Before this change the VFS cache cleaner would loop indefinitely while
the cache was above quota. This used up all the CPU.
This fix prevents the cache cleaner from looping. It will be kicked on
ENOSPACE and run in its scheduled time otherwise so this should be
sufficient.
See: https://forum.rclone.org/t/vfs-keeps-checking-same-files/32120
When using filepath.Dir, a difference to path.Dir is that it returns os PathSeparator
instead of slash when the path consists entirely of separators.
Also fixed casing of the function name, use OS in all caps instead of Os
as recommended here: https://github.com/golang/go/wiki/CodeReviewComments#initialisms
This is possible now that we no longer support go1.12 and brings
rclone into line with standard practices in the Go world.
This also removes errors.New and errors.Errorf from lib/errors and
prefers the stdlib errors package over lib/errors.
This replaces built-in os.MkdirAll with a patched version that stops the recursion
when reaching the volume part of the path. The original version would continue recursion,
and for extended length paths end up with \\? as the top-level directory, and the error
message would then be something like:
mkdir \\?: The filename, directory name, or volume label syntax is incorrect.
Before this change but after:
aea8776a43 vfs: fix modtimes not updating when writing via cache #4763
When a file was opened read-only the modtime was read from the cached
file. However this modtime wasn't correct leading to an incorrect
result.
This change fixes the definition of `item.IsDirty` to be true only
when the data is dirty. This fixes the problem as a read only file
isn't considered dirty.
The vfs-cache-max-size parameter is probably confusing to many users.
The cache cleaner checks cache size periodically at the --vfs-cache-poll-interval
(default 60 seconds) interval and remove cache items in the following order.
(1) cache items that are not in use and with age > vfs-cache-max-age
(2) if the cache space used at this time still is larger than
vfs-cache-max-size, the cleaner continues to remove cache items that are
not in use.
The cache cleaning process does not remove cache items that are currently in use.
If the total space consumed by in-use cache items exceeds vfs-cache-max-size, the
periodical cache cleaner thread does not do anything further and leaves the in-use
cache items alone with a total space larger than vfs-cache-max-size.
A cache reset feature was introduced in 1.53 which resets in-use (but not dirty,
i.e., not being updated) cache items when additional cache data incurs an ENOSPC
error. But this code was not activated in the periodical cache cleaning thread.
This patch adds the cache reset step in the cache cleaner thread during cache
poll to reset cache items until the total size of the remaining cache items is
below vfs-cache-max-size.
The initial ':' is included in the ad-hoc remote name, but is illegal character
in Windows path. Replacing it with '^', which is legal in filesystems but illegal
in regular remote names, so name conflict is avoided.
Fixes#4544
If --cache-dir is passed in as a relative path, then rclone will not
be able to turn it into a UNC path under Windows, which means that
file names longer than 260 chars will fail when stored in the cache.
This patch makes the --cache-dir path absolute before using it.
See: https://forum.rclone.org/t/handling-of-long-paths-on-windows-260-characters/20913
This is done by making fs.Config private and attaching it to the
context instead.
The Config should be obtained with fs.GetConfig and fs.AddConfig
should be used to get a new mutable config that can be changed.
This adds a context.Context parameter to NewFs and related calls.
This is necessary as part of reading config from the context -
backends need to be able to read the global config.
The missed update can cause incorrect before-cleaning cache stats
and a pre-mature condition broadcast in purgeOld before the cache
space use is reduced below the quota.
Add an exponentially increasing delay during retries up ENOSPC error
to avoid exhausting the 10 retries too soon when the cache space
recovery from item resets is not available from the file system yet
or consumed by other large cache writes.
A failed item reset is saved in the errItems for retryFailedResets
to process. If the item gets closed before the retry, the item may
have been removed from the c.item array. Previous code did not
account for this condition. This patch adds the check for the
exitence of the retry items in retryFailedResets.
This patch provides the support of synchronous cache space recovery
to allow read threads to recover from ENOSPC errors when cache space
can be recovered from cache items that are not in use or safe to be
reset/emptied .
The patch complements the existing cache cleaning process in two ways.
Firstly, the existing cache cleaning process is time-driven that runs
periodically. The cache space can run out while the cache cleaner
thread is still waiting for its next scheduled run. The io threads
encountering ENOSPC return an internal error to the applications
in this case even when cache space can be recovered to avoid this
error. This patch addresses this problem by having the read threads
kick the cache cleaner thread in this condition to recover cache
space preventing unnecessary ENOSPC errors from being seen by the
applications.
Secondly, this patch enhances the cache cleaner to support cache
item reset. Currently the cache purge process removes cache
items that are not in use. This may not be sufficient when the
total size of the working set exceeds the cache directory's
capacity. Like in the current code, this patch starts the purge
process by removing cache files that are not in use. Cache items
whose access times are older than vfs-cache-max-age are removed first.
After that, other not-in-use items are removed in LRU order until
vfs-cache-max-size is reached. If the vfs-cache-max-size (the quota)
is still not reached at this time, this patch adds a cache reset
step to reset/empty cache files that are still in use but not
dirtied. This enables application processes to continue without
seeing an error even when the working set depletes the cache space
as long as there is not a large write working set hoarding the
entire cache space.
By design this patch does not add ENOSPC error recovery for write
IOs. Rclone does not empty a write cache item until the file data
is written back to the backend upon close. Allowing more cache
space to be consumed by dirty cache items when the cache space is
already running low would increase the risk of exhausting the cache
space in a way that the vfs mount becomes unreadable.
Before this change, if we restarted an upload after a restart then the
file would get uploaded but never added to the directory listings.
This change makes sure we add virtual items to the directory cache
when reloading the cache so that they show up properly.
- fix deadlock when cancelling upload
- fix double upload and panic after cancelled upload
- fix cancelation strategy of uploading files
- don't cancel uploads if we don't modify the file
- cancel uploads if we do modify the file
- fix deadlock between Item and writeback
- fix confusion about whether writeback item was being uploaded
- fix cornercases in cancelling uploads and removing files
On file Remove
- cancel any writebacks in progress
- ignore error message deleting non existent file if file was in the
process of being uploaded
Writeback
- Don't transfer the file if it has disappeared in the meantime
- Take our own copy of the file name to avoid deadlocks
- Fix delayed retry logic
- Wait for upload to finish when cancelling upload
Fix race condition in item saving
Fix race condition in vfscache test
Make sure we delete the file on the error path - this makes cascading
failures much less likely
This allows reads to only read part of the file and it keeps on disk a
cache of what parts of each file have been loaded.
File data itself is kept in sparse files.
