Comment 0 for bug 1791320

Some applications (Kubernetes/Docker) create rather long lines in /proc/mounts, and libhugetlbfs emits an error when it attempts to read one of lines with a size greater than 2048.

See the method find_mounts starting near line 619 in hugeutils.c (https://github.com/libhugetlbfs/libhugetlbfs/blob/master/hugeutils.c#L619).

Error message: libhugetlbfs: ERROR: Line too long when parsing mounts

From strace of the process emitting that error:

read(3, "overlay /var/lib/docker/overlay2"..., 2048) = 2048
write(2, "libhugetlbfs", 12) = 12
write(2, ": ERROR: Line too long when pars"..., 43) = 43
close(3) = 0

Example line:

overlay /var/lib/docker/overlay2/497a00428de0950f98c30f625690832c409f92b6fc58c4d622bc0502fd7695ab/merged overlay rw,relatime,lowerdir=/var/lib/docker/overlay2/l/ESOO6DE7GB55IF4NZXMRFPKNY6:/var/lib/docker/overlay2/l/6NICHWKR5XI4MHV52ARYZQNVLG:/var/lib/docker/overlay2/l/7ZUCDNLHVUCOXOMUD7OBZJ4IDS:/var/lib/docker/overlay2/l/DNRGSMML2MTR2RJV4F2BAJ6FQU:/var/lib/docker/overlay2/l/CQLJGOF6WY5LQ6VX4O725X5IFO:/var/lib/docker/overlay2/l/6CK6EC5OVJHA5ILZMDXDKP2QJB:/var/lib/docker/overlay2/l/KTTUFSD7UEZRB22676OQLGIVMI:/var/lib/docker/overlay2/l/A25DTWZA7SE34D4BZFHSQMT4EO:/var/lib/docker/overlay2/l/CQRGOFOQSJGGQY2UZM2OMIDAJM:/var/lib/docker/overlay2/l/6K4TML6YASNW6XCWT4QFFLSTWE:/var/lib/docker/overlay2/l/O2KYUOVWX7WBRKL5ABL36FLUYK:/var/lib/docker/overlay2/l/FMJPLIDTQCRVLY7ZLCDKX33WXA:/var/lib/docker/overlay2/l/BXVOFLNKH6ETJ4I2SJC6XSNT5R:/var/lib/docker/overlay2/l/5WSNNJ2MGA4XVDMLC7BL5LY7PM:/var/lib/docker/overlay2/l/NKJYMIONXW25FZESMJEY2FG37M:/var/lib/docker/overlay2/l/H5XSSPSIH2VETF3LEZNUEQHPPO:/var/lib/docker/overlay2/l/4I3JGFDNMKTKINC64SLVQMRC5Y:/var/lib/docker/overlay2/l/LL2NPZVNWTTQEHOEE746HA3JRL:/var/lib/docker/overlay2/l/67X5X4XMVCLHIIF7PHQJF62BB2:/var/lib/docker/overlay2/l/PCDJDQQEVWNUU4REIBSFT7NIWF:/var/lib/docker/overlay2/l/QU3HK4NWJXZFFPOG6DDK47ZR6W:/var/lib/docker/overlay2/l/YUVCEWCIGHMAC76MBXV74WQNNO:/var/lib/docker/overlay2/l/LAHUMO6YLJLS3GGFLNCI76SWW3:/var/lib/docker/overlay2/l/DVDLA3VPNXEMUD4FFSMXET7F4Z:/var/lib/docker/overlay2/l/65IXWDQ2J3ATGX4UFGZJIG5U2J:/var/lib/docker/overlay2/l/YX2EW5G7WP3TDY43GV224URQJ5:/var/lib/docker/overlay2/l/QQUGRJFQM7CGZXKBWCUZX7XRTR:/var/lib/docker/overlay2/l/TDUN2SRUZIVA2BZCMBRJN3W33U:/var/lib/docker/overlay2/l/QUVJNMZUFKO36KUHESL3H6X3G3:/var/lib/docker/overlay2/l/OLYWPTCWJIXLH7QDVLNVXLNOIP:/var/lib/docker/overlay2/l/4KK6T3HWRM4P6RP5TD2VCD3RGD:/var/lib/docker/overlay2/l/3QGJKH5MBSC7JQ3TWPNDTCZEZV,upperdir=/var/lib/docker/overlay2/497a00428de0950f98c30f625690832c409f92b6fc58c4d622bc0502fd7695ab/diff,workdir=/var/lib/docker/overlay2/497a00428de0950f98c30f625690832c409f92b6fc58c4d622bc0502fd7695ab/work 0 0