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authorChris Down <chris@chrisdown.name>2020-08-06 23:20:25 -0700
committerLinus Torvalds <torvalds@linux-foundation.org>2020-08-07 11:33:24 -0700
commitea3271f7196c65ae5d3e1c7b3f733892c017dbd6 (patch)
treeb8e35df0da0afea4a25cfdaf2ceaf07d7db30f62 /fs/Kconfig
parente809d5f0b5c912fe981dce738f3283b2010665f0 (diff)
downloadlwn-ea3271f7196c65ae5d3e1c7b3f733892c017dbd6.tar.gz
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tmpfs: support 64-bit inums per-sb
The default is still set to inode32 for backwards compatibility, but system administrators can opt in to the new 64-bit inode numbers by either: 1. Passing inode64 on the command line when mounting, or 2. Configuring the kernel with CONFIG_TMPFS_INODE64=y The inode64 and inode32 names are used based on existing precedent from XFS. [hughd@google.com: Kconfig fixes] Link: http://lkml.kernel.org/r/alpine.LSU.2.11.2008011928010.13320@eggly.anvils Signed-off-by: Chris Down <chris@chrisdown.name> Signed-off-by: Hugh Dickins <hughd@google.com> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> Reviewed-by: Amir Goldstein <amir73il@gmail.com> Acked-by: Hugh Dickins <hughd@google.com> Cc: Al Viro <viro@zeniv.linux.org.uk> Cc: Matthew Wilcox <willy@infradead.org> Cc: Jeff Layton <jlayton@kernel.org> Cc: Johannes Weiner <hannes@cmpxchg.org> Cc: Tejun Heo <tj@kernel.org> Link: http://lkml.kernel.org/r/8b23758d0c66b5e2263e08baf9c4b6a7565cbd8f.1594661218.git.chris@chrisdown.name Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'fs/Kconfig')
-rw-r--r--fs/Kconfig21
1 files changed, 21 insertions, 0 deletions
diff --git a/fs/Kconfig b/fs/Kconfig
index a88aa3af73c1..aa4c12282301 100644
--- a/fs/Kconfig
+++ b/fs/Kconfig
@@ -201,6 +201,27 @@ config TMPFS_XATTR
If unsure, say N.
+config TMPFS_INODE64
+ bool "Use 64-bit ino_t by default in tmpfs"
+ depends on TMPFS && 64BIT
+ default n
+ help
+ tmpfs has historically used only inode numbers as wide as an unsigned
+ int. In some cases this can cause wraparound, potentially resulting
+ in multiple files with the same inode number on a single device. This
+ option makes tmpfs use the full width of ino_t by default, without
+ needing to specify the inode64 option when mounting.
+
+ But if a long-lived tmpfs is to be accessed by 32-bit applications so
+ ancient that opening a file larger than 2GiB fails with EINVAL, then
+ the INODE64 config option and inode64 mount option risk operations
+ failing with EOVERFLOW once 33-bit inode numbers are reached.
+
+ To override this configured default, use the inode32 or inode64
+ option when mounting.
+
+ If unsure, say N.
+
config HUGETLBFS
bool "HugeTLB file system support"
depends on X86 || IA64 || SPARC64 || (S390 && 64BIT) || \