The flow of getSourceMount was:
1 get all entries from /proc/self/mountinfo
2 do a linear search for the `source` directory
3 if found, return its data
4 get the parent directory of `source`, goto 2
The repeated linear search through the whole mountinfo (which can have
thousands of records) is inefficient. Instead, let's just
1 collect all the relevant records (only those mount points
that can be a parent of `source`)
2 find the record with the longest mountpath, return its data
This was tested manually with something like
```go
func TestGetSourceMount(t *testing.T) {
mnt, flags, err := getSourceMount("/sys/devices/msr/")
assert.NoError(t, err)
t.Logf("mnt: %v, flags: %v", mnt, flags)
}
```
...but it relies on having a specific mount points on the system
being used for testing.
[v2: add unit tests for ParentsFilter]
Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
Upstream-commit: 871c957242df9f8c74faf751a2f14eb5178d4140
Component: engine
pkg/ is a collection of utility packages used by the Moby project without being specific to its internals.
Utility packages are kept separate from the moby core codebase to keep it as small and concise as possible. If some utilities grow larger and their APIs stabilize, they may be moved to their own repository under the Moby organization, to facilitate re-use by other projects. However that is not the priority.
The directory pkg is named after the same directory in the camlistore project. Since Brad is a core
Go maintainer, we thought it made sense to copy his methods for organizing Go code :) Thanks Brad!
Because utility packages are small and neatly separated from the rest of the codebase, they are a good place to start for aspiring maintainers and contributors. Get in touch if you want to help maintain them!