diff options
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/ntfs.txt | 42 | ||||
| -rw-r--r-- | Documentation/filesystems/xfs.txt | 142 |
2 files changed, 146 insertions, 38 deletions
diff --git a/Documentation/filesystems/ntfs.txt b/Documentation/filesystems/ntfs.txt index a5fbc8e897f..614de312490 100644 --- a/Documentation/filesystems/ntfs.txt +++ b/Documentation/filesystems/ntfs.txt @@ -50,9 +50,14 @@ userspace utilities, etc. Features ======== -- This is a complete rewrite of the NTFS driver that used to be in the kernel. - This new driver implements NTFS read support and is functionally equivalent - to the old ntfs driver. +- This is a complete rewrite of the NTFS driver that used to be in the 2.4 and + earlier kernels. This new driver implements NTFS read support and is + functionally equivalent to the old ntfs driver and it also implements limited + write support. The biggest limitation at present is that files/directories + cannot be created or deleted. See below for the list of write features that + are so far supported. Another limitation is that writing to compressed files + is not implemented at all. Also, neither read nor write access to encrypted + files is so far implemented. - The new driver has full support for sparse files on NTFS 3.x volumes which the old driver isn't happy with. - The new driver supports execution of binaries due to mmap() now being @@ -78,7 +83,20 @@ Features - The new driver supports fsync(2), fdatasync(2), and msync(2). - The new driver supports readv(2) and writev(2). - The new driver supports access time updates (including mtime and ctime). - +- The new driver supports truncate(2) and open(2) with O_TRUNC. But at present + only very limited support for highly fragmented files, i.e. ones which have + their data attribute split across multiple extents, is included. Another + limitation is that at present truncate(2) will never create sparse files, + since to mark a file sparse we need to modify the directory entry for the + file and we do not implement directory modifications yet. +- The new driver supports write(2) which can both overwrite existing data and + extend the file size so that you can write beyond the existing data. Also, + writing into sparse regions is supported and the holes are filled in with + clusters. But at present only limited support for highly fragmented files, + i.e. ones which have their data attribute split across multiple extents, is + included. Another limitation is that write(2) will never create sparse + files, since to mark a file sparse we need to modify the directory entry for + the file and we do not implement directory modifications yet. Supported mount options ======================= @@ -439,6 +457,22 @@ ChangeLog Note, a technical ChangeLog aimed at kernel hackers is in fs/ntfs/ChangeLog. +2.1.25: + - Write support is now extended with write(2) being able to both + overwrite existing file data and to extend files. Also, if a write + to a sparse region occurs, write(2) will fill in the hole. Note, + mmap(2) based writes still do not support writing into holes or + writing beyond the initialized size. + - Write support has a new feature and that is that truncate(2) and + open(2) with O_TRUNC are now implemented thus files can be both made + smaller and larger. + - Note: Both write(2) and truncate(2)/open(2) with O_TRUNC still have + limitations in that they + - only provide limited support for highly fragmented files. + - only work on regular, i.e. uncompressed and unencrypted files. + - never create sparse files although this will change once directory + operations are implemented. + - Lots of bug fixes and enhancements across the board. 2.1.24: - Support journals ($LogFile) which have been modified by chkdsk. This means users can boot into Windows after we marked the volume dirty. diff --git a/Documentation/filesystems/xfs.txt b/Documentation/filesystems/xfs.txt index c7d5d0c7067..74aeb142ae5 100644 --- a/Documentation/filesystems/xfs.txt +++ b/Documentation/filesystems/xfs.txt @@ -19,15 +19,43 @@ Mount Options When mounting an XFS filesystem, the following options are accepted. - biosize=size - Sets the preferred buffered I/O size (default size is 64K). - "size" must be expressed as the logarithm (base2) of the - desired I/O size. - Valid values for this option are 14 through 16, inclusive - (i.e. 16K, 32K, and 64K bytes). On machines with a 4K - pagesize, 13 (8K bytes) is also a valid size. - The preferred buffered I/O size can also be altered on an - individual file basis using the ioctl(2) system call. + allocsize=size + Sets the buffered I/O end-of-file preallocation size when + doing delayed allocation writeout (default size is 64KiB). + Valid values for this option are page size (typically 4KiB) + through to 1GiB, inclusive, in power-of-2 increments. + + attr2/noattr2 + The options enable/disable (default is disabled for backward + compatibility on-disk) an "opportunistic" improvement to be + made in the way inline extended attributes are stored on-disk. + When the new form is used for the first time (by setting or + removing extended attributes) the on-disk superblock feature + bit field will be updated to reflect this format being in use. + + barrier + Enables the use of block layer write barriers for writes into + the journal and unwritten extent conversion. This allows for + drive level write caching to be enabled, for devices that + support write barriers. + + dmapi + Enable the DMAPI (Data Management API) event callouts. + Use with the "mtpt" option. + + grpid/bsdgroups and nogrpid/sysvgroups + These options define what group ID a newly created file gets. + When grpid is set, it takes the group ID of the directory in + which it is created; otherwise (the default) it takes the fsgid + of the current process, unless the directory has the setgid bit + set, in which case it takes the gid from the parent directory, + and also gets the setgid bit set if it is a directory itself. + + ihashsize=value + Sets the number of hash buckets available for hashing the + in-memory inodes of the specified mount point. If a value + of zero is used, the value selected by the default algorithm + will be displayed in /proc/mounts. ikeep/noikeep When inode clusters are emptied of inodes, keep them around @@ -35,12 +63,31 @@ When mounting an XFS filesystem, the following options are accepted. and is still the default for now. Using the noikeep option, inode clusters are returned to the free space pool. + inode64 + Indicates that XFS is allowed to create inodes at any location + in the filesystem, including those which will result in inode + numbers occupying more than 32 bits of significance. This is + provided for backwards compatibility, but causes problems for + backup applications that cannot handle large inode numbers. + + largeio/nolargeio + If "nolargeio" is specified, the optimal I/O reported in + st_blksize by stat(2) will be as small as possible to allow user + applications to avoid inefficient read/modify/write I/O. + If "largeio" specified, a filesystem that has a "swidth" specified + will return the "swidth" value (in bytes) in st_blksize. If the + filesystem does not have a "swidth" specified but does specify + an "allocsize" then "allocsize" (in bytes) will be returned + instead. + If neither of these two options are specified, then filesystem + will behave as if "nolargeio" was specified. + logbufs=value Set the number of in-memory log buffers. Valid numbers range from 2-8 inclusive. The default value is 8 buffers for filesystems with a - blocksize of 64K, 4 buffers for filesystems with a blocksize - of 32K, 3 buffers for filesystems with a blocksize of 16K + blocksize of 64KiB, 4 buffers for filesystems with a blocksize + of 32KiB, 3 buffers for filesystems with a blocksize of 16KiB and 2 buffers for all other configurations. Increasing the number of buffers may increase performance on some workloads at the cost of the memory used for the additional log buffers @@ -49,10 +96,10 @@ When mounting an XFS filesystem, the following options are accepted. logbsize=value Set the size of each in-memory log buffer. Size may be specified in bytes, or in kilobytes with a "k" suffix. - Valid sizes for version 1 and version 2 logs are 16384 (16k) and - 32768 (32k). Valid sizes for version 2 logs also include + Valid sizes for version 1 and version 2 logs are 16384 (16k) and + 32768 (32k). Valid sizes for version 2 logs also include 65536 (64k), 131072 (128k) and 262144 (256k). - The default value for machines with more than 32MB of memory + The default value for machines with more than 32MiB of memory is 32768, machines with less memory use 16384 by default. logdev=device and rtdev=device @@ -62,6 +109,11 @@ When mounting an XFS filesystem, the following options are accepted. optional, and the log section can be separate from the data section or contained within it. + mtpt=mountpoint + Use with the "dmapi" option. The value specified here will be + included in the DMAPI mount event, and should be the path of + the actual mountpoint that is used. + noalign Data allocations will not be aligned at stripe unit boundaries. @@ -91,13 +143,17 @@ When mounting an XFS filesystem, the following options are accepted. O_SYNC writes can be lost if the system crashes. If timestamp updates are critical, use the osyncisosync option. - quota/usrquota/uqnoenforce + uquota/usrquota/uqnoenforce/quota User disk quota accounting enabled, and limits (optionally) - enforced. + enforced. Refer to xfs_quota(8) for further details. - grpquota/gqnoenforce + gquota/grpquota/gqnoenforce Group disk quota accounting enabled and limits (optionally) - enforced. + enforced. Refer to xfs_quota(8) for further details. + + pquota/prjquota/pqnoenforce + Project disk quota accounting enabled and limits (optionally) + enforced. Refer to xfs_quota(8) for further details. sunit=value and swidth=value Used to specify the stripe unit and width for a RAID device or @@ -113,15 +169,21 @@ When mounting an XFS filesystem, the following options are accepted. The "swidth" option is required if the "sunit" option has been specified, and must be a multiple of the "sunit" value. + swalloc + Data allocations will be rounded up to stripe width boundaries + when the current end of file is being extended and the file + size is larger than the stripe width size. + + sysctls ======= The following sysctls are available for the XFS filesystem: fs.xfs.stats_clear (Min: 0 Default: 0 Max: 1) - Setting this to "1" clears accumulated XFS statistics + Setting this to "1" clears accumulated XFS statistics in /proc/fs/xfs/stat. It then immediately resets to "0". - + fs.xfs.xfssyncd_centisecs (Min: 100 Default: 3000 Max: 720000) The interval at which the xfssyncd thread flushes metadata out to disk. This thread will flush log activity out, and @@ -143,9 +205,9 @@ The following sysctls are available for the XFS filesystem: XFS_ERRLEVEL_HIGH: 5 fs.xfs.panic_mask (Min: 0 Default: 0 Max: 127) - Causes certain error conditions to call BUG(). Value is a bitmask; + Causes certain error conditions to call BUG(). Value is a bitmask; AND together the tags which represent errors which should cause panics: - + XFS_NO_PTAG 0 XFS_PTAG_IFLUSH 0x00000001 XFS_PTAG_LOGRES 0x00000002 @@ -155,7 +217,7 @@ The following sysctls are available for the XFS filesystem: XFS_PTAG_SHUTDOWN_IOERROR 0x00000020 XFS_PTAG_SHUTDOWN_LOGERROR 0x00000040 - This option is intended for debugging only. + This option is intended for debugging only. fs.xfs.irix_symlink_mode (Min: 0 Default: 0 Max: 1) Controls whether symlinks are created with mode 0777 (default) @@ -164,25 +226,37 @@ The following sysctls are available for the XFS filesystem: fs.xfs.irix_sgid_inherit (Min: 0 Default: 0 Max: 1) Controls files created in SGID directories. If the group ID of the new file does not match the effective group - ID or one of the supplementary group IDs of the parent dir, the - ISGID bit is cleared if the irix_sgid_inherit compatibility sysctl + ID or one of the supplementary group IDs of the parent dir, the + ISGID bit is cleared if the irix_sgid_inherit compatibility sysctl is set. fs.xfs.restrict_chown (Min: 0 Default: 1 Max: 1) Controls whether unprivileged users can use chown to "give away" a file to another user. - fs.xfs.inherit_sync (Min: 0 Default: 1 Max 1) - Setting this to "1" will cause the "sync" flag set - by the chattr(1) command on a directory to be + fs.xfs.inherit_sync (Min: 0 Default: 1 Max: 1) + Setting this to "1" will cause the "sync" flag set + by the xfs_io(8) chattr command on a directory to be inherited by files in that directory. - fs.xfs.inherit_nodump (Min: 0 Default: 1 Max 1) - Setting this to "1" will cause the "nodump" flag set - by the chattr(1) command on a directory to be + fs.xfs.inherit_nodump (Min: 0 Default: 1 Max: 1) + Setting this to "1" will cause the "nodump" flag set + by the xfs_io(8) chattr command on a directory to be inherited by files in that directory. - fs.xfs.inherit_noatime (Min: 0 Default: 1 Max 1) - Setting this to "1" will cause the "noatime" flag set - by the chattr(1) command on a directory to be + fs.xfs.inherit_noatime (Min: 0 Default: 1 Max: 1) + Setting this to "1" will cause the "noatime" flag set + by the xfs_io(8) chattr command on a directory to be inherited by files in that directory. + + fs.xfs.inherit_nosymlinks (Min: 0 Default: 1 Max: 1) + Setting this to "1" will cause the "nosymlinks" flag set + by the xfs_io(8) chattr command on a directory to be + inherited by files in that directory. + + fs.xfs.rotorstep (Min: 1 Default: 1 Max: 256) + In "inode32" allocation mode, this option determines how many + files the allocator attempts to allocate in the same allocation + group before moving to the next allocation group. The intent + is to control the rate at which the allocator moves between + allocation groups when allocating extents for new files. |