inode) or the parent directory (@dir) are synchronous, this
+ * function synchronizes the write-buffer.
+ *
+ * This function marks the @dir and @inode inodes as clean and returns zero on
+ * success. In case of failure, a negative error code is returned.
+ */
+int ubifs_jnl_update(struct ubifs_info *c, const struct inode *dir,
+ const struct qstr *nm, const struct inode *inode,
+ int deletion, int xent)
+{
+ int err, dlen, ilen, len, lnum, ino_offs, dent_offs;
+ int aligned_dlen, aligned_ilen, sync = IS_DIRSYNC(dir);
+ int last_reference = !!(deletion && inode->i_nlink == 0);
+ struct ubifs_inode *ui = ubifs_inode(inode);
+ struct ubifs_inode *host_ui = ubifs_inode(dir);
+ struct ubifs_dent_node *dent;
+ struct ubifs_ino_node *ino;
+ union ubifs_key dent_key, ino_key;
+
+ dbg_jnl("ino %lu, dent '%.*s', data len %d in dir ino %lu",
+ inode->i_ino, nm->len, nm->name, ui->data_len, dir->i_ino);
+ ubifs_assert(mutex_is_locked(&host_ui->ui_mutex));
+
+ dlen = UBIFS_DENT_NODE_SZ + nm->len + 1;
+ ilen = UBIFS_INO_NODE_SZ;
+
+ /*
+ * If the last reference to the inode is being deleted, then there is
+ * no need to attach and write inode data, it is being deleted anyway.
+ * And if the inode is being deleted, no need to synchronize
+ * write-buffer even if the inode is synchronous.
+ */
+ if (!last_reference) {
+ ilen += ui->data_len;
+ sync |= IS_SYNC(inode);
+ }
+
+ aligned_dlen = ALIGN(dlen, 8);
+ aligned_ilen = ALIGN(ilen, 8);
+
+ len = aligned_dlen + aligned_ilen + UBIFS_INO_NODE_SZ;
+ /* Make sure to also account for extended attributes */
+ len += host_ui->data_len;
+
+ dent = kmalloc(len, GFP_NOFS);
+ if (!dent)
+ return -ENOMEM;
+
+ /* Make reservation before allocating sequence numbers */
+ err = make_reservation(c, BASEHD, len);
+ if (err)
+ goto out_free;
+
+ if (!xent) {
+ dent->ch.node_type = UBIFS_DENT_NODE;
+ dent_key_init(c, &dent_key, dir->i_ino, nm);
+ } else {
+ dent->ch.node_type = UBIFS_XENT_NODE;
+ xent_key_init(c, &dent_key, dir->i_ino, nm);
+ }
+
+ key_write(c, &dent_key, dent->key);
+ dent->inum = deletion ? 0 : cpu_to_le64(inode->i_ino);
+ dent->type = get_dent_type(inode->i_mode);
+ dent->nlen = cpu_to_le16(nm->len);
+ memcpy(dent->name, nm->name, nm->len);
+ dent->name[nm->len] = '\0';
+ zero_dent_node_unused(dent);
+ ubifs_prep_grp_node(c, dent, dlen, 0);
+
+ ino = (void *)dent + aligned_dlen;
+ pack_inode(c, ino, inode, 0);
+ ino = (void *)ino + aligned_ilen;
+ pack_inode(c, ino, dir, 1);
+
+ if (last_reference) {
+ err = ubifs_add_orphan(c, inode->i_ino);
+ if (err) {
+ release_head(c, BASEHD);
+ goto out_finish;
+ }
+ ui->del_cmtno = c->cmt_no;
+ }
+
+ err = write_head(c, BASEHD, dent, len, &lnum, &dent_offs, sync);
+ if (err)
+ goto out_release;
+ if (!sync) {
+ struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf;
+
+ ubifs_wbuf_add_ino_nolock(wbuf, inode->i_ino);
+ ubifs_wbuf_add_ino_nolock(wbuf, dir->i_ino);
+ }
+ release_head(c, BASEHD);
+ kfree(dent);
+
+ if (deletion) {
+ err = ubifs_tnc_remove_nm(c, &dent_key, nm);
+ if (err)
+ goto out_ro;
+ err = ubifs_add_dirt(c, lnum, dlen);
+ } else
+ err = ubifs_tnc_add_nm(c, &dent_key, lnum, dent_offs, dlen, nm);
+ if (err)
+ goto out_ro;
+
+ /*
+ * Note, we do not remove the inode from TNC even if the last reference
+ * to it has just been deleted, because the inode may still be opened.
+ * Instead, the inode has been added to orphan lists and the orphan
+ * subsystem will take further care about it.
+ */
+ ino_key_init(c, &ino_key, inode->i_ino);
+ ino_offs = dent_offs + aligned_dlen;
+ err = ubifs_tnc_add(c, &ino_key, lnum, ino_offs, ilen);
+ if (err)
+ goto out_ro;
+
+ ino_key_init(c, &ino_key, dir->i_ino);
+ ino_offs += aligned_ilen;
+ err = ubifs_tnc_add(c, &ino_key, lnum, ino_offs,
+ UBIFS_INO_NODE_SZ + host_ui->data_len);
+ if (err)
+ goto out_ro;
+
+ finish_reservation(c);
+ spin_lock(&ui->ui_lock);
+ ui->synced_i_size = ui->ui_size;
+ spin_unlock(&ui->ui_lock);
+ mark_inode_clean(c, ui);
+ mark_inode_clean(c, host_ui);
+ return 0;
+
+out_finish:
+ finish_reservation(c);
+out_free:
+ kfree(dent);
+ return err;
+
+out_release:
+ release_head(c, BASEHD);
+ kfree(dent);
+out_ro:
+ ubifs_ro_mode(c, err);
+ if (last_reference)
+ ubifs_delete_orphan(c, inode->i_ino);
+ finish_reservation(c);
+ return err;
+}
+
+/**
+ * ubifs_jnl_write_data - write a data node to the journal.
+ * @c: UBIFS file-system description object
+ * @inode: inode the data node belongs to
+ * @key: node key
+ * @buf: buffer to write
+ * @len: data length (must not exceed %UBIFS_BLOCK_SIZE)
+ *
+ * This function writes a data node to the journal. Returns %0 if the data node
+ * was successfully written, and a negative error code in case of failure.
+ */
+int ubifs_jnl_write_data(struct ubifs_info *c, const struct inode *inode,
+ const union ubifs_key *key, const void *buf, int len)
+{
+ struct ubifs_data_node *data;
+ int err, lnum, offs, compr_type, out_len;
+ int dlen = COMPRESSED_DATA_NODE_BUF_SZ, allocated = 1;
+ struct ubifs_inode *ui = ubifs_inode(inode);
+
+ dbg_jnlk(key, "ino %lu, blk %u, len %d, key ",
+ (unsigned long)key_inum(c, key), key_block(c, key), len);
+ ubifs_assert(len <= UBIFS_BLOCK_SIZE);
+
+ data = kmalloc(dlen, GFP_NOFS | __GFP_NOWARN);
+ if (!data) {
+ /*
+ * Fall-back to the write reserve buffer. Note, we might be
+ * currently on the memory reclaim path, when the kernel is
+ * trying to free some memory by writing out dirty pages. The
+ * write reserve buffer helps us to guarantee that we are
+ * always able to write the data.
+ */
+ allocated = 0;
+ mutex_lock(&c->write_reserve_mutex);
+ data = c->write_reserve_buf;
+ }
+
+ data->ch.node_type = UBIFS_DATA_NODE;
+ key_write(c, key, &data->key);
+ data->size = cpu_to_le32(len);
+ zero_data_node_unused(data);
+
+ if (!(ui->flags & UBIFS_COMPR_FL))
+ /* Compression is disabled for this inode */
+ compr_type = UBIFS_COMPR_NONE;
+ else
+ compr_type = ui->compr_type;
+
+ out_len = dlen - UBIFS_DATA_NODE_SZ;
+ ubifs_compress(c, buf, len, &data->data, &out_len, &compr_type);
+ ubifs_assert(out_len <= UBIFS_BLOCK_SIZE);
+
+ dlen = UBIFS_DATA_NODE_SZ + out_len;
+ data->compr_type = cpu_to_le16(compr_type);
+
+ /* Make reservation before allocating sequence numbers */
+ err = make_reservation(c, DATAHD, dlen);
+ if (err)
+ goto out_free;
+
+ err = write_node(c, DATAHD, data, dlen, &lnum, &offs);
+ if (err)
+ goto out_release;
+ ubifs_wbuf_add_ino_nolock(&c->jheads[DATAHD].wbuf, key_inum(c, key));
+ release_head(c, DATAHD);
+
+ err = ubifs_tnc_add(c, key, lnum, offs, dlen);
+ if (err)
+ goto out_ro;
+
+ finish_reservation(c);
+ if (!allocated)
+ mutex_unlock(&c->write_reserve_mutex);
+ else
+ kfree(data);
+ return 0;
+
+out_release:
+ release_head(c, DATAHD);
+out_ro:
+ ubifs_ro_mode(c, err);
+ finish_reservation(c);
+out_free:
+ if (!allocated)
+ mutex_unlock(&c->write_reserve_mutex);
+ else
+ kfree(data);
+ return err;
+}
+
+/**
+ * ubifs_jnl_write_inode - flush inode to the journal.
+ * @c: UBIFS file-system description object
+ * @inode: inode to flush
+ *
+ * This function writes inode @inode to the journal. If the inode is
+ * synchronous, it also synchronizes the write-buffer. Returns zero in case of
+ * success and a negative error code in case of failure.
+ */
+int ubifs_jnl_write_inode(struct ubifs_info *c, const struct inode *inode)
+{
+ int err, lnum, offs;
+ struct ubifs_ino_node *ino;
+ struct ubifs_inode *ui = ubifs_inode(inode);
+ int sync = 0, len = UBIFS_INO_NODE_SZ, last_reference = !inode->i_nlink;
+
+ dbg_jnl("ino %lu, nlink %u", inode->i_ino, inode->i_nlink);
+
+ /*
+ * If the inode is being deleted, do not write the attached data. No
+ * need to synchronize the write-buffer either.
+ */
+ if (!last_reference) {
+ len += ui->data_len;
+ sync = IS_SYNC(inode);
+ }
+ ino = kmalloc(len, GFP_NOFS);
+ if (!ino)
+ return -ENOMEM;
+
+ /* Make reservation before allocating sequence numbers */
+ err = make_reservation(c, BASEHD, len);
+ if (err)
+ goto out_free;
+
+ pack_inode(c, ino, inode, 1);
+ err = write_head(c, BASEHD, ino, len, &lnum, &offs, sync);
+ if (err)
+ goto out_release;
+ if (!sync)
+ ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf,
+ inode->i_ino);
+ release_head(c, BASEHD);
+
+ if (last_reference) {
+ err = ubifs_tnc_remove_ino(c, inode->i_ino);
+ if (err)
+ goto out_ro;
+ ubifs_delete_orphan(c, inode->i_ino);
+ err = ubifs_add_dirt(c, lnum, len);
+ } else {
+ union ubifs_key key;
+
+ ino_key_init(c, &key, inode->i_ino);
+ err = ubifs_tnc_add(c, &key, lnum, offs, len);
+ }
+ if (err)
+ goto out_ro;
+
+ finish_reservation(c);
+ spin_lock(&ui->ui_lock);
+ ui->synced_i_size = ui->ui_size;
+ spin_unlock(&ui->ui_lock);
+ kfree(ino);
+ return 0;
+
+out_release:
+ release_head(c, BASEHD);
+out_ro:
+ ubifs_ro_mode(c, err);
+ finish_reservation(c);
+out_free:
+ kfree(ino);
+ return err;
+}
+
+/**
+ * ubifs_jnl_delete_inode - delete an inode.
+ * @c: UBIFS file-system description object
+ * @inode: inode to delete
+ *
+ * This function deletes inode @inode which includes removing it from orphans,
+ * deleting it from TNC and, in some cases, writing a deletion inode to the
+ * journal.
+ *
+ * When regular file inodes are unlinked or a directory inode is removed, the
+ * 'ubifs_jnl_update()' function writes a corresponding deletion inode and
+ * direntry to the media, and adds the inode to orphans. After this, when the
+ * last reference to this inode has been dropped, this function is called. In
+ * general, it has to write one more deletion inode to the media, because if
+ * a commit happened between 'ubifs_jnl_update()' and
+ * 'ubifs_jnl_delete_inode()', the deletion inode is not in the journal
+ * anymore, and in fact it might not be on the flash anymore, because it might
+ * have been garbage-collected already. And for optimization reasons UBIFS does
+ * not read the orphan area if it has been unmounted cleanly, so it would have
+ * no indication in the journal that there is a deleted inode which has to be
+ * removed from TNC.
+ *
+ * However, if there was no commit between 'ubifs_jnl_update()' and
+ * 'ubifs_jnl_delete_inode()', then there is no need to write the deletion
+ * inode to the media for the second time. And this is quite a typical case.
+ *
+ * This function returns zero in case of success and a negative error code in
+ * case of failure.
+ */
+int ubifs_jnl_delete_inode(struct ubifs_info *c, const struct inode *inode)
+{
+ int err;
+ struct ubifs_inode *ui = ubifs_inode(inode);
+
+ ubifs_assert(inode->i_nlink == 0);
+
+ if (ui->del_cmtno != c->cmt_no)
+ /* A commit happened for sure */
+ return ubifs_jnl_write_inode(c, inode);
+
+ down_read(&c->commit_sem);
+ /*
+ * Check commit number again, because the first test has been done
+ * without @c->commit_sem, so a commit might have happened.
+ */
+ if (ui->del_cmtno != c->cmt_no) {
+ up_read(&c->commit_sem);
+ return ubifs_jnl_write_inode(c, inode);
+ }
+
+ err = ubifs_tnc_remove_ino(c, inode->i_ino);
+ if (err)
+ ubifs_ro_mode(c, err);
+ else
+ ubifs_delete_orphan(c, inode->i_ino);
+ up_read(&c->commit_sem);
+ return err;
+}
+
+/**
+ * ubifs_jnl_rename - rename a directory entry.
+ * @c: UBIFS file-system description object
+ * @old_dir: parent inode of directory entry to rename
+ * @old_dentry: directory entry to rename
+ * @new_dir: parent inode of directory entry to rename
+ * @new_dentry: new directory entry (or directory entry to replace)
+ * @sync: non-zero if the write-buffer has to be synchronized
+ *
+ * This function implements the re-name operation which may involve writing up
+ * to 3 inodes and 2 directory entries. It marks the written inodes as clean
+ * and returns zero on success. In case of failure, a negative error code is
+ * returned.
+ */
+int ubifs_jnl_rename(struct ubifs_info *c, const struct inode *old_dir,
+ const struct dentry *old_dentry,
+ const struct inode *new_dir,
+ const struct dentry *new_dentry, int sync)
+{
+ void *p;
+ union ubifs_key key;
+ struct ubifs_dent_node *dent, *dent2;
+ int err, dlen1, dlen2, ilen, lnum, offs, len;
+ const struct inode *old_inode = d_inode(old_dentry);
+ const struct inode *new_inode = d_inode(new_dentry);
+ int aligned_dlen1, aligned_dlen2, plen = UBIFS_INO_NODE_SZ;
+ int last_reference = !!(new_inode && new_inode->i_nlink == 0);
+ int move = (old_dir != new_dir);
+ struct ubifs_inode *uninitialized_var(new_ui);
+
+ dbg_jnl("dent '%pd' in dir ino %lu to dent '%pd' in dir ino %lu",
+ old_dentry, old_dir->i_ino, new_dentry, new_dir->i_ino);
+ ubifs_assert(ubifs_inode(old_dir)->data_len == 0);
+ ubifs_assert(ubifs_inode(new_dir)->data_len == 0);
+ ubifs_assert(mutex_is_locked(&ubifs_inode(old_dir)->ui_mutex));
+ ubifs_assert(mutex_is_locked(&ubifs_inode(new_dir)->ui_mutex));
+
+ dlen1 = UBIFS_DENT_NODE_SZ + new_dentry->d_name.len + 1;
+ dlen2 = UBIFS_DENT_NODE_SZ + old_dentry->d_name.len + 1;
+ if (new_inode) {
+ new_ui = ubifs_inode(new_inode);
+ ubifs_assert(mutex_is_locked(&new_ui->ui_mutex));
+ ilen = UBIFS_INO_NODE_SZ;
+ if (!last_reference)
+ ilen += new_ui->data_len;
+ } else
+ ilen = 0;
+
+ aligned_dlen1 = ALIGN(dlen1, 8);
+ aligned_dlen2 = ALIGN(dlen2, 8);
+ len = aligned_dlen1 + aligned_dlen2 + ALIGN(ilen, 8) + ALIGN(plen, 8);
+ if (old_dir != new_dir)
+ len += plen;
+ dent = kmalloc(len, GFP_NOFS);
+ if (!dent)
+ return -ENOMEM;
+
+ /* Make reservation before allocating sequence numbers */
+ err = make_reservation(c, BASEHD, len);
+ if (err)
+ goto out_free;
+
+ /* Make new dent */
+ dent->ch.node_type = UBIFS_DENT_NODE;
+ dent_key_init_flash(c, &dent->key, new_dir->i_ino, &new_dentry->d_name);
+ dent->inum = cpu_to_le64(old_inode->i_ino);
+ dent->type = get_dent_type(old_inode->i_mode);
+ dent->nlen = cpu_to_le16(new_dentry->d_name.len);
+ memcpy(dent->name, new_dentry->d_name.name, new_dentry->d_name.len);
+ dent->name[new_dentry->d_name.len] = '\0';
+ zero_dent_node_unused(dent);
+ ubifs_prep_grp_node(c, dent, dlen1, 0);
+
+ /* Make deletion dent */
+ dent2 = (void *)dent + aligned_dlen1;
+ dent2->ch.node_type = UBIFS_DENT_NODE;
+ dent_key_init_flash(c, &dent2->key, old_dir->i_ino,
+ &old_dentry->d_name);
+ dent2->inum = 0;
+ dent2->type = DT_UNKNOWN;
+ dent2->nlen = cpu_to_le16(old_dentry->d_name.len);
+ memcpy(dent2->name, old_dentry->d_name.name, old_dentry->d_name.len);
+ dent2->name[old_dentry->d_name.len] = '\0';
+ zero_dent_node_unused(dent2);
+ ubifs_prep_grp_node(c, dent2, dlen2, 0);
+
+ p = (void *)dent2 + aligned_dlen2;
+ if (new_inode) {
+ pack_inode(c, p, new_inode, 0);
+ p += ALIGN(ilen, 8);
+ }
+
+ if (!move)
+ pack_inode(c, p, old_dir, 1);
+ else {
+ pack_inode(c, p, old_dir, 0);
+ p += ALIGN(plen, 8);
+ pack_inode(c, p, new_dir, 1);
+ }
+
+ if (last_reference) {
+ err = ubifs_add_orphan(c, new_inode->i_ino);
+ if (err) {
+ release_head(c, BASEHD);
+ goto out_finish;
+ }
+ new_ui->del_cmtno = c->cmt_no;
+ }
+
+ err = write_head(c, BASEHD, dent, len, &lnum, &offs, sync);
+ if (err)
+ goto out_release;
+ if (!sync) {
+ struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf;
+
+ ubifs_wbuf_add_ino_nolock(wbuf, new_dir->i_ino);
+ ubifs_wbuf_add_ino_nolock(wbuf, old_dir->i_ino);
+ if (new_inode)
+ ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf,
+ new_inode->i_ino);
+ }
+ release_head(c, BASEHD);
+
+ dent_key_init(c, &key, new_dir->i_ino, &new_dentry->d_name);
+ err = ubifs_tnc_add_nm(c, &key, lnum, offs, dlen1, &new_dentry->d_name);
+ if (err)
+ goto out_ro;
+
+ err = ubifs_add_dirt(c, lnum, dlen2);
+ if (err)
+ goto out_ro;
+
+ dent_key_init(c, &key, old_dir->i_ino, &old_dentry->d_name);
+ err = ubifs_tnc_remove_nm(c, &key, &old_dentry->d_name);
+ if (err)
+ goto out_ro;
+
+ offs += aligned_dlen1 + aligned_dlen2;
+ if (new_inode) {
+ ino_key_init(c, &key, new_inode->i_ino);
+ err = ubifs_tnc_add(c, &key, lnum, offs, ilen);
+ if (err)
+ goto out_ro;
+ offs += ALIGN(ilen, 8);
+ }
+
+ ino_key_init(c, &key, old_dir->i_ino);
+ err = ubifs_tnc_add(c, &key, lnum, offs, plen);
+ if (err)
+ goto out_ro;
+
+ if (old_dir != new_dir) {
+ offs += ALIGN(plen, 8);
+ ino_key_init(c, &key, new_dir->i_ino);
+ err = ubifs_tnc_add(c, &key, lnum, offs, plen);
+ if (err)
+ goto out_ro;
+ }
+
+ finish_reservation(c);
+ if (new_inode) {
+ mark_inode_clean(c, new_ui);
+ spin_lock(&new_ui->ui_lock);
+ new_ui->synced_i_size = new_ui->ui_size;
+ spin_unlock(&new_ui->ui_lock);
+ }
+ mark_inode_clean(c, ubifs_inode(old_dir));
+ if (move)
+ mark_inode_clean(c, ubifs_inode(new_dir));
+ kfree(dent);
+ return 0;
+
+out_release:
+ release_head(c, BASEHD);
+out_ro:
+ ubifs_ro_mode(c, err);
+ if (last_reference)
+ ubifs_delete_orphan(c, new_inode->i_ino);
+out_finish:
+ finish_reservation(c);
+out_free:
+ kfree(dent);
+ return err;
+}
+
+/**
+ * recomp_data_node - re-compress a truncated data node.
+ * @dn: data node to re-compress
+ * @new_len: new length
+ *
+ * This function is used when an inode is truncated and the last data node of
+ * the inode has to be re-compressed and re-written.
+ */
+static int recomp_data_node(const struct ubifs_info *c,
+ struct ubifs_data_node *dn, int *new_len)
+{
+ void *buf;
+ int err, len, compr_type, out_len;
+
+ out_len = le32_to_cpu(dn->size);
+ buf = kmalloc(out_len * WORST_COMPR_FACTOR, GFP_NOFS);
+ if (!buf)
+ return -ENOMEM;
+
+ len = le32_to_cpu(dn->ch.len) - UBIFS_DATA_NODE_SZ;
+ compr_type = le16_to_cpu(dn->compr_type);
+ err = ubifs_decompress(c, &dn->data, len, buf, &out_len, compr_type);
+ if (err)
+ goto out;
+
+ ubifs_compress(c, buf, *new_len, &dn->data, &out_len, &compr_type);
+ ubifs_assert(out_len <= UBIFS_BLOCK_SIZE);
+ dn->compr_type = cpu_to_le16(compr_type);
+ dn->size = cpu_to_le32(*new_len);
+ *new_len = UBIFS_DATA_NODE_SZ + out_len;
+out:
+ kfree(buf);
+ return err;
+}
+
+/**
+ * ubifs_jnl_truncate - update the journal for a truncation.
+ * @c: UBIFS file-system description object
+ * @inode: inode to truncate
+ * @old_size: old size
+ * @new_size: new size
+ *
+ * When the size of a file decreases due to truncation, a truncation node is
+ * written, the journal tree is updated, and the last data block is re-written
+ * if it has been affected. The inode is also updated in order to synchronize
+ * the new inode size.
+ *
+ * This function marks the inode as clean and returns zero on success. In case
+ * of failure, a negative error code is returned.
+ */
+int ubifs_jnl_truncate(struct ubifs_info *c, const struct inode *inode,
+ loff_t old_size, loff_t new_size)
+{
+ union ubifs_key key, to_key;
+ struct ubifs_ino_node *ino;
+ struct ubifs_trun_node *trun;
+ struct ubifs_data_node *uninitialized_var(dn);
+ int err, dlen, len, lnum, offs, bit, sz, sync = IS_SYNC(inode);
+ struct ubifs_inode *ui = ubifs_inode(inode);
+ ino_t inum = inode->i_ino;
+ unsigned int blk;
+
+ dbg_jnl("ino %lu, size %lld -> %lld",
+ (unsigned long)inum, old_size, new_size);
+ ubifs_assert(!ui->data_len);
+ ubifs_assert(S_ISREG(inode->i_mode));
+ ubifs_assert(mutex_is_locked(&ui->ui_mutex));
+
+ sz = UBIFS_TRUN_NODE_SZ + UBIFS_INO_NODE_SZ +
+ UBIFS_MAX_DATA_NODE_SZ * WORST_COMPR_FACTOR;
+ ino = kmalloc(sz, GFP_NOFS);
+ if (!ino)
+ return -ENOMEM;
+
+ trun = (void *)ino + UBIFS_INO_NODE_SZ;
+ trun->ch.node_type = UBIFS_TRUN_NODE;
+ trun->inum = cpu_to_le32(inum);
+ trun->old_size = cpu_to_le64(old_size);
+ trun->new_size = cpu_to_le64(new_size);
+ zero_trun_node_unused(trun);
+
+ dlen = new_size & (UBIFS_BLOCK_SIZE - 1);
+ if (dlen) {
+ /* Get last data block so it can be truncated */
+ dn = (void *)trun + UBIFS_TRUN_NODE_SZ;
+ blk = new_size >> UBIFS_BLOCK_SHIFT;
+ data_key_init(c, &key, inum, blk);
+ dbg_jnlk(&key, "last block key ");
+ err = ubifs_tnc_lookup(c, &key, dn);
+ if (err == -ENOENT)
+ dlen = 0; /* Not found (so it is a hole) */
+ else if (err)
+ goto out_free;
+ else {
+ if (le32_to_cpu(dn->size) <= dlen)
+ dlen = 0; /* Nothing to do */
+ else {
+ int compr_type = le16_to_cpu(dn->compr_type);
+
+ if (compr_type != UBIFS_COMPR_NONE) {
+ err = recomp_data_node(c, dn, &dlen);
+ if (err)
+ goto out_free;
+ } else {
+ dn->size = cpu_to_le32(dlen);
+ dlen += UBIFS_DATA_NODE_SZ;
+ }
+ zero_data_node_unused(dn);
+ }
+ }
+ }
+
+ /* Must make reservation before allocating sequence numbers */
+ len = UBIFS_TRUN_NODE_SZ + UBIFS_INO_NODE_SZ;
+ if (dlen)
+ len += dlen;
+ err = make_reservation(c, BASEHD, len);
+ if (err)
+ goto out_free;
+
+ pack_inode(c, ino, inode, 0);
+ ubifs_prep_grp_node(c, trun, UBIFS_TRUN_NODE_SZ, dlen ? 0 : 1);
+ if (dlen)
+ ubifs_prep_grp_node(c, dn, dlen, 1);
+
+ err = write_head(c, BASEHD, ino, len, &lnum, &offs, sync);
+ if (err)
+ goto out_release;
+ if (!sync)
+ ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, inum);
+ release_head(c, BASEHD);
+
+ if (dlen) {
+ sz = offs + UBIFS_INO_NODE_SZ + UBIFS_TRUN_NODE_SZ;
+ err = ubifs_tnc_add(c, &key, lnum, sz, dlen);
+ if (err)
+ goto out_ro;
+ }
+
+ ino_key_init(c, &key, inum);
+ err = ubifs_tnc_add(c, &key, lnum, offs, UBIFS_INO_NODE_SZ);
+ if (err)
+ goto out_ro;
+
+ err = ubifs_add_dirt(c, lnum, UBIFS_TRUN_NODE_SZ);
+ if (err)
+ goto out_ro;
+
+ bit = new_size & (UBIFS_BLOCK_SIZE - 1);
+ blk = (new_size >> UBIFS_BLOCK_SHIFT) + (bit ? 1 : 0);
+ data_key_init(c, &key, inum, blk);
+
+ bit = old_size & (UBIFS_BLOCK_SIZE - 1);
+ blk = (old_size >> UBIFS_BLOCK_SHIFT) - (bit ? 0 : 1);
+ data_key_init(c, &to_key, inum, blk);
+
+ err = ubifs_tnc_remove_range(c, &key, &to_key);
+ if (err)
+ goto out_ro;
+
+ finish_reservation(c);
+ spin_lock(&ui->ui_lock);
+ ui->synced_i_size = ui->ui_size;
+ spin_unlock(&ui->ui_lock);
+ mark_inode_clean(c, ui);
+ kfree(ino);
+ return 0;
+
+out_release:
+ release_head(c, BASEHD);
+out_ro:
+ ubifs_ro_mode(c, err);
+ finish_reservation(c);
+out_free:
+ kfree(ino);
+ return err;
+}
+
+
+/**
+ * ubifs_jnl_delete_xattr - delete an extended attribute.
+ * @c: UBIFS file-system description object
+ * @host: host inode
+ * @inode: extended attribute inode
+ * @nm: extended attribute entry name
+ *
+ * This function delete an extended attribute which is very similar to
+ * un-linking regular files - it writes a deletion xentry, a deletion inode and
+ * updates the target inode. Returns zero in case of success and a negative
+ * error code in case of failure.
+ */
+int ubifs_jnl_delete_xattr(struct ubifs_info *c, const struct inode *host,
+ const struct inode *inode, const struct qstr *nm)
+{
+ int err, xlen, hlen, len, lnum, xent_offs, aligned_xlen;
+ struct ubifs_dent_node *xent;
+ struct ubifs_ino_node *ino;
+ union ubifs_key xent_key, key1, key2;
+ int sync = IS_DIRSYNC(host);
+ struct ubifs_inode *host_ui = ubifs_inode(host);
+
+ dbg_jnl("host %lu, xattr ino %lu, name '%s', data len %d",
+ host->i_ino, inode->i_ino, nm->name,
+ ubifs_inode(inode)->data_len);
+ ubifs_assert(inode->i_nlink == 0);
+ ubifs_assert(mutex_is_locked(&host_ui->ui_mutex));
+
+ /*
+ * Since we are deleting the inode, we do not bother to attach any data
+ * to it and assume its length is %UBIFS_INO_NODE_SZ.
+ */
+ xlen = UBIFS_DENT_NODE_SZ + nm->len + 1;
+ aligned_xlen = ALIGN(xlen, 8);
+ hlen = host_ui->data_len + UBIFS_INO_NODE_SZ;
+ len = aligned_xlen + UBIFS_INO_NODE_SZ + ALIGN(hlen, 8);
+
+ xent = kmalloc(len, GFP_NOFS);
+ if (!xent)
+ return -ENOMEM;
+
+ /* Make reservation before allocating sequence numbers */
+ err = make_reservation(c, BASEHD, len);
+ if (err) {
+ kfree(xent);
+ return err;
+ }
+
+ xent->ch.node_type = UBIFS_XENT_NODE;
+ xent_key_init(c, &xent_key, host->i_ino, nm);
+ key_write(c, &xent_key, xent->key);
+ xent->inum = 0;
+ xent->type = get_dent_type(inode->i_mode);
+ xent->nlen = cpu_to_le16(nm->len);
+ memcpy(xent->name, nm->name, nm->len);
+ xent->name[nm->len] = '\0';
+ zero_dent_node_unused(xent);
+ ubifs_prep_grp_node(c, xent, xlen, 0);
+
+ ino = (void *)xent + aligned_xlen;
+ pack_inode(c, ino, inode, 0);
+ ino = (void *)ino + UBIFS_INO_NODE_SZ;
+ pack_inode(c, ino, host, 1);
+
+ err = write_head(c, BASEHD, xent, len, &lnum, &xent_offs, sync);
+ if (!sync && !err)
+ ubifs_wbuf_add_ino_nolock(&c->jheads[BASEHD].wbuf, host->i_ino);
+ release_head(c, BASEHD);
+ kfree(xent);
+ if (err)
+ goto out_ro;
+
+ /* Remove the extended attribute entry from TNC */
+ err = ubifs_tnc_remove_nm(c, &xent_key, nm);
+ if (err)
+ goto out_ro;
+ err = ubifs_add_dirt(c, lnum, xlen);
+ if (err)
+ goto out_ro;
+
+ /*
+ * Remove all nodes belonging to the extended attribute inode from TNC.
+ * Well, there actually must be only one node - the inode itself.
+ */
+ lowest_ino_key(c, &key1, inode->i_ino);
+ highest_ino_key(c, &key2, inode->i_ino);
+ err = ubifs_tnc_remove_range(c, &key1, &key2);
+ if (err)
+ goto out_ro;
+ err = ubifs_add_dirt(c, lnum, UBIFS_INO_NODE_SZ);
+ if (err)
+ goto out_ro;
+
+ /* And update TNC with the new host inode position */
+ ino_key_init(c, &key1, host->i_ino);
+ err = ubifs_tnc_add(c, &key1, lnum, xent_offs + len - hlen, hlen);
+ if (err)
+ goto out_ro;
+
+ finish_reservation(c);
+ spin_lock(&host_ui->ui_lock);
+ host_ui->synced_i_size = host_ui->ui_size;
+ spin_unlock(&host_ui->ui_lock);
+ mark_inode_clean(c, host_ui);
+ return 0;
+
+out_ro:
+ ubifs_ro_mode(c, err);
+ finish_reservation(c);
+ return err;
+}
+
+/**
+ * ubifs_jnl_change_xattr - change an extended attribute.
+ * @c: UBIFS file-system description object
+ * @inode: extended attribute inode
+ * @host: host inode
+ *
+ * This function writes the updated version of an extended attribute inode and
+ * the host inode to the journal (to the base head). The host inode is written
+ * after the extended attribute inode in order to guarantee that the extended
+ * attribute will be flushed when the inode is synchronized by 'fsync()' and
+ * consequently, the write-buffer is synchronized. This function returns zero
+ * in case of success and a negative error code in case of failure.
+ */
+int ubifs_jnl_change_xattr(struct ubifs_info *c, const struct inode *inode,
+ const struct inode *host)
+{
+ int err, len1, len2, aligned_len, aligned_len1, lnum, offs;
+ struct ubifs_inode *host_ui = ubifs_inode(host);
+ struct ubifs_ino_node *ino;
+ union ubifs_key key;
+ int sync = IS_DIRSYNC(host);
+
+ dbg_jnl("ino %lu, ino %lu", host->i_ino, inode->i_ino);
+ ubifs_assert(host->i_nlink > 0);
+ ubifs_assert(inode->i_nlink > 0);
+ ubifs_assert(mutex_is_locked(&host_ui->ui_mutex));
+
+ len1 = UBIFS_INO_NODE_SZ + host_ui->data_len;
+ len2 = UBIFS_INO_NODE_SZ + ubifs_inode(inode)->data_len;
+ aligned_len1 = ALIGN(len1, 8);
+ aligned_len = aligned_len1 + ALIGN(len2, 8);
+
+ ino = kmalloc(aligned_len, GFP_NOFS);
+ if (!ino)
+ return -ENOMEM;
+
+ /* Make reservation before allocating sequence numbers */
+ err = make_reservation(c, BASEHD, aligned_len);
+ if (err)
+ goto out_free;
+
+ pack_inode(c, ino, host, 0);
+ pack_inode(c, (void *)ino + aligned_len1, inode, 1);
+
+ err = write_head(c, BASEHD, ino, aligned_len, &lnum, &offs, 0);
+ if (!sync && !err) {
+ struct ubifs_wbuf *wbuf = &c->jheads[BASEHD].wbuf;
+
+ ubifs_wbuf_add_ino_nolock(wbuf, host->i_ino);
+ ubifs_wbuf_add_ino_nolock(wbuf, inode->i_ino);
+ }
+ release_head(c, BASEHD);
+ if (err)
+ goto out_ro;
+
+ ino_key_init(c, &key, host->i_ino);
+ err = ubifs_tnc_add(c, &key, lnum, offs, len1);
+ if (err)
+ goto out_ro;
+
+ ino_key_init(c, &key, inode->i_ino);
+ err = ubifs_tnc_add(c, &key, lnum, offs + aligned_len1, len2);
+ if (err)
+ goto out_ro;
+
+ finish_reservation(c);
+ spin_lock(&host_ui->ui_lock);
+ host_ui->synced_i_size = host_ui->ui_size;
+ spin_unlock(&host_ui->ui_lock);
+ mark_inode_clean(c, host_ui);
+ kfree(ino);
+ return 0;
+
+out_ro:
+ ubifs_ro_mode(c, err);
+ finish_reservation(c);
+out_free:
+ kfree(ino);
+ return err;
+}
+