kernel/linux.git/include/linux/xarray.h, branch v5.0.15

XArray: Fix an arithmetic error in xa_is_err

2019-01-17T12:19:42+00:00

There is a math problem here which leads to a lot of static checker warnings for me: net/sunrpc/clnt.c:451 rpc_new_client() error: (-4096) too low for ERR_PTR Error values are from -1 to -4095 or from 0xffffffff to 0xfffff001 in hexadecimal. (I am assuming a 32 bit system for simplicity). We are using the lowest two bits to hold some internal XArray data so the error is shifted two spaces to the left. 0xfffff001 << 2 is 0xffffc004. And finally we want to check that BIT(1) is set so we add 2 which gives us 0xffffc006. In other words, we should be checking that "entry >= 0xffffc006", but the check is actually testing if "entry >= 0xffffc002". Fixes: 76b4e5299565 ("XArray: Permit storing 2-byte-aligned pointers") Signed-off-by: Dan Carpenter [Use xa_mk_internal() instead of changing the bracketing] Signed-off-by: Matthew Wilcox

XArray: Fix typo in comment

2019-01-14T17:52:16+00:00

Seems copy and paste typo, not a big deal but still for consistency sake better to fix. Signed-off-by: Cyrill Gorcunov Signed-off-by: Matthew Wilcox

XArray: Honour reserved entries in xa_insert

2019-01-07T03:12:58+00:00

xa_insert() should treat reserved entries as occupied, not as available. Also, it should treat requests to insert a NULL pointer as a request to reserve the slot. Add xa_insert_bh() and xa_insert_irq() for completeness. Signed-off-by: Matthew Wilcox

XArray: Permit storing 2-byte-aligned pointers

2019-01-07T03:12:57+00:00

On m68k, statically allocated pointers may only be two-byte aligned. This clashes with the XArray's method for tagging internal pointers. Permit storing these pointers in single slots (ie not in multislots). Signed-off-by: Matthew Wilcox

XArray: Change xa_for_each iterator

2019-01-07T02:24:43+00:00

There were three problems with this API: 1. It took too many arguments; almost all users wanted to iterate over every element in the array rather than a subset. 2. It required that 'index' be initialised before use, and there's no realistic way to make GCC catch that. 3. 'index' and 'entry' were the opposite way round from every other member of the XArray APIs. So split it into three different APIs: xa_for_each(xa, index, entry) xa_for_each_start(xa, index, entry, start) xa_for_each_marked(xa, index, entry, filter) Signed-off-by: Matthew Wilcox

XArray: Turn xa_init_flags into a static inline

2019-01-07T02:24:43+00:00

A regular xa_init_flags() put all dynamically-initialised XArrays into the same locking class. That leads to lockdep believing that taking one XArray lock while holding another is a deadlock. It's possible to work around some of these situations with separate locking classes for irq/bh/regular XArrays, and SINGLE_DEPTH_NESTING, but that's ugly, and it doesn't work for all situations (where we have completely unrelated XArrays). Signed-off-by: Matthew Wilcox

XArray: Add xa_cmpxchg_irq and xa_cmpxchg_bh

2018-12-06T13:26:17+00:00

These convenience wrappers match the other _irq and _bh wrappers we already have. It turns out I'd already open-coded xa_cmpxchg_irq() in the shmem code, so convert that. Signed-off-by: Matthew Wilcox

XArray: Fix Documentation

2018-11-05T21:38:10+00:00

Minor fixes. Signed-off-by: Matthew Wilcox

XArray: Add xa_store_bh() and xa_store_irq()

2018-11-05T21:38:09+00:00

These convenience wrappers disable interrupts while taking the spinlock. A number of drivers would otherwise have to open-code these functions. Signed-off-by: Matthew Wilcox

XArray: Turn xa_erase into an exported function

2018-11-05T21:38:09+00:00

Make xa_erase() take the spinlock and then call __xa_erase(), but make it out of line since it's such a common function. Signed-off-by: Matthew Wilcox