+++ /dev/null
-/*
- * linux/fs/ext3/inode.c
- *
- * Copyright (C) 1992, 1993, 1994, 1995
- * Remy Card (card@masi.ibp.fr)
- * Laboratoire MASI - Institut Blaise Pascal
- * Universite Pierre et Marie Curie (Paris VI)
- *
- * from
- *
- * linux/fs/minix/inode.c
- *
- * Copyright (C) 1991, 1992 Linus Torvalds
- *
- * Goal-directed block allocation by Stephen Tweedie
- * (sct@redhat.com), 1993, 1998
- * Big-endian to little-endian byte-swapping/bitmaps by
- * David S. Miller (davem@caip.rutgers.edu), 1995
- * 64-bit file support on 64-bit platforms by Jakub Jelinek
- * (jj@sunsite.ms.mff.cuni.cz)
- *
- * Assorted race fixes, rewrite of ext3_get_block() by Al Viro, 2000
- */
-
-#include <linux/highuid.h>
-#include <linux/quotaops.h>
-#include <linux/writeback.h>
-#include <linux/mpage.h>
-#include <linux/namei.h>
-#include <linux/uio.h>
-#include "ext3.h"
-#include "xattr.h"
-#include "acl.h"
-
-static int ext3_writepage_trans_blocks(struct inode *inode);
-static int ext3_block_truncate_page(struct inode *inode, loff_t from);
-
-/*
- * Test whether an inode is a fast symlink.
- */
-static int ext3_inode_is_fast_symlink(struct inode *inode)
-{
- int ea_blocks = EXT3_I(inode)->i_file_acl ?
- (inode->i_sb->s_blocksize >> 9) : 0;
-
- return (S_ISLNK(inode->i_mode) && inode->i_blocks - ea_blocks == 0);
-}
-
-/*
- * The ext3 forget function must perform a revoke if we are freeing data
- * which has been journaled. Metadata (eg. indirect blocks) must be
- * revoked in all cases.
- *
- * "bh" may be NULL: a metadata block may have been freed from memory
- * but there may still be a record of it in the journal, and that record
- * still needs to be revoked.
- */
-int ext3_forget(handle_t *handle, int is_metadata, struct inode *inode,
- struct buffer_head *bh, ext3_fsblk_t blocknr)
-{
- int err;
-
- might_sleep();
-
- trace_ext3_forget(inode, is_metadata, blocknr);
- BUFFER_TRACE(bh, "enter");
-
- jbd_debug(4, "forgetting bh %p: is_metadata = %d, mode %o, "
- "data mode %lx\n",
- bh, is_metadata, inode->i_mode,
- test_opt(inode->i_sb, DATA_FLAGS));
-
- /* Never use the revoke function if we are doing full data
- * journaling: there is no need to, and a V1 superblock won't
- * support it. Otherwise, only skip the revoke on un-journaled
- * data blocks. */
-
- if (test_opt(inode->i_sb, DATA_FLAGS) == EXT3_MOUNT_JOURNAL_DATA ||
- (!is_metadata && !ext3_should_journal_data(inode))) {
- if (bh) {
- BUFFER_TRACE(bh, "call journal_forget");
- return ext3_journal_forget(handle, bh);
- }
- return 0;
- }
-
- /*
- * data!=journal && (is_metadata || should_journal_data(inode))
- */
- BUFFER_TRACE(bh, "call ext3_journal_revoke");
- err = ext3_journal_revoke(handle, blocknr, bh);
- if (err)
- ext3_abort(inode->i_sb, __func__,
- "error %d when attempting revoke", err);
- BUFFER_TRACE(bh, "exit");
- return err;
-}
-
-/*
- * Work out how many blocks we need to proceed with the next chunk of a
- * truncate transaction.
- */
-static unsigned long blocks_for_truncate(struct inode *inode)
-{
- unsigned long needed;
-
- needed = inode->i_blocks >> (inode->i_sb->s_blocksize_bits - 9);
-
- /* Give ourselves just enough room to cope with inodes in which
- * i_blocks is corrupt: we've seen disk corruptions in the past
- * which resulted in random data in an inode which looked enough
- * like a regular file for ext3 to try to delete it. Things
- * will go a bit crazy if that happens, but at least we should
- * try not to panic the whole kernel. */
- if (needed < 2)
- needed = 2;
-
- /* But we need to bound the transaction so we don't overflow the
- * journal. */
- if (needed > EXT3_MAX_TRANS_DATA)
- needed = EXT3_MAX_TRANS_DATA;
-
- return EXT3_DATA_TRANS_BLOCKS(inode->i_sb) + needed;
-}
-
-/*
- * Truncate transactions can be complex and absolutely huge. So we need to
- * be able to restart the transaction at a conventient checkpoint to make
- * sure we don't overflow the journal.
- *
- * start_transaction gets us a new handle for a truncate transaction,
- * and extend_transaction tries to extend the existing one a bit. If
- * extend fails, we need to propagate the failure up and restart the
- * transaction in the top-level truncate loop. --sct
- */
-static handle_t *start_transaction(struct inode *inode)
-{
- handle_t *result;
-
- result = ext3_journal_start(inode, blocks_for_truncate(inode));
- if (!IS_ERR(result))
- return result;
-
- ext3_std_error(inode->i_sb, PTR_ERR(result));
- return result;
-}
-
-/*
- * Try to extend this transaction for the purposes of truncation.
- *
- * Returns 0 if we managed to create more room. If we can't create more
- * room, and the transaction must be restarted we return 1.
- */
-static int try_to_extend_transaction(handle_t *handle, struct inode *inode)
-{
- if (handle->h_buffer_credits > EXT3_RESERVE_TRANS_BLOCKS)
- return 0;
- if (!ext3_journal_extend(handle, blocks_for_truncate(inode)))
- return 0;
- return 1;
-}
-
-/*
- * Restart the transaction associated with *handle. This does a commit,
- * so before we call here everything must be consistently dirtied against
- * this transaction.
- */
-static int truncate_restart_transaction(handle_t *handle, struct inode *inode)
-{
- int ret;
-
- jbd_debug(2, "restarting handle %p\n", handle);
- /*
- * Drop truncate_mutex to avoid deadlock with ext3_get_blocks_handle
- * At this moment, get_block can be called only for blocks inside
- * i_size since page cache has been already dropped and writes are
- * blocked by i_mutex. So we can safely drop the truncate_mutex.
- */
- mutex_unlock(&EXT3_I(inode)->truncate_mutex);
- ret = ext3_journal_restart(handle, blocks_for_truncate(inode));
- mutex_lock(&EXT3_I(inode)->truncate_mutex);
- return ret;
-}
-
-/*
- * Called at inode eviction from icache
- */
-void ext3_evict_inode (struct inode *inode)
-{
- struct ext3_inode_info *ei = EXT3_I(inode);
- struct ext3_block_alloc_info *rsv;
- handle_t *handle;
- int want_delete = 0;
-
- trace_ext3_evict_inode(inode);
- if (!inode->i_nlink && !is_bad_inode(inode)) {
- dquot_initialize(inode);
- want_delete = 1;
- }
-
- /*
- * When journalling data dirty buffers are tracked only in the journal.
- * So although mm thinks everything is clean and ready for reaping the
- * inode might still have some pages to write in the running
- * transaction or waiting to be checkpointed. Thus calling
- * journal_invalidatepage() (via truncate_inode_pages()) to discard
- * these buffers can cause data loss. Also even if we did not discard
- * these buffers, we would have no way to find them after the inode
- * is reaped and thus user could see stale data if he tries to read
- * them before the transaction is checkpointed. So be careful and
- * force everything to disk here... We use ei->i_datasync_tid to
- * store the newest transaction containing inode's data.
- *
- * Note that directories do not have this problem because they don't
- * use page cache.
- *
- * The s_journal check handles the case when ext3_get_journal() fails
- * and puts the journal inode.
- */
- if (inode->i_nlink && ext3_should_journal_data(inode) &&
- EXT3_SB(inode->i_sb)->s_journal &&
- (S_ISLNK(inode->i_mode) || S_ISREG(inode->i_mode)) &&
- inode->i_ino != EXT3_JOURNAL_INO) {
- tid_t commit_tid = atomic_read(&ei->i_datasync_tid);
- journal_t *journal = EXT3_SB(inode->i_sb)->s_journal;
-
- log_start_commit(journal, commit_tid);
- log_wait_commit(journal, commit_tid);
- filemap_write_and_wait(&inode->i_data);
- }
- truncate_inode_pages_final(&inode->i_data);
-
- ext3_discard_reservation(inode);
- rsv = ei->i_block_alloc_info;
- ei->i_block_alloc_info = NULL;
- if (unlikely(rsv))
- kfree(rsv);
-
- if (!want_delete)
- goto no_delete;
-
- handle = start_transaction(inode);
- if (IS_ERR(handle)) {
- /*
- * If we're going to skip the normal cleanup, we still need to
- * make sure that the in-core orphan linked list is properly
- * cleaned up.
- */
- ext3_orphan_del(NULL, inode);
- goto no_delete;
- }
-
- if (IS_SYNC(inode))
- handle->h_sync = 1;
- inode->i_size = 0;
- if (inode->i_blocks)
- ext3_truncate(inode);
- /*
- * Kill off the orphan record created when the inode lost the last
- * link. Note that ext3_orphan_del() has to be able to cope with the
- * deletion of a non-existent orphan - ext3_truncate() could
- * have removed the record.
- */
- ext3_orphan_del(handle, inode);
- ei->i_dtime = get_seconds();
-
- /*
- * One subtle ordering requirement: if anything has gone wrong
- * (transaction abort, IO errors, whatever), then we can still
- * do these next steps (the fs will already have been marked as
- * having errors), but we can't free the inode if the mark_dirty
- * fails.
- */
- if (ext3_mark_inode_dirty(handle, inode)) {
- /* If that failed, just dquot_drop() and be done with that */
- dquot_drop(inode);
- clear_inode(inode);
- } else {
- ext3_xattr_delete_inode(handle, inode);
- dquot_free_inode(inode);
- dquot_drop(inode);
- clear_inode(inode);
- ext3_free_inode(handle, inode);
- }
- ext3_journal_stop(handle);
- return;
-no_delete:
- clear_inode(inode);
- dquot_drop(inode);
-}
-
-typedef struct {
- __le32 *p;
- __le32 key;
- struct buffer_head *bh;
-} Indirect;
-
-static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v)
-{
- p->key = *(p->p = v);
- p->bh = bh;
-}
-
-static int verify_chain(Indirect *from, Indirect *to)
-{
- while (from <= to && from->key == *from->p)
- from++;
- return (from > to);
-}
-
-/**
- * ext3_block_to_path - parse the block number into array of offsets
- * @inode: inode in question (we are only interested in its superblock)
- * @i_block: block number to be parsed
- * @offsets: array to store the offsets in
- * @boundary: set this non-zero if the referred-to block is likely to be
- * followed (on disk) by an indirect block.
- *
- * To store the locations of file's data ext3 uses a data structure common
- * for UNIX filesystems - tree of pointers anchored in the inode, with
- * data blocks at leaves and indirect blocks in intermediate nodes.
- * This function translates the block number into path in that tree -
- * return value is the path length and @offsets[n] is the offset of
- * pointer to (n+1)th node in the nth one. If @block is out of range
- * (negative or too large) warning is printed and zero returned.
- *
- * Note: function doesn't find node addresses, so no IO is needed. All
- * we need to know is the capacity of indirect blocks (taken from the
- * inode->i_sb).
- */
-
-/*
- * Portability note: the last comparison (check that we fit into triple
- * indirect block) is spelled differently, because otherwise on an
- * architecture with 32-bit longs and 8Kb pages we might get into trouble
- * if our filesystem had 8Kb blocks. We might use long long, but that would
- * kill us on x86. Oh, well, at least the sign propagation does not matter -
- * i_block would have to be negative in the very beginning, so we would not
- * get there at all.
- */
-
-static int ext3_block_to_path(struct inode *inode,
- long i_block, int offsets[4], int *boundary)
-{
- int ptrs = EXT3_ADDR_PER_BLOCK(inode->i_sb);
- int ptrs_bits = EXT3_ADDR_PER_BLOCK_BITS(inode->i_sb);
- const long direct_blocks = EXT3_NDIR_BLOCKS,
- indirect_blocks = ptrs,
- double_blocks = (1 << (ptrs_bits * 2));
- int n = 0;
- int final = 0;
-
- if (i_block < 0) {
- ext3_warning (inode->i_sb, "ext3_block_to_path", "block < 0");
- } else if (i_block < direct_blocks) {
- offsets[n++] = i_block;
- final = direct_blocks;
- } else if ( (i_block -= direct_blocks) < indirect_blocks) {
- offsets[n++] = EXT3_IND_BLOCK;
- offsets[n++] = i_block;
- final = ptrs;
- } else if ((i_block -= indirect_blocks) < double_blocks) {
- offsets[n++] = EXT3_DIND_BLOCK;
- offsets[n++] = i_block >> ptrs_bits;
- offsets[n++] = i_block & (ptrs - 1);
- final = ptrs;
- } else if (((i_block -= double_blocks) >> (ptrs_bits * 2)) < ptrs) {
- offsets[n++] = EXT3_TIND_BLOCK;
- offsets[n++] = i_block >> (ptrs_bits * 2);
- offsets[n++] = (i_block >> ptrs_bits) & (ptrs - 1);
- offsets[n++] = i_block & (ptrs - 1);
- final = ptrs;
- } else {
- ext3_warning(inode->i_sb, "ext3_block_to_path", "block > big");
- }
- if (boundary)
- *boundary = final - 1 - (i_block & (ptrs - 1));
- return n;
-}
-
-/**
- * ext3_get_branch - read the chain of indirect blocks leading to data
- * @inode: inode in question
- * @depth: depth of the chain (1 - direct pointer, etc.)
- * @offsets: offsets of pointers in inode/indirect blocks
- * @chain: place to store the result
- * @err: here we store the error value
- *
- * Function fills the array of triples <key, p, bh> and returns %NULL
- * if everything went OK or the pointer to the last filled triple
- * (incomplete one) otherwise. Upon the return chain[i].key contains
- * the number of (i+1)-th block in the chain (as it is stored in memory,
- * i.e. little-endian 32-bit), chain[i].p contains the address of that
- * number (it points into struct inode for i==0 and into the bh->b_data
- * for i>0) and chain[i].bh points to the buffer_head of i-th indirect
- * block for i>0 and NULL for i==0. In other words, it holds the block
- * numbers of the chain, addresses they were taken from (and where we can
- * verify that chain did not change) and buffer_heads hosting these
- * numbers.
- *
- * Function stops when it stumbles upon zero pointer (absent block)
- * (pointer to last triple returned, *@err == 0)
- * or when it gets an IO error reading an indirect block
- * (ditto, *@err == -EIO)
- * or when it notices that chain had been changed while it was reading
- * (ditto, *@err == -EAGAIN)
- * or when it reads all @depth-1 indirect blocks successfully and finds
- * the whole chain, all way to the data (returns %NULL, *err == 0).
- */
-static Indirect *ext3_get_branch(struct inode *inode, int depth, int *offsets,
- Indirect chain[4], int *err)
-{
- struct super_block *sb = inode->i_sb;
- Indirect *p = chain;
- struct buffer_head *bh;
-
- *err = 0;
- /* i_data is not going away, no lock needed */
- add_chain (chain, NULL, EXT3_I(inode)->i_data + *offsets);
- if (!p->key)
- goto no_block;
- while (--depth) {
- bh = sb_bread(sb, le32_to_cpu(p->key));
- if (!bh)
- goto failure;
- /* Reader: pointers */
- if (!verify_chain(chain, p))
- goto changed;
- add_chain(++p, bh, (__le32*)bh->b_data + *++offsets);
- /* Reader: end */
- if (!p->key)
- goto no_block;
- }
- return NULL;
-
-changed:
- brelse(bh);
- *err = -EAGAIN;
- goto no_block;
-failure:
- *err = -EIO;
-no_block:
- return p;
-}
-
-/**
- * ext3_find_near - find a place for allocation with sufficient locality
- * @inode: owner
- * @ind: descriptor of indirect block.
- *
- * This function returns the preferred place for block allocation.
- * It is used when heuristic for sequential allocation fails.
- * Rules are:
- * + if there is a block to the left of our position - allocate near it.
- * + if pointer will live in indirect block - allocate near that block.
- * + if pointer will live in inode - allocate in the same
- * cylinder group.
- *
- * In the latter case we colour the starting block by the callers PID to
- * prevent it from clashing with concurrent allocations for a different inode
- * in the same block group. The PID is used here so that functionally related
- * files will be close-by on-disk.
- *
- * Caller must make sure that @ind is valid and will stay that way.
- */
-static ext3_fsblk_t ext3_find_near(struct inode *inode, Indirect *ind)
-{
- struct ext3_inode_info *ei = EXT3_I(inode);
- __le32 *start = ind->bh ? (__le32*) ind->bh->b_data : ei->i_data;
- __le32 *p;
- ext3_fsblk_t bg_start;
- ext3_grpblk_t colour;
-
- /* Try to find previous block */
- for (p = ind->p - 1; p >= start; p--) {
- if (*p)
- return le32_to_cpu(*p);
- }
-
- /* No such thing, so let's try location of indirect block */
- if (ind->bh)
- return ind->bh->b_blocknr;
-
- /*
- * It is going to be referred to from the inode itself? OK, just put it
- * into the same cylinder group then.
- */
- bg_start = ext3_group_first_block_no(inode->i_sb, ei->i_block_group);
- colour = (current->pid % 16) *
- (EXT3_BLOCKS_PER_GROUP(inode->i_sb) / 16);
- return bg_start + colour;
-}
-
-/**
- * ext3_find_goal - find a preferred place for allocation.
- * @inode: owner
- * @block: block we want
- * @partial: pointer to the last triple within a chain
- *
- * Normally this function find the preferred place for block allocation,
- * returns it.
- */
-
-static ext3_fsblk_t ext3_find_goal(struct inode *inode, long block,
- Indirect *partial)
-{
- struct ext3_block_alloc_info *block_i;
-
- block_i = EXT3_I(inode)->i_block_alloc_info;
-
- /*
- * try the heuristic for sequential allocation,
- * failing that at least try to get decent locality.
- */
- if (block_i && (block == block_i->last_alloc_logical_block + 1)
- && (block_i->last_alloc_physical_block != 0)) {
- return block_i->last_alloc_physical_block + 1;
- }
-
- return ext3_find_near(inode, partial);
-}
-
-/**
- * ext3_blks_to_allocate - Look up the block map and count the number
- * of direct blocks need to be allocated for the given branch.
- *
- * @branch: chain of indirect blocks
- * @k: number of blocks need for indirect blocks
- * @blks: number of data blocks to be mapped.
- * @blocks_to_boundary: the offset in the indirect block
- *
- * return the total number of blocks to be allocate, including the
- * direct and indirect blocks.
- */
-static int ext3_blks_to_allocate(Indirect *branch, int k, unsigned long blks,
- int blocks_to_boundary)
-{
- unsigned long count = 0;
-
- /*
- * Simple case, [t,d]Indirect block(s) has not allocated yet
- * then it's clear blocks on that path have not allocated
- */
- if (k > 0) {
- /* right now we don't handle cross boundary allocation */
- if (blks < blocks_to_boundary + 1)
- count += blks;
- else
- count += blocks_to_boundary + 1;
- return count;
- }
-
- count++;
- while (count < blks && count <= blocks_to_boundary &&
- le32_to_cpu(*(branch[0].p + count)) == 0) {
- count++;
- }
- return count;
-}
-
-/**
- * ext3_alloc_blocks - multiple allocate blocks needed for a branch
- * @handle: handle for this transaction
- * @inode: owner
- * @goal: preferred place for allocation
- * @indirect_blks: the number of blocks need to allocate for indirect
- * blocks
- * @blks: number of blocks need to allocated for direct blocks
- * @new_blocks: on return it will store the new block numbers for
- * the indirect blocks(if needed) and the first direct block,
- * @err: here we store the error value
- *
- * return the number of direct blocks allocated
- */
-static int ext3_alloc_blocks(handle_t *handle, struct inode *inode,
- ext3_fsblk_t goal, int indirect_blks, int blks,
- ext3_fsblk_t new_blocks[4], int *err)
-{
- int target, i;
- unsigned long count = 0;
- int index = 0;
- ext3_fsblk_t current_block = 0;
- int ret = 0;
-
- /*
- * Here we try to allocate the requested multiple blocks at once,
- * on a best-effort basis.
- * To build a branch, we should allocate blocks for
- * the indirect blocks(if not allocated yet), and at least
- * the first direct block of this branch. That's the
- * minimum number of blocks need to allocate(required)
- */
- target = blks + indirect_blks;
-
- while (1) {
- count = target;
- /* allocating blocks for indirect blocks and direct blocks */
- current_block = ext3_new_blocks(handle,inode,goal,&count,err);
- if (*err)
- goto failed_out;
-
- target -= count;
- /* allocate blocks for indirect blocks */
- while (index < indirect_blks && count) {
- new_blocks[index++] = current_block++;
- count--;
- }
-
- if (count > 0)
- break;
- }
-
- /* save the new block number for the first direct block */
- new_blocks[index] = current_block;
-
- /* total number of blocks allocated for direct blocks */
- ret = count;
- *err = 0;
- return ret;
-failed_out:
- for (i = 0; i <index; i++)
- ext3_free_blocks(handle, inode, new_blocks[i], 1);
- return ret;
-}
-
-/**
- * ext3_alloc_branch - allocate and set up a chain of blocks.
- * @handle: handle for this transaction
- * @inode: owner
- * @indirect_blks: number of allocated indirect blocks
- * @blks: number of allocated direct blocks
- * @goal: preferred place for allocation
- * @offsets: offsets (in the blocks) to store the pointers to next.
- * @branch: place to store the chain in.
- *
- * This function allocates blocks, zeroes out all but the last one,
- * links them into chain and (if we are synchronous) writes them to disk.
- * In other words, it prepares a branch that can be spliced onto the
- * inode. It stores the information about that chain in the branch[], in
- * the same format as ext3_get_branch() would do. We are calling it after
- * we had read the existing part of chain and partial points to the last
- * triple of that (one with zero ->key). Upon the exit we have the same
- * picture as after the successful ext3_get_block(), except that in one
- * place chain is disconnected - *branch->p is still zero (we did not
- * set the last link), but branch->key contains the number that should
- * be placed into *branch->p to fill that gap.
- *
- * If allocation fails we free all blocks we've allocated (and forget
- * their buffer_heads) and return the error value the from failed
- * ext3_alloc_block() (normally -ENOSPC). Otherwise we set the chain
- * as described above and return 0.
- */
-static int ext3_alloc_branch(handle_t *handle, struct inode *inode,
- int indirect_blks, int *blks, ext3_fsblk_t goal,
- int *offsets, Indirect *branch)
-{
- int blocksize = inode->i_sb->s_blocksize;
- int i, n = 0;
- int err = 0;
- struct buffer_head *bh;
- int num;
- ext3_fsblk_t new_blocks[4];
- ext3_fsblk_t current_block;
-
- num = ext3_alloc_blocks(handle, inode, goal, indirect_blks,
- *blks, new_blocks, &err);
- if (err)
- return err;
-
- branch[0].key = cpu_to_le32(new_blocks[0]);
- /*
- * metadata blocks and data blocks are allocated.
- */
- for (n = 1; n <= indirect_blks; n++) {
- /*
- * Get buffer_head for parent block, zero it out
- * and set the pointer to new one, then send
- * parent to disk.
- */
- bh = sb_getblk(inode->i_sb, new_blocks[n-1]);
- if (unlikely(!bh)) {
- err = -ENOMEM;
- goto failed;
- }
- branch[n].bh = bh;
- lock_buffer(bh);
- BUFFER_TRACE(bh, "call get_create_access");
- err = ext3_journal_get_create_access(handle, bh);
- if (err) {
- unlock_buffer(bh);
- brelse(bh);
- goto failed;
- }
-
- memset(bh->b_data, 0, blocksize);
- branch[n].p = (__le32 *) bh->b_data + offsets[n];
- branch[n].key = cpu_to_le32(new_blocks[n]);
- *branch[n].p = branch[n].key;
- if ( n == indirect_blks) {
- current_block = new_blocks[n];
- /*
- * End of chain, update the last new metablock of
- * the chain to point to the new allocated
- * data blocks numbers
- */
- for (i=1; i < num; i++)
- *(branch[n].p + i) = cpu_to_le32(++current_block);
- }
- BUFFER_TRACE(bh, "marking uptodate");
- set_buffer_uptodate(bh);
- unlock_buffer(bh);
-
- BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
- err = ext3_journal_dirty_metadata(handle, bh);
- if (err)
- goto failed;
- }
- *blks = num;
- return err;
-failed:
- /* Allocation failed, free what we already allocated */
- for (i = 1; i <= n ; i++) {
- BUFFER_TRACE(branch[i].bh, "call journal_forget");
- ext3_journal_forget(handle, branch[i].bh);
- }
- for (i = 0; i < indirect_blks; i++)
- ext3_free_blocks(handle, inode, new_blocks[i], 1);
-
- ext3_free_blocks(handle, inode, new_blocks[i], num);
-
- return err;
-}
-
-/**
- * ext3_splice_branch - splice the allocated branch onto inode.
- * @handle: handle for this transaction
- * @inode: owner
- * @block: (logical) number of block we are adding
- * @where: location of missing link
- * @num: number of indirect blocks we are adding
- * @blks: number of direct blocks we are adding
- *
- * This function fills the missing link and does all housekeeping needed in
- * inode (->i_blocks, etc.). In case of success we end up with the full
- * chain to new block and return 0.
- */
-static int ext3_splice_branch(handle_t *handle, struct inode *inode,
- long block, Indirect *where, int num, int blks)
-{
- int i;
- int err = 0;
- struct ext3_block_alloc_info *block_i;
- ext3_fsblk_t current_block;
- struct ext3_inode_info *ei = EXT3_I(inode);
- struct timespec now;
-
- block_i = ei->i_block_alloc_info;
- /*
- * If we're splicing into a [td]indirect block (as opposed to the
- * inode) then we need to get write access to the [td]indirect block
- * before the splice.
- */
- if (where->bh) {
- BUFFER_TRACE(where->bh, "get_write_access");
- err = ext3_journal_get_write_access(handle, where->bh);
- if (err)
- goto err_out;
- }
- /* That's it */
-
- *where->p = where->key;
-
- /*
- * Update the host buffer_head or inode to point to more just allocated
- * direct blocks blocks
- */
- if (num == 0 && blks > 1) {
- current_block = le32_to_cpu(where->key) + 1;
- for (i = 1; i < blks; i++)
- *(where->p + i ) = cpu_to_le32(current_block++);
- }
-
- /*
- * update the most recently allocated logical & physical block
- * in i_block_alloc_info, to assist find the proper goal block for next
- * allocation
- */
- if (block_i) {
- block_i->last_alloc_logical_block = block + blks - 1;
- block_i->last_alloc_physical_block =
- le32_to_cpu(where[num].key) + blks - 1;
- }
-
- /* We are done with atomic stuff, now do the rest of housekeeping */
- now = CURRENT_TIME_SEC;
- if (!timespec_equal(&inode->i_ctime, &now) || !where->bh) {
- inode->i_ctime = now;
- ext3_mark_inode_dirty(handle, inode);
- }
- /* ext3_mark_inode_dirty already updated i_sync_tid */
- atomic_set(&ei->i_datasync_tid, handle->h_transaction->t_tid);
-
- /* had we spliced it onto indirect block? */
- if (where->bh) {
- /*
- * If we spliced it onto an indirect block, we haven't
- * altered the inode. Note however that if it is being spliced
- * onto an indirect block at the very end of the file (the
- * file is growing) then we *will* alter the inode to reflect
- * the new i_size. But that is not done here - it is done in
- * generic_commit_write->__mark_inode_dirty->ext3_dirty_inode.
- */
- jbd_debug(5, "splicing indirect only\n");
- BUFFER_TRACE(where->bh, "call ext3_journal_dirty_metadata");
- err = ext3_journal_dirty_metadata(handle, where->bh);
- if (err)
- goto err_out;
- } else {
- /*
- * OK, we spliced it into the inode itself on a direct block.
- * Inode was dirtied above.
- */
- jbd_debug(5, "splicing direct\n");
- }
- return err;
-
-err_out:
- for (i = 1; i <= num; i++) {
- BUFFER_TRACE(where[i].bh, "call journal_forget");
- ext3_journal_forget(handle, where[i].bh);
- ext3_free_blocks(handle,inode,le32_to_cpu(where[i-1].key),1);
- }
- ext3_free_blocks(handle, inode, le32_to_cpu(where[num].key), blks);
-
- return err;
-}
-
-/*
- * Allocation strategy is simple: if we have to allocate something, we will
- * have to go the whole way to leaf. So let's do it before attaching anything
- * to tree, set linkage between the newborn blocks, write them if sync is
- * required, recheck the path, free and repeat if check fails, otherwise
- * set the last missing link (that will protect us from any truncate-generated
- * removals - all blocks on the path are immune now) and possibly force the
- * write on the parent block.
- * That has a nice additional property: no special recovery from the failed
- * allocations is needed - we simply release blocks and do not touch anything
- * reachable from inode.
- *
- * `handle' can be NULL if create == 0.
- *
- * The BKL may not be held on entry here. Be sure to take it early.
- * return > 0, # of blocks mapped or allocated.
- * return = 0, if plain lookup failed.
- * return < 0, error case.
- */
-int ext3_get_blocks_handle(handle_t *handle, struct inode *inode,
- sector_t iblock, unsigned long maxblocks,
- struct buffer_head *bh_result,
- int create)
-{
- int err = -EIO;
- int offsets[4];
- Indirect chain[4];
- Indirect *partial;
- ext3_fsblk_t goal;
- int indirect_blks;
- int blocks_to_boundary = 0;
- int depth;
- struct ext3_inode_info *ei = EXT3_I(inode);
- int count = 0;
- ext3_fsblk_t first_block = 0;
-
-
- trace_ext3_get_blocks_enter(inode, iblock, maxblocks, create);
- J_ASSERT(handle != NULL || create == 0);
- depth = ext3_block_to_path(inode,iblock,offsets,&blocks_to_boundary);
-
- if (depth == 0)
- goto out;
-
- partial = ext3_get_branch(inode, depth, offsets, chain, &err);
-
- /* Simplest case - block found, no allocation needed */
- if (!partial) {
- first_block = le32_to_cpu(chain[depth - 1].key);
- clear_buffer_new(bh_result);
- count++;
- /*map more blocks*/
- while (count < maxblocks && count <= blocks_to_boundary) {
- ext3_fsblk_t blk;
-
- if (!verify_chain(chain, chain + depth - 1)) {
- /*
- * Indirect block might be removed by
- * truncate while we were reading it.
- * Handling of that case: forget what we've
- * got now. Flag the err as EAGAIN, so it
- * will reread.
- */
- err = -EAGAIN;
- count = 0;
- break;
- }
- blk = le32_to_cpu(*(chain[depth-1].p + count));
-
- if (blk == first_block + count)
- count++;
- else
- break;
- }
- if (err != -EAGAIN)
- goto got_it;
- }
-
- /* Next simple case - plain lookup or failed read of indirect block */
- if (!create || err == -EIO)
- goto cleanup;
-
- /*
- * Block out ext3_truncate while we alter the tree
- */
- mutex_lock(&ei->truncate_mutex);
-
- /*
- * If the indirect block is missing while we are reading
- * the chain(ext3_get_branch() returns -EAGAIN err), or
- * if the chain has been changed after we grab the semaphore,
- * (either because another process truncated this branch, or
- * another get_block allocated this branch) re-grab the chain to see if
- * the request block has been allocated or not.
- *
- * Since we already block the truncate/other get_block
- * at this point, we will have the current copy of the chain when we
- * splice the branch into the tree.
- */
- if (err == -EAGAIN || !verify_chain(chain, partial)) {
- while (partial > chain) {
- brelse(partial->bh);
- partial--;
- }
- partial = ext3_get_branch(inode, depth, offsets, chain, &err);
- if (!partial) {
- count++;
- mutex_unlock(&ei->truncate_mutex);
- if (err)
- goto cleanup;
- clear_buffer_new(bh_result);
- goto got_it;
- }
- }
-
- /*
- * Okay, we need to do block allocation. Lazily initialize the block
- * allocation info here if necessary
- */
- if (S_ISREG(inode->i_mode) && (!ei->i_block_alloc_info))
- ext3_init_block_alloc_info(inode);
-
- goal = ext3_find_goal(inode, iblock, partial);
-
- /* the number of blocks need to allocate for [d,t]indirect blocks */
- indirect_blks = (chain + depth) - partial - 1;
-
- /*
- * Next look up the indirect map to count the totoal number of
- * direct blocks to allocate for this branch.
- */
- count = ext3_blks_to_allocate(partial, indirect_blks,
- maxblocks, blocks_to_boundary);
- err = ext3_alloc_branch(handle, inode, indirect_blks, &count, goal,
- offsets + (partial - chain), partial);
-
- /*
- * The ext3_splice_branch call will free and forget any buffers
- * on the new chain if there is a failure, but that risks using
- * up transaction credits, especially for bitmaps where the
- * credits cannot be returned. Can we handle this somehow? We
- * may need to return -EAGAIN upwards in the worst case. --sct
- */
- if (!err)
- err = ext3_splice_branch(handle, inode, iblock,
- partial, indirect_blks, count);
- mutex_unlock(&ei->truncate_mutex);
- if (err)
- goto cleanup;
-
- set_buffer_new(bh_result);
-got_it:
- map_bh(bh_result, inode->i_sb, le32_to_cpu(chain[depth-1].key));
- if (count > blocks_to_boundary)
- set_buffer_boundary(bh_result);
- err = count;
- /* Clean up and exit */
- partial = chain + depth - 1; /* the whole chain */
-cleanup:
- while (partial > chain) {
- BUFFER_TRACE(partial->bh, "call brelse");
- brelse(partial->bh);
- partial--;
- }
- BUFFER_TRACE(bh_result, "returned");
-out:
- trace_ext3_get_blocks_exit(inode, iblock,
- depth ? le32_to_cpu(chain[depth-1].key) : 0,
- count, err);
- return err;
-}
-
-/* Maximum number of blocks we map for direct IO at once. */
-#define DIO_MAX_BLOCKS 4096
-/*
- * Number of credits we need for writing DIO_MAX_BLOCKS:
- * We need sb + group descriptor + bitmap + inode -> 4
- * For B blocks with A block pointers per block we need:
- * 1 (triple ind.) + (B/A/A + 2) (doubly ind.) + (B/A + 2) (indirect).
- * If we plug in 4096 for B and 256 for A (for 1KB block size), we get 25.
- */
-#define DIO_CREDITS 25
-
-static int ext3_get_block(struct inode *inode, sector_t iblock,
- struct buffer_head *bh_result, int create)
-{
- handle_t *handle = ext3_journal_current_handle();
- int ret = 0, started = 0;
- unsigned max_blocks = bh_result->b_size >> inode->i_blkbits;
-
- if (create && !handle) { /* Direct IO write... */
- if (max_blocks > DIO_MAX_BLOCKS)
- max_blocks = DIO_MAX_BLOCKS;
- handle = ext3_journal_start(inode, DIO_CREDITS +
- EXT3_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb));
- if (IS_ERR(handle)) {
- ret = PTR_ERR(handle);
- goto out;
- }
- started = 1;
- }
-
- ret = ext3_get_blocks_handle(handle, inode, iblock,
- max_blocks, bh_result, create);
- if (ret > 0) {
- bh_result->b_size = (ret << inode->i_blkbits);
- ret = 0;
- }
- if (started)
- ext3_journal_stop(handle);
-out:
- return ret;
-}
-
-int ext3_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
- u64 start, u64 len)
-{
- return generic_block_fiemap(inode, fieinfo, start, len,
- ext3_get_block);
-}
-
-/*
- * `handle' can be NULL if create is zero
- */
-struct buffer_head *ext3_getblk(handle_t *handle, struct inode *inode,
- long block, int create, int *errp)
-{
- struct buffer_head dummy;
- int fatal = 0, err;
-
- J_ASSERT(handle != NULL || create == 0);
-
- dummy.b_state = 0;
- dummy.b_blocknr = -1000;
- buffer_trace_init(&dummy.b_history);
- err = ext3_get_blocks_handle(handle, inode, block, 1,
- &dummy, create);
- /*
- * ext3_get_blocks_handle() returns number of blocks
- * mapped. 0 in case of a HOLE.
- */
- if (err > 0) {
- WARN_ON(err > 1);
- err = 0;
- }
- *errp = err;
- if (!err && buffer_mapped(&dummy)) {
- struct buffer_head *bh;
- bh = sb_getblk(inode->i_sb, dummy.b_blocknr);
- if (unlikely(!bh)) {
- *errp = -ENOMEM;
- goto err;
- }
- if (buffer_new(&dummy)) {
- J_ASSERT(create != 0);
- J_ASSERT(handle != NULL);
-
- /*
- * Now that we do not always journal data, we should
- * keep in mind whether this should always journal the
- * new buffer as metadata. For now, regular file
- * writes use ext3_get_block instead, so it's not a
- * problem.
- */
- lock_buffer(bh);
- BUFFER_TRACE(bh, "call get_create_access");
- fatal = ext3_journal_get_create_access(handle, bh);
- if (!fatal && !buffer_uptodate(bh)) {
- memset(bh->b_data,0,inode->i_sb->s_blocksize);
- set_buffer_uptodate(bh);
- }
- unlock_buffer(bh);
- BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
- err = ext3_journal_dirty_metadata(handle, bh);
- if (!fatal)
- fatal = err;
- } else {
- BUFFER_TRACE(bh, "not a new buffer");
- }
- if (fatal) {
- *errp = fatal;
- brelse(bh);
- bh = NULL;
- }
- return bh;
- }
-err:
- return NULL;
-}
-
-struct buffer_head *ext3_bread(handle_t *handle, struct inode *inode,
- int block, int create, int *err)
-{
- struct buffer_head * bh;
-
- bh = ext3_getblk(handle, inode, block, create, err);
- if (!bh)
- return bh;
- if (bh_uptodate_or_lock(bh))
- return bh;
- get_bh(bh);
- bh->b_end_io = end_buffer_read_sync;
- submit_bh(READ | REQ_META | REQ_PRIO, bh);
- wait_on_buffer(bh);
- if (buffer_uptodate(bh))
- return bh;
- put_bh(bh);
- *err = -EIO;
- return NULL;
-}
-
-static int walk_page_buffers( handle_t *handle,
- struct buffer_head *head,
- unsigned from,
- unsigned to,
- int *partial,
- int (*fn)( handle_t *handle,
- struct buffer_head *bh))
-{
- struct buffer_head *bh;
- unsigned block_start, block_end;
- unsigned blocksize = head->b_size;
- int err, ret = 0;
- struct buffer_head *next;
-
- for ( bh = head, block_start = 0;
- ret == 0 && (bh != head || !block_start);
- block_start = block_end, bh = next)
- {
- next = bh->b_this_page;
- block_end = block_start + blocksize;
- if (block_end <= from || block_start >= to) {
- if (partial && !buffer_uptodate(bh))
- *partial = 1;
- continue;
- }
- err = (*fn)(handle, bh);
- if (!ret)
- ret = err;
- }
- return ret;
-}
-
-/*
- * To preserve ordering, it is essential that the hole instantiation and
- * the data write be encapsulated in a single transaction. We cannot
- * close off a transaction and start a new one between the ext3_get_block()
- * and the commit_write(). So doing the journal_start at the start of
- * prepare_write() is the right place.
- *
- * Also, this function can nest inside ext3_writepage() ->
- * block_write_full_page(). In that case, we *know* that ext3_writepage()
- * has generated enough buffer credits to do the whole page. So we won't
- * block on the journal in that case, which is good, because the caller may
- * be PF_MEMALLOC.
- *
- * By accident, ext3 can be reentered when a transaction is open via
- * quota file writes. If we were to commit the transaction while thus
- * reentered, there can be a deadlock - we would be holding a quota
- * lock, and the commit would never complete if another thread had a
- * transaction open and was blocking on the quota lock - a ranking
- * violation.
- *
- * So what we do is to rely on the fact that journal_stop/journal_start
- * will _not_ run commit under these circumstances because handle->h_ref
- * is elevated. We'll still have enough credits for the tiny quotafile
- * write.
- */
-static int do_journal_get_write_access(handle_t *handle,
- struct buffer_head *bh)
-{
- int dirty = buffer_dirty(bh);
- int ret;
-
- if (!buffer_mapped(bh) || buffer_freed(bh))
- return 0;
- /*
- * __block_prepare_write() could have dirtied some buffers. Clean
- * the dirty bit as jbd2_journal_get_write_access() could complain
- * otherwise about fs integrity issues. Setting of the dirty bit
- * by __block_prepare_write() isn't a real problem here as we clear
- * the bit before releasing a page lock and thus writeback cannot
- * ever write the buffer.
- */
- if (dirty)
- clear_buffer_dirty(bh);
- ret = ext3_journal_get_write_access(handle, bh);
- if (!ret && dirty)
- ret = ext3_journal_dirty_metadata(handle, bh);
- return ret;
-}
-
-/*
- * Truncate blocks that were not used by write. We have to truncate the
- * pagecache as well so that corresponding buffers get properly unmapped.
- */
-static void ext3_truncate_failed_write(struct inode *inode)
-{
- truncate_inode_pages(inode->i_mapping, inode->i_size);
- ext3_truncate(inode);
-}
-
-/*
- * Truncate blocks that were not used by direct IO write. We have to zero out
- * the last file block as well because direct IO might have written to it.
- */
-static void ext3_truncate_failed_direct_write(struct inode *inode)
-{
- ext3_block_truncate_page(inode, inode->i_size);
- ext3_truncate(inode);
-}
-
-static int ext3_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;
- int ret;
- handle_t *handle;
- int retries = 0;
- struct page *page;
- pgoff_t index;
- unsigned from, to;
- /* Reserve one block more for addition to orphan list in case
- * we allocate blocks but write fails for some reason */
- int needed_blocks = ext3_writepage_trans_blocks(inode) + 1;
-
- trace_ext3_write_begin(inode, pos, len, flags);
-
- index = pos >> PAGE_CACHE_SHIFT;
- from = pos & (PAGE_CACHE_SIZE - 1);
- to = from + len;
-
-retry:
- page = grab_cache_page_write_begin(mapping, index, flags);
- if (!page)
- return -ENOMEM;
- *pagep = page;
-
- handle = ext3_journal_start(inode, needed_blocks);
- if (IS_ERR(handle)) {
- unlock_page(page);
- page_cache_release(page);
- ret = PTR_ERR(handle);
- goto out;
- }
- ret = __block_write_begin(page, pos, len, ext3_get_block);
- if (ret)
- goto write_begin_failed;
-
- if (ext3_should_journal_data(inode)) {
- ret = walk_page_buffers(handle, page_buffers(page),
- from, to, NULL, do_journal_get_write_access);
- }
-write_begin_failed:
- if (ret) {
- /*
- * block_write_begin may have instantiated a few blocks
- * outside i_size. Trim these off again. Don't need
- * i_size_read because we hold i_mutex.
- *
- * Add inode to orphan list in case we crash before truncate
- * finishes. Do this only if ext3_can_truncate() agrees so
- * that orphan processing code is happy.
- */
- if (pos + len > inode->i_size && ext3_can_truncate(inode))
- ext3_orphan_add(handle, inode);
- ext3_journal_stop(handle);
- unlock_page(page);
- page_cache_release(page);
- if (pos + len > inode->i_size)
- ext3_truncate_failed_write(inode);
- }
- if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
- goto retry;
-out:
- return ret;
-}
-
-
-int ext3_journal_dirty_data(handle_t *handle, struct buffer_head *bh)
-{
- int err = journal_dirty_data(handle, bh);
- if (err)
- ext3_journal_abort_handle(__func__, __func__,
- bh, handle, err);
- return err;
-}
-
-/* For ordered writepage and write_end functions */
-static int journal_dirty_data_fn(handle_t *handle, struct buffer_head *bh)
-{
- /*
- * Write could have mapped the buffer but it didn't copy the data in
- * yet. So avoid filing such buffer into a transaction.
- */
- if (buffer_mapped(bh) && buffer_uptodate(bh))
- return ext3_journal_dirty_data(handle, bh);
- return 0;
-}
-
-/* For write_end() in data=journal mode */
-static int write_end_fn(handle_t *handle, struct buffer_head *bh)
-{
- if (!buffer_mapped(bh) || buffer_freed(bh))
- return 0;
- set_buffer_uptodate(bh);
- return ext3_journal_dirty_metadata(handle, bh);
-}
-
-/*
- * This is nasty and subtle: ext3_write_begin() could have allocated blocks
- * for the whole page but later we failed to copy the data in. Update inode
- * size according to what we managed to copy. The rest is going to be
- * truncated in write_end function.
- */
-static void update_file_sizes(struct inode *inode, loff_t pos, unsigned copied)
-{
- /* What matters to us is i_disksize. We don't write i_size anywhere */
- if (pos + copied > inode->i_size)
- i_size_write(inode, pos + copied);
- if (pos + copied > EXT3_I(inode)->i_disksize) {
- EXT3_I(inode)->i_disksize = pos + copied;
- mark_inode_dirty(inode);
- }
-}
-
-/*
- * We need to pick up the new inode size which generic_commit_write gave us
- * `file' can be NULL - eg, when called from page_symlink().
- *
- * ext3 never places buffers on inode->i_mapping->private_list. metadata
- * buffers are managed internally.
- */
-static int ext3_ordered_write_end(struct file *file,
- struct address_space *mapping,
- loff_t pos, unsigned len, unsigned copied,
- struct page *page, void *fsdata)
-{
- handle_t *handle = ext3_journal_current_handle();
- struct inode *inode = file->f_mapping->host;
- unsigned from, to;
- int ret = 0, ret2;
-
- trace_ext3_ordered_write_end(inode, pos, len, copied);
- copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
-
- from = pos & (PAGE_CACHE_SIZE - 1);
- to = from + copied;
- ret = walk_page_buffers(handle, page_buffers(page),
- from, to, NULL, journal_dirty_data_fn);
-
- if (ret == 0)
- update_file_sizes(inode, pos, copied);
- /*
- * There may be allocated blocks outside of i_size because
- * we failed to copy some data. Prepare for truncate.
- */
- if (pos + len > inode->i_size && ext3_can_truncate(inode))
- ext3_orphan_add(handle, inode);
- ret2 = ext3_journal_stop(handle);
- if (!ret)
- ret = ret2;
- unlock_page(page);
- page_cache_release(page);
-
- if (pos + len > inode->i_size)
- ext3_truncate_failed_write(inode);
- return ret ? ret : copied;
-}
-
-static int ext3_writeback_write_end(struct file *file,
- struct address_space *mapping,
- loff_t pos, unsigned len, unsigned copied,
- struct page *page, void *fsdata)
-{
- handle_t *handle = ext3_journal_current_handle();
- struct inode *inode = file->f_mapping->host;
- int ret;
-
- trace_ext3_writeback_write_end(inode, pos, len, copied);
- copied = block_write_end(file, mapping, pos, len, copied, page, fsdata);
- update_file_sizes(inode, pos, copied);
- /*
- * There may be allocated blocks outside of i_size because
- * we failed to copy some data. Prepare for truncate.
- */
- if (pos + len > inode->i_size && ext3_can_truncate(inode))
- ext3_orphan_add(handle, inode);
- ret = ext3_journal_stop(handle);
- unlock_page(page);
- page_cache_release(page);
-
- if (pos + len > inode->i_size)
- ext3_truncate_failed_write(inode);
- return ret ? ret : copied;
-}
-
-static int ext3_journalled_write_end(struct file *file,
- struct address_space *mapping,
- loff_t pos, unsigned len, unsigned copied,
- struct page *page, void *fsdata)
-{
- handle_t *handle = ext3_journal_current_handle();
- struct inode *inode = mapping->host;
- struct ext3_inode_info *ei = EXT3_I(inode);
- int ret = 0, ret2;
- int partial = 0;
- unsigned from, to;
-
- trace_ext3_journalled_write_end(inode, pos, len, copied);
- from = pos & (PAGE_CACHE_SIZE - 1);
- to = from + len;
-
- if (copied < len) {
- if (!PageUptodate(page))
- copied = 0;
- page_zero_new_buffers(page, from + copied, to);
- to = from + copied;
- }
-
- ret = walk_page_buffers(handle, page_buffers(page), from,
- to, &partial, write_end_fn);
- if (!partial)
- SetPageUptodate(page);
-
- if (pos + copied > inode->i_size)
- i_size_write(inode, pos + copied);
- /*
- * There may be allocated blocks outside of i_size because
- * we failed to copy some data. Prepare for truncate.
- */
- if (pos + len > inode->i_size && ext3_can_truncate(inode))
- ext3_orphan_add(handle, inode);
- ext3_set_inode_state(inode, EXT3_STATE_JDATA);
- atomic_set(&ei->i_datasync_tid, handle->h_transaction->t_tid);
- if (inode->i_size > ei->i_disksize) {
- ei->i_disksize = inode->i_size;
- ret2 = ext3_mark_inode_dirty(handle, inode);
- if (!ret)
- ret = ret2;
- }
-
- ret2 = ext3_journal_stop(handle);
- if (!ret)
- ret = ret2;
- unlock_page(page);
- page_cache_release(page);
-
- if (pos + len > inode->i_size)
- ext3_truncate_failed_write(inode);
- return ret ? ret : copied;
-}
-
-/*
- * bmap() is special. It gets used by applications such as lilo and by
- * the swapper to find the on-disk block of a specific piece of data.
- *
- * Naturally, this is dangerous if the block concerned is still in the
- * journal. If somebody makes a swapfile on an ext3 data-journaling
- * filesystem and enables swap, then they may get a nasty shock when the
- * data getting swapped to that swapfile suddenly gets overwritten by
- * the original zero's written out previously to the journal and
- * awaiting writeback in the kernel's buffer cache.
- *
- * So, if we see any bmap calls here on a modified, data-journaled file,
- * take extra steps to flush any blocks which might be in the cache.
- */
-static sector_t ext3_bmap(struct address_space *mapping, sector_t block)
-{
- struct inode *inode = mapping->host;
- journal_t *journal;
- int err;
-
- if (ext3_test_inode_state(inode, EXT3_STATE_JDATA)) {
- /*
- * This is a REALLY heavyweight approach, but the use of
- * bmap on dirty files is expected to be extremely rare:
- * only if we run lilo or swapon on a freshly made file
- * do we expect this to happen.
- *
- * (bmap requires CAP_SYS_RAWIO so this does not
- * represent an unprivileged user DOS attack --- we'd be
- * in trouble if mortal users could trigger this path at
- * will.)
- *
- * NB. EXT3_STATE_JDATA is not set on files other than
- * regular files. If somebody wants to bmap a directory
- * or symlink and gets confused because the buffer
- * hasn't yet been flushed to disk, they deserve
- * everything they get.
- */
-
- ext3_clear_inode_state(inode, EXT3_STATE_JDATA);
- journal = EXT3_JOURNAL(inode);
- journal_lock_updates(journal);
- err = journal_flush(journal);
- journal_unlock_updates(journal);
-
- if (err)
- return 0;
- }
-
- return generic_block_bmap(mapping,block,ext3_get_block);
-}
-
-static int bget_one(handle_t *handle, struct buffer_head *bh)
-{
- get_bh(bh);
- return 0;
-}
-
-static int bput_one(handle_t *handle, struct buffer_head *bh)
-{
- put_bh(bh);
- return 0;
-}
-
-static int buffer_unmapped(handle_t *handle, struct buffer_head *bh)
-{
- return !buffer_mapped(bh);
-}
-
-/*
- * Note that whenever we need to map blocks we start a transaction even if
- * we're not journalling data. This is to preserve ordering: any hole
- * instantiation within __block_write_full_page -> ext3_get_block() should be
- * journalled along with the data so we don't crash and then get metadata which
- * refers to old data.
- *
- * In all journalling modes block_write_full_page() will start the I/O.
- *
- * We don't honour synchronous mounts for writepage(). That would be
- * disastrous. Any write() or metadata operation will sync the fs for
- * us.
- */
-static int ext3_ordered_writepage(struct page *page,
- struct writeback_control *wbc)
-{
- struct inode *inode = page->mapping->host;
- struct buffer_head *page_bufs;
- handle_t *handle = NULL;
- int ret = 0;
- int err;
-
- J_ASSERT(PageLocked(page));
- /*
- * We don't want to warn for emergency remount. The condition is
- * ordered to avoid dereferencing inode->i_sb in non-error case to
- * avoid slow-downs.
- */
- WARN_ON_ONCE(IS_RDONLY(inode) &&
- !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS));
-
- /*
- * We give up here if we're reentered, because it might be for a
- * different filesystem.
- */
- if (ext3_journal_current_handle())
- goto out_fail;
-
- trace_ext3_ordered_writepage(page);
- if (!page_has_buffers(page)) {
- create_empty_buffers(page, inode->i_sb->s_blocksize,
- (1 << BH_Dirty)|(1 << BH_Uptodate));
- page_bufs = page_buffers(page);
- } else {
- page_bufs = page_buffers(page);
- if (!walk_page_buffers(NULL, page_bufs, 0, PAGE_CACHE_SIZE,
- NULL, buffer_unmapped)) {
- /* Provide NULL get_block() to catch bugs if buffers
- * weren't really mapped */
- return block_write_full_page(page, NULL, wbc);
- }
- }
- handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
-
- if (IS_ERR(handle)) {
- ret = PTR_ERR(handle);
- goto out_fail;
- }
-
- walk_page_buffers(handle, page_bufs, 0,
- PAGE_CACHE_SIZE, NULL, bget_one);
-
- ret = block_write_full_page(page, ext3_get_block, wbc);
-
- /*
- * The page can become unlocked at any point now, and
- * truncate can then come in and change things. So we
- * can't touch *page from now on. But *page_bufs is
- * safe due to elevated refcount.
- */
-
- /*
- * And attach them to the current transaction. But only if
- * block_write_full_page() succeeded. Otherwise they are unmapped,
- * and generally junk.
- */
- if (ret == 0)
- ret = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE,
- NULL, journal_dirty_data_fn);
- walk_page_buffers(handle, page_bufs, 0,
- PAGE_CACHE_SIZE, NULL, bput_one);
- err = ext3_journal_stop(handle);
- if (!ret)
- ret = err;
- return ret;
-
-out_fail:
- redirty_page_for_writepage(wbc, page);
- unlock_page(page);
- return ret;
-}
-
-static int ext3_writeback_writepage(struct page *page,
- struct writeback_control *wbc)
-{
- struct inode *inode = page->mapping->host;
- handle_t *handle = NULL;
- int ret = 0;
- int err;
-
- J_ASSERT(PageLocked(page));
- /*
- * We don't want to warn for emergency remount. The condition is
- * ordered to avoid dereferencing inode->i_sb in non-error case to
- * avoid slow-downs.
- */
- WARN_ON_ONCE(IS_RDONLY(inode) &&
- !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS));
-
- if (ext3_journal_current_handle())
- goto out_fail;
-
- trace_ext3_writeback_writepage(page);
- if (page_has_buffers(page)) {
- if (!walk_page_buffers(NULL, page_buffers(page), 0,
- PAGE_CACHE_SIZE, NULL, buffer_unmapped)) {
- /* Provide NULL get_block() to catch bugs if buffers
- * weren't really mapped */
- return block_write_full_page(page, NULL, wbc);
- }
- }
-
- handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode));
- if (IS_ERR(handle)) {
- ret = PTR_ERR(handle);
- goto out_fail;
- }
-
- ret = block_write_full_page(page, ext3_get_block, wbc);
-
- err = ext3_journal_stop(handle);
- if (!ret)
- ret = err;
- return ret;
-
-out_fail:
- redirty_page_for_writepage(wbc, page);
- unlock_page(page);
- return ret;
-}
-
-static int ext3_journalled_writepage(struct page *page,
- struct writeback_control *wbc)
-{
- struct inode *inode = page->mapping->host;
- handle_t *handle = NULL;
- int ret = 0;
- int err;
-
- J_ASSERT(PageLocked(page));
- /*
- * We don't want to warn for emergency remount. The condition is
- * ordered to avoid dereferencing inode->i_sb in non-error case to
- * avoid slow-downs.
- */
- WARN_ON_ONCE(IS_RDONLY(inode) &&
- !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ERROR_FS));
-
- trace_ext3_journalled_writepage(page);
- if (!page_has_buffers(page) || PageChecked(page)) {
- if (ext3_journal_current_handle())
- goto no_write;
-
- handle = ext3_journal_start(inode,
- ext3_writepage_trans_blocks(inode));
- if (IS_ERR(handle)) {
- ret = PTR_ERR(handle);
- goto no_write;
- }
- /*
- * It's mmapped pagecache. Add buffers and journal it. There
- * doesn't seem much point in redirtying the page here.
- */
- ClearPageChecked(page);
- ret = __block_write_begin(page, 0, PAGE_CACHE_SIZE,
- ext3_get_block);
- if (ret != 0) {
- ext3_journal_stop(handle);
- goto out_unlock;
- }
- ret = walk_page_buffers(handle, page_buffers(page), 0,
- PAGE_CACHE_SIZE, NULL, do_journal_get_write_access);
-
- err = walk_page_buffers(handle, page_buffers(page), 0,
- PAGE_CACHE_SIZE, NULL, write_end_fn);
- if (ret == 0)
- ret = err;
- ext3_set_inode_state(inode, EXT3_STATE_JDATA);
- atomic_set(&EXT3_I(inode)->i_datasync_tid,
- handle->h_transaction->t_tid);
- unlock_page(page);
- err = ext3_journal_stop(handle);
- if (!ret)
- ret = err;
- } else {
- /*
- * It is a page full of checkpoint-mode buffers. Go and write
- * them. They should have been already mapped when they went
- * to the journal so provide NULL get_block function to catch
- * errors.
- */
- ret = block_write_full_page(page, NULL, wbc);
- }
-out:
- return ret;
-
-no_write:
- redirty_page_for_writepage(wbc, page);
-out_unlock:
- unlock_page(page);
- goto out;
-}
-
-static int ext3_readpage(struct file *file, struct page *page)
-{
- trace_ext3_readpage(page);
- return mpage_readpage(page, ext3_get_block);
-}
-
-static int
-ext3_readpages(struct file *file, struct address_space *mapping,
- struct list_head *pages, unsigned nr_pages)
-{
- return mpage_readpages(mapping, pages, nr_pages, ext3_get_block);
-}
-
-static void ext3_invalidatepage(struct page *page, unsigned int offset,
- unsigned int length)
-{
- journal_t *journal = EXT3_JOURNAL(page->mapping->host);
-
- trace_ext3_invalidatepage(page, offset, length);
-
- /*
- * If it's a full truncate we just forget about the pending dirtying
- */
- if (offset == 0 && length == PAGE_CACHE_SIZE)
- ClearPageChecked(page);
-
- journal_invalidatepage(journal, page, offset, length);
-}
-
-static int ext3_releasepage(struct page *page, gfp_t wait)
-{
- journal_t *journal = EXT3_JOURNAL(page->mapping->host);
-
- trace_ext3_releasepage(page);
- WARN_ON(PageChecked(page));
- if (!page_has_buffers(page))
- return 0;
- return journal_try_to_free_buffers(journal, page, wait);
-}
-
-/*
- * If the O_DIRECT write will extend the file then add this inode to the
- * orphan list. So recovery will truncate it back to the original size
- * if the machine crashes during the write.
- *
- * If the O_DIRECT write is intantiating holes inside i_size and the machine
- * crashes then stale disk data _may_ be exposed inside the file. But current
- * VFS code falls back into buffered path in that case so we are safe.
- */
-static ssize_t ext3_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
- loff_t offset)
-{
- struct file *file = iocb->ki_filp;
- struct inode *inode = file->f_mapping->host;
- struct ext3_inode_info *ei = EXT3_I(inode);
- handle_t *handle;
- ssize_t ret;
- int orphan = 0;
- size_t count = iov_iter_count(iter);
- int retries = 0;
-
- trace_ext3_direct_IO_enter(inode, offset, count, iov_iter_rw(iter));
-
- if (iov_iter_rw(iter) == WRITE) {
- loff_t final_size = offset + count;
-
- if (final_size > inode->i_size) {
- /* Credits for sb + inode write */
- handle = ext3_journal_start(inode, 2);
- if (IS_ERR(handle)) {
- ret = PTR_ERR(handle);
- goto out;
- }
- ret = ext3_orphan_add(handle, inode);
- if (ret) {
- ext3_journal_stop(handle);
- goto out;
- }
- orphan = 1;
- ei->i_disksize = inode->i_size;
- ext3_journal_stop(handle);
- }
- }
-
-retry:
- ret = blockdev_direct_IO(iocb, inode, iter, offset, ext3_get_block);
- /*
- * In case of error extending write may have instantiated a few
- * blocks outside i_size. Trim these off again.
- */
- if (unlikely(iov_iter_rw(iter) == WRITE && ret < 0)) {
- loff_t isize = i_size_read(inode);
- loff_t end = offset + count;
-
- if (end > isize)
- ext3_truncate_failed_direct_write(inode);
- }
- if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
- goto retry;
-
- if (orphan) {
- int err;
-
- /* Credits for sb + inode write */
- handle = ext3_journal_start(inode, 2);
- if (IS_ERR(handle)) {
- /* This is really bad luck. We've written the data
- * but cannot extend i_size. Truncate allocated blocks
- * and pretend the write failed... */
- ext3_truncate_failed_direct_write(inode);
- ret = PTR_ERR(handle);
- if (inode->i_nlink)
- ext3_orphan_del(NULL, inode);
- goto out;
- }
- if (inode->i_nlink)
- ext3_orphan_del(handle, inode);
- if (ret > 0) {
- loff_t end = offset + ret;
- if (end > inode->i_size) {
- ei->i_disksize = end;
- i_size_write(inode, end);
- /*
- * We're going to return a positive `ret'
- * here due to non-zero-length I/O, so there's
- * no way of reporting error returns from
- * ext3_mark_inode_dirty() to userspace. So
- * ignore it.
- */
- ext3_mark_inode_dirty(handle, inode);
- }
- }
- err = ext3_journal_stop(handle);
- if (ret == 0)
- ret = err;
- }
-out:
- trace_ext3_direct_IO_exit(inode, offset, count, iov_iter_rw(iter), ret);
- return ret;
-}
-
-/*
- * Pages can be marked dirty completely asynchronously from ext3's journalling
- * activity. By filemap_sync_pte(), try_to_unmap_one(), etc. We cannot do
- * much here because ->set_page_dirty is called under VFS locks. The page is
- * not necessarily locked.
- *
- * We cannot just dirty the page and leave attached buffers clean, because the
- * buffers' dirty state is "definitive". We cannot just set the buffers dirty
- * or jbddirty because all the journalling code will explode.
- *
- * So what we do is to mark the page "pending dirty" and next time writepage
- * is called, propagate that into the buffers appropriately.
- */
-static int ext3_journalled_set_page_dirty(struct page *page)
-{
- SetPageChecked(page);
- return __set_page_dirty_nobuffers(page);
-}
-
-static const struct address_space_operations ext3_ordered_aops = {
- .readpage = ext3_readpage,
- .readpages = ext3_readpages,
- .writepage = ext3_ordered_writepage,
- .write_begin = ext3_write_begin,
- .write_end = ext3_ordered_write_end,
- .bmap = ext3_bmap,
- .invalidatepage = ext3_invalidatepage,
- .releasepage = ext3_releasepage,
- .direct_IO = ext3_direct_IO,
- .migratepage = buffer_migrate_page,
- .is_partially_uptodate = block_is_partially_uptodate,
- .is_dirty_writeback = buffer_check_dirty_writeback,
- .error_remove_page = generic_error_remove_page,
-};
-
-static const struct address_space_operations ext3_writeback_aops = {
- .readpage = ext3_readpage,
- .readpages = ext3_readpages,
- .writepage = ext3_writeback_writepage,
- .write_begin = ext3_write_begin,
- .write_end = ext3_writeback_write_end,
- .bmap = ext3_bmap,
- .invalidatepage = ext3_invalidatepage,
- .releasepage = ext3_releasepage,
- .direct_IO = ext3_direct_IO,
- .migratepage = buffer_migrate_page,
- .is_partially_uptodate = block_is_partially_uptodate,
- .error_remove_page = generic_error_remove_page,
-};
-
-static const struct address_space_operations ext3_journalled_aops = {
- .readpage = ext3_readpage,
- .readpages = ext3_readpages,
- .writepage = ext3_journalled_writepage,
- .write_begin = ext3_write_begin,
- .write_end = ext3_journalled_write_end,
- .set_page_dirty = ext3_journalled_set_page_dirty,
- .bmap = ext3_bmap,
- .invalidatepage = ext3_invalidatepage,
- .releasepage = ext3_releasepage,
- .is_partially_uptodate = block_is_partially_uptodate,
- .error_remove_page = generic_error_remove_page,
-};
-
-void ext3_set_aops(struct inode *inode)
-{
- if (ext3_should_order_data(inode))
- inode->i_mapping->a_ops = &ext3_ordered_aops;
- else if (ext3_should_writeback_data(inode))
- inode->i_mapping->a_ops = &ext3_writeback_aops;
- else
- inode->i_mapping->a_ops = &ext3_journalled_aops;
-}
-
-/*
- * ext3_block_truncate_page() zeroes out a mapping from file offset `from'
- * up to the end of the block which corresponds to `from'.
- * This required during truncate. We need to physically zero the tail end
- * of that block so it doesn't yield old data if the file is later grown.
- */
-static int ext3_block_truncate_page(struct inode *inode, loff_t from)
-{
- ext3_fsblk_t index = from >> PAGE_CACHE_SHIFT;
- unsigned offset = from & (PAGE_CACHE_SIZE - 1);
- unsigned blocksize, iblock, length, pos;
- struct page *page;
- handle_t *handle = NULL;
- struct buffer_head *bh;
- int err = 0;
-
- /* Truncated on block boundary - nothing to do */
- blocksize = inode->i_sb->s_blocksize;
- if ((from & (blocksize - 1)) == 0)
- return 0;
-
- page = grab_cache_page(inode->i_mapping, index);
- if (!page)
- return -ENOMEM;
- length = blocksize - (offset & (blocksize - 1));
- iblock = index << (PAGE_CACHE_SHIFT - inode->i_sb->s_blocksize_bits);
-
- if (!page_has_buffers(page))
- create_empty_buffers(page, blocksize, 0);
-
- /* Find the buffer that contains "offset" */
- bh = page_buffers(page);
- pos = blocksize;
- while (offset >= pos) {
- bh = bh->b_this_page;
- iblock++;
- pos += blocksize;
- }
-
- err = 0;
- if (buffer_freed(bh)) {
- BUFFER_TRACE(bh, "freed: skip");
- goto unlock;
- }
-
- if (!buffer_mapped(bh)) {
- BUFFER_TRACE(bh, "unmapped");
- ext3_get_block(inode, iblock, bh, 0);
- /* unmapped? It's a hole - nothing to do */
- if (!buffer_mapped(bh)) {
- BUFFER_TRACE(bh, "still unmapped");
- goto unlock;
- }
- }
-
- /* Ok, it's mapped. Make sure it's up-to-date */
- if (PageUptodate(page))
- set_buffer_uptodate(bh);
-
- if (!bh_uptodate_or_lock(bh)) {
- err = bh_submit_read(bh);
- /* Uhhuh. Read error. Complain and punt. */
- if (err)
- goto unlock;
- }
-
- /* data=writeback mode doesn't need transaction to zero-out data */
- if (!ext3_should_writeback_data(inode)) {
- /* We journal at most one block */
- handle = ext3_journal_start(inode, 1);
- if (IS_ERR(handle)) {
- clear_highpage(page);
- flush_dcache_page(page);
- err = PTR_ERR(handle);
- goto unlock;
- }
- }
-
- if (ext3_should_journal_data(inode)) {
- BUFFER_TRACE(bh, "get write access");
- err = ext3_journal_get_write_access(handle, bh);
- if (err)
- goto stop;
- }
-
- zero_user(page, offset, length);
- BUFFER_TRACE(bh, "zeroed end of block");
-
- err = 0;
- if (ext3_should_journal_data(inode)) {
- err = ext3_journal_dirty_metadata(handle, bh);
- } else {
- if (ext3_should_order_data(inode))
- err = ext3_journal_dirty_data(handle, bh);
- mark_buffer_dirty(bh);
- }
-stop:
- if (handle)
- ext3_journal_stop(handle);
-
-unlock:
- unlock_page(page);
- page_cache_release(page);
- return err;
-}
-
-/*
- * Probably it should be a library function... search for first non-zero word
- * or memcmp with zero_page, whatever is better for particular architecture.
- * Linus?
- */
-static inline int all_zeroes(__le32 *p, __le32 *q)
-{
- while (p < q)
- if (*p++)
- return 0;
- return 1;
-}
-
-/**
- * ext3_find_shared - find the indirect blocks for partial truncation.
- * @inode: inode in question
- * @depth: depth of the affected branch
- * @offsets: offsets of pointers in that branch (see ext3_block_to_path)
- * @chain: place to store the pointers to partial indirect blocks
- * @top: place to the (detached) top of branch
- *
- * This is a helper function used by ext3_truncate().
- *
- * When we do truncate() we may have to clean the ends of several
- * indirect blocks but leave the blocks themselves alive. Block is
- * partially truncated if some data below the new i_size is referred
- * from it (and it is on the path to the first completely truncated
- * data block, indeed). We have to free the top of that path along
- * with everything to the right of the path. Since no allocation
- * past the truncation point is possible until ext3_truncate()
- * finishes, we may safely do the latter, but top of branch may
- * require special attention - pageout below the truncation point
- * might try to populate it.
- *
- * We atomically detach the top of branch from the tree, store the
- * block number of its root in *@top, pointers to buffer_heads of
- * partially truncated blocks - in @chain[].bh and pointers to
- * their last elements that should not be removed - in
- * @chain[].p. Return value is the pointer to last filled element
- * of @chain.
- *
- * The work left to caller to do the actual freeing of subtrees:
- * a) free the subtree starting from *@top
- * b) free the subtrees whose roots are stored in
- * (@chain[i].p+1 .. end of @chain[i].bh->b_data)
- * c) free the subtrees growing from the inode past the @chain[0].
- * (no partially truncated stuff there). */
-
-static Indirect *ext3_find_shared(struct inode *inode, int depth,
- int offsets[4], Indirect chain[4], __le32 *top)
-{
- Indirect *partial, *p;
- int k, err;
-
- *top = 0;
- /* Make k index the deepest non-null offset + 1 */
- for (k = depth; k > 1 && !offsets[k-1]; k--)
- ;
- partial = ext3_get_branch(inode, k, offsets, chain, &err);
- /* Writer: pointers */
- if (!partial)
- partial = chain + k-1;
- /*
- * If the branch acquired continuation since we've looked at it -
- * fine, it should all survive and (new) top doesn't belong to us.
- */
- if (!partial->key && *partial->p)
- /* Writer: end */
- goto no_top;
- for (p=partial; p>chain && all_zeroes((__le32*)p->bh->b_data,p->p); p--)
- ;
- /*
- * OK, we've found the last block that must survive. The rest of our
- * branch should be detached before unlocking. However, if that rest
- * of branch is all ours and does not grow immediately from the inode
- * it's easier to cheat and just decrement partial->p.
- */
- if (p == chain + k - 1 && p > chain) {
- p->p--;
- } else {
- *top = *p->p;
- /* Nope, don't do this in ext3. Must leave the tree intact */
-#if 0
- *p->p = 0;
-#endif
- }
- /* Writer: end */
-
- while(partial > p) {
- brelse(partial->bh);
- partial--;
- }
-no_top:
- return partial;
-}
-
-/*
- * Zero a number of block pointers in either an inode or an indirect block.
- * If we restart the transaction we must again get write access to the
- * indirect block for further modification.
- *
- * We release `count' blocks on disk, but (last - first) may be greater
- * than `count' because there can be holes in there.
- */
-static void ext3_clear_blocks(handle_t *handle, struct inode *inode,
- struct buffer_head *bh, ext3_fsblk_t block_to_free,
- unsigned long count, __le32 *first, __le32 *last)
-{
- __le32 *p;
- if (try_to_extend_transaction(handle, inode)) {
- if (bh) {
- BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
- if (ext3_journal_dirty_metadata(handle, bh))
- return;
- }
- ext3_mark_inode_dirty(handle, inode);
- truncate_restart_transaction(handle, inode);
- if (bh) {
- BUFFER_TRACE(bh, "retaking write access");
- if (ext3_journal_get_write_access(handle, bh))
- return;
- }
- }
-
- /*
- * Any buffers which are on the journal will be in memory. We find
- * them on the hash table so journal_revoke() will run journal_forget()
- * on them. We've already detached each block from the file, so
- * bforget() in journal_forget() should be safe.
- *
- * AKPM: turn on bforget in journal_forget()!!!
- */
- for (p = first; p < last; p++) {
- u32 nr = le32_to_cpu(*p);
- if (nr) {
- struct buffer_head *bh;
-
- *p = 0;
- bh = sb_find_get_block(inode->i_sb, nr);
- ext3_forget(handle, 0, inode, bh, nr);
- }
- }
-
- ext3_free_blocks(handle, inode, block_to_free, count);
-}
-
-/**
- * ext3_free_data - free a list of data blocks
- * @handle: handle for this transaction
- * @inode: inode we are dealing with
- * @this_bh: indirect buffer_head which contains *@first and *@last
- * @first: array of block numbers
- * @last: points immediately past the end of array
- *
- * We are freeing all blocks referred from that array (numbers are stored as
- * little-endian 32-bit) and updating @inode->i_blocks appropriately.
- *
- * We accumulate contiguous runs of blocks to free. Conveniently, if these
- * blocks are contiguous then releasing them at one time will only affect one
- * or two bitmap blocks (+ group descriptor(s) and superblock) and we won't
- * actually use a lot of journal space.
- *
- * @this_bh will be %NULL if @first and @last point into the inode's direct
- * block pointers.
- */
-static void ext3_free_data(handle_t *handle, struct inode *inode,
- struct buffer_head *this_bh,
- __le32 *first, __le32 *last)
-{
- ext3_fsblk_t block_to_free = 0; /* Starting block # of a run */
- unsigned long count = 0; /* Number of blocks in the run */
- __le32 *block_to_free_p = NULL; /* Pointer into inode/ind
- corresponding to
- block_to_free */
- ext3_fsblk_t nr; /* Current block # */
- __le32 *p; /* Pointer into inode/ind
- for current block */
- int err;
-
- if (this_bh) { /* For indirect block */
- BUFFER_TRACE(this_bh, "get_write_access");
- err = ext3_journal_get_write_access(handle, this_bh);
- /* Important: if we can't update the indirect pointers
- * to the blocks, we can't free them. */
- if (err)
- return;
- }
-
- for (p = first; p < last; p++) {
- nr = le32_to_cpu(*p);
- if (nr) {
- /* accumulate blocks to free if they're contiguous */
- if (count == 0) {
- block_to_free = nr;
- block_to_free_p = p;
- count = 1;
- } else if (nr == block_to_free + count) {
- count++;
- } else {
- ext3_clear_blocks(handle, inode, this_bh,
- block_to_free,
- count, block_to_free_p, p);
- block_to_free = nr;
- block_to_free_p = p;
- count = 1;
- }
- }
- }
-
- if (count > 0)
- ext3_clear_blocks(handle, inode, this_bh, block_to_free,
- count, block_to_free_p, p);
-
- if (this_bh) {
- BUFFER_TRACE(this_bh, "call ext3_journal_dirty_metadata");
-
- /*
- * The buffer head should have an attached journal head at this
- * point. However, if the data is corrupted and an indirect
- * block pointed to itself, it would have been detached when
- * the block was cleared. Check for this instead of OOPSing.
- */
- if (bh2jh(this_bh))
- ext3_journal_dirty_metadata(handle, this_bh);
- else
- ext3_error(inode->i_sb, "ext3_free_data",
- "circular indirect block detected, "
- "inode=%lu, block=%llu",
- inode->i_ino,
- (unsigned long long)this_bh->b_blocknr);
- }
-}
-
-/**
- * ext3_free_branches - free an array of branches
- * @handle: JBD handle for this transaction
- * @inode: inode we are dealing with
- * @parent_bh: the buffer_head which contains *@first and *@last
- * @first: array of block numbers
- * @last: pointer immediately past the end of array
- * @depth: depth of the branches to free
- *
- * We are freeing all blocks referred from these branches (numbers are
- * stored as little-endian 32-bit) and updating @inode->i_blocks
- * appropriately.
- */
-static void ext3_free_branches(handle_t *handle, struct inode *inode,
- struct buffer_head *parent_bh,
- __le32 *first, __le32 *last, int depth)
-{
- ext3_fsblk_t nr;
- __le32 *p;
-
- if (is_handle_aborted(handle))
- return;
-
- if (depth--) {
- struct buffer_head *bh;
- int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
- p = last;
- while (--p >= first) {
- nr = le32_to_cpu(*p);
- if (!nr)
- continue; /* A hole */
-
- /* Go read the buffer for the next level down */
- bh = sb_bread(inode->i_sb, nr);
-
- /*
- * A read failure? Report error and clear slot
- * (should be rare).
- */
- if (!bh) {
- ext3_error(inode->i_sb, "ext3_free_branches",
- "Read failure, inode=%lu, block="E3FSBLK,
- inode->i_ino, nr);
- continue;
- }
-
- /* This zaps the entire block. Bottom up. */
- BUFFER_TRACE(bh, "free child branches");
- ext3_free_branches(handle, inode, bh,
- (__le32*)bh->b_data,
- (__le32*)bh->b_data + addr_per_block,
- depth);
-
- /*
- * Everything below this this pointer has been
- * released. Now let this top-of-subtree go.
- *
- * We want the freeing of this indirect block to be
- * atomic in the journal with the updating of the
- * bitmap block which owns it. So make some room in
- * the journal.
- *
- * We zero the parent pointer *after* freeing its
- * pointee in the bitmaps, so if extend_transaction()
- * for some reason fails to put the bitmap changes and
- * the release into the same transaction, recovery
- * will merely complain about releasing a free block,
- * rather than leaking blocks.
- */
- if (is_handle_aborted(handle))
- return;
- if (try_to_extend_transaction(handle, inode)) {
- ext3_mark_inode_dirty(handle, inode);
- truncate_restart_transaction(handle, inode);
- }
-
- /*
- * We've probably journalled the indirect block several
- * times during the truncate. But it's no longer
- * needed and we now drop it from the transaction via
- * journal_revoke().
- *
- * That's easy if it's exclusively part of this
- * transaction. But if it's part of the committing
- * transaction then journal_forget() will simply
- * brelse() it. That means that if the underlying
- * block is reallocated in ext3_get_block(),
- * unmap_underlying_metadata() will find this block
- * and will try to get rid of it. damn, damn. Thus
- * we don't allow a block to be reallocated until
- * a transaction freeing it has fully committed.
- *
- * We also have to make sure journal replay after a
- * crash does not overwrite non-journaled data blocks
- * with old metadata when the block got reallocated for
- * data. Thus we have to store a revoke record for a
- * block in the same transaction in which we free the
- * block.
- */
- ext3_forget(handle, 1, inode, bh, bh->b_blocknr);
-
- ext3_free_blocks(handle, inode, nr, 1);
-
- if (parent_bh) {
- /*
- * The block which we have just freed is
- * pointed to by an indirect block: journal it
- */
- BUFFER_TRACE(parent_bh, "get_write_access");
- if (!ext3_journal_get_write_access(handle,
- parent_bh)){
- *p = 0;
- BUFFER_TRACE(parent_bh,
- "call ext3_journal_dirty_metadata");
- ext3_journal_dirty_metadata(handle,
- parent_bh);
- }
- }
- }
- } else {
- /* We have reached the bottom of the tree. */
- BUFFER_TRACE(parent_bh, "free data blocks");
- ext3_free_data(handle, inode, parent_bh, first, last);
- }
-}
-
-int ext3_can_truncate(struct inode *inode)
-{
- if (S_ISREG(inode->i_mode))
- return 1;
- if (S_ISDIR(inode->i_mode))
- return 1;
- if (S_ISLNK(inode->i_mode))
- return !ext3_inode_is_fast_symlink(inode);
- return 0;
-}
-
-/*
- * ext3_truncate()
- *
- * We block out ext3_get_block() block instantiations across the entire
- * transaction, and VFS/VM ensures that ext3_truncate() cannot run
- * simultaneously on behalf of the same inode.
- *
- * As we work through the truncate and commit bits of it to the journal there
- * is one core, guiding principle: the file's tree must always be consistent on
- * disk. We must be able to restart the truncate after a crash.
- *
- * The file's tree may be transiently inconsistent in memory (although it
- * probably isn't), but whenever we close off and commit a journal transaction,
- * the contents of (the filesystem + the journal) must be consistent and
- * restartable. It's pretty simple, really: bottom up, right to left (although
- * left-to-right works OK too).
- *
- * Note that at recovery time, journal replay occurs *before* the restart of
- * truncate against the orphan inode list.
- *
- * The committed inode has the new, desired i_size (which is the same as
- * i_disksize in this case). After a crash, ext3_orphan_cleanup() will see
- * that this inode's truncate did not complete and it will again call
- * ext3_truncate() to have another go. So there will be instantiated blocks
- * to the right of the truncation point in a crashed ext3 filesystem. But
- * that's fine - as long as they are linked from the inode, the post-crash
- * ext3_truncate() run will find them and release them.
- */
-void ext3_truncate(struct inode *inode)
-{
- handle_t *handle;
- struct ext3_inode_info *ei = EXT3_I(inode);
- __le32 *i_data = ei->i_data;
- int addr_per_block = EXT3_ADDR_PER_BLOCK(inode->i_sb);
- int offsets[4];
- Indirect chain[4];
- Indirect *partial;
- __le32 nr = 0;
- int n;
- long last_block;
- unsigned blocksize = inode->i_sb->s_blocksize;
-
- trace_ext3_truncate_enter(inode);
-
- if (!ext3_can_truncate(inode))
- goto out_notrans;
-
- if (inode->i_size == 0 && ext3_should_writeback_data(inode))
- ext3_set_inode_state(inode, EXT3_STATE_FLUSH_ON_CLOSE);
-
- handle = start_transaction(inode);
- if (IS_ERR(handle))
- goto out_notrans;
-
- last_block = (inode->i_size + blocksize-1)
- >> EXT3_BLOCK_SIZE_BITS(inode->i_sb);
- n = ext3_block_to_path(inode, last_block, offsets, NULL);
- if (n == 0)
- goto out_stop; /* error */
-
- /*
- * OK. This truncate is going to happen. We add the inode to the
- * orphan list, so that if this truncate spans multiple transactions,
- * and we crash, we will resume the truncate when the filesystem
- * recovers. It also marks the inode dirty, to catch the new size.
- *
- * Implication: the file must always be in a sane, consistent
- * truncatable state while each transaction commits.
- */
- if (ext3_orphan_add(handle, inode))
- goto out_stop;
-
- /*
- * The orphan list entry will now protect us from any crash which
- * occurs before the truncate completes, so it is now safe to propagate
- * the new, shorter inode size (held for now in i_size) into the
- * on-disk inode. We do this via i_disksize, which is the value which
- * ext3 *really* writes onto the disk inode.
- */
- ei->i_disksize = inode->i_size;
-
- /*
- * From here we block out all ext3_get_block() callers who want to
- * modify the block allocation tree.
- */
- mutex_lock(&ei->truncate_mutex);
-
- if (n == 1) { /* direct blocks */
- ext3_free_data(handle, inode, NULL, i_data+offsets[0],
- i_data + EXT3_NDIR_BLOCKS);
- goto do_indirects;
- }
-
- partial = ext3_find_shared(inode, n, offsets, chain, &nr);
- /* Kill the top of shared branch (not detached) */
- if (nr) {
- if (partial == chain) {
- /* Shared branch grows from the inode */
- ext3_free_branches(handle, inode, NULL,
- &nr, &nr+1, (chain+n-1) - partial);
- *partial->p = 0;
- /*
- * We mark the inode dirty prior to restart,
- * and prior to stop. No need for it here.
- */
- } else {
- /* Shared branch grows from an indirect block */
- ext3_free_branches(handle, inode, partial->bh,
- partial->p,
- partial->p+1, (chain+n-1) - partial);
- }
- }
- /* Clear the ends of indirect blocks on the shared branch */
- while (partial > chain) {
- ext3_free_branches(handle, inode, partial->bh, partial->p + 1,
- (__le32*)partial->bh->b_data+addr_per_block,
- (chain+n-1) - partial);
- BUFFER_TRACE(partial->bh, "call brelse");
- brelse (partial->bh);
- partial--;
- }
-do_indirects:
- /* Kill the remaining (whole) subtrees */
- switch (offsets[0]) {
- default:
- nr = i_data[EXT3_IND_BLOCK];
- if (nr) {
- ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 1);
- i_data[EXT3_IND_BLOCK] = 0;
- }
- case EXT3_IND_BLOCK:
- nr = i_data[EXT3_DIND_BLOCK];
- if (nr) {
- ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 2);
- i_data[EXT3_DIND_BLOCK] = 0;
- }
- case EXT3_DIND_BLOCK:
- nr = i_data[EXT3_TIND_BLOCK];
- if (nr) {
- ext3_free_branches(handle, inode, NULL, &nr, &nr+1, 3);
- i_data[EXT3_TIND_BLOCK] = 0;
- }
- case EXT3_TIND_BLOCK:
- ;
- }
-
- ext3_discard_reservation(inode);
-
- mutex_unlock(&ei->truncate_mutex);
- inode->i_mtime = inode->i_ctime = CURRENT_TIME_SEC;
- ext3_mark_inode_dirty(handle, inode);
-
- /*
- * In a multi-transaction truncate, we only make the final transaction
- * synchronous
- */
- if (IS_SYNC(inode))
- handle->h_sync = 1;
-out_stop:
- /*
- * If this was a simple ftruncate(), and the file will remain alive
- * then we need to clear up the orphan record which we created above.
- * However, if this was a real unlink then we were called by
- * ext3_evict_inode(), and we allow that function to clean up the
- * orphan info for us.
- */
- if (inode->i_nlink)
- ext3_orphan_del(handle, inode);
-
- ext3_journal_stop(handle);
- trace_ext3_truncate_exit(inode);
- return;
-out_notrans:
- /*
- * Delete the inode from orphan list so that it doesn't stay there
- * forever and trigger assertion on umount.
- */
- if (inode->i_nlink)
- ext3_orphan_del(NULL, inode);
- trace_ext3_truncate_exit(inode);
-}
-
-static ext3_fsblk_t ext3_get_inode_block(struct super_block *sb,
- unsigned long ino, struct ext3_iloc *iloc)
-{
- unsigned long block_group;
- unsigned long offset;
- ext3_fsblk_t block;
- struct ext3_group_desc *gdp;
-
- if (!ext3_valid_inum(sb, ino)) {
- /*
- * This error is already checked for in namei.c unless we are
- * looking at an NFS filehandle, in which case no error
- * report is needed
- */
- return 0;
- }
-
- block_group = (ino - 1) / EXT3_INODES_PER_GROUP(sb);
- gdp = ext3_get_group_desc(sb, block_group, NULL);
- if (!gdp)
- return 0;
- /*
- * Figure out the offset within the block group inode table
- */
- offset = ((ino - 1) % EXT3_INODES_PER_GROUP(sb)) *
- EXT3_INODE_SIZE(sb);
- block = le32_to_cpu(gdp->bg_inode_table) +
- (offset >> EXT3_BLOCK_SIZE_BITS(sb));
-
- iloc->block_group = block_group;
- iloc->offset = offset & (EXT3_BLOCK_SIZE(sb) - 1);
- return block;
-}
-
-/*
- * ext3_get_inode_loc returns with an extra refcount against the inode's
- * underlying buffer_head on success. If 'in_mem' is true, we have all
- * data in memory that is needed to recreate the on-disk version of this
- * inode.
- */
-static int __ext3_get_inode_loc(struct inode *inode,
- struct ext3_iloc *iloc, int in_mem)
-{
- ext3_fsblk_t block;
- struct buffer_head *bh;
-
- block = ext3_get_inode_block(inode->i_sb, inode->i_ino, iloc);
- if (!block)
- return -EIO;
-
- bh = sb_getblk(inode->i_sb, block);
- if (unlikely(!bh)) {
- ext3_error (inode->i_sb, "ext3_get_inode_loc",
- "unable to read inode block - "
- "inode=%lu, block="E3FSBLK,
- inode->i_ino, block);
- return -ENOMEM;
- }
- if (!buffer_uptodate(bh)) {
- lock_buffer(bh);
-
- /*
- * If the buffer has the write error flag, we have failed
- * to write out another inode in the same block. In this
- * case, we don't have to read the block because we may
- * read the old inode data successfully.
- */
- if (buffer_write_io_error(bh) && !buffer_uptodate(bh))
- set_buffer_uptodate(bh);
-
- if (buffer_uptodate(bh)) {
- /* someone brought it uptodate while we waited */
- unlock_buffer(bh);
- goto has_buffer;
- }
-
- /*
- * If we have all information of the inode in memory and this
- * is the only valid inode in the block, we need not read the
- * block.
- */
- if (in_mem) {
- struct buffer_head *bitmap_bh;
- struct ext3_group_desc *desc;
- int inodes_per_buffer;
- int inode_offset, i;
- int block_group;
- int start;
-
- block_group = (inode->i_ino - 1) /
- EXT3_INODES_PER_GROUP(inode->i_sb);
- inodes_per_buffer = bh->b_size /
- EXT3_INODE_SIZE(inode->i_sb);
- inode_offset = ((inode->i_ino - 1) %
- EXT3_INODES_PER_GROUP(inode->i_sb));
- start = inode_offset & ~(inodes_per_buffer - 1);
-
- /* Is the inode bitmap in cache? */
- desc = ext3_get_group_desc(inode->i_sb,
- block_group, NULL);
- if (!desc)
- goto make_io;
-
- bitmap_bh = sb_getblk(inode->i_sb,
- le32_to_cpu(desc->bg_inode_bitmap));
- if (unlikely(!bitmap_bh))
- goto make_io;
-
- /*
- * If the inode bitmap isn't in cache then the
- * optimisation may end up performing two reads instead
- * of one, so skip it.
- */
- if (!buffer_uptodate(bitmap_bh)) {
- brelse(bitmap_bh);
- goto make_io;
- }
- for (i = start; i < start + inodes_per_buffer; i++) {
- if (i == inode_offset)
- continue;
- if (ext3_test_bit(i, bitmap_bh->b_data))
- break;
- }
- brelse(bitmap_bh);
- if (i == start + inodes_per_buffer) {
- /* all other inodes are free, so skip I/O */
- memset(bh->b_data, 0, bh->b_size);
- set_buffer_uptodate(bh);
- unlock_buffer(bh);
- goto has_buffer;
- }
- }
-
-make_io:
- /*
- * There are other valid inodes in the buffer, this inode
- * has in-inode xattrs, or we don't have this inode in memory.
- * Read the block from disk.
- */
- trace_ext3_load_inode(inode);
- get_bh(bh);
- bh->b_end_io = end_buffer_read_sync;
- submit_bh(READ | REQ_META | REQ_PRIO, bh);
- wait_on_buffer(bh);
- if (!buffer_uptodate(bh)) {
- ext3_error(inode->i_sb, "ext3_get_inode_loc",
- "unable to read inode block - "
- "inode=%lu, block="E3FSBLK,
- inode->i_ino, block);
- brelse(bh);
- return -EIO;
- }
- }
-has_buffer:
- iloc->bh = bh;
- return 0;
-}
-
-int ext3_get_inode_loc(struct inode *inode, struct ext3_iloc *iloc)
-{
- /* We have all inode data except xattrs in memory here. */
- return __ext3_get_inode_loc(inode, iloc,
- !ext3_test_inode_state(inode, EXT3_STATE_XATTR));
-}
-
-void ext3_set_inode_flags(struct inode *inode)
-{
- unsigned int flags = EXT3_I(inode)->i_flags;
-
- inode->i_flags &= ~(S_SYNC|S_APPEND|S_IMMUTABLE|S_NOATIME|S_DIRSYNC);
- if (flags & EXT3_SYNC_FL)
- inode->i_flags |= S_SYNC;
- if (flags & EXT3_APPEND_FL)
- inode->i_flags |= S_APPEND;
- if (flags & EXT3_IMMUTABLE_FL)
- inode->i_flags |= S_IMMUTABLE;
- if (flags & EXT3_NOATIME_FL)
- inode->i_flags |= S_NOATIME;
- if (flags & EXT3_DIRSYNC_FL)
- inode->i_flags |= S_DIRSYNC;
-}
-
-/* Propagate flags from i_flags to EXT3_I(inode)->i_flags */
-void ext3_get_inode_flags(struct ext3_inode_info *ei)
-{
- unsigned int flags = ei->vfs_inode.i_flags;
-
- ei->i_flags &= ~(EXT3_SYNC_FL|EXT3_APPEND_FL|
- EXT3_IMMUTABLE_FL|EXT3_NOATIME_FL|EXT3_DIRSYNC_FL);
- if (flags & S_SYNC)
- ei->i_flags |= EXT3_SYNC_FL;
- if (flags & S_APPEND)
- ei->i_flags |= EXT3_APPEND_FL;
- if (flags & S_IMMUTABLE)
- ei->i_flags |= EXT3_IMMUTABLE_FL;
- if (flags & S_NOATIME)
- ei->i_flags |= EXT3_NOATIME_FL;
- if (flags & S_DIRSYNC)
- ei->i_flags |= EXT3_DIRSYNC_FL;
-}
-
-struct inode *ext3_iget(struct super_block *sb, unsigned long ino)
-{
- struct ext3_iloc iloc;
- struct ext3_inode *raw_inode;
- struct ext3_inode_info *ei;
- struct buffer_head *bh;
- struct inode *inode;
- journal_t *journal = EXT3_SB(sb)->s_journal;
- transaction_t *transaction;
- long ret;
- int block;
- uid_t i_uid;
- gid_t i_gid;
-
- inode = iget_locked(sb, ino);
- if (!inode)
- return ERR_PTR(-ENOMEM);
- if (!(inode->i_state & I_NEW))
- return inode;
-
- ei = EXT3_I(inode);
- ei->i_block_alloc_info = NULL;
-
- ret = __ext3_get_inode_loc(inode, &iloc, 0);
- if (ret < 0)
- goto bad_inode;
- bh = iloc.bh;
- raw_inode = ext3_raw_inode(&iloc);
- inode->i_mode = le16_to_cpu(raw_inode->i_mode);
- i_uid = (uid_t)le16_to_cpu(raw_inode->i_uid_low);
- i_gid = (gid_t)le16_to_cpu(raw_inode->i_gid_low);
- if(!(test_opt (inode->i_sb, NO_UID32))) {
- i_uid |= le16_to_cpu(raw_inode->i_uid_high) << 16;
- i_gid |= le16_to_cpu(raw_inode->i_gid_high) << 16;
- }
- i_uid_write(inode, i_uid);
- i_gid_write(inode, i_gid);
- set_nlink(inode, le16_to_cpu(raw_inode->i_links_count));
- inode->i_size = le32_to_cpu(raw_inode->i_size);
- inode->i_atime.tv_sec = (signed)le32_to_cpu(raw_inode->i_atime);
- inode->i_ctime.tv_sec = (signed)le32_to_cpu(raw_inode->i_ctime);
- inode->i_mtime.tv_sec = (signed)le32_to_cpu(raw_inode->i_mtime);
- inode->i_atime.tv_nsec = inode->i_ctime.tv_nsec = inode->i_mtime.tv_nsec = 0;
-
- ei->i_state_flags = 0;
- ei->i_dir_start_lookup = 0;
- ei->i_dtime = le32_to_cpu(raw_inode->i_dtime);
- /* We now have enough fields to check if the inode was active or not.
- * This is needed because nfsd might try to access dead inodes
- * the test is that same one that e2fsck uses
- * NeilBrown 1999oct15
- */
- if (inode->i_nlink == 0) {
- if (inode->i_mode == 0 ||
- !(EXT3_SB(inode->i_sb)->s_mount_state & EXT3_ORPHAN_FS)) {
- /* this inode is deleted */
- brelse (bh);
- ret = -ESTALE;
- goto bad_inode;
- }
- /* The only unlinked inodes we let through here have
- * valid i_mode and are being read by the orphan
- * recovery code: that's fine, we're about to complete
- * the process of deleting those. */
- }
- inode->i_blocks = le32_to_cpu(raw_inode->i_blocks);
- ei->i_flags = le32_to_cpu(raw_inode->i_flags);
-#ifdef EXT3_FRAGMENTS
- ei->i_faddr = le32_to_cpu(raw_inode->i_faddr);
- ei->i_frag_no = raw_inode->i_frag;
- ei->i_frag_size = raw_inode->i_fsize;
-#endif
- ei->i_file_acl = le32_to_cpu(raw_inode->i_file_acl);
- if (!S_ISREG(inode->i_mode)) {
- ei->i_dir_acl = le32_to_cpu(raw_inode->i_dir_acl);
- } else {
- inode->i_size |=
- ((__u64)le32_to_cpu(raw_inode->i_size_high)) << 32;
- }
- ei->i_disksize = inode->i_size;
- inode->i_generation = le32_to_cpu(raw_inode->i_generation);
- ei->i_block_group = iloc.block_group;
- /*
- * NOTE! The in-memory inode i_data array is in little-endian order
- * even on big-endian machines: we do NOT byteswap the block numbers!
- */
- for (block = 0; block < EXT3_N_BLOCKS; block++)
- ei->i_data[block] = raw_inode->i_block[block];
- INIT_LIST_HEAD(&ei->i_orphan);
-
- /*
- * Set transaction id's of transactions that have to be committed
- * to finish f[data]sync. We set them to currently running transaction
- * as we cannot be sure that the inode or some of its metadata isn't
- * part of the transaction - the inode could have been reclaimed and
- * now it is reread from disk.
- */
- if (journal) {
- tid_t tid;
-
- spin_lock(&journal->j_state_lock);
- if (journal->j_running_transaction)
- transaction = journal->j_running_transaction;
- else
- transaction = journal->j_committing_transaction;
- if (transaction)
- tid = transaction->t_tid;
- else
- tid = journal->j_commit_sequence;
- spin_unlock(&journal->j_state_lock);
- atomic_set(&ei->i_sync_tid, tid);
- atomic_set(&ei->i_datasync_tid, tid);
- }
-
- if (inode->i_ino >= EXT3_FIRST_INO(inode->i_sb) + 1 &&
- EXT3_INODE_SIZE(inode->i_sb) > EXT3_GOOD_OLD_INODE_SIZE) {
- /*
- * When mke2fs creates big inodes it does not zero out
- * the unused bytes above EXT3_GOOD_OLD_INODE_SIZE,
- * so ignore those first few inodes.
- */
- ei->i_extra_isize = le16_to_cpu(raw_inode->i_extra_isize);
- if (EXT3_GOOD_OLD_INODE_SIZE + ei->i_extra_isize >
- EXT3_INODE_SIZE(inode->i_sb)) {
- brelse (bh);
- ret = -EIO;
- goto bad_inode;
- }
- if (ei->i_extra_isize == 0) {
- /* The extra space is currently unused. Use it. */
- ei->i_extra_isize = sizeof(struct ext3_inode) -
- EXT3_GOOD_OLD_INODE_SIZE;
- } else {
- __le32 *magic = (void *)raw_inode +
- EXT3_GOOD_OLD_INODE_SIZE +
- ei->i_extra_isize;
- if (*magic == cpu_to_le32(EXT3_XATTR_MAGIC))
- ext3_set_inode_state(inode, EXT3_STATE_XATTR);
- }
- } else
- ei->i_extra_isize = 0;
-
- if (S_ISREG(inode->i_mode)) {
- inode->i_op = &ext3_file_inode_operations;
- inode->i_fop = &ext3_file_operations;
- ext3_set_aops(inode);
- } else if (S_ISDIR(inode->i_mode)) {
- inode->i_op = &ext3_dir_inode_operations;
- inode->i_fop = &ext3_dir_operations;
- } else if (S_ISLNK(inode->i_mode)) {
- if (ext3_inode_is_fast_symlink(inode)) {
- inode->i_op = &ext3_fast_symlink_inode_operations;
- nd_terminate_link(ei->i_data, inode->i_size,
- sizeof(ei->i_data) - 1);
- } else {
- inode->i_op = &ext3_symlink_inode_operations;
- ext3_set_aops(inode);
- }
- } else {
- inode->i_op = &ext3_special_inode_operations;
- if (raw_inode->i_block[0])
- init_special_inode(inode, inode->i_mode,
- old_decode_dev(le32_to_cpu(raw_inode->i_block[0])));
- else
- init_special_inode(inode, inode->i_mode,
- new_decode_dev(le32_to_cpu(raw_inode->i_block[1])));
- }
- brelse (iloc.bh);
- ext3_set_inode_flags(inode);
- unlock_new_inode(inode);
- return inode;
-
-bad_inode:
- iget_failed(inode);
- return ERR_PTR(ret);
-}
-
-/*
- * Post the struct inode info into an on-disk inode location in the
- * buffer-cache. This gobbles the caller's reference to the
- * buffer_head in the inode location struct.
- *
- * The caller must have write access to iloc->bh.
- */
-static int ext3_do_update_inode(handle_t *handle,
- struct inode *inode,
- struct ext3_iloc *iloc)
-{
- struct ext3_inode *raw_inode = ext3_raw_inode(iloc);
- struct ext3_inode_info *ei = EXT3_I(inode);
- struct buffer_head *bh = iloc->bh;
- int err = 0, rc, block;
- int need_datasync = 0;
- __le32 disksize;
- uid_t i_uid;
- gid_t i_gid;
-
-again:
- /* we can't allow multiple procs in here at once, its a bit racey */
- lock_buffer(bh);
-
- /* For fields not not tracking in the in-memory inode,
- * initialise them to zero for new inodes. */
- if (ext3_test_inode_state(inode, EXT3_STATE_NEW))
- memset(raw_inode, 0, EXT3_SB(inode->i_sb)->s_inode_size);
-
- ext3_get_inode_flags(ei);
- raw_inode->i_mode = cpu_to_le16(inode->i_mode);
- i_uid = i_uid_read(inode);
- i_gid = i_gid_read(inode);
- if(!(test_opt(inode->i_sb, NO_UID32))) {
- raw_inode->i_uid_low = cpu_to_le16(low_16_bits(i_uid));
- raw_inode->i_gid_low = cpu_to_le16(low_16_bits(i_gid));
-/*
- * Fix up interoperability with old kernels. Otherwise, old inodes get
- * re-used with the upper 16 bits of the uid/gid intact
- */
- if(!ei->i_dtime) {
- raw_inode->i_uid_high =
- cpu_to_le16(high_16_bits(i_uid));
- raw_inode->i_gid_high =
- cpu_to_le16(high_16_bits(i_gid));
- } else {
- raw_inode->i_uid_high = 0;
- raw_inode->i_gid_high = 0;
- }
- } else {
- raw_inode->i_uid_low =
- cpu_to_le16(fs_high2lowuid(i_uid));
- raw_inode->i_gid_low =
- cpu_to_le16(fs_high2lowgid(i_gid));
- raw_inode->i_uid_high = 0;
- raw_inode->i_gid_high = 0;
- }
- raw_inode->i_links_count = cpu_to_le16(inode->i_nlink);
- disksize = cpu_to_le32(ei->i_disksize);
- if (disksize != raw_inode->i_size) {
- need_datasync = 1;
- raw_inode->i_size = disksize;
- }
- raw_inode->i_atime = cpu_to_le32(inode->i_atime.tv_sec);
- raw_inode->i_ctime = cpu_to_le32(inode->i_ctime.tv_sec);
- raw_inode->i_mtime = cpu_to_le32(inode->i_mtime.tv_sec);
- raw_inode->i_blocks = cpu_to_le32(inode->i_blocks);
- raw_inode->i_dtime = cpu_to_le32(ei->i_dtime);
- raw_inode->i_flags = cpu_to_le32(ei->i_flags);
-#ifdef EXT3_FRAGMENTS
- raw_inode->i_faddr = cpu_to_le32(ei->i_faddr);
- raw_inode->i_frag = ei->i_frag_no;
- raw_inode->i_fsize = ei->i_frag_size;
-#endif
- raw_inode->i_file_acl = cpu_to_le32(ei->i_file_acl);
- if (!S_ISREG(inode->i_mode)) {
- raw_inode->i_dir_acl = cpu_to_le32(ei->i_dir_acl);
- } else {
- disksize = cpu_to_le32(ei->i_disksize >> 32);
- if (disksize != raw_inode->i_size_high) {
- raw_inode->i_size_high = disksize;
- need_datasync = 1;
- }
- if (ei->i_disksize > 0x7fffffffULL) {
- struct super_block *sb = inode->i_sb;
- if (!EXT3_HAS_RO_COMPAT_FEATURE(sb,
- EXT3_FEATURE_RO_COMPAT_LARGE_FILE) ||
- EXT3_SB(sb)->s_es->s_rev_level ==
- cpu_to_le32(EXT3_GOOD_OLD_REV)) {
- /* If this is the first large file
- * created, add a flag to the superblock.
- */
- unlock_buffer(bh);
- err = ext3_journal_get_write_access(handle,
- EXT3_SB(sb)->s_sbh);
- if (err)
- goto out_brelse;
-
- ext3_update_dynamic_rev(sb);
- EXT3_SET_RO_COMPAT_FEATURE(sb,
- EXT3_FEATURE_RO_COMPAT_LARGE_FILE);
- handle->h_sync = 1;
- err = ext3_journal_dirty_metadata(handle,
- EXT3_SB(sb)->s_sbh);
- /* get our lock and start over */
- goto again;
- }
- }
- }
- raw_inode->i_generation = cpu_to_le32(inode->i_generation);
- if (S_ISCHR(inode->i_mode) || S_ISBLK(inode->i_mode)) {
- if (old_valid_dev(inode->i_rdev)) {
- raw_inode->i_block[0] =
- cpu_to_le32(old_encode_dev(inode->i_rdev));
- raw_inode->i_block[1] = 0;
- } else {
- raw_inode->i_block[0] = 0;
- raw_inode->i_block[1] =
- cpu_to_le32(new_encode_dev(inode->i_rdev));
- raw_inode->i_block[2] = 0;
- }
- } else for (block = 0; block < EXT3_N_BLOCKS; block++)
- raw_inode->i_block[block] = ei->i_data[block];
-
- if (ei->i_extra_isize)
- raw_inode->i_extra_isize = cpu_to_le16(ei->i_extra_isize);
-
- BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata");
- unlock_buffer(bh);
- rc = ext3_journal_dirty_metadata(handle, bh);
- if (!err)
- err = rc;
- ext3_clear_inode_state(inode, EXT3_STATE_NEW);
-
- atomic_set(&ei->i_sync_tid, handle->h_transaction->t_tid);
- if (need_datasync)
- atomic_set(&ei->i_datasync_tid, handle->h_transaction->t_tid);
-out_brelse:
- brelse (bh);
- ext3_std_error(inode->i_sb, err);
- return err;
-}
-
-/*
- * ext3_write_inode()
- *
- * We are called from a few places:
- *
- * - Within generic_file_aio_write() -> generic_write_sync() for O_SYNC files.
- * Here, there will be no transaction running. We wait for any running
- * transaction to commit.
- *
- * - Within flush work (for sys_sync(), kupdate and such).
- * We wait on commit, if told to.
- *
- * - Within iput_final() -> write_inode_now()
- * We wait on commit, if told to.
- *
- * In all cases it is actually safe for us to return without doing anything,
- * because the inode has been copied into a raw inode buffer in
- * ext3_mark_inode_dirty(). This is a correctness thing for WB_SYNC_ALL
- * writeback.
- *
- * Note that we are absolutely dependent upon all inode dirtiers doing the
- * right thing: they *must* call mark_inode_dirty() after dirtying info in
- * which we are interested.
- *
- * It would be a bug for them to not do this. The code:
- *
- * mark_inode_dirty(inode)
- * stuff();
- * inode->i_size = expr;
- *
- * is in error because write_inode() could occur while `stuff()' is running,
- * and the new i_size will be lost. Plus the inode will no longer be on the
- * superblock's dirty inode list.
- */
-int ext3_write_inode(struct inode *inode, struct writeback_control *wbc)
-{
- if (WARN_ON_ONCE(current->flags & PF_MEMALLOC))
- return 0;
-
- if (ext3_journal_current_handle()) {
- jbd_debug(1, "called recursively, non-PF_MEMALLOC!\n");
- dump_stack();
- return -EIO;
- }
-
- /*
- * No need to force transaction in WB_SYNC_NONE mode. Also
- * ext3_sync_fs() will force the commit after everything is
- * written.
- */
- if (wbc->sync_mode != WB_SYNC_ALL || wbc->for_sync)
- return 0;
-
- return ext3_force_commit(inode->i_sb);
-}
-
-/*
- * ext3_setattr()
- *
- * Called from notify_change.
- *
- * We want to trap VFS attempts to truncate the file as soon as
- * possible. In particular, we want to make sure that when the VFS
- * shrinks i_size, we put the inode on the orphan list and modify
- * i_disksize immediately, so that during the subsequent flushing of
- * dirty pages and freeing of disk blocks, we can guarantee that any
- * commit will leave the blocks being flushed in an unused state on
- * disk. (On recovery, the inode will get truncated and the blocks will
- * be freed, so we have a strong guarantee that no future commit will
- * leave these blocks visible to the user.)
- *
- * Called with inode->sem down.
- */
-int ext3_setattr(struct dentry *dentry, struct iattr *attr)
-{
- struct inode *inode = d_inode(dentry);
- int error, rc = 0;
- const unsigned int ia_valid = attr->ia_valid;
-
- error = inode_change_ok(inode, attr);
- if (error)
- return error;
-
- if (is_quota_modification(inode, attr))
- dquot_initialize(inode);
- if ((ia_valid & ATTR_UID && !uid_eq(attr->ia_uid, inode->i_uid)) ||
- (ia_valid & ATTR_GID && !gid_eq(attr->ia_gid, inode->i_gid))) {
- handle_t *handle;
-
- /* (user+group)*(old+new) structure, inode write (sb,
- * inode block, ? - but truncate inode update has it) */
- handle = ext3_journal_start(inode, EXT3_MAXQUOTAS_INIT_BLOCKS(inode->i_sb)+
- EXT3_MAXQUOTAS_DEL_BLOCKS(inode->i_sb)+3);
- if (IS_ERR(handle)) {
- error = PTR_ERR(handle);
- goto err_out;
- }
- error = dquot_transfer(inode, attr);
- if (error) {
- ext3_journal_stop(handle);
- return error;
- }
- /* Update corresponding info in inode so that everything is in
- * one transaction */
- if (attr->ia_valid & ATTR_UID)
- inode->i_uid = attr->ia_uid;
- if (attr->ia_valid & ATTR_GID)
- inode->i_gid = attr->ia_gid;
- error = ext3_mark_inode_dirty(handle, inode);
- ext3_journal_stop(handle);
- }
-
- if (attr->ia_valid & ATTR_SIZE)
- inode_dio_wait(inode);
-
- if (S_ISREG(inode->i_mode) &&
- attr->ia_valid & ATTR_SIZE && attr->ia_size < inode->i_size) {
- handle_t *handle;
-
- handle = ext3_journal_start(inode, 3);
- if (IS_ERR(handle)) {
- error = PTR_ERR(handle);
- goto err_out;
- }
-
- error = ext3_orphan_add(handle, inode);
- if (error) {
- ext3_journal_stop(handle);
- goto err_out;
- }
- EXT3_I(inode)->i_disksize = attr->ia_size;
- error = ext3_mark_inode_dirty(handle, inode);
- ext3_journal_stop(handle);
- if (error) {
- /* Some hard fs error must have happened. Bail out. */
- ext3_orphan_del(NULL, inode);
- goto err_out;
- }
- rc = ext3_block_truncate_page(inode, attr->ia_size);
- if (rc) {
- /* Cleanup orphan list and exit */
- handle = ext3_journal_start(inode, 3);
- if (IS_ERR(handle)) {
- ext3_orphan_del(NULL, inode);
- goto err_out;
- }
- ext3_orphan_del(handle, inode);
- ext3_journal_stop(handle);
- goto err_out;
- }
- }
-
- if ((attr->ia_valid & ATTR_SIZE) &&
- attr->ia_size != i_size_read(inode)) {
- truncate_setsize(inode, attr->ia_size);
- ext3_truncate(inode);
- }
-
- setattr_copy(inode, attr);
- mark_inode_dirty(inode);
-
- if (ia_valid & ATTR_MODE)
- rc = posix_acl_chmod(inode, inode->i_mode);
-
-err_out:
- ext3_std_error(inode->i_sb, error);
- if (!error)
- error = rc;
- return error;
-}
-
-
-/*
- * How many blocks doth make a writepage()?
- *
- * With N blocks per page, it may be:
- * N data blocks
- * 2 indirect block
- * 2 dindirect
- * 1 tindirect
- * N+5 bitmap blocks (from the above)
- * N+5 group descriptor summary blocks
- * 1 inode block
- * 1 superblock.
- * 2 * EXT3_SINGLEDATA_TRANS_BLOCKS for the quote files
- *
- * 3 * (N + 5) + 2 + 2 * EXT3_SINGLEDATA_TRANS_BLOCKS
- *
- * With ordered or writeback data it's the same, less the N data blocks.
- *
- * If the inode's direct blocks can hold an integral number of pages then a
- * page cannot straddle two indirect blocks, and we can only touch one indirect
- * and dindirect block, and the "5" above becomes "3".
- *
- * This still overestimates under most circumstances. If we were to pass the
- * start and end offsets in here as well we could do block_to_path() on each
- * block and work out the exact number of indirects which are touched. Pah.
- */
-
-static int ext3_writepage_trans_blocks(struct inode *inode)
-{
- int bpp = ext3_journal_blocks_per_page(inode);
- int indirects = (EXT3_NDIR_BLOCKS % bpp) ? 5 : 3;
- int ret;
-
- if (ext3_should_journal_data(inode))
- ret = 3 * (bpp + indirects) + 2;
- else
- ret = 2 * (bpp + indirects) + indirects + 2;
-
-#ifdef CONFIG_QUOTA
- /* We know that structure was already allocated during dquot_initialize so
- * we will be updating only the data blocks + inodes */
- ret += EXT3_MAXQUOTAS_TRANS_BLOCKS(inode->i_sb);
-#endif
-
- return ret;
-}
-
-/*
- * The caller must have previously called ext3_reserve_inode_write().
- * Give this, we know that the caller already has write access to iloc->bh.
- */
-int ext3_mark_iloc_dirty(handle_t *handle,
- struct inode *inode, struct ext3_iloc *iloc)
-{
- int err = 0;
-
- /* the do_update_inode consumes one bh->b_count */
- get_bh(iloc->bh);
-
- /* ext3_do_update_inode() does journal_dirty_metadata */
- err = ext3_do_update_inode(handle, inode, iloc);
- put_bh(iloc->bh);
- return err;
-}
-
-/*
- * On success, We end up with an outstanding reference count against
- * iloc->bh. This _must_ be cleaned up later.
- */
-
-int
-ext3_reserve_inode_write(handle_t *handle, struct inode *inode,
- struct ext3_iloc *iloc)
-{
- int err = 0;
- if (handle) {
- err = ext3_get_inode_loc(inode, iloc);
- if (!err) {
- BUFFER_TRACE(iloc->bh, "get_write_access");
- err = ext3_journal_get_write_access(handle, iloc->bh);
- if (err) {
- brelse(iloc->bh);
- iloc->bh = NULL;
- }
- }
- }
- ext3_std_error(inode->i_sb, err);
- return err;
-}
-
-/*
- * What we do here is to mark the in-core inode as clean with respect to inode
- * dirtiness (it may still be data-dirty).
- * This means that the in-core inode may be reaped by prune_icache
- * without having to perform any I/O. This is a very good thing,
- * because *any* task may call prune_icache - even ones which
- * have a transaction open against a different journal.
- *
- * Is this cheating? Not really. Sure, we haven't written the
- * inode out, but prune_icache isn't a user-visible syncing function.
- * Whenever the user wants stuff synced (sys_sync, sys_msync, sys_fsync)
- * we start and wait on commits.
- */
-int ext3_mark_inode_dirty(handle_t *handle, struct inode *inode)
-{
- struct ext3_iloc iloc;
- int err;
-
- might_sleep();
- trace_ext3_mark_inode_dirty(inode, _RET_IP_);
- err = ext3_reserve_inode_write(handle, inode, &iloc);
- if (!err)
- err = ext3_mark_iloc_dirty(handle, inode, &iloc);
- return err;
-}
-
-/*
- * ext3_dirty_inode() is called from __mark_inode_dirty()
- *
- * We're really interested in the case where a file is being extended.
- * i_size has been changed by generic_commit_write() and we thus need
- * to include the updated inode in the current transaction.
- *
- * Also, dquot_alloc_space() will always dirty the inode when blocks
- * are allocated to the file.
- *
- * If the inode is marked synchronous, we don't honour that here - doing
- * so would cause a commit on atime updates, which we don't bother doing.
- * We handle synchronous inodes at the highest possible level.
- */
-void ext3_dirty_inode(struct inode *inode, int flags)
-{
- handle_t *current_handle = ext3_journal_current_handle();
- handle_t *handle;
-
- handle = ext3_journal_start(inode, 2);
- if (IS_ERR(handle))
- goto out;
- if (current_handle &&
- current_handle->h_transaction != handle->h_transaction) {
- /* This task has a transaction open against a different fs */
- printk(KERN_EMERG "%s: transactions do not match!\n",
- __func__);
- } else {
- jbd_debug(5, "marking dirty. outer handle=%p\n",
- current_handle);
- ext3_mark_inode_dirty(handle, inode);
- }
- ext3_journal_stop(handle);
-out:
- return;
-}
-
-#if 0
-/*
- * Bind an inode's backing buffer_head into this transaction, to prevent
- * it from being flushed to disk early. Unlike
- * ext3_reserve_inode_write, this leaves behind no bh reference and
- * returns no iloc structure, so the caller needs to repeat the iloc
- * lookup to mark the inode dirty later.
- */
-static int ext3_pin_inode(handle_t *handle, struct inode *inode)
-{
- struct ext3_iloc iloc;
-
- int err = 0;
- if (handle) {
- err = ext3_get_inode_loc(inode, &iloc);
- if (!err) {
- BUFFER_TRACE(iloc.bh, "get_write_access");
- err = journal_get_write_access(handle, iloc.bh);
- if (!err)
- err = ext3_journal_dirty_metadata(handle,
- iloc.bh);
- brelse(iloc.bh);
- }
- }
- ext3_std_error(inode->i_sb, err);
- return err;
-}
-#endif
-
-int ext3_change_inode_journal_flag(struct inode *inode, int val)
-{
- journal_t *journal;
- handle_t *handle;
- int err;
-
- /*
- * We have to be very careful here: changing a data block's
- * journaling status dynamically is dangerous. If we write a
- * data block to the journal, change the status and then delete
- * that block, we risk forgetting to revoke the old log record
- * from the journal and so a subsequent replay can corrupt data.
- * So, first we make sure that the journal is empty and that
- * nobody is changing anything.
- */
-
- journal = EXT3_JOURNAL(inode);
- if (is_journal_aborted(journal))
- return -EROFS;
-
- journal_lock_updates(journal);
- journal_flush(journal);
-
- /*
- * OK, there are no updates running now, and all cached data is
- * synced to disk. We are now in a completely consistent state
- * which doesn't have anything in the journal, and we know that
- * no filesystem updates are running, so it is safe to modify
- * the inode's in-core data-journaling state flag now.
- */
-
- if (val)
- EXT3_I(inode)->i_flags |= EXT3_JOURNAL_DATA_FL;
- else
- EXT3_I(inode)->i_flags &= ~EXT3_JOURNAL_DATA_FL;
- ext3_set_aops(inode);
-
- journal_unlock_updates(journal);
-
- /* Finally we can mark the inode as dirty. */
-
- handle = ext3_journal_start(inode, 1);
- if (IS_ERR(handle))
- return PTR_ERR(handle);
-
- err = ext3_mark_inode_dirty(handle, inode);
- handle->h_sync = 1;
- ext3_journal_stop(handle);
- ext3_std_error(inode->i_sb, err);
-
- return err;
-}
Code Review / kvmfornfv.git / blobdiff