add umask for s3 gateway and refactor code

[zhijian-pro]

No description provided.

[codecov-commenter]

Codecov Report

Merging #1537 (bb01c5a) into main (78b11ae) will decrease coverage by 0.03%.
The diff coverage is 71.42%.

@@            Coverage Diff             @@
##             main    #1537      +/-   ##
==========================================
- Coverage   61.29%   61.25%   -0.04%     
==========================================
  Files         133      133              
  Lines       22269    22277       +8     
==========================================
- Hits        13650    13646       -4     
- Misses       7078     7087       +9     
- Partials     1541     1544       +3     

Impacted Files	Coverage Δ
pkg/gateway/gateway.go	46.36% <66.66%> (ø)
cmd/gateway.go	87.30% <77.77%> (-0.84%)	⬇️
pkg/meta/tkv.go	75.44% <0.00%> (-0.77%)	⬇️
pkg/meta/redis.go	72.78% <0.00%> (-0.23%)	⬇️
pkg/meta/sql.go	67.06% <0.00%> (-0.11%)	⬇️
pkg/vfs/reader.go	83.39% <0.00%> (+1.82%)	⬆️

---

Continue to review full report at Codecov.

Legend - Click here to learn more
Δ = absolute <relative> (impact), ø = not affected, ? = missing data
Powered by Codecov. Last update 7ae2e9f...bb01c5a. Read the comment docs.