diff options
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/ext3/inode.c | 270 |
1 files changed, 193 insertions, 77 deletions
diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c index fcfb10f..34e5b0d 100644 --- a/fs/ext3/inode.c +++ b/fs/ext3/inode.c @@ -235,16 +235,6 @@ no_delete: clear_inode(inode); /* We must guarantee clearing of inode... */ } -static int ext3_alloc_block (handle_t *handle, - struct inode * inode, unsigned long goal, int *err) -{ - unsigned long result; - - result = ext3_new_block(handle, inode, goal, err); - return result; -} - - typedef struct { __le32 *p; __le32 key; @@ -476,15 +466,115 @@ static unsigned long ext3_find_goal(struct inode *inode, long block, 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 don't hanel 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 + * @indirect_blks: the number of blocks need to allocate for indirect + * blocks + * + * @new_blocks: on return it will store the new block numbers for + * the indirect blocks(if needed) and the first direct block, + * @blks: on return it will store the total number of allocated + * direct blocks + */ +static int ext3_alloc_blocks(handle_t *handle, struct inode *inode, + unsigned long goal, int indirect_blks, int blks, + unsigned long long new_blocks[4], int *err) +{ + int target, i; + unsigned long count = 0; + int index = 0; + unsigned long 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. * @inode: owner - * @num: depth of the chain (number of blocks to allocate) + * @indirect_blks: number of allocated indirect blocks + * @blks: number of allocated direct blocks * @offsets: offsets (in the blocks) to store the pointers to next. * @branch: place to store the chain in. * - * This function allocates @num blocks, zeroes out all but the last one, + * 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 @@ -503,71 +593,79 @@ static unsigned long ext3_find_goal(struct inode *inode, long block, */ static int ext3_alloc_branch(handle_t *handle, struct inode *inode, - int num, - unsigned long goal, - int *offsets, - Indirect *branch) + int indirect_blks, int *blks, unsigned long goal, + int *offsets, Indirect *branch) { int blocksize = inode->i_sb->s_blocksize; - int n = 0, keys = 0; + int i, n = 0; int err = 0; - int i; - int parent = ext3_alloc_block(handle, inode, goal, &err); - - branch[0].key = cpu_to_le32(parent); - if (parent) { - for (n = 1; n < num; n++) { - struct buffer_head *bh; - /* Allocate the next block */ - int nr = ext3_alloc_block(handle, inode, parent, &err); - if (!nr) - break; - branch[n].key = cpu_to_le32(nr); + struct buffer_head *bh; + int num; + unsigned long long new_blocks[4]; + unsigned long long current_block; - /* - * 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, parent); - if (!bh) - break; - keys = 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); - break; - } + num = ext3_alloc_blocks(handle, inode, goal, indirect_blks, + *blks, new_blocks, &err); + if (err) + return err; - memset(bh->b_data, 0, blocksize); - branch[n].p = (__le32*) bh->b_data + offsets[n]; - *branch[n].p = branch[n].key; - BUFFER_TRACE(bh, "marking uptodate"); - set_buffer_uptodate(bh); + 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; + } - BUFFER_TRACE(bh, "call ext3_journal_dirty_metadata"); - err = ext3_journal_dirty_metadata(handle, bh); - if (err) - break; - - parent = nr; + 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); } - } - if (n == num) - return 0; + 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 < keys; i++) { + 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 < keys; i++) - ext3_free_blocks(handle, inode, le32_to_cpu(branch[i].key), 1); + 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; } @@ -578,7 +676,8 @@ static int ext3_alloc_branch(handle_t *handle, struct inode *inode, * @chain: chain of indirect blocks (with a missing link - see * ext3_alloc_branch) * @where: location of missing link - * @num: number of blocks we are adding + * @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 @@ -586,12 +685,12 @@ static int ext3_alloc_branch(handle_t *handle, struct inode *inode, */ static int ext3_splice_branch(handle_t *handle, struct inode *inode, long block, - Indirect chain[4], Indirect *where, int num) + Indirect *where, int num, int blks) { int i; int err = 0; struct ext3_block_alloc_info *block_i = EXT3_I(inode)->i_block_alloc_info; - + unsigned long current_block; /* * 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 @@ -606,6 +705,13 @@ static int ext3_splice_branch(handle_t *handle, struct inode *inode, long block, /* That's it */ *where->p = where->key; + /* update host bufferhead 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 @@ -613,8 +719,8 @@ static int ext3_splice_branch(handle_t *handle, struct inode *inode, long block, * allocation */ if (block_i) { - block_i->last_alloc_logical_block = block; - block_i->last_alloc_physical_block = le32_to_cpu(where[num-1].key); + 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 */ @@ -647,10 +753,13 @@ static int ext3_splice_branch(handle_t *handle, struct inode *inode, long block, return err; err_out: - for (i = 1; i < num; i++) { + 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; } @@ -684,7 +793,7 @@ ext3_get_blocks_handle(handle_t *handle, struct inode *inode, sector_t iblock, Indirect chain[4]; Indirect *partial; unsigned long goal; - int left; + int indirect_blks; int blocks_to_boundary = 0; int depth; struct ext3_inode_info *ei = EXT3_I(inode); @@ -772,12 +881,19 @@ ext3_get_blocks_handle(handle_t *handle, struct inode *inode, sector_t iblock, goal = ext3_find_goal(inode, iblock, chain, partial); - left = (chain + depth) - 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); + /* * Block out ext3_truncate while we alter the tree */ - err = ext3_alloc_branch(handle, inode, left, goal, + err = ext3_alloc_branch(handle, inode, indirect_blks, &count, goal, offsets + (partial - chain), partial); /* @@ -788,8 +904,8 @@ ext3_get_blocks_handle(handle_t *handle, struct inode *inode, sector_t iblock, * may need to return -EAGAIN upwards in the worst case. --sct */ if (!err) - err = ext3_splice_branch(handle, inode, iblock, chain, - partial, left); + err = ext3_splice_branch(handle, inode, iblock, + partial, indirect_blks, count); /* * i_disksize growing is protected by truncate_mutex. Don't forget to * protect it if you're about to implement concurrent @@ -824,8 +940,8 @@ out: static int ext3_direct_io_get_blocks(struct inode *inode, sector_t iblock, - unsigned long max_blocks, struct buffer_head *bh_result, - int create) + unsigned long max_blocks, + struct buffer_head *bh_result, int create) { handle_t *handle = journal_current_handle(); int ret = 0; |
