BMC/Intel-BMC/linux.git/fs/nilfs2/btree.c, branch dev

nilfs2: fix sanity check of btree level in nilfs_btree_root_broken()

2015-05-06T00:10:11+00:00

The range check for b-tree level parameter in nilfs_btree_root_broken() is wrong; it accepts the case of "level == NILFS_BTREE_LEVEL_MAX" even though the level is limited to values in the range of 0 to (NILFS_BTREE_LEVEL_MAX - 1). Since the level parameter is read from storage device and used to index nilfs_btree_path array whose element count is NILFS_BTREE_LEVEL_MAX, it can cause memory overrun during btree operations if the boundary value is set to the level parameter on device. This fixes the broken sanity check and adds a comment to clarify that the upper bound NILFS_BTREE_LEVEL_MAX is exclusive. Signed-off-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nilfs2: add bmap function to seek a valid key

2015-04-17T13:04:03+00:00

Add a new bmap function, nilfs_bmap_seek_key(), which seeks a valid entry and returns its key starting from a given key. This function can be used to skip hole blocks efficiently. Signed-off-by: Ryusuke Konishi Cc: Dan Carpenter Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nilfs2: fix potential memory overrun on inode

2015-02-28T17:57:51+00:00

Each inode of nilfs2 stores a root node of a b-tree, and it turned out to have a memory overrun issue: Each b-tree node of nilfs2 stores a set of key-value pairs and the number of them (in "bn_nchildren" member of nilfs_btree_node struct), as well as a few other "bn_*" members. Since the value of "bn_nchildren" is used for operations on the key-values within the b-tree node, it can cause memory access overrun if a large number is incorrectly set to "bn_nchildren". For instance, nilfs_btree_node_lookup() function determines the range of binary search with it, and too large "bn_nchildren" leads nilfs_btree_node_get_key() in that function to overrun. As for intermediate b-tree nodes, this is prevented by a sanity check performed when each node is read from a drive, however, no sanity check has been done for root nodes stored in inodes. This patch fixes the issue by adding missing sanity check against b-tree root nodes so that it's called when on-memory inodes are read from ifile, inode metadata file. Signed-off-by: Ryusuke Konishi Cc: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds

nilfs2: fix missing block address termination in btree node shrinking

2011-06-11T06:51:15+00:00

nilfs_btree_delete function does not terminate part of virtual block addresses when shrinking the last remaining child node into the root node. The missing address termination causes that dead btree node blocks persist and chip away free disk space. This fixes the leak bug on the btree node deletion. Signed-off-by: Ryusuke Konishi

nilfs2: fix incorrect block address termination in node concatenation

2011-06-11T06:51:15+00:00

nilfs_btree_delete function wrongly terminates virtual block address of the btree node held by its parent at index 0. When concatenating the index-0 node with its right sibling node, nilfs_btree_delete terminates the block address of index-0 node instead of the right sibling node which should be deleted. This bug not only wears disk space in the long run, but also causes file system corruption. This will fix it. Signed-off-by: Ryusuke Konishi

nilfs2: use mark_buffer_dirty to mark btnode or meta data dirty

2011-05-10T13:21:57+00:00

This replaces nilfs_mdt_mark_buffer_dirty and nilfs_btnode_mark_dirty macros with mark_buffer_dirty and gets rid of nilfs_mark_buffer_dirty, an own mark buffer dirty function. Signed-off-by: Ryusuke Konishi

nilfs2: record used amount of each checkpoint in checkpoint list

2011-03-08T05:58:31+00:00

This records the number of used blocks per checkpoint in each checkpoint entry of cpfile. Even though userland tools can get the block count via nilfs_get_cpinfo ioctl, it was not updated by the nilfs2 kernel code. This fixes the issue and makes it available for userland tools to calculate used amount per checkpoint. Signed-off-by: Ryusuke Konishi Cc: Jiro SEKIBA

nilfs2: apply read-ahead for nilfs_btree_lookup_contig

2010-07-23T01:02:16+00:00

This applies read-ahead to nilfs_btree_do_lookup and nilfs_btree_lookup_contig functions and extends them to read ahead siblings of level 1 btree nodes that hold data blocks. At present, the read-ahead is not applied to most btree operations; only get_block() callback function, which is used during read of regular files or directories, receives the benefit. Signed-off-by: Ryusuke Konishi

nilfs2: introduce check flag to btree node buffer

2010-07-23T01:02:15+00:00

nilfs_btree_get_block() now may return untested buffer due to read-ahead. This adds a new flag for buffer heads so that the btree code can check whether the buffer is already verified or not. Signed-off-by: Ryusuke Konishi

nilfs2: add btree get block function with readahead option

2010-07-23T01:02:15+00:00

This adds __nilfs_btree_get_block() function that can issue a series of read-ahead requests for sibling btree nodes. This read-ahead needs parent node block, so nilfs_btree_readahead_info structure is added to pass the information that __nilfs_btree_get_block() needs. This also replaces the previous nilfs_btree_get_block() implementation with a wrapper function of __nilfs_btree_get_block(). Signed-off-by: Ryusuke Konishi