diff options
Diffstat (limited to 'Documentation/filesystems')
| -rw-r--r-- | Documentation/filesystems/afs.txt | 4 | ||||
| -rw-r--r-- | Documentation/filesystems/cramfs.txt | 42 | ||||
| -rw-r--r-- | Documentation/filesystems/porting | 4 | ||||
| -rw-r--r-- | Documentation/filesystems/proc.txt | 4 |
4 files changed, 47 insertions, 7 deletions
diff --git a/Documentation/filesystems/afs.txt b/Documentation/filesystems/afs.txt index 060da408923b..ba99b5ac4fd8 100644 --- a/Documentation/filesystems/afs.txt +++ b/Documentation/filesystems/afs.txt @@ -91,8 +91,8 @@ Filesystems can be mounted anywhere by commands similar to the following: mount -t afs "#root.cell." /afs/cambridge Where the initial character is either a hash or a percent symbol depending on -whether you definitely want a R/W volume (hash) or whether you'd prefer a R/O -volume, but are willing to use a R/W volume instead (percent). +whether you definitely want a R/W volume (percent) or whether you'd prefer a +R/O volume, but are willing to use a R/W volume instead (hash). The name of the volume can be suffixes with ".backup" or ".readonly" to specify connection to only volumes of those types. diff --git a/Documentation/filesystems/cramfs.txt b/Documentation/filesystems/cramfs.txt index 4006298f6707..8e19a53d648b 100644 --- a/Documentation/filesystems/cramfs.txt +++ b/Documentation/filesystems/cramfs.txt @@ -45,6 +45,48 @@ you can just change the #define in mkcramfs.c, so long as you don't mind the filesystem becoming unreadable to future kernels. +Memory Mapped cramfs image +-------------------------- + +The CRAMFS_MTD Kconfig option adds support for loading data directly from +a physical linear memory range (usually non volatile memory like Flash) +instead of going through the block device layer. This saves some memory +since no intermediate buffering is necessary to hold the data before +decompressing. + +And when data blocks are kept uncompressed and properly aligned, they will +automatically be mapped directly into user space whenever possible providing +eXecute-In-Place (XIP) from ROM of read-only segments. Data segments mapped +read-write (hence they have to be copied to RAM) may still be compressed in +the cramfs image in the same file along with non compressed read-only +segments. Both MMU and no-MMU systems are supported. This is particularly +handy for tiny embedded systems with very tight memory constraints. + +The location of the cramfs image in memory is system dependent. You must +know the proper physical address where the cramfs image is located and +configure an MTD device for it. Also, that MTD device must be supported +by a map driver that implements the "point" method. Examples of such +MTD drivers are cfi_cmdset_0001 (Intel/Sharp CFI flash) or physmap +(Flash device in physical memory map). MTD partitions based on such devices +are fine too. Then that device should be specified with the "mtd:" prefix +as the mount device argument. For example, to mount the MTD device named +"fs_partition" on the /mnt directory: + +$ mount -t cramfs mtd:fs_partition /mnt + +To boot a kernel with this as root filesystem, suffice to specify +something like "root=mtd:fs_partition" on the kernel command line. + + +Tools +----- + +A version of mkcramfs that can take advantage of the latest capabilities +described above can be found here: + +https://github.com/npitre/cramfs-tools + + For /usr/share/magic -------------------- diff --git a/Documentation/filesystems/porting b/Documentation/filesystems/porting index 93e0a2404532..17bb4dc28fae 100644 --- a/Documentation/filesystems/porting +++ b/Documentation/filesystems/porting @@ -502,10 +502,6 @@ in your dentry operations instead. store it as cookie. -- [mandatory] - __fd_install() & fd_install() can now sleep. Callers should not - hold a spinlock or other resources that do not allow a schedule. --- -[mandatory] any symlink that might use page_follow_link_light/page_put_link() must have inode_nohighmem(inode) called before anything might start playing with its pagecache. No highmem pages should end up in the pagecache of such diff --git a/Documentation/filesystems/proc.txt b/Documentation/filesystems/proc.txt index adba21b5ada7..2a84bb334894 100644 --- a/Documentation/filesystems/proc.txt +++ b/Documentation/filesystems/proc.txt @@ -181,6 +181,7 @@ read the file /proc/PID/status: VmPTE: 20 kb VmSwap: 0 kB HugetlbPages: 0 kB + CoreDumping: 0 Threads: 1 SigQ: 0/28578 SigPnd: 0000000000000000 @@ -250,10 +251,11 @@ Table 1-2: Contents of the status files (as of 4.8) VmExe size of text segment VmLib size of shared library code VmPTE size of page table entries - VmPMD size of second level page tables VmSwap amount of swap used by anonymous private data (shmem swap usage is not included) HugetlbPages size of hugetlb memory portions + CoreDumping process's memory is currently being dumped + (killing the process may lead to a corrupted core) Threads number of threads SigQ number of signals queued/max. number for queue SigPnd bitmap of pending signals for the thread |
