diff options
| -rw-r--r-- | fs/ext4/extents.c | 9 | ||||
| -rw-r--r-- | fs/ext4/inode.c | 69 | ||||
| -rw-r--r-- | include/linux/ext4_fs.h | 2 |
3 files changed, 16 insertions, 64 deletions
diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c index 8593e59020fe..ec5019fa552f 100644 --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2129,6 +2129,10 @@ out: return err ? err : allocated; } +/* + * Need to be called with + * mutex_lock(&EXT4_I(inode)->truncate_mutex); + */ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, ext4_lblk_t iblock, unsigned long max_blocks, struct buffer_head *bh_result, @@ -2144,7 +2148,6 @@ int ext4_ext_get_blocks(handle_t *handle, struct inode *inode, __clear_bit(BH_New, &bh_result->b_state); ext_debug("blocks %u/%lu requested for inode %u\n", iblock, max_blocks, inode->i_ino); - mutex_lock(&EXT4_I(inode)->truncate_mutex); /* check in cache */ goal = ext4_ext_in_cache(inode, iblock, &newex); @@ -2318,8 +2321,6 @@ out2: ext4_ext_drop_refs(path); kfree(path); } - mutex_unlock(&EXT4_I(inode)->truncate_mutex); - return err ? err : allocated; } @@ -2449,6 +2450,7 @@ long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len) * modify 1 super block, 1 block bitmap and 1 group descriptor. */ credits = EXT4_DATA_TRANS_BLOCKS(inode->i_sb) + 3; + mutex_lock(&EXT4_I(inode)->truncate_mutex) retry: while (ret >= 0 && ret < max_blocks) { block = block + ret; @@ -2505,6 +2507,7 @@ retry: if (ret == -ENOSPC && ext4_should_retry_alloc(inode->i_sb, &retries)) goto retry; + mutex_unlock(&EXT4_I(inode)->truncate_mutex) /* * Time to update the file size. * Update only when preallocation was requested beyond the file size. diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index eaace1373ccb..71c7ad0c6723 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -243,13 +243,6 @@ static inline void add_chain(Indirect *p, struct buffer_head *bh, __le32 *v) p->bh = bh; } -static int verify_chain(Indirect *from, Indirect *to) -{ - while (from <= to && from->key == *from->p) - from++; - return (from > to); -} - /** * ext4_block_to_path - parse the block number into array of offsets * @inode: inode in question (we are only interested in its superblock) @@ -348,10 +341,11 @@ static int ext4_block_to_path(struct inode *inode, * (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). + * + * Need to be called with + * mutex_lock(&EXT4_I(inode)->truncate_mutex) */ static Indirect *ext4_get_branch(struct inode *inode, int depth, ext4_lblk_t *offsets, @@ -370,9 +364,6 @@ static Indirect *ext4_get_branch(struct inode *inode, int 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) @@ -380,10 +371,6 @@ static Indirect *ext4_get_branch(struct inode *inode, int depth, } return NULL; -changed: - brelse(bh); - *err = -EAGAIN; - goto no_block; failure: *err = -EIO; no_block: @@ -787,6 +774,10 @@ err_out: * return > 0, # of blocks mapped or allocated. * return = 0, if plain lookup failed. * return < 0, error case. + * + * + * Need to be called with + * mutex_lock(&EXT4_I(inode)->truncate_mutex) */ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode, ext4_lblk_t iblock, unsigned long maxblocks, @@ -825,18 +816,6 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode, while (count < maxblocks && count <= blocks_to_boundary) { ext4_fsblk_t blk; - if (!verify_chain(chain, partial)) { - /* - * 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) @@ -844,44 +823,13 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode, else break; } - if (err != -EAGAIN) - goto got_it; + goto got_it; } /* Next simple case - plain lookup or failed read of indirect block */ if (!create || err == -EIO) goto cleanup; - mutex_lock(&ei->truncate_mutex); - - /* - * If the indirect block is missing while we are reading - * the chain(ext4_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 = ext4_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 @@ -923,7 +871,6 @@ int ext4_get_blocks_handle(handle_t *handle, struct inode *inode, */ if (!err && extend_disksize && inode->i_size > ei->i_disksize) ei->i_disksize = inode->i_size; - mutex_unlock(&ei->truncate_mutex); if (err) goto cleanup; diff --git a/include/linux/ext4_fs.h b/include/linux/ext4_fs.h index 55a376e7bca0..583049c1d366 100644 --- a/include/linux/ext4_fs.h +++ b/include/linux/ext4_fs.h @@ -1113,6 +1113,7 @@ ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block, int create, int extend_disksize) { int retval; + mutex_lock(&EXT4_I(inode)->truncate_mutex); if (EXT4_I(inode)->i_flags & EXT4_EXTENTS_FL) { retval = ext4_ext_get_blocks(handle, inode, (ext4_lblk_t)block, max_blocks, @@ -1122,6 +1123,7 @@ ext4_get_blocks_wrap(handle_t *handle, struct inode *inode, sector_t block, (ext4_lblk_t)block, max_blocks, bh, create, extend_disksize); } + mutex_unlock(&EXT4_I(inode)->truncate_mutex); return retval; } |