diff options
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/fscrypt.rst | 2 | ||||
| -rw-r--r-- | Documentation/filesystems/iomap/operations.rst | 50 | ||||
| -rw-r--r-- | Documentation/filesystems/porting.rst | 15 | ||||
| -rw-r--r-- | Documentation/filesystems/resctrl.rst | 134 |
4 files changed, 169 insertions, 32 deletions
diff --git a/Documentation/filesystems/fscrypt.rst b/Documentation/filesystems/fscrypt.rst index 696a5844bfa3..70af896822e1 100644 --- a/Documentation/filesystems/fscrypt.rst +++ b/Documentation/filesystems/fscrypt.rst @@ -450,9 +450,7 @@ API, but the filenames mode still does. - CONFIG_CRYPTO_HCTR2 - Recommended: - arm64: CONFIG_CRYPTO_AES_ARM64_CE_BLK - - arm64: CONFIG_CRYPTO_POLYVAL_ARM64_CE - x86: CONFIG_CRYPTO_AES_NI_INTEL - - x86: CONFIG_CRYPTO_POLYVAL_CLMUL_NI - Adiantum - Mandatory: diff --git a/Documentation/filesystems/iomap/operations.rst b/Documentation/filesystems/iomap/operations.rst index 387fd9cc72ca..da982ca7e413 100644 --- a/Documentation/filesystems/iomap/operations.rst +++ b/Documentation/filesystems/iomap/operations.rst @@ -135,6 +135,27 @@ These ``struct kiocb`` flags are significant for buffered I/O with iomap: * ``IOCB_DONTCACHE``: Turns on ``IOMAP_DONTCACHE``. +``struct iomap_read_ops`` +-------------------------- + +.. code-block:: c + + struct iomap_read_ops { + int (*read_folio_range)(const struct iomap_iter *iter, + struct iomap_read_folio_ctx *ctx, size_t len); + void (*submit_read)(struct iomap_read_folio_ctx *ctx); + }; + +iomap calls these functions: + + - ``read_folio_range``: Called to read in the range. This must be provided + by the caller. If this succeeds, iomap_finish_folio_read() must be called + after the range is read in, regardless of whether the read succeeded or + failed. + + - ``submit_read``: Submit any pending read requests. This function is + optional. + Internal per-Folio State ------------------------ @@ -182,6 +203,28 @@ The ``flags`` argument to ``->iomap_begin`` will be set to zero. The pagecache takes whatever locks it needs before calling the filesystem. +Both ``iomap_readahead`` and ``iomap_read_folio`` pass in a ``struct +iomap_read_folio_ctx``: + +.. code-block:: c + + struct iomap_read_folio_ctx { + const struct iomap_read_ops *ops; + struct folio *cur_folio; + struct readahead_control *rac; + void *read_ctx; + }; + +``iomap_readahead`` must set: + * ``ops->read_folio_range()`` and ``rac`` + +``iomap_read_folio`` must set: + * ``ops->read_folio_range()`` and ``cur_folio`` + +``ops->submit_read()`` and ``read_ctx`` are optional. ``read_ctx`` is used to +pass in any custom data the caller needs accessible in the ops callbacks for +fulfilling reads. + Buffered Writes --------------- @@ -317,6 +360,9 @@ The fields are as follows: delalloc reservations to avoid having delalloc reservations for clean pagecache. This function must be supplied by the filesystem. + If this succeeds, iomap_finish_folio_write() must be called once writeback + completes for the range, regardless of whether the writeback succeeded or + failed. - ``writeback_submit``: Submit the previous built writeback context. Block based file systems should use the iomap_ioend_writeback_submit @@ -444,10 +490,6 @@ These ``struct kiocb`` flags are significant for direct I/O with iomap: Only meaningful for asynchronous I/O, and only if the entire I/O can be issued as a single ``struct bio``. - * ``IOCB_DIO_CALLER_COMP``: Try to run I/O completion from the caller's - process context. - See ``linux/fs.h`` for more details. - Filesystems should call ``iomap_dio_rw`` from ``->read_iter`` and ``->write_iter``, and set ``FMODE_CAN_ODIRECT`` in the ``->open`` function for the file. diff --git a/Documentation/filesystems/porting.rst b/Documentation/filesystems/porting.rst index 7233b04668fc..d33429294252 100644 --- a/Documentation/filesystems/porting.rst +++ b/Documentation/filesystems/porting.rst @@ -211,7 +211,7 @@ test and set for you. e.g.:: inode = iget_locked(sb, ino); - if (inode->i_state & I_NEW) { + if (inode_state_read_once(inode) & I_NEW) { err = read_inode_from_disk(inode); if (err < 0) { iget_failed(inode); @@ -1309,3 +1309,16 @@ a different length, use vfs_parse_fs_qstr(fc, key, &QSTR_LEN(value, len)) instead. + +--- + +**mandatory** + +vfs_mkdir() now returns a dentry - the one returned by ->mkdir(). If +that dentry is different from the dentry passed in, including if it is +an IS_ERR() dentry pointer, the original dentry is dput(). + +When vfs_mkdir() returns an error, and so both dputs() the original +dentry and doesn't provide a replacement, it also unlocks the parent. +Consequently the return value from vfs_mkdir() can be passed to +end_creating() and the parent will be unlocked precisely when necessary. diff --git a/Documentation/filesystems/resctrl.rst b/Documentation/filesystems/resctrl.rst index b7f35b07876a..8c8ce678148a 100644 --- a/Documentation/filesystems/resctrl.rst +++ b/Documentation/filesystems/resctrl.rst @@ -17,17 +17,18 @@ AMD refers to this feature as AMD Platform Quality of Service(AMD QoS). This feature is enabled by the CONFIG_X86_CPU_RESCTRL and the x86 /proc/cpuinfo flag bits: -=============================================== ================================ -RDT (Resource Director Technology) Allocation "rdt_a" -CAT (Cache Allocation Technology) "cat_l3", "cat_l2" -CDP (Code and Data Prioritization) "cdp_l3", "cdp_l2" -CQM (Cache QoS Monitoring) "cqm_llc", "cqm_occup_llc" -MBM (Memory Bandwidth Monitoring) "cqm_mbm_total", "cqm_mbm_local" -MBA (Memory Bandwidth Allocation) "mba" -SMBA (Slow Memory Bandwidth Allocation) "" -BMEC (Bandwidth Monitoring Event Configuration) "" -ABMC (Assignable Bandwidth Monitoring Counters) "" -=============================================== ================================ +=============================================================== ================================ +RDT (Resource Director Technology) Allocation "rdt_a" +CAT (Cache Allocation Technology) "cat_l3", "cat_l2" +CDP (Code and Data Prioritization) "cdp_l3", "cdp_l2" +CQM (Cache QoS Monitoring) "cqm_llc", "cqm_occup_llc" +MBM (Memory Bandwidth Monitoring) "cqm_mbm_total", "cqm_mbm_local" +MBA (Memory Bandwidth Allocation) "mba" +SMBA (Slow Memory Bandwidth Allocation) "" +BMEC (Bandwidth Monitoring Event Configuration) "" +ABMC (Assignable Bandwidth Monitoring Counters) "" +SDCIAE (Smart Data Cache Injection Allocation Enforcement) "" +=============================================================== ================================ Historically, new features were made visible by default in /proc/cpuinfo. This resulted in the feature flags becoming hard to parse by humans. Adding a new @@ -72,6 +73,11 @@ The 'info' directory contains information about the enabled resources. Each resource has its own subdirectory. The subdirectory names reflect the resource names. +Most of the files in the resource's subdirectory are read-only, and +describe properties of the resource. Resources that support global +configuration options also include writable files that can be used +to modify those settings. + Each subdirectory contains the following files with respect to allocation: @@ -90,12 +96,19 @@ related to allocation: must be set when writing a mask. "shareable_bits": - Bitmask of shareable resource with other executing - entities (e.g. I/O). User can use this when - setting up exclusive cache partitions. Note that - some platforms support devices that have their - own settings for cache use which can over-ride - these bits. + Bitmask of shareable resource with other executing entities + (e.g. I/O). Applies to all instances of this resource. User + can use this when setting up exclusive cache partitions. + Note that some platforms support devices that have their + own settings for cache use which can over-ride these bits. + + When "io_alloc" is enabled, a portion of each cache instance can + be configured for shared use between hardware and software. + "bit_usage" should be used to see which portions of each cache + instance is configured for hardware use via "io_alloc" feature + because every cache instance can have its "io_alloc" bitmask + configured independently via "io_alloc_cbm". + "bit_usage": Annotated capacity bitmasks showing how all instances of the resource are used. The legend is: @@ -109,16 +122,16 @@ related to allocation: "H": Corresponding region is used by hardware only but available for software use. If a resource - has bits set in "shareable_bits" but not all - of these bits appear in the resource groups' - schematas then the bits appearing in - "shareable_bits" but no resource group will - be marked as "H". + has bits set in "shareable_bits" or "io_alloc_cbm" + but not all of these bits appear in the resource + groups' schemata then the bits appearing in + "shareable_bits" or "io_alloc_cbm" but no + resource group will be marked as "H". "X": Corresponding region is available for sharing and - used by hardware and software. These are the - bits that appear in "shareable_bits" as - well as a resource group's allocation. + used by hardware and software. These are the bits + that appear in "shareable_bits" or "io_alloc_cbm" + as well as a resource group's allocation. "S": Corresponding region is used by software and available for sharing. @@ -136,6 +149,77 @@ related to allocation: "1": Non-contiguous 1s value in CBM is supported. +"io_alloc": + "io_alloc" enables system software to configure the portion of + the cache allocated for I/O traffic. File may only exist if the + system supports this feature on some of its cache resources. + + "disabled": + Resource supports "io_alloc" but the feature is disabled. + Portions of cache used for allocation of I/O traffic cannot + be configured. + "enabled": + Portions of cache used for allocation of I/O traffic + can be configured using "io_alloc_cbm". + "not supported": + Support not available for this resource. + + The feature can be modified by writing to the interface, for example: + + To enable:: + + # echo 1 > /sys/fs/resctrl/info/L3/io_alloc + + To disable:: + + # echo 0 > /sys/fs/resctrl/info/L3/io_alloc + + The underlying implementation may reduce resources available to + general (CPU) cache allocation. See architecture specific notes + below. Depending on usage requirements the feature can be enabled + or disabled. + + On AMD systems, io_alloc feature is supported by the L3 Smart + Data Cache Injection Allocation Enforcement (SDCIAE). The CLOSID for + io_alloc is the highest CLOSID supported by the resource. When + io_alloc is enabled, the highest CLOSID is dedicated to io_alloc and + no longer available for general (CPU) cache allocation. When CDP is + enabled, io_alloc routes I/O traffic using the highest CLOSID allocated + for the instruction cache (CDP_CODE), making this CLOSID no longer + available for general (CPU) cache allocation for both the CDP_CODE + and CDP_DATA resources. + +"io_alloc_cbm": + Capacity bitmasks that describe the portions of cache instances to + which I/O traffic from supported I/O devices are routed when "io_alloc" + is enabled. + + CBMs are displayed in the following format: + + <cache_id0>=<cbm>;<cache_id1>=<cbm>;... + + Example:: + + # cat /sys/fs/resctrl/info/L3/io_alloc_cbm + 0=ffff;1=ffff + + CBMs can be configured by writing to the interface. + + Example:: + + # echo 1=ff > /sys/fs/resctrl/info/L3/io_alloc_cbm + # cat /sys/fs/resctrl/info/L3/io_alloc_cbm + 0=ffff;1=00ff + + # echo "0=ff;1=f" > /sys/fs/resctrl/info/L3/io_alloc_cbm + # cat /sys/fs/resctrl/info/L3/io_alloc_cbm + 0=00ff;1=000f + + When CDP is enabled "io_alloc_cbm" associated with the CDP_DATA and CDP_CODE + resources may reflect the same values. For example, values read from and + written to /sys/fs/resctrl/info/L3DATA/io_alloc_cbm may be reflected by + /sys/fs/resctrl/info/L3CODE/io_alloc_cbm and vice versa. + Memory bandwidth(MB) subdirectory contains the following files with respect to allocation: |