From b2122ea4983c8b59802c8f2a346fe5f44d967042 Mon Sep 17 00:00:00 2001 From: Lubomir Rintel Date: Wed, 31 Jul 2013 15:37:33 +0200 Subject: doc: Convert the posix translator documentation to markdown Change-Id: I6b6c3b2063c81e8799c3273434119dd9bff1be79 Signed-off-by: Lubomir Rintel Reviewed-on: http://review.gluster.org/5486 Reviewed-by: Vijay Bellur Tested-by: Vijay Bellur --- doc/hacker-guide/en-US/markdown/posix.md | 59 ++++++++++++++++++++++++++++++++ 1 file changed, 59 insertions(+) create mode 100644 doc/hacker-guide/en-US/markdown/posix.md (limited to 'doc/hacker-guide/en-US') diff --git a/doc/hacker-guide/en-US/markdown/posix.md b/doc/hacker-guide/en-US/markdown/posix.md new file mode 100644 index 00000000..84c813e5 --- /dev/null +++ b/doc/hacker-guide/en-US/markdown/posix.md @@ -0,0 +1,59 @@ +storage/posix translator +======================== + +Notes +----- + +### `SET_FS_ID` + +This is so that all filesystem checks are done with the user's +uid/gid and not GlusterFS's uid/gid. + +### `MAKE_REAL_PATH` + +This macro concatenates the base directory of the posix volume +('option directory') with the given path. + +### `need_xattr` in lookup + +If this flag is passed, lookup returns a xattr dictionary that contains +the file's create time, the file's contents, and the version number +of the file. + +This is a hack to increase small file performance. If an application +wants to read a small file, it can finish its job with just a lookup +call instead of a lookup followed by read. + +### `getdents`/`setdents` + +These are used by unify to set and get directory entries. + +### `ALIGN_BUF` + +Macro to align an address to a page boundary (4K). + +### `priv->export_statfs` + +In some cases, two exported volumes may reside on the same +partition on the server. Sending statvfs info for both +the volumes will lead to erroneous df output at the client, +since free space on the partition will be counted twice. + +In such cases, user can disable exporting statvfs info +on one of the volumes by setting this option. + +### `xattrop` + +This fop is used by replicate to set version numbers on files. + +### `getxattr`/`setxattr` hack to read/write files + +A key, `GLUSTERFS_FILE_CONTENT_STRING`, is handled in a special way by +`getxattr`/`setxattr`. A getxattr with the key will return the entire +content of the file as the value. A `setxattr` with the key will write +the value as the entire content of the file. + +### `posix_checksum` + +This calculates a simple XOR checksum on all entry names in a +directory that is used by unify to compare directory contents. -- cgit