5.4-stable review patch. If anyone has any objections, please let me know.
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From: Baokun Li libaokun1@huawei.com
[ Upstream commit e9fe2b882bd5b26b987c9ba110c2222796f72af5 ]
If __es_remove_extent() returns an error it means that when splitting extent, allocating an extent that must be kept failed, where returning an error directly would cause the extent tree to be inconsistent. So we use GFP_NOFAIL to pre-allocate an extent_status and pass it to __es_remove_extent() to avoid this problem.
In addition, since the allocated memory is outside the i_es_lock, the extent_status tree may change and the pre-allocated extent_status is no longer needed, so we release the pre-allocated extent_status when es->es_len is not initialized.
Suggested-by: Jan Kara jack@suse.cz Signed-off-by: Baokun Li libaokun1@huawei.com Reviewed-by: Jan Kara jack@suse.cz Link: https://lore.kernel.org/r/20230424033846.4732-7-libaokun1@huawei.com Signed-off-by: Theodore Ts'o tytso@mit.edu Stable-dep-of: 8e387c89e96b ("ext4: make sure allocate pending entry not fail") Signed-off-by: Sasha Levin sashal@kernel.org --- fs/ext4/extents_status.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-)
diff --git a/fs/ext4/extents_status.c b/fs/ext4/extents_status.c index 1bfee9dff9c38..854d865e9bfa2 100644 --- a/fs/ext4/extents_status.c +++ b/fs/ext4/extents_status.c @@ -1439,6 +1439,7 @@ int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk, ext4_lblk_t end; int err = 0; int reserved = 0; + struct extent_status *es = NULL;
trace_ext4_es_remove_extent(inode, lblk, len); es_debug("remove [%u/%u) from extent status tree of inode %lu\n", @@ -1450,17 +1451,25 @@ int ext4_es_remove_extent(struct inode *inode, ext4_lblk_t lblk, end = lblk + len - 1; BUG_ON(end < lblk);
+retry: + if (err && !es) + es = __es_alloc_extent(true); /* * ext4_clear_inode() depends on us taking i_es_lock unconditionally * so that we are sure __es_shrink() is done with the inode before it * is reclaimed. */ write_lock(&EXT4_I(inode)->i_es_lock); - err = __es_remove_extent(inode, lblk, end, &reserved, NULL); + err = __es_remove_extent(inode, lblk, end, &reserved, es); + if (es && !es->es_len) + __es_free_extent(es); write_unlock(&EXT4_I(inode)->i_es_lock); + if (err) + goto retry; + ext4_es_print_tree(inode); ext4_da_release_space(inode, reserved); - return err; + return 0; }
static int __es_shrink(struct ext4_sb_info *sbi, int nr_to_scan,