diff options
Diffstat (limited to 'include/linux/shmem_fs.h')
| -rw-r--r-- | include/linux/shmem_fs.h | 23 |
1 files changed, 23 insertions, 0 deletions
diff --git a/include/linux/shmem_fs.h b/include/linux/shmem_fs.h index 5e4b3c1ae5c2..e2069b3179c4 100644 --- a/include/linux/shmem_fs.h +++ b/include/linux/shmem_fs.h @@ -10,6 +10,7 @@ #include <linux/xattr.h> #include <linux/fs_parser.h> #include <linux/userfaultfd_k.h> +#include <linux/bits.h> struct swap_iocb; @@ -19,6 +20,19 @@ struct swap_iocb; #define SHMEM_MAXQUOTAS 2 #endif +/* Suppress pre-accounting of the entire object size. */ +#define SHMEM_F_NORESERVE BIT(0) +/* Disallow swapping. */ +#define SHMEM_F_LOCKED BIT(1) +/* + * Disallow growing, shrinking, or hole punching in the inode. Combined with + * folio pinning, makes sure the inode's mapping stays fixed. + * + * In some ways similar to F_SEAL_GROW | F_SEAL_SHRINK, but can be removed and + * isn't directly visible to userspace. + */ +#define SHMEM_F_MAPPING_FROZEN BIT(2) + struct shmem_inode_info { spinlock_t lock; unsigned int seals; /* shmem seals */ @@ -186,6 +200,15 @@ static inline bool shmem_file(struct file *file) return shmem_mapping(file->f_mapping); } +/* Must be called with inode lock taken exclusive. */ +static inline void shmem_freeze(struct inode *inode, bool freeze) +{ + if (freeze) + SHMEM_I(inode)->flags |= SHMEM_F_MAPPING_FROZEN; + else + SHMEM_I(inode)->flags &= ~SHMEM_F_MAPPING_FROZEN; +} + /* * If fallocate(FALLOC_FL_KEEP_SIZE) has been used, there may be pages * beyond i_size's notion of EOF, which fallocate has committed to reserving: |