iomap: Fix conflicting values of iomap flags
Subsystems (2)
PATCH 1/1 iomap: Fix conflicting values of iomap flags
IOMAP_F_ATOMIC_BIO mistakenly took the same value as of IOMAP_F_SIZE_CHANGED in patch '370a6de7651b ("iomap: rework IOMAP atomic flags")'. Let's fix this and let's also create some more space for filesystem reported flags to avoid this in future. This patch makes the core iomap flags to start from bit 15, moving downwards. Note that "flags" member within struct iomap is of type u16.
--- include/linux/iomap.h | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-)
include/linux/iomap.h +7 -8
@@ -78,6 +78,11 @@ struct vm_fault;#define IOMAP_F_ANON_WRITE (1U << 7)#define IOMAP_F_ATOMIC_BIO (1U << 8) +/* +* Flag reserved for file system specific usage +*/ +#define IOMAP_F_PRIVATE (1U << 12) +/* * Flags set by the core iomap code during operations: *
@@ -88,14 +93,8 @@ struct vm_fault;* range it covers needs to be remapped by the high level before the operation * can proceed. */ -#define IOMAP_F_SIZE_CHANGED (1U << 8) -#define IOMAP_F_STALE (1U << 9) - -/* -* Flags from 0x1000 up are for file system specific usage: -*/ -#define IOMAP_F_PRIVATE (1U << 12) - +#define IOMAP_F_SIZE_CHANGED (1U << 14) +#define IOMAP_F_STALE (1U << 15)/* * Magic value for addr:
Quoted 6 lines · Ritesh Harjani (IBM)
IOMAP_F_ATOMIC_BIOmistakenly took the same value as ofIOMAP_F_SIZE_CHANGEDin patch '370a6de7651b("iomap: rework IOMAP atomic flags")'. Let's fix this and let's also create some more space for filesystem reported flags to avoid this in future. This patch makes the core iomap flags to start from bit 15, moving downwards. Note that "flags" member within struct iomap is of type u16.
Just my opinion - and others will prob disagree - but I think that the reason this was missed (my fault, though) was because we have separate grouping of flags within the same struct member. Maybe having separate flags altogether would help avoid this.
Quoted 3 lines
Fixes 370a6de7651b ("iomap: rework IOMAP atomic flags")Signed-off-by Ritesh Harjani (IBM) <[email protected]>
Quoted 37 lines
--- include/linux/iomap.h | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-)include/linux/iomap.h +7
-8@@ -78,6 +78,11 @@ struct vm_fault;#define IOMAP_F_ANON_WRITE (1U << 7)#define IOMAP_F_ATOMIC_BIO (1U << 8) +/* +* Flag reserved for file system specific usage +*/ +#define IOMAP_F_PRIVATE (1U << 12) +/* * Flags set by the core iomap code during operations: * @@ -88,14 +93,8 @@ struct vm_fault;* range it covers needs to be remapped by the high level before the operation * can proceed. */ -#define IOMAP_F_SIZE_CHANGED (1U << 8) -#define IOMAP_F_STALE (1U << 9) - -/* -* Flags from 0x1000 up are for file system specific usage: -*/ -#define IOMAP_F_PRIVATE (1U << 12) - +#define IOMAP_F_SIZE_CHANGED (1U << 14) +#define IOMAP_F_STALE (1U << 15)/* * Magic value for addr:
Quoted 4 lines · John Garry
Just my opinion - and others will prob disagree - but I think that the reason this was missed (my fault, though) was because we have separate grouping of flags within the same struct member. Maybe having separate flags altogether would help avoid this.
Yes. But going down to less than 16 bit fields also has downsides, as does growing the struture.
Quoted 8 lines · Ritesh Harjani (IBM)
IOMAP_F_ATOMIC_BIOmistakenly took the same value as ofIOMAP_F_SIZE_CHANGEDin patch '370a6de7651b("iomap: rework IOMAP atomic flags")'. Let's fix this and let's also create some more space for filesystem reported flags to avoid this in future. This patch makes the core iomap flags to start from bit 15, moving downwards. Note that "flags" member within struct iomap is of type u16.[...]
Applied to the vfs.fixes branch of the vfs/vfs.git tree. Patches in the vfs.fixes branch should appear in linux-next soon.
Please report any outstanding bugs that were missed during review in a new review to the original patch series allowing us to drop it.
It's encouraged to provide Acked-bys and Reviewed-bys even though the patch has now been applied. If possible patch trailers will be updated.
Note that commit hashes shown below are subject to change due to rebase, trailer updates or similar. If in doubt, please check the listed branch.
tree: https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git branch: vfs.fixes
[1/1] iomap: Fix conflicting values of iomap flags
https://git.kernel.org/vfs/vfs/c/923936efeb74
Quoted 9 lines · Ritesh Harjani (IBM)
IOMAP_F_ATOMIC_BIOmistakenly took the same value as ofIOMAP_F_SIZE_CHANGEDin patch '370a6de7651b("iomap: rework IOMAP atomic flags")'. Let's fix this and let's also create some more space for filesystem reported flags to avoid this in future. This patch makes the core iomap flags to start from bit 15, moving downwards. Note that "flags" member within struct iomap is of type u16.Fixes 370a6de7651b ("iomap: rework IOMAP atomic flags")Signed-off-by Ritesh Harjani (IBM) <[email protected]>
Looks good: