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| author | Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com> | 2018-10-30 15:06:14 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2019-12-01 09:13:54 +0100 |
| commit | 71db3989910218b45c624473029228a56a82cb88 (patch) | |
| tree | e0945176c047571c8ea9563aba05151ddb64c713 /fs/hfsplus/btree.c | |
| parent | 44ddfe1ced43d2da1237cbfae6392a1d3532c09e (diff) | |
hfsplus: prevent btree data loss on ENOSPC
[ Upstream commit d92915c35bfaf763d78bf1d5ac7f183420e3bd99 ]
Inserting or deleting a record in a btree may require splitting several of
its nodes. If we hit ENOSPC halfway through, the new nodes will be left
orphaned and their records will be lost. This could mean lost inodes,
extents or xattrs.
Henceforth, check the available disk space before making any changes.
This still leaves the potential problem of corruption on ENOMEM.
The patch can be tested with xfstests generic/027.
Link: http://lkml.kernel.org/r/4596eef22fbda137b4ffa0272d92f0da15364421.1536269129.git.ernesto.mnd.fernandez@gmail.com
Signed-off-by: Ernesto A. Fernández <ernesto.mnd.fernandez@gmail.com>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Diffstat (limited to 'fs/hfsplus/btree.c')
| -rw-r--r-- | fs/hfsplus/btree.c | 44 |
1 files changed, 28 insertions, 16 deletions
diff --git a/fs/hfsplus/btree.c b/fs/hfsplus/btree.c index 3de3bc4918b5..66774f4cb4fd 100644 --- a/fs/hfsplus/btree.c +++ b/fs/hfsplus/btree.c @@ -342,26 +342,21 @@ static struct hfs_bnode *hfs_bmap_new_bmap(struct hfs_bnode *prev, u32 idx) return node; } -struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree) +/* Make sure @tree has enough space for the @rsvd_nodes */ +int hfs_bmap_reserve(struct hfs_btree *tree, int rsvd_nodes) { - struct hfs_bnode *node, *next_node; - struct page **pagep; - u32 nidx, idx; - unsigned off; - u16 off16; - u16 len; - u8 *data, byte, m; - int i; + struct inode *inode = tree->inode; + struct hfsplus_inode_info *hip = HFSPLUS_I(inode); + u32 count; + int res; - while (!tree->free_nodes) { - struct inode *inode = tree->inode; - struct hfsplus_inode_info *hip = HFSPLUS_I(inode); - u32 count; - int res; + if (rsvd_nodes <= 0) + return 0; + while (tree->free_nodes < rsvd_nodes) { res = hfsplus_file_extend(inode, hfs_bnode_need_zeroout(tree)); if (res) - return ERR_PTR(res); + return res; hip->phys_size = inode->i_size = (loff_t)hip->alloc_blocks << HFSPLUS_SB(tree->sb)->alloc_blksz_shift; @@ -369,9 +364,26 @@ struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree) hip->alloc_blocks << HFSPLUS_SB(tree->sb)->fs_shift; inode_set_bytes(inode, inode->i_size); count = inode->i_size >> tree->node_size_shift; - tree->free_nodes = count - tree->node_count; + tree->free_nodes += count - tree->node_count; tree->node_count = count; } + return 0; +} + +struct hfs_bnode *hfs_bmap_alloc(struct hfs_btree *tree) +{ + struct hfs_bnode *node, *next_node; + struct page **pagep; + u32 nidx, idx; + unsigned off; + u16 off16; + u16 len; + u8 *data, byte, m; + int i, res; + + res = hfs_bmap_reserve(tree, 1); + if (res) + return ERR_PTR(res); nidx = 0; node = hfs_bnode_find(tree, nidx); |