diff options
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/Locking | 10 | ||||
| -rw-r--r-- | Documentation/filesystems/affs.txt | 9 | ||||
| -rw-r--r-- | Documentation/filesystems/f2fs.txt | 29 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 17 |
4 files changed, 52 insertions, 13 deletions
diff --git a/Documentation/filesystems/Locking b/Documentation/filesystems/Locking index f424e0e5b46b..efca5c1bbb10 100644 --- a/Documentation/filesystems/Locking +++ b/Documentation/filesystems/Locking @@ -529,6 +529,7 @@ locking rules: open: yes close: yes fault: yes can return with page locked +map_pages: yes page_mkwrite: yes can return with page locked access: yes @@ -540,6 +541,15 @@ the page, then ensure it is not already truncated (the page lock will block 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 +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_mkwrite() is called when a previously read-only pte is about to become writeable. The filesystem again must ensure that there are no truncate/invalidate races, and then return with the page locked. If diff --git a/Documentation/filesystems/affs.txt b/Documentation/filesystems/affs.txt index 81ac488e3758..71b63c2b9841 100644 --- a/Documentation/filesystems/affs.txt +++ b/Documentation/filesystems/affs.txt @@ -49,6 +49,10 @@ mode=mode Sets the mode flags to the given (octal) value, regardless This is useful since most of the plain AmigaOS files will map to 600. +nofilenametruncate + The file system will return an error when filename exceeds + standard maximum filename length (30 characters). + reserved=num Sets the number of reserved blocks at the start of the partition to num. You should never need this option. Default is 2. @@ -181,9 +185,8 @@ tested, though several hundred MB have been read and written using this fs. For a most up-to-date list of bugs please consult fs/affs/Changes. -Filenames are truncated to 30 characters without warning (this -can be changed by setting the compile-time option AFFS_NO_TRUNCATE -in include/linux/amigaffs.h). +By default, filenames are truncated to 30 characters without warning. +'nofilenametruncate' mount option can change that behavior. Case is ignored by the affs in filename matching, but Linux shells do care about the case. Example (with /wb being an affs mounted fs): diff --git a/Documentation/filesystems/f2fs.txt b/Documentation/filesystems/f2fs.txt index b8d284975f0f..25311e113e75 100644 --- a/Documentation/filesystems/f2fs.txt +++ b/Documentation/filesystems/f2fs.txt @@ -122,6 +122,10 @@ disable_ext_identify Disable the extension list configured by mkfs, so f2fs inline_xattr Enable the inline xattrs feature. inline_data Enable the inline data feature: New created small(<~3.4k) files can be written into inode block. +flush_merge Merge concurrent cache_flush commands as much as possible + to eliminate redundant command issues. If the underlying + device handles the cache_flush command relatively slowly, + recommend to enable this option. ================================================================================ DEBUGFS ENTRIES @@ -169,9 +173,11 @@ Files in /sys/fs/f2fs/<devname> reclaim_segments This parameter controls the number of prefree segments to be reclaimed. If the number of prefree - segments is larger than this number, f2fs tries to - conduct checkpoint to reclaim the prefree segments - to free segments. By default, 100 segments, 200MB. + segments is larger than the number of segments + in the proportion to the percentage over total + volume size, f2fs tries to conduct checkpoint to + reclaim the prefree segments to free segments. + By default, 5% over total # of segments. max_small_discards This parameter controls the number of discard commands that consist small blocks less than 2MB. @@ -195,6 +201,17 @@ Files in /sys/fs/f2fs/<devname> cleaning operations. The default value is 4096 which covers 8GB block address range. + dir_level This parameter controls the directory level to + support large directory. If a directory has a + number of files, it can reduce the file lookup + latency by increasing this dir_level value. + Otherwise, it needs to decrease this value to + reduce the space overhead. The default value is 0. + + ram_thresh This parameter controls the memory footprint used + by free nids and cached nat entries. By default, + 10 is set, which indicates 10 MB / 1 GB RAM. + ================================================================================ USAGE ================================================================================ @@ -444,9 +461,11 @@ The number of blocks and buckets are determined by, # of blocks in level #n = | `- 4, Otherwise - ,- 2^n, if n < MAX_DIR_HASH_DEPTH / 2, + ,- 2^ (n + dir_level), + | if n < MAX_DIR_HASH_DEPTH / 2, # of buckets in level #n = | - `- 2^((MAX_DIR_HASH_DEPTH / 2) - 1), Otherwise + `- 2^((MAX_DIR_HASH_DEPTH / 2 + dir_level) - 1), + Otherwise When F2FS finds a file name in a directory, at first a hash value of the file name is calculated. Then, F2FS scans the hash table in level #0 to find the diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index f00bee144add..8b9cd8eb3f91 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -1648,18 +1648,21 @@ pids, so one need to either stop or freeze processes being inspected if precise results are needed. -3.7 /proc/<pid>/fdinfo/<fd> - Information about opened file +3.8 /proc/<pid>/fdinfo/<fd> - Information about opened file --------------------------------------------------------------- This file provides information associated with an opened file. The regular -files have at least two fields -- 'pos' and 'flags'. The 'pos' represents -the current offset of the opened file in decimal form [see lseek(2) for -details] and 'flags' denotes the octal O_xxx mask the file has been -created with [see open(2) for details]. +files have at least three fields -- 'pos', 'flags' and mnt_id. The 'pos' +represents the current offset of the opened file in decimal form [see lseek(2) +for details], 'flags' denotes the octal O_xxx mask the file has been +created with [see open(2) for details] and 'mnt_id' represents mount ID of +the file system containing the opened file [see 3.5 /proc/<pid>/mountinfo +for details]. A typical output is pos: 0 flags: 0100002 + mnt_id: 19 The files such as eventfd, fsnotify, signalfd, epoll among the regular pos/flags pair provide additional information particular to the objects they represent. @@ -1668,6 +1671,7 @@ pair provide additional information particular to the objects they represent. ~~~~~~~~~~~~~ pos: 0 flags: 04002 + mnt_id: 9 eventfd-count: 5a where 'eventfd-count' is hex value of a counter. @@ -1676,6 +1680,7 @@ pair provide additional information particular to the objects they represent. ~~~~~~~~~~~~~~ pos: 0 flags: 04002 + mnt_id: 9 sigmask: 0000000000000200 where 'sigmask' is hex value of the signal mask associated @@ -1685,6 +1690,7 @@ pair provide additional information particular to the objects they represent. ~~~~~~~~~~~ pos: 0 flags: 02 + mnt_id: 9 tfd: 5 events: 1d data: ffffffffffffffff where 'tfd' is a target file descriptor number in decimal form, @@ -1718,6 +1724,7 @@ pair provide additional information particular to the objects they represent. pos: 0 flags: 02 + mnt_id: 9 fanotify flags:10 event-flags:0 fanotify mnt_id:12 mflags:40 mask:38 ignored_mask:40000003 fanotify ino:4f969 sdev:800013 mflags:0 mask:3b ignored_mask:40000000 fhandle-bytes:8 fhandle-type:1 f_handle:69f90400c275b5b4 |