| /* |
| * 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 "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))) { |
| 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(&inode->i_data, 0); |
| |
| 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]); |
| 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) { |
| if (err > 1) |
| WARN_ON(1); |
| err = 0; |
| } |
| *errp = err; |
| if (!err && buffer_mapped(&dummy)) { |
| struct buffer_head *bh; |
| bh = sb_getblk(inode->i_sb, dummy.b_blocknr); |
| if (!bh) { |
| *errp = -EIO; |
| 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 we always 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. |
| * |
| * Problem: |
| * |
| * ext3_writepage() -> kmalloc() -> __alloc_pages() -> page_launder() -> |
| * ext3_writepage() |
| * |
| * Similar for: |
| * |
| * ext3_file_write() -> generic_file_write() -> __alloc_pages() -> ... |
| * |
| * Same applies to ext3_get_block(). We will deadlock on various things like |
| * lock_journal and i_truncate_mutex. |
| * |
| * Setting PF_MEMALLOC here doesn't work - too many internal memory |
| * allocations fail. |
| * |
| * 16May01: If we're reentered then journal_current_handle() will be |
| * non-zero. We simply *return*. |
| * |
| * 1 July 2001: @@@ FIXME: |
| * In journalled data mode, a data buffer may be metadata against the |
| * current transaction. But the same file is part of a shared mapping |
| * and someone does a writepage() on it. |
| * |
| * We will move the buffer onto the async_data list, but *after* it has |
| * been dirtied. So there's a small window where we have dirty data on |
| * BJ_Metadata. |
| * |
| * Note that this only applies to the last partial page in the file. The |
| * bit which block_write_full_page() uses prepare/commit for. (That's |
| * broken code anyway: it's wrong for msync()). |
| * |
| * It's a rare case: affects the final partial page, for journalled data |
| * where the file is subject to bith write() and writepage() in the same |
| * transction. To fix it we'll need a custom block_write_full_page(). |
| * We'll probably need that anyway for journalling writepage() output. |
| * |
| * We don't honour synchronous mounts for writepage(). That would be |
| * disastrous. Any write() or metadata operation will sync the fs for |
| * us. |
| * |
| * AKPM2: if all the page's buffers are mapped to disk and !data=journal, |
| * we don't need to open a transaction here. |
| */ |
| 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) { |
| err = walk_page_buffers(handle, page_bufs, 0, PAGE_CACHE_SIZE, |
| NULL, journal_dirty_data_fn); |
| if (!ret) |
| ret = err; |
| } |
| 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)); |
| |
| if (ext3_journal_current_handle()) |
| goto no_write; |
| |
| trace_ext3_journalled_writepage(page); |
| handle = ext3_journal_start(inode, ext3_writepage_trans_blocks(inode)); |
| if (IS_ERR(handle)) { |
| ret = PTR_ERR(handle); |
| goto no_write; |
| } |
| |
| if (!page_has_buffers(page) || PageChecked(page)) { |
| /* |
| * 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); |
| } else { |
| /* |
| * It may be a page full of checkpoint-mode buffers. We don't |
| * really know unless we go poke around in the buffer_heads. |
| * But block_write_full_page will do the right thing. |
| */ |
| ret = block_write_full_page(page, ext3_get_block, wbc); |
| } |
| err = ext3_journal_stop(handle); |
| if (!ret) |
| ret = err; |
| 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 long offset) |
| { |
| journal_t *journal = EXT3_JOURNAL(page->mapping->host); |
| |
| trace_ext3_invalidatepage(page, offset); |
| |
| /* |
| * If it's a full truncate we just forget about the pending dirtying |
| */ |
| if (offset == 0) |
| ClearPageChecked(page); |
| |
| journal_invalidatepage(journal, page, offset); |
| } |
| |
| 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(int rw, struct kiocb *iocb, |
| const struct iovec *iov, loff_t offset, |
| unsigned long nr_segs) |
| { |
| 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_length(iov, nr_segs); |
| int retries = 0; |
| |
| trace_ext3_direct_IO_enter(inode, offset, iov_length(iov, nr_segs), rw); |
| |
| if (rw == 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(rw, iocb, inode, iov, offset, nr_segs, |
| ext3_get_block); |
| /* |
| * In case of error extending write may have instantiated a few |
| * blocks outside i_size. Trim these off again. |
| */ |
| if (unlikely((rw & WRITE) && ret < 0)) { |
| loff_t isize = i_size_read(inode); |
| loff_t end = offset + iov_length(iov, nr_segs); |
| |
| 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); |
| 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, |
| iov_length(iov, nr_segs), rw, 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, |
| .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 (!bh) { |
| ext3_error (inode->i_sb, "ext3_get_inode_loc", |
| "unable to read inode block - " |
| "inode=%lu, block="E3FSBLK, |
| inode->i_ino, block); |
| return -EIO; |
| } |
| 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 (!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; |
| } |
| } |
| } |
|