From: yangerkun yangerkun@huawei.com
commit 4268496e48dc681cfa53b92357314b5d7221e625 upstream.
Like ext4_ext_rm_leaf, we can ensure that there are enough credits before every call that will consume credits. As part of this fix we fold the functionality of ext4_access_path() into ext4_ext_shift_path_extents(). This change is needed as a preparation for the next bugfix patch.
Cc: stable@kernel.org Link: https://lore.kernel.org/r/20210903062748.4118886-3-yangerkun@huawei.com Signed-off-by: yangerkun yangerkun@huawei.com Reviewed-by: Jan Kara jack@suse.cz Signed-off-by: Theodore Ts'o tytso@mit.edu Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- fs/ext4/extents.c | 49 +++++++++++++++---------------------------------- 1 file changed, 15 insertions(+), 34 deletions(-)
--- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -4978,36 +4978,6 @@ int ext4_get_es_cache(struct inode *inod }
/* - * ext4_access_path: - * Function to access the path buffer for marking it dirty. - * It also checks if there are sufficient credits left in the journal handle - * to update path. - */ -static int -ext4_access_path(handle_t *handle, struct inode *inode, - struct ext4_ext_path *path) -{ - int credits, err; - - if (!ext4_handle_valid(handle)) - return 0; - - /* - * Check if need to extend journal credits - * 3 for leaf, sb, and inode plus 2 (bmap and group - * descriptor) for each block group; assume two block - * groups - */ - credits = ext4_writepage_trans_blocks(inode); - err = ext4_datasem_ensure_credits(handle, inode, 7, credits, 0); - if (err < 0) - return err; - - err = ext4_ext_get_access(handle, inode, path); - return err; -} - -/* * ext4_ext_shift_path_extents: * Shift the extents of a path structure lying between path[depth].p_ext * and EXT_LAST_EXTENT(path[depth].p_hdr), by @shift blocks. @SHIFT tells @@ -5021,6 +4991,7 @@ ext4_ext_shift_path_extents(struct ext4_ int depth, err = 0; struct ext4_extent *ex_start, *ex_last; bool update = false; + int credits, restart_credits; depth = path->p_depth;
while (depth >= 0) { @@ -5030,13 +5001,23 @@ ext4_ext_shift_path_extents(struct ext4_ return -EFSCORRUPTED;
ex_last = EXT_LAST_EXTENT(path[depth].p_hdr); + /* leaf + sb + inode */ + credits = 3; + if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr)) { + update = true; + /* extent tree + sb + inode */ + credits = depth + 2; + }
- err = ext4_access_path(handle, inode, path + depth); + restart_credits = ext4_writepage_trans_blocks(inode); + err = ext4_datasem_ensure_credits(handle, inode, credits, + restart_credits, 0); if (err) goto out;
- if (ex_start == EXT_FIRST_EXTENT(path[depth].p_hdr)) - update = true; + err = ext4_ext_get_access(handle, inode, path + depth); + if (err) + goto out;
while (ex_start <= ex_last) { if (SHIFT == SHIFT_LEFT) { @@ -5067,7 +5048,7 @@ ext4_ext_shift_path_extents(struct ext4_ }
/* Update index too */ - err = ext4_access_path(handle, inode, path + depth); + err = ext4_ext_get_access(handle, inode, path + depth); if (err) goto out;