diff options
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/Locking | 14 | ||||
| -rw-r--r-- | Documentation/filesystems/dax.txt | 6 | ||||
| -rw-r--r-- | Documentation/filesystems/f2fs.txt | 7 | ||||
| -rw-r--r-- | Documentation/filesystems/ocfs2-online-filecheck.txt | 10 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 11 | ||||
| -rw-r--r-- | Documentation/filesystems/vfs.txt | 11 |
6 files changed, 45 insertions, 14 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index 75eea7ce3d7c..5a7386e38e2d 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -195,7 +195,9 @@ prototypes: int (*releasepage) (struct page *, int); void (*freepage)(struct page *); int (*direct_IO)(struct kiocb *, struct iov_iter *iter); + bool (*isolate_page) (struct page *, isolate_mode_t); int (*migratepage)(struct address_space *, struct page *, struct page *); + void (*putback_page) (struct page *); int (*launder_page)(struct page *); int (*is_partially_uptodate)(struct page *, unsigned long, unsigned long); int (*error_remove_page)(struct address_space *, struct page *); @@ -219,7 +221,9 @@ invalidatepage: yes releasepage: yes freepage: yes direct_IO: +isolate_page: yes migratepage: yes (both) +putback_page: yes launder_page: yes is_partially_uptodate: yes error_remove_page: yes @@ -544,13 +548,13 @@ subsequent truncate), and then return with VM_FAULT_LOCKED, and the page locked. The VM will unlock the page. ->map_pages() is called when VM asks to map easy accessible pages. -Filesystem should find and map pages associated with offsets from "pgoff" -till "max_pgoff". ->map_pages() is called with page table locked and must +Filesystem should find and map pages associated with offsets from "start_pgoff" +till "end_pgoff". ->map_pages() is called with page table locked and must not block. If it's not possible to reach a page without blocking, filesystem should skip it. Filesystem should use do_set_pte() to setup -page table entry. Pointer to entry associated with offset "pgoff" is -passed in "pte" field in vm_fault structure. Pointers to entries for other -offsets should be calculated relative to "pte". +page table entry. Pointer to entry associated with the page is passed in +"pte" field in fault_env structure. Pointers to entries for other offsets +should be calculated relative to "pte". ->page_mkwrite() is called when a previously read-only pte is about to become writeable. The filesystem again must ensure that there are diff --git a/Documentation/filesystems/dax.txt b/Documentation/filesystems/dax.txt index ce4587d257d2..0c16a22521a8 100644 --- a/Documentation/filesystems/dax.txt +++ b/Documentation/filesystems/dax.txt @@ -49,6 +49,7 @@ These block devices may be used for inspiration: - axonram: Axon DDR2 device driver - brd: RAM backed block device driver - dcssblk: s390 dcss block device driver +- pmem: NVDIMM persistent memory driver Implementation Tips for Filesystem Writers @@ -75,8 +76,9 @@ calls to get_block() (for example by a page-fault racing with a read() or a write()) work correctly. These filesystems may be used for inspiration: -- ext2: the second extended filesystem, see Documentation/filesystems/ext2.txt -- ext4: the fourth extended filesystem, see Documentation/filesystems/ext4.txt +- ext2: see Documentation/filesystems/ext2.txt +- ext4: see Documentation/filesystems/ext4.txt +- xfs: see Documentation/filesystems/xfs.txt Handling Media Errors diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt index e1c9f0849da6..ecd808088362 100644 --- a/Documentation/filesystems/f2fs.txt +++ b/Documentation/filesystems/f2fs.txt @@ -109,7 +109,9 @@ background_gc=%s Turn on/off cleaning operations, namely garbage disable_roll_forward Disable the roll-forward recovery routine norecovery Disable the roll-forward recovery routine, mounted read- only (i.e., -o ro,disable_roll_forward) -discard Issue discard/TRIM commands when a segment is cleaned. +discard/nodiscard Enable/disable real-time discard in f2fs, if discard is + enabled, f2fs will issue discard/TRIM commands when a + segment is cleaned. no_heap Disable heap-style segment allocation which finds free segments for data from the beginning of main area, while for node from the end of main area. @@ -151,6 +153,9 @@ noinline_data Disable the inline data feature, inline data feature is enabled by default. data_flush Enable data flushing before checkpoint in order to persist data of regular and symlink. +mode=%s Control block allocation mode which supports "adaptive" + and "lfs". In "lfs" mode, there should be no random + writes towards main area. ================================================================================ DEBUGFS ENTRIES diff --git a/Documentation/filesystems/ocfs2-online-filecheck.txt b/Documentation/filesystems/ocfs2-online-filecheck.txt index 1ab07860430d..139fab175c8a 100644 --- a/Documentation/filesystems/ocfs2-online-filecheck.txt +++ b/Documentation/filesystems/ocfs2-online-filecheck.txt @@ -5,12 +5,12 @@ This document will describe OCFS2 online file check feature. Introduction ============ -OCFS2 is often used in high-availaibility systems. However, OCFS2 usually +OCFS2 is often used in high-availability systems. However, OCFS2 usually converts the filesystem to read-only when encounters an error. This may not be necessary, since turning the filesystem read-only would affect other running processes as well, decreasing availability. Then, a mount option (errors=continue) is introduced, which would return the --EIO errno to the calling process and terminate furhter processing so that the +-EIO errno to the calling process and terminate further processing so that the filesystem is not corrupted further. The filesystem is not converted to read-only, and the problematic file's inode number is reported in the kernel log. The user can try to check/fix this file via online filecheck feature. @@ -44,7 +44,7 @@ There is a sysfs directory for each OCFS2 file system mounting: /sys/fs/ocfs2/<devname>/filecheck -Here, <devname> indicates the name of OCFS2 volumn device which has been already +Here, <devname> indicates the name of OCFS2 volume device which has been already mounted. The file above would accept inode numbers. This could be used to communicate with kernel space, tell which file(inode number) will be checked or fixed. Currently, three operations are supported, which includes checking @@ -76,14 +76,14 @@ The output is like this: This time, the <ERROR> column indicates whether this fix is successful or not. 3. The record cache is used to store the history of check/fix results. It's -defalut size is 10, and can be adjust between the range of 10 ~ 100. You can +default size is 10, and can be adjust between the range of 10 ~ 100. You can adjust the size like this: # echo "<size>" > /sys/fs/ocfs2/<devname>/filecheck/set Fixing stuff ============ -On receivng the inode, the filesystem would read the inode and the +On receiving the inode, the filesystem would read the inode and the file metadata. In case of errors, the filesystem would fix the errors and report the problems it fixed in the kernel log. As a precautionary measure, the inode must first be checked for errors before performing a final fix. diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index e8d00759bfa5..68080ad6a75e 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -436,6 +436,7 @@ Private_Dirty: 0 kB Referenced: 892 kB Anonymous: 0 kB AnonHugePages: 0 kB +ShmemPmdMapped: 0 kB Shared_Hugetlb: 0 kB Private_Hugetlb: 0 kB Swap: 0 kB @@ -464,6 +465,8 @@ accessed. a mapping associated with a file may contain anonymous pages: when MAP_PRIVATE and a page is modified, the file page is replaced by a private anonymous copy. "AnonHugePages" shows the ammount of memory backed by transparent hugepage. +"ShmemPmdMapped" shows the ammount of shared (shmem/tmpfs) memory backed by +huge pages. "Shared_Hugetlb" and "Private_Hugetlb" show the ammounts of memory backed by hugetlbfs page which is *not* counted in "RSS" or "PSS" field for historical reasons. And these are not included in {Shared,Private}_{Clean,Dirty} field. @@ -725,7 +728,7 @@ IRQ, you can set it by doing: > echo 1 > /proc/irq/10/smp_affinity This means that only the first CPU will handle the IRQ, but you can also echo -5 which means that only the first and fourth CPU can handle the IRQ. +5 which means that only the first and third CPU can handle the IRQ. The contents of each smp_affinity file is the same by default: @@ -868,6 +871,9 @@ VmallocTotal: 112216 kB VmallocUsed: 428 kB VmallocChunk: 111088 kB AnonHugePages: 49152 kB +ShmemHugePages: 0 kB +ShmemPmdMapped: 0 kB + MemTotal: Total usable ram (i.e. physical ram minus a few reserved bits and the kernel binary code) @@ -912,6 +918,9 @@ MemAvailable: An estimate of how much memory is available for starting new AnonHugePages: Non-file backed huge pages mapped into userspace page tables Mapped: files which have been mmaped, such as libraries Shmem: Total memory used by shared memory (shmem) and tmpfs +ShmemHugePages: Memory used by shared memory (shmem) and tmpfs allocated + with huge pages +ShmemPmdMapped: Shared memory mapped into userspace with huge pages Slab: in-kernel data structures cache SReclaimable: Part of Slab, that might be reclaimed, such as caches SUnreclaim: Part of Slab, that cannot be reclaimed on memory pressure diff --git a/Documentation/filesystems/vfs.txt b/Documentation/filesystems/vfs.txt index c61a223ef3ff..900360cbcdae 100644 --- a/Documentation/filesystems/vfs.txt +++ b/Documentation/filesystems/vfs.txt @@ -592,9 +592,14 @@ struct address_space_operations { int (*releasepage) (struct page *, int); void (*freepage)(struct page *); ssize_t (*direct_IO)(struct kiocb *, struct iov_iter *iter); + /* isolate a page for migration */ + bool (*isolate_page) (struct page *, isolate_mode_t); /* migrate the contents of a page to the specified target */ int (*migratepage) (struct page *, struct page *); + /* put migration-failed page back to right list */ + void (*putback_page) (struct page *); int (*launder_page) (struct page *); + int (*is_partially_uptodate) (struct page *, unsigned long, unsigned long); void (*is_dirty_writeback) (struct page *, bool *, bool *); @@ -747,6 +752,10 @@ struct address_space_operations { and transfer data directly between the storage and the application's address space. + isolate_page: Called by the VM when isolating a movable non-lru page. + If page is successfully isolated, VM marks the page as PG_isolated + via __SetPageIsolated. + migrate_page: This is used to compact the physical memory usage. If the VM wants to relocate a page (maybe off a memory card that is signalling imminent failure) it will pass a new page @@ -754,6 +763,8 @@ struct address_space_operations { transfer any private data across and update any references that it has to the page. + putback_page: Called by the VM when isolated page's migration fails. + launder_page: Called before freeing a page - it writes back the dirty page. To prevent redirtying the page, it is kept locked during the whole operation. |