kernel/git/stable/linux.git/fs/f2fs/segment.h, branch master

f2fs: support resizable tail section and unify pinned allocation

2026-08-27T04:47:36+00:00

Currently, zoned block devices restrict pinned file allocations to conventional zones at the beginning of the storage (before first_seq_zone_segno), triggering range GC when conventional space is exhausted. On regular block devices, when preparing for future online filesystem resizing (e.g. partition shrinking), pinned files must not be allocated in the tail area that will be truncated, as pinned files cannot be relocated by GC. Specifying the resizable tail area size (in sections) allows uniform mount configuration across devices of different storage capacities. To support this, introduce a unified `pinned_area_max_secno` boundary abstraction in `f2fs_sb_info`: 1. Add `-o resizable_tail_secno=%u` mount option to specify the number of sections at the tail of the filesystem reserved for resizing. 2. In `f2fs_fill_super()`, initialize `sbi->pinned_area_max_secno` as: min(MAIN_SECS(sbi) - resizable_tail_sec, zoned_max_sec). 3. In `get_new_segment()`, restrict segment allocation for pinned files (`pinning == true`) to `0 .. sbi->pinned_area_max_secno - 1`. If no free section is available in the pinned area, return -EAGAIN. 4. In `f2fs_allocate_pinning_section()`, unify the range GC trigger to run `f2fs_gc_range()` up to `sbi->pinned_area_max_secno` whenever `sbi->pinned_area_max_secno < MAIN_SECS(sbi)` and allocation returns -EAGAIN. 5. Expose `/sys/fs/f2fs//pinned_area_max_secno` as a read-only sysfs node. Signed-off-by: Daeho Jeong Signed-off-by: Sunmin Jeong Reviewed-by: Wenjie Qi Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: support dynamic reserve/release for device aliasing

2026-08-11T04:16:04+00:00

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

f2fs: Remove unused curseg_segno() and curseg_alloc_type()

2026-08-04T00:18:36+00:00

The only callers of curseg_segno() and curseg_alloc_type() were removed by commit 5a4fed7cd97a ("f2fs: simplify do_checkpoint"); both helpers have been unused since then. Being static inline functions they do not trigger -Wunused-function, so the dead code has gone unnoticed. Remove them. No functional change. Signed-off-by: Zhan Xusheng Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

Revert: "f2fs: check in-memory sit version bitmap"

2026-06-22T19:52:35+00:00

Commit ae27d62e6bef ("f2fs: check in-memory sit version bitmap") added a mirror for sit version bitmap, it expects to detect in-memory corruption, however we never got any reports from the check points for almost decade, let's remove the code, it can help to save memories. Cc: wallentx Suggested-by: Jaegeuk Kim Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

Revert: "f2fs: check in-memory block bitmap"

2026-06-22T19:52:35+00:00

Commit 355e78913c0d ("f2fs: check in-memory block bitmap") added a mirror for valid block bitmap, it expects to detect in-memory corruption, however we never got any reports from the check points for almost decade, let's remove the code, it can help to save memories. Cc: wallentx Suggested-by: Jaegeuk Kim Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: stop using writeback internals for dirty_exceeded checks

2026-02-17T12:25:14+00:00

Replace direct dereferences of dirty_exceeded with the core helper bdi_wb_dirty_exceeded(), removing f2fs dependencies on writeback internals. Reviewed-by: Jeff Layton Reviewed-by: Andreas Gruenbacher Suggested-by: Christoph Hellwig Signed-off-by: Kundan Kumar Signed-off-by: Anuj Gupta Link: https://patch.msgid.link/20260213054634.79785-3-kundan.kumar@samsung.com Signed-off-by: Christian Brauner

f2fs: support non-4KB block size without packed_ssa feature

2026-01-17T00:00:34+00:00

Currently, F2FS requires the packed_ssa feature to be enabled when utilizing non-4KB block sizes (e.g., 16KB). This restriction limits the flexibility of filesystem formatting options. This patch allows F2FS to support non-4KB block sizes even when the packed_ssa feature is disabled. It adjusts the SSA calculation logic to correctly handle summary entries in larger blocks without the packed layout. Cc: stable@kernel.org Fixes: 7ee8bc3942f2 ("f2fs: revert summary entry count from 2048 to 512 in 16kb block support") Signed-off-by: Daeho Jeong Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: improve check for enough free sections

2025-12-16T00:49:25+00:00

The check for enough sections in segment.h has the following issues: 1. has_not_enough_free_secs() should return "enough secs" when "free_secs >= upper_secs", not just structly greater. Conversely, it should only return "not enough secs" when "free_secs < lower_secs", not when they are equal. This accounts for the possibility that blocks can fit within curseg without requiring an additional free section. 2. __get_secs_required() currently separates the needed space to section and block parts, checking them against free sections and curseg, respectively. This does not consider the case where curseg cannot hold the whole block part, but excess free sections beyond the section part can accommodate some of the block part. 3. has_curseg_enough_space() only checks CURSEG_HOT_DATA for dentry blocks, but when active_logs=6, they may be placed in WARM and COLD sections. Also, the current logic does not consider that dentry and data blocks can be put in the same section when active_logs=2 or 6. This patch modifies the three functions to address the above issues: 1. Rename has_curseg_enough_space() to get_additional_blocks_required(). Calculate the minimum node, dentry, and data blocks curseg can accommodate. Then subtract these from the total required blocks of respective type to determine the worst-case number of blocks that must be placed in free sections. 2. In __get_secs_required(), get the number of blocks needing new sections from the new get_additional_blocks_required(). Return the upper bound of necessary free sections for these blocks. For active_logs=2 or 6, dentry blocks are combined with data blocks. 3. In has_not_enough_free_secs(), get the required sections from __get_secs_required(), and return “not enough secs” if “free_secs < required_secs”. Signed-off-by: Joanne Chang Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: fix to not account invalid blocks in get_left_section_blocks()

2025-12-04T02:00:05+00:00

w/ LFS mode, in get_left_section_blocks(), we should not account the blocks which were used before and now are invalided, otherwise those blocks will be counted as freed one in has_curseg_enough_space(), result in missing to trigger GC in time. Cc: stable@kernel.org Fixes: 249ad438e1d9 ("f2fs: add a method for calculating the remaining blocks in the current segment in LFS mode.") Fixes: bf34c93d2645 ("f2fs: check curseg space before foreground GC") Signed-off-by: Chao Yu Signed-off-by: Jaegeuk Kim

f2fs: wrap all unusable_blocks_per_sec code in CONFIG_BLK_DEV_ZONED

2025-12-04T02:00:04+00:00

The usage of unusable_blocks_per_sec is already wrapped by CONFIG_BLK_DEV_ZONED, except for its declaration and the definitions of CAP_BLKS_PER_SEC and CAP_SEGS_PER_SEC. This patch ensures that all code related to unusable_blocks_per_sec is properly wrapped under the CONFIG_BLK_DEV_ZONED option. Signed-off-by: Yongpeng Yang Reviewed-by: Chao Yu Signed-off-by: Jaegeuk Kim