From eae3faf210bdc69181be717ce90437eadc6b3c80 Mon Sep 17 00:00:00 2001 From: Daeho Jeong Date: Wed, 5 Aug 2026 18:48:13 -0700 Subject: f2fs: support dynamic reserve/release for device aliasing This patch adds a dynamic management feature to the existing device aliasing functionality. It allows users to dynamically reserve or release specific devices from the filesystem's free pool at runtime through new ioctls. To support this, three new ioctls are introduced: - F2FS_IOC_RESERVE_DEV_ALIAS: This reclaims the space occupied by a device aliasing file. It first performs a capacity check, resets GC victim information for the target range, marks the segments as in-use to prevent new allocations, and then triggers GC to migrate existing valid data out of the range. Finally, it reserves these blocks in the SIT to effectively exclude the device from the usable capacity. - F2FS_IOC_RELEASE_DEV_ALIAS: This releases the reserved space of a previously reserved device aliasing file. It truncates the blocks associated with the file, which makes them available for general filesystem allocation again. - F2FS_IOC_GET_DEV_ALIAS_STATUS: This retrieves the current aliasing status of a device aliasing file, returning whether the file is released (inactive alias) or reserved (active alias, with blocks fully allocated on the device). Signed-off-by: Daeho Jeong Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim --- include/uapi/linux/f2fs.h | 7 +++++++ 1 file changed, 7 insertions(+) (limited to 'include/uapi/linux') diff --git a/include/uapi/linux/f2fs.h b/include/uapi/linux/f2fs.h index 795e26258355..4409ada2fecb 100644 --- a/include/uapi/linux/f2fs.h +++ b/include/uapi/linux/f2fs.h @@ -45,6 +45,9 @@ #define F2FS_IOC_START_ATOMIC_REPLACE _IO(F2FS_IOCTL_MAGIC, 25) #define F2FS_IOC_GET_DEV_ALIAS_FILE _IOR(F2FS_IOCTL_MAGIC, 26, __u32) #define F2FS_IOC_IO_PRIO _IOW(F2FS_IOCTL_MAGIC, 27, __u32) +#define F2FS_IOC_RESERVE_DEV_ALIAS _IO(F2FS_IOCTL_MAGIC, 28) +#define F2FS_IOC_RELEASE_DEV_ALIAS _IO(F2FS_IOCTL_MAGIC, 29) +#define F2FS_IOC_GET_DEV_ALIAS_STATUS _IOR(F2FS_IOCTL_MAGIC, 30, __u32) /* * should be same as XFS_IOC_GOINGDOWN. @@ -70,6 +73,10 @@ enum { F2FS_IOPRIO_MAX, }; +/* for F2FS_IOC_GET_DEV_ALIAS_STATUS */ +#define F2FS_DEV_ALIAS_STATUS_RELEASED 0 +#define F2FS_DEV_ALIAS_STATUS_RESERVED 1 + struct f2fs_gc_range { __u32 sync; __u64 start; -- cgit v1.2.3