kernel/linux.git/Documentation/admin-guide/xfs.rst, branch linux-7.1.y

xfs: expose the number of open zones in sysfs

2026-04-07T11:28:47+00:00

Add a sysfs attribute for the current number of open zones so that it can be trivially read from userspace in monitoring or testing software. Signed-off-by: Christoph Hellwig Reviewed-by: Hans Holmberg Reviewed-by: Damien Le Moal Signed-off-by: Carlos Maiolino

xfs: allow setting errortags at mount time

2026-01-30T09:41:42+00:00

Add an errortag mount option that enables an errortag with the default injection frequency. This allows injecting errors into the mount process instead of just on live file systems, and thus test mount error handling. Signed-off-by: Christoph Hellwig Reviewed-by: Hans Holmberg Reviewed-by: Carlos Maiolino Signed-off-by: Carlos Maiolino

xfs: extend removed sysctls table

2025-09-16T10:24:13+00:00

Commit 21d59d00221e4e ("xfs: remove deprecated sysctl knobs") moves recently-removed sysctls to the removed sysctls table but fails to extend the table, hence triggering Sphinx warning: Documentation/admin-guide/xfs.rst:365: ERROR: Malformed table. Text in column margin in table line 8. ============================= ======= Name Removed ============================= ======= fs.xfs.xfsbufd_centisec v4.0 fs.xfs.age_buffer_centisecs v4.0 fs.xfs.irix_symlink_mode v6.18 fs.xfs.irix_sgid_inherit v6.18 fs.xfs.speculative_cow_prealloc_lifetime v6.18 ============================= ======= [docutils] Extend "Name" column of the table to fit the now-longest sysctl, which is fs.xfs.speculative_cow_prealloc_lifetime. Fixes: 21d59d00221e ("xfs: remove deprecated sysctl knobs") Reported-by: Stephen Rothwell Closes: https://lore.kernel.org/linux-next/20250908180406.32124fb7@canb.auug.org.au/ Signed-off-by: Bagas Sanjaya Reviewed-by: Darrick J. Wong Reviewed-by: Randy Dunlap Signed-off-by: Carlos Maiolino

xfs: remove deprecated sysctl knobs

2025-09-05T15:48:23+00:00

These sysctl knobs were scheduled for removal in September 2025. That time has come, so remove them. Signed-off-by: "Darrick J. Wong" Reviewed-by: Carlos Maiolino

xfs: remove deprecated mount options

2025-09-05T15:48:23+00:00

These four mount options were scheduled for removal in September 2025, so remove them now. Cc: preichl@redhat.com Signed-off-by: "Darrick J. Wong" Reviewed-by: Carlos Maiolino

xfs: disable deprecated features by default in Kconfig

2025-09-05T15:48:23+00:00

We promised to turn off these old features by default in September 2025. Do so now. Signed-off-by: "Darrick J. Wong" Reviewed-by: Carlos Maiolino

xfs: allow sysadmins to specify a maximum atomic write limit at mount time

2025-05-07T21:25:33+00:00

Introduce a mount option to allow sysadmins to specify the maximum size of an atomic write. If the filesystem can work with the supplied value, that becomes the new guaranteed maximum. The value mustn't be too big for the existing filesystem geometry (max write size, max AG/rtgroup size). We dynamically recompute the tr_atomic_write transaction reservation based on the given block size, check that the current log size isn't less than the new minimum log size constraints, and set a new maximum. The actual software atomic write max is still computed based off of tr_atomic_ioend the same way it has for the past few commits. Note also that xfs_calc_atomic_write_log_geometry is non-static because mkfs will need that. Signed-off-by: Darrick J. Wong Signed-off-by: John Garry Reviewed-by: John Garry

xfs: remove duplicate Zoned Filesystems sections in admin-guide

2025-04-22T14:05:24+00:00

Remove the duplicated section and while at it, turn spaces into tabs. Signed-off-by: Hans Holmberg Reviewed-by: Christoph Hellwig Reviewed-by: Carlos Maiolino Fixes: c7b67ddc3c99 ("xfs: document zoned rt specifics in admin-guide") Signed-off-by: Carlos Maiolino

xfs: document zoned rt specifics in admin-guide

2025-04-17T06:16:59+00:00

Document the lifetime, nolifetime and max_open_zones mount options added for zoned rt file systems. Also add documentation describing the max_open_zones sysfs attribute exposed in /sys/fs/xfs//zoned/ Fixes: 4e4d52075577 ("xfs: add the zoned space allocator") Signed-off-by: Hans Holmberg Reviewed-by: Christoph Hellwig Reviewed-by: Darrick J. Wong Signed-off-by: Carlos Maiolino

xfs: add tunable threshold parameter for triggering zone GC

2025-04-14T08:41:33+00:00

Presently we start garbage collection late - when we start running out of free zones to backfill max_open_zones. This is a reasonable default as it minimizes write amplification. The longer we wait, the more blocks are invalidated and reclaim cost less in terms of blocks to relocate. Starting this late however introduces a risk of GC being outcompeted by user writes. If GC can't keep up, user writes will be forced to wait for free zones with high tail latencies as a result. This is not a problem under normal circumstances, but if fragmentation is bad and user write pressure is high (multiple full-throttle writers) we will "bottom out" of free zones. To mitigate this, introduce a zonegc_low_space tunable that lets the user specify a percentage of how much of the unused space that GC should keep available for writing. A high value will reclaim more of the space occupied by unused blocks, creating a larger buffer against write bursts. This comes at a cost as write amplification is increased. To illustrate this using a sample workload, setting zonegc_low_space to 60% avoids high (500ms) max latencies while increasing write amplification by 15%. Signed-off-by: Hans Holmberg Reviewed-by: Christoph Hellwig Signed-off-by: Carlos Maiolino