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path: root/pkg/sentry/fs/gofer/cache_policy.go
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2019-06-13Update canonical repository.Adin Scannell
This can be merged after: https://github.com/google/gvisor-website/pull/77 or https://github.com/google/gvisor-website/pull/78 PiperOrigin-RevId: 253132620
2019-05-03gofer: don't leak file descriptorsAndrei Vagin
Fixes #219 PiperOrigin-RevId: 246568639 Change-Id: Ic7afd15dde922638d77f6429c508d1cbe2e4288a
2019-04-29Change copyright notice to "The gVisor Authors"Michael Pratt
Based on the guidelines at https://opensource.google.com/docs/releasing/authors/. 1. $ rg -l "Google LLC" | xargs sed -i 's/Google LLC.*/The gVisor Authors./' 2. Manual fixup of "Google Inc" references. 3. Add AUTHORS file. Authors may request to be added to this file. 4. Point netstack AUTHORS to gVisor AUTHORS. Drop CONTRIBUTORS. Fixes #209 PiperOrigin-RevId: 245823212 Change-Id: I64530b24ad021a7d683137459cafc510f5ee1de9
2019-04-29Allow and document bug ids in gVisor codebase.Nicolas Lacasse
PiperOrigin-RevId: 245818639 Change-Id: I03703ef0fb9b6675955637b9fe2776204c545789
2019-03-28Clean up gofer handle caching.Jamie Liu
- Document fsutil.CachedFileObject.FD() requirements on access permissions, and change gofer.inodeFileState.FD() to honor them. Fixes #147. - Combine gofer.inodeFileState.readonly and gofer.inodeFileState.readthrough, and simplify handle caching logic. - Inline gofer.cachePolicy.cacheHandles into gofer.inodeFileState.setSharedHandles, because users with access to gofer.inodeFileState don't necessarily have access to the fs.Inode (predictably, this is a save/restore problem). Before this CL: $ docker run --runtime=runsc-d -v $(pwd)/gvisor/repro:/root/repro -it ubuntu bash root@34d51017ed67:/# /root/repro/runsc-b147 mmap: 0x7f3c01e45000 Segmentation fault After this CL: $ docker run --runtime=runsc-d -v $(pwd)/gvisor/repro:/root/repro -it ubuntu bash root@d3c3cb56bbf9:/# /root/repro/runsc-b147 mmap: 0x7f78987ec000 o PiperOrigin-RevId: 240818413 Change-Id: I49e1d4a81a0cb9177832b0a9f31a10da722a896b
2019-01-25Make cacheRemoteRevalidating detect changes to file sizeFabricio Voznika
When file size changes outside the sandbox, page cache was not refreshing file size which is required for cacheRemoteRevalidating. In fact, cacheRemoteRevalidating should be skipping the cache completely since it's not really benefiting from it. The cache is cache is already bypassed for unstable attributes (see cachePolicy.cacheUAttrs). And althought the cache is called to map pages, they will always miss the cache and map directly from the host. Created a HostMappable struct that maps directly to the host and use it for files with cacheRemoteRevalidating. Closes #124 PiperOrigin-RevId: 230998440 Change-Id: Ic5f632eabe33b47241e05e98c95e9b2090ae08fc
2018-10-19Use correct company name in copyright headerIan Gudger
PiperOrigin-RevId: 217951017 Change-Id: Ie08bf6987f98467d07457bcf35b5f1ff6e43c035
2018-08-27fs: Fix remote-revalidate cache policy.Nicolas Lacasse
When revalidating a Dirent, if the inode id is the same, then we don't need to throw away the entire Dirent. We can just update the unstable attributes in place. If the inode id has changed, then the remote file has been deleted or moved, and we have no choice but to throw away the dirent we have a look up another. In this case, we may still end up losing a mounted dirent that is a child of the revalidated dirent. However, that seems appropriate here because the entire mount point has been pulled out from underneath us. Because gVisor's overlay is at the Inode level rather than the Dirent level, we must pass the parent Inode and name along with the Inode that is being revalidated. PiperOrigin-RevId: 210431270 Change-Id: I705caef9c68900234972d5aac4ae3a78c61c7d42
2018-08-14runsc: Change cache policy for root fs and volume mounts.Nicolas Lacasse
Previously, gofer filesystems were configured with the default "fscache" policy, which caches filesystem metadata and contents aggressively. While this setting is best for performance, it means that changes from inside the sandbox may not be immediately propagated outside the sandbox, and vice-versa. This CL changes volumes and the root fs configuration to use a new "remote-revalidate" cache policy which tries to retain as much caching as possible while still making fs changes visible across the sandbox boundary. This cache policy is enabled by default for the root filesystem. The default value for the "--file-access" flag is still "proxy", but the behavior is changed to use the new cache policy. A new value for the "--file-access" flag is added, called "proxy-exclusive", which turns on the previous aggressive caching behavior. As the name implies, this flag should be used when the sandbox has "exclusive" access to the filesystem. All volume mounts are configured to use the new cache policy, since it is safest and most likely to be correct. There is not currently a way to change this behavior, but it's possible to add such a mechanism in the future. The configurability is a smaller issue for volumes, since most of the expensive application fs operations (walking + stating files) will likely served by the root fs. PiperOrigin-RevId: 208735037 Change-Id: Ife048fab1948205f6665df8563434dbc6ca8cfc9
2018-08-07fs: Add new cache policy "remote_revalidate".Nicolas Lacasse
This CL adds a new cache-policy for gofer filesystems that uses the host page cache, but causes dirents to be reloaded on each Walk, and does not cache readdir results. This policy is useful when the remote filesystem may change out from underneath us, as any remote changes will be reflected on the next Walk. Importantly, this cache policy is only consistent if we do not use gVisor's internal page cache, since that page cache is tied to the Inode and may be thrown away upon Revalidation. This cache policy should only be used when the gofer supports donating host FDs, since then gVisor will make use of the host kernel page cache, which will be consistent for all open files in the gofer. In fact, a panic will be raised if a file is opened without a donated FD. PiperOrigin-RevId: 207752937 Change-Id: I233cb78b4695bbe00a4605ae64080a47629329b8
2018-06-19Add a new cache policy FSCACHE_WRITETHROUGH.Nicolas Lacasse
The new policy is identical to FSCACHE (which caches everything in memory), but it also flushes writes to the backing fs agent immediately. All gofer cache policy decisions have been moved into the cachePolicy type. Previously they were sprinkled around the codebase. There are many different things that we cache (page cache, negative dirents, dirent LRU, unstable attrs, readdir results....), and I don't think we should have individual flags to control each of these. Instead, we should have a few high-level cache policies that are consistent and useful to users. This refactoring makes it easy to add more such policies. PiperOrigin-RevId: 201206937 Change-Id: I6e225c382b2e5e1b0ad4ccf8ca229873f4cd389d