mirror of
https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
synced 2026-05-03 12:24:37 -04:00
005abf9e5e
Previously, we have two mechanisms to cache & submit small discards: a) set max small discard number in /sys/fs/f2fs/vdb/max_small_discards, and checkpoint will cache small discard candidates w/ configured maximum number. b) call FITRIM ioctl, also, checkpoint in f2fs_trim_fs() will cache small discard candidates w/ configured discard granularity, but w/o limitation of number. FSTRIM interface is asynchronized, so it won't submit discard directly. Finally, discard thread will submit them in background periodically. However, after commit9ac00e7cef("f2fs: do not issue small discard commands during checkpoint"), the mechanism a) is broken, since no matter how we configure the sysfs entry /sys/fs/f2fs/vdb/max_small_discards, checkpoint will not cache small discard candidates any more. echo 0 > /sys/fs/f2fs/vdb/max_small_discards xfs_io -f /mnt/f2fs/file -c "pwrite 0 2m" -c "fsync" xfs_io /mnt/f2fs/file -c "fpunch 0 4k" sync cat /proc/fs/f2fs/vdb/discard_plist_info |head -2 echo 100 > /sys/fs/f2fs/vdb/max_small_discards rm /mnt/f2fs/file xfs_io -f /mnt/f2fs/file -c "pwrite 0 2m" -c "fsync" xfs_io /mnt/f2fs/file -c "fpunch 0 4k" sync cat /proc/fs/f2fs/vdb/discard_plist_info |head -2 Before the patch: Discard pend list(Show diacrd_cmd count on each entry, .:not exist): 0 . . . . . . . . Discard pend list(Show diacrd_cmd count on each entry, .:not exist): 0 3 1 . . . . . . After the patch: Discard pend list(Show diacrd_cmd count on each entry, .:not exist): 0 . . . . . . . . Discard pend list(Show diacrd_cmd count on each entry, .:not exist): 0 . . . . . . . . This patch reverts commit9ac00e7cef("f2fs: do not issue small discard commands during checkpoint") in order to fix this issue. Fixes:9ac00e7cef("f2fs: do not issue small discard commands during checkpoint") Signed-off-by: Chao Yu <chao@kernel.org> Signed-off-by: Jaegeuk Kim <jaegeuk@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.